ORCID Profile
0000-0002-8311-2010
Current Organisation
Macquarie University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Medical Devices | Biomedical Engineering Not Elsewhere Classified | Biomedical Engineering | Cardiorespiratory Medicine and Haematology | Microelectronics and Integrated Circuits | Biomedical Engineering not elsewhere classified | Cardiology (incl. Cardiovascular Diseases) | Biomechanical Engineering | Cardiology (Incl. Cardiovascular Diseases) | Electrical and Electronic Engineering | Rheumatology And Arthritis | Surgery | Biochemistry and Cell Biology | Medical Physiology Not Elsewhere Classified | Artificial Intelligence and Image Processing | Biochemistry and Cell Biology not elsewhere classified | Animal Cell and Molecular Biology | Central Nervous System | Basic Pharmacology | Medical Biotechnology Diagnostics (incl. Biosensors) | Photonics, Optoelectronics and Optical Communications | Radiology and Organ Imaging | Pharmacology and Pharmaceutical Sciences | Simulation And Modelling | Biomedical Instrumentation | Interdisciplinary Engineering not elsewhere classified | Health Information Systems (Incl. Surveillance) | Biomechanical Engineering | Wireless Communications | Genetics not elsewhere classified | Cellular Interactions (incl. Adhesion, Matrix, Cell Wall) | Signal Processing | Animal Physiology—Biophysics | Autonomic Nervous System | Cell Neurochemistry
ANZSRC Socio-Economic Objective (SEO)
Cardiovascular System and Diseases | Cardiovascular system and diseases | Expanding Knowledge in the Medical and Health Sciences | Surgical Methods and Procedures | Other | Medical instrumentation | Diagnostic Methods | Medical Instruments | Computer Hardware and Electronic Equipment not elsewhere classified | Nervous System and Disorders | Information services not elsewhere classified | Skeletal system and disorders (incl. arthritis) | Communication Networks and Services not elsewhere classified | Nervous system and disorders | Diagnostic methods | Surgical methods and procedures | Expanding Knowledge in Technology | Computer software and services not elsewhere classified | Telemetry Equipment |
Related Links
Publications
The Hidden Diagnostic Information of the Heart Rhythm Revealed by Entropy Proportions
Publisher: S. Karger AG
Date: 2020
DOI: 10.1159/000516822
Cerebral hemodynamics and the role of transcranial Doppler applications in the assessment and management of cerebral arteriovenous malformations
Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.JOCN.2016.01.029
Abstract: Dramatic hemodynamic changes occur following resection of brain arteriovenous malformations (AVM). Transcranial Doppler (TCD) records non-invasive velocity and pulsatility parameters. We undertook a systematic review to assess AVM hemodynamics including the time course of changes in velocity and pulsatility in patients undergoing AVM resection. The review employed the Embase and Medline databases. A search strategy was designed. An initial title search for clinical series on AVM and TCD was performed followed by a search for reports on AVM and TCD. A total of 283 publications were selected. Full text analysis produced 54 studies with extractable data regarding AVM, velocity and pulsatility. Two TCD techniques were utilized: conventional "blind" TCD (blind TCD) and transcranial color duplex Doppler (TCCD). Of these, 23 publications reported on blind TCD and seven on TCCD. The presence of high velocity and low pulsatility within AVM feeding arteries preoperatively followed by a postoperative decrease in velocity and subsequent increase in pulsatility of feeding arteries is established. The time sequence of hemodynamic changes following AVM resection using TCD remains uncertain, confounded by variations in methodology and timing of perioperative measurements. Of the two techniques, TCCD reported qualitative aspects including improved differentiation of feeding arteries from draining veins. However, there are a limited number of studies supporting this conclusion. Furthermore, none report reproducible changes with time from treatment. TCCD appears to be a useful technique to analyze the hemodynamic changes occurring following treatment of AVM, however little data is available. This is a field of research that is appropriate to pursue.
5.2 CUFF AND TONOMETER BASED DEVICE FOR ASSESSMENT OF CAROTID TO FEMORAL PULSE WAVE VELOCITY: VALIDATION ACCORDING TO ARTERY SOCIETY GUIDELINES
Publisher: Springer Science and Business Media LLC
Date: 2012
Effects of arterial dilator agents on central aortic systolic pressure and on left ventricular hydraulic load
Publisher: Elsevier BV
Date: 06-1989
DOI: 10.1016/0002-9149(89)90127-6
Abstract: Recordings of pressure in the brachial or peripheral arteries fail to disclose the marked increase in systolic pressure that occurs in the proximal aorta and central arteries with increasing age and with hypertension. This systolic pressure boost is caused by wave reflection returning from the periphery of the body while the ventricle is still contracting. Such early wave reflection is caused in turn by increased pulse-wave velocity, attributable to stiffening of the aorta and major conduit arteries. Drugs have little effect on arterial stiffening, whereas wave reflection can be markedly reduced by agents that dilate peripheral arteries. Such reduction in wave reflection causes substantial decrease of systolic pressure in central arteries. Because of differential timing of wave reflection, however, such reduction is not apparent from pressure recordings taken in the brachial or other peripheral arteries. The sphygmomanometer, therefore, fails to show the favorable effects of reduced wave reflection in the proximal aorta and central arteries. Noninvasive tonometric pressure wave recordings can supplement the sphygmomanometer to assess the magnitude of beneficial effect.
Hemodynamics changes with acute carotid baroreceptor field stimulation are age-dependent in normotensive rats
Publisher: IEEE
Date: 08-2015
Towards a consensus on the understanding and analysis of the pulse waveform: Results from the 2016 Workshop on Arterial Hemodynamics: Past, present and future
Publisher: Springer Science and Business Media LLC
Date: 2017
Applicability and benefit of arterial transfer functions
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2003
138 IN-VITRO AND IN-VIVO USE OF VASOACTIVE AGENTS IN CHARACTERISING AORTIC STIFFNESS IN RATS
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2012
Aortic stiffness is associated with vascular calcification and remodeling in a chronic kidney disease rat model
Publisher: American Physiological Society
Date: 06-2011
DOI: 10.1152/AJPRENAL.00079.2011
Abstract: Increased aortic pulse-wave velocity (PWV) reflects increased arterial stiffness and is a strong predictor of cardiovascular risk in chronic kidney disease (CKD). We examined functional and structural correlations among PWV, aortic calcification, and vascular remodeling in a rodent model of CKD, the Lewis polycystic kidney (LPK) rat. Hemodynamic parameters and beat-to-beat aortic PWV were recorded in urethane-anesthetized animals [12-wk-old hypertensive female LPK rats ( n = 5)] before the onset of end-stage renal disease and their age- and sex-matched normotensive controls (Lewis, n = 6). Animals were euthanized, and the aorta was collected to measure calcium content by atomic absorption spectrophotometry. A separate cohort of animals ( n = 5/group) were anesthetized with pentobarbitone sodium and pressure perfused with formalin, and the aorta was collected for histomorphometry, which allowed calculation of aortic wall thickness, medial cross-sectional area (MCSA), elastic modulus (EM), and wall stress (WS), size and density of smooth muscle nuclei, and relative content of lamellae, interlamellae elastin, and collagen. Mean arterial pressure (MAP) and PWV were significantly greater in the LPK compared with Lewis (72 and 33%, respectively) animals. The LPK group had 6.8-fold greater aortic calcification, 38% greater aortic MCSA, 56% greater EM/WS, 13% greater aortic wall thickness, 21% smaller smooth muscle cell area, and 20% less elastin density with no difference in collagen fiber density. These findings demonstrate vascular remodeling and increased calcification with a functional increase in PWV and therefore aortic stiffness in hypertensive LPK rats.
Pulse-wave propagation in the arterial system of the diamond python Morelia spilotes
Publisher: American Physiological Society
Date: 12-1983
DOI: 10.1152/AJPREGU.1983.245.6.R831
Abstract: Pulse-wave velocity (PWV) and pulse-wave lification (PWA) were measured over a proximal [51 +/- 3 (SE) cm] and distal segment (60 +/- 6 cm) of the common descending aorta of 10 anesthetized diamond python snakes (Morelia spilotes). For proximal and distal segments, PWV values were 551 +/- 66 and 921 +/- 116 cm/s and PWA were 0.91 +/- 0.05 and 0.91 +/- 0.06, respectively. PWV for proximal and distal segments were significantly different (P less than 0.02), but PWA were not. PWA for separate harmonics of heart frequency showed no significant increase above unity. Increase of PWV between distal and proximal aorta indicates a reduction in arterial distensibility, a phenomenon that in other species is associated with lification of the pressure pulse this was not observed in snakes. Using a simple elastic tube model 56 cm in length and 3 mm in diameter it was found that the lification produced by the measured PWV changes is offset by attenuation due to viscous d ing. Thus similarity of pulse-wave contour throughout the snake's aorta is attributable to the opposing effects of elastic nonuniformity and viscous d ing.
Options for Dealing with Pressure Dependence of Pulse Wave Velocity as a Measure of Arterial Stiffness: An Update of Cardio-Ankle Vascular Index (CAVI) and CAVI0
Publisher: S. Karger AG
Date: 2017
DOI: 10.1159/000479322
Abstract: Pulse wave velocity (PWV), a marker of arterial stiffness, is known to change instantaneously with changes in blood pressure. In this mini-review, we discuss two main approaches for handling the blood pressure dependence of PWV: (1) converting PWV into a pressure-independent index, and (2) correcting PWV per se for the pressure dependence. Under option 1, we focus on cardio-ankle vascular index (CAVI). CAVI is essentially a form of stiffness index β - CAVI is estimated for a (heart-to-ankle) trajectory, whereas β is estimated for a single artery from pressure and diameter measurements. Stiffness index β, and therefore also CAVI, have been shown to theoretically exhibit a slight residual blood pressure dependence due to the use of diastolic blood pressure instead of a fixed reference blood pressure. Additionally, CAVI exhibits pressure dependence due to the use of an estimated derivative of the pressure-diameter relationship. In this mini-review, we will address CAVI's blood pressure dependence theoretically, but also statistically. Furthermore, we review corrected indices (CAVI sub /sub and β sub /sub ) that theoretically do not show a residual blood pressure dependence. Under option 2, three ways of correcting PWV are reviewed: (1) using an exponential relationship between pressure and cross-sectional area, (2) by statistical model adjustment, and (3) through reference values or rule of thumb. Method 2 requires a population to be studied to characterise the statistical model, and method 3 requires a representative reference study. Given these limitations, method 1 seems preferable for correcting PWV per se for its blood pressure dependence. In summary, several options are available to handle the blood pressure dependence of PWV. If a blood pressure-independent index is sought, CAVI sub /sub is theoretically preferable over CAVI. If correcting PWV per se is required, using an exponential pressure-area relationship provides the user with a method to correct PWV on an in idual basis.
Characterisation of structural changes in the arterial elastic matrix by a new fractal feature: directional fractal curve
Publisher: Springer Science and Business Media LLC
Date: 05-1997
DOI: 10.1007/BF02530045
Abstract: Membrane protein efflux pumps confer antibiotic resistance by extruding structurally distinct compounds and lowering their intracellular concentration. Yet, there are no clinically approved drugs to inhibit efflux pumps, which would potentiate the efficacy of existing antibiotics rendered ineffective by drug efflux. Here we identified synthetic antigen-binding fragments (Fabs) that inhibit the quinolone transporter NorA from methicillin-resistant Staphylococcus aureus (MRSA). Structures of two NorA-Fab complexes determined using cryo-electron microscopy reveal a Fab loop deeply inserted in the substrate-binding pocket of NorA. An arginine residue on this loop interacts with two neighboring aspartate and glutamate residues essential for NorA-mediated antibiotic resistance in MRSA. Peptide mimics of the Fab loop inhibit NorA with submicromolar potency and ablate MRSA growth in combination with the antibiotic norfloxacin. These findings establish a class of peptide inhibitors that block antibiotic efflux in MRSA by targeting indispensable residues in NorA without the need for membrane permeability.
Simulation of reduction of proximal aortic stiffness by an elastic wrap and effects on pulse pressure
Publisher: IEEE
Date: 08-2012
Validation of non-invasive central blood pressure devices: Artery society task force (abridged) consensus statement on protocol standardization
Publisher: Springer Science and Business Media LLC
Date: 2017
Estimation of central aortic pressure waveform features derived from the brachial cuff volume displacement waveform
Publisher: IEEE
Date: 08-2012
Quantification of Wave Reflection in the Human Aorta From Pressure Alone
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2006
DOI: 10.1161/01.HYP.0000238330.08894.17
Abstract: Wave reflections affect the proximal aortic pressure and flow waves and play a role in systolic hypertension. A measure of wave reflection, receiving much attention, is the augmentation index (AI), the ratio of the secondary rise in pressure and pulse pressure. AI can be limiting, because it depends not only on the magnitude of wave reflection but also on wave shapes and timing of incident and reflected waves. More accurate measures are obtainable after separation of pressure in its forward (P f ) and reflected (P b ) components. However, this calculation requires measurement of aortic flow. We explore the possibility of replacing the unknown flow by a triangular wave, with duration equal to ejection time, and peak flow at the inflection point of pressure (F tIP ) and, for a second analysis, at 30% of ejection time (F t30 ). Wave form analysis gave forward and backward pressure waves. Reflection magnitude (RM) and reflection index (RI) were defined as RM=P b /P f and RI=P b /(P f +P b ), respectively. Healthy subjects, including interventions such as exercise and Valsalva maneuvers, and patients with ischemic heart disease and failure were analyzed. RMs and RIs using F tIP and F t30 were compared with those using measured flow (F m ). Pressure and flow were recorded with high fidelity pressure and velocity sensors. Relations are: RM tIP =0.82RM mf +0.06 ( R 2 =0.79 n=24), RM t30 =0.79RM mf +0.08 ( R 2 =0.85 n=29) and RI tIP =0.89RI mf +0.02 ( R 2 =0.81 n=24), RI t30 =0.83RI mf +0.05 ( R 2 =0.88 n=29). We suggest that wave reflection can be derived from uncalibrated aortic pressure alone, even when no clear inflection point is distinguishable and AI cannot be obtained. Epidemiological studies should establish its clinical value.
REDUCTION OF AORTIC PULSE PRESSURE FOLLOWING SUBLINGUAL GLYCERYL TRINITRATE IS NOT EXPLAINED BY PHYSIOLOGICAL CHANGES IN AORTIC WINDKESSEL PROPERTIES - A MODELING STUDY: PP.10.401
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2010
1026 EARLY BRIEF TREATMENT WITH ANGIOTENSIN CONVERTING ENZYME INHIBITOR, PERINDOPRIL, PREVENTS AORTIC CALCIFICATION IN ADULT SPONTANEOUSLY HYPERTENSIVE RATS
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2012
Heart rate variability and stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2013
Improving the quality of the evidence
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.JOCN.2017.09.004
Abstract: Published systematic reviews and meta-analyses should comply with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, or PRISMA checklist. Variable reporting of systematic reviews has recently led to a number of publications demonstrating a lack of compliance with PRISMA. Poor reporting compliance can lower researchers' and clinicians' ability to detect bias in published research and can also lead to impaired clinical decision-making. The authors of this paper support the need for greater adherence to PRISMA standards when preparing systematic reviews and meta-analyses for publication and call on researchers who are drawing attention to this problem to lead by ex le.
Brachial‐Ankle Pulse Wave Velocity Versus Its Stiffness Index β‐Transformed Value as Risk Marker for Cardiovascular Disease
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 17-12-2019
Abstract: The difference in the predictive ability of the brachial‐ankle pulse wave velocity (ba PWV ) and its stiffness index β‐transformed value (β‐ba PWV , ie, ba PWV adjusted for the pulse pressure) for the development of pathophysiological abnormalities related to cardiovascular disease or future occurrence of cardiovascular disease was examined. In study 1, a 7‐year prospective observational study in cohorts of 3274 men and 3490 men, the area under the curve in the receiver operator characteristic curve analysis was higher for ba PWV than for β‐ba PWV for predicting the development of hypertension (0.73, 95% CI =0.70 to 0.75 versus 0.59, 95% CI =0.56 to 0.62 P .01) and/or the development of retinopathy (0.78, 95% CI =0.73 to 0.82 versus 0.66, 95% CI =0.60 to 0.71 P .01) by the end of the study period. During study 2, a 3‐year observation period on 511 patients with coronary artery disease, 72 cardiovascular events were confirmed. The C statistics of both markers for predicting the development of cardiovascular events were similar. Stiffness index β transformation of the ba PWV may attenuate the significance of the ba PWV as a risk marker for development of pathophysiological abnormalities related to cardiovascular disease in male subjects.
Residual Stress and Circumferential Stress Distribution in a Finite Element Model of the Arterial Wall
Publisher: ASMEDC
Date: 2004
Abstract: Stress distribution of the arterial wall is an important factor in biomechanics of arteries. It has been suggested that excessive stress leads to arterial degeneration and lesion formation. In addition to circumferential tensile stress caused by luminal pressure, arterial wall contains circumferential residual stress with compressive and tensile components with maximum values on intima and adventitia respectively. The compressive residual stress component compensates part of maximum tensile stress, and therefore decreases severity of tension on endothelial lining. If an arterial ring is cut in radial direction it opens. The degree of opening angle is a determinant of circumferential residual stress. In this investigation, Finite element modeling was used to evaluate circumferential residual stress in a typical model of cross section of human aorta with differing opening angle and Young’s modulus of elasticity. Results show that residual stress values are influenced by structural and mechanical parameters. Elevation of the opening angle and stiffening of the arterial wall resulted in increase of residual stress level.
Measuring Arterial Stiffness in Animal Experimental Studies
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2020
DOI: 10.1161/ATVBAHA.119.313861
Abstract: The arterial wall is a composite material of elastin, collagen, and extracellular matrix with acutely modifiable material properties through the action of smooth muscle cells. Therefore, arterial stiffness is a complex parameter that changes not only with long-term remodeling of the wall constituents but also with acute contraction or relaxation of smooth muscle or with changes in the acute distending pressure to which the artery is exposed. It is not possible to test all these aspects using noninvasive or even invasive techniques in humans. Full characterization of the mechanical properties of the artery and the specific arterial factors causing changes to stiffness with disease or modified lifestyle currently require animal studies. This article summarizes the major in vivo and ex vivo techniques to measure the different aspects of arterial stiffness in animal studies.
Response to Modeled Decomposition of Aortic Pressure Waveforms Does Not Provide Estimates for Pulse Wave Velocity
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2008
Obstructive hydrocephalus due to unruptured brain arteriovenous malformation
Publisher: Cureus, Inc.
Date: 18-11-2019
DOI: 10.7759/CUREUS.6181
Central blood pressure can be validly assessed from radial pulse waveforms in growing children – a longitudinal study
Publisher: Elsevier BV
Date: 2015
Central blood pressure measurement in children - development and validation of a paediatric transfer function
Publisher: Elsevier BV
Date: 2015
Basic principles that determine relationships between pulsatile hemodynamic phenomena and function of elastic vessels
Publisher: Elsevier
Date: 2022
Pulse pressure and inflammatory markers
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2004
Ultrasound-based method for individualized estimation of central aortic blood pressure from flow velocity and diameter
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.COMPBIOMED.2022.105254
Abstract: Central aortic blood pressure (CABP) is a better predictor for cardiovascular events than brachial blood pressure. However, direct CABP measurement is invasive. The objective of this paper is to develop an ultrasound-based method using in idualized Windkessel (WK) models for non-invasive estimation of CABP. Three WK models (with two-, three- and four-element WK, named, WK2, WK3 and WK4, respectively) were created and the model parameters were in idualized based on aortic flow velocity and diameter waveforms measured by ultrasound (US). Experimental data were acquired in 42 subjects aged 21-67 years. The CABP estimated by WK models was compared with the reference CABP obtained using a commercial system. The results showed that the overall performance of the WK3 and WK4 models was similar, outperforming the WK2 model. The estimated CABP based on WK3/WK4 model showed good agreement with the reference CABP: the absolute errors of systolic blood pressure (SBP), 2.4 ± 2.1/2.4 ± 2.0 mmHg diastolic blood pressure (DBP), 1.4 ± 1.1/1.7 ± 1.5 mmHg mean blood pressure (MBP), 1.3 ± 0.8/1.3 ± 0.8 mmHg pulse pressure (PP), 3.0 ± 2.3/3.2 ± 2.6 mmHg the root mean square error (RMSE) of the waveforms, 2.5 ± 1.0/2.6 ± 1.1 mmHg. Therefore, the proposed method can provide a non-invasive CABP estimation during routine cardiac US examination.
P9 Repeatability and Predictors of a Potentially Blood Pressure-Independent Parameter of Arterial Stiffness
Publisher: Springer Science and Business Media LLC
Date: 2020
145 SYMPATHETICALLY MEDIATED AGE RELATED CHANGES IN ABDOMINAL AORTIC STIFFNESS PARAMETERS IN THE RAT
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2012
Ambulatory blood pressure and arterial stiffness web‐based telemonitoring in patients at cardiovascular risk. First results of the VASOTENS (Vascular health ASsessment Of The hypertENSive patients) Re
Publisher: Wiley
Date: 11-07-2019
DOI: 10.1111/JCH.13623
Sensitivity of Video-Based Pulse Arrival Time to Dynamic Blood Pressure Changes
Publisher: IEEE
Date: 07-2018
4.3 SEGMENTAL AORTIC STIFFNESS DETERMINED BY THE ASSOCIATION OF ELASTIN DEGRADATION AND CALCIUM DEPOSITION IN RAT MODELS OF HYPERTENSION AND AORTIC CALCIFICATION
Publisher: Springer Science and Business Media LLC
Date: 2012
P3.22 EFFECT OF TISSUE TRANSGLUTAMINASE (TG2) ON CARDIAC AND VASCULAR FUNCTION IN YOUNG TG2 KNOCKOUT MICE
Publisher: Springer Science and Business Media LLC
Date: 2012
P3.16 EFFECTS OF SYMPATHETIC BLOCKADE ON PRESSURE DEPENDENT ABDOMINAL AORTIC STIFFNESS IN THE SPONTANEOUSLY HYPERTENSIVE RAT
Publisher: Springer Science and Business Media LLC
Date: 2012
Albumin-genipin solder for laser tissue-welding
Publisher: SPIE
Date: 13-07-2004
DOI: 10.1117/12.531466
Relationship Between Brachial‐Ankle Pulse Wave Velocity and Incident Hypertension According to 2017 ACC/AHA High Blood Pressure Guidelines
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 20-08-2019
Abstract: Arterial stiffness predicts both cardiovascular events and incident hypertension. However, whether brachial‐ankle pulse wave velocity (ba PWV ) is predictive of incident hypertension based on the 2017 American College of Cardiology/American Heart Association (ACC/AHA) High Blood Pressure Guidelines has not been established . We performed a large cohort study to investigate whether incident hypertension could be predicted from ba PWV measurements as a measure of arterial stiffness, even when applying updated hypertension criteria. A total of 10 360 Korean adults who underwent ba PWV examination during a health‐screening program between 2010 and 2016 were enrolled. Hypertension was defined according to the 2017 ACC / AHA Guidelines as 130/80 mm Hg. Cox proportional hazard analysis was used to assess the risk of incident hypertension according to ba PWV quartiles. The mean age of the study subjects was 40.2 years and 75.6% were men. During the follow‐up period (median 2.17 years), 2000 subjects (19.3%) developed hypertension. The subjects in the highest ba PWV quartile group showed an increased risk of hypertension compared with the lowest ba PWV quartile group as confirmed by multivariate adjusted hazard ratios of 1.64 (95% CI 1.41–1.89 P .001) in men and 12.36 (95% CI 4.41–34.62 P =0.005) in women. The increased risk of developing hypertension was consistent after adjusting for several confounding factors. Arterial stiffness measured by ba PWV is associated with incident hypertension according to the updated 2017 ACC / AHA Guidelines and is a useful independent predictor of incident hypertension among relatively healthy people.
Increased arterial stiffness does not respond to renal denervation in an animal model of secondary hypertension
Publisher: IEEE
Date: 07-2017
Validation of a cuff-based device for measuring carotid-femoral pulse wave velocity in children and adolescents
Publisher: Springer Science and Business Media LLC
Date: 15-03-2019
DOI: 10.1038/S41371-019-0191-1
Abstract: Carotid-femoral pulse wave velocity is associated with arterial stiffness in major elastic arteries, and predicts future cardiovascular events. However, little is known about carotid-femoral pulse wave velocity as a marker of vascular health in children. Semi-automated cuff-based devices for assessing pulse wave velocity are increasingly popular, although these utilize an algorithm developed and validated in adults. Physiological differences between adults and children may, however, reduce the accuracy of cuff-based methods. We sought to determine the accuracy of a cuff-based pulse wave velocity device in healthy children, and determine whether a novel age-appropriate algorithm increases accuracy. We recruited 29 healthy children between the ages of 2 and 20 years. Pulse wave velocity was measured both by using a tonometer on the carotid artery and an inflated cuff on the thigh, and using a tonometer on both the carotid artery and femoral artery as a reference standard. Accuracy of the cuff-based device with its standard algorithm developed in adults, and a novel age-appropriate algorithm corrected for physiological differences in leg pulse wave velocity was assessed with Regression analysis and Bland-Altman plots. Cuff-based device estimates of pulse wave velocity had excellent agreement to the reference standard (Δ = -0.26 ms
Estimation of pressure pulse amplification between aorta and brachial artery using stepwise multiple regression models
Publisher: IOP Publishing
Date: 23-07-2004
DOI: 10.1088/0967-3334/25/4/008
Abstract: The pressure pulse is lified between the aorta and peripheral sites. This study compares two methods to estimate pressure pulse lification (PPA) between the aorta and the brachial artery. Method 1: PPA was determined from a multi-parameter linear regression of subject parameters (gender, age, height, weight, heart rate (HR), brachial systolic pressure (BSP), diastolic pressure (BDP), mean pressure (MP)). Method 2: PPA was calculated from central aortic pressure waveforms (CW) estimated from the same subject parameters. The s le population (1421 male, 992 female) was selected from a database where aortic pressure was estimated by mathematical transformation of a peripheral (radial) pulse calibrated to sphygmomanometric BSP and BDP. The two methods were consistent in showing HR and MP as the most important parameters to estimate PPA. Correlation coefficients (R2) of 0.48 (method 1) and 0.44 (method 2) were obtained using height, weight, HR, BSP, BDP and age. Inclusion of MP increased R2 to 0.77 (method 1) and 0.71 (method 2). This study shows that databases containing peripheral and central aortic pressure waveforms can be used to construct multiple regression models for PPA estimation. These models could be applied to studies of similar subject groups where peripheral waveforms may not be available.
Impact of Obesity Phenotype on Central Aortic Hemodynamics and Arterial Stiffness in a Chinese Health Assessment Population
Publisher: IMR Press
Date: 15-06-2022
Spontaneous retinal venous pulsatility in patients with cyanotic congenital heart disease
Publisher: Springer Science and Business Media LLC
Date: 17-11-2012
DOI: 10.1007/S00380-011-0201-X
Abstract: Spontaneous retinal venous pulsations (SRVP) are assessed as a clinical marker for patients with ophthalmic or neurological disorders. The pulsations are influenced by intraocular pressure (IOP), cerebrospinal fluid pressure (CSFp), and retinal venous pressure (RVP). However, little is known about the effect of cyanosis with polycythemia, a common finding in adults with complex congenital heart disease (CHD), on SRVP. This study investigated 11 subjects with long-standing cyanosis secondary to CHD and 11 control subjects to determine if there were measurable differences in resting pulsatility for a given IOP level. Intraocular pressure was measured using Goldman tonometry, and dynamic SRVP was recorded noninvasively using a retinal vessel imaging system. Peak litude of SRVP at each cardiac cycle was measured and compared with IOP. Heart rate was also monitored during the tests. Results show that for a similar baseline IOP, SRVP litudes are significantly lower in cyanotic patients compared with normal subjects (P < 0.0001). This may be explained by an increased RVP or high CSFp in these patients. Mean venous diameter is also significantly higher in cyanotic patients (P < 0.01), but no significant relationship was found between SRVP or diameter with blood parameters.
CHARACTERIZATION OF SEGMENTAL AORTIC STIFFNESS AND PULSE PRESSURE AMPLIFICATION IN WISTAR-KYOTO RATS: PP.10.385
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2010
Evaluation of Brain Extracranial-to-Intracranial (EC-IC) Bypass Treatments by Using Computational Hemodynamic Technology
Publisher: Springer Berlin Heidelberg
Date: 2010
10.9 ARTERIAL STIFFNESS INDEX BETA AND CARDIO-ANKLE VASCULAR INDEX INHERENTLY DEPEND ON BLOOD PRESSURE, BUT CAN BE READILY CORRECTED
Publisher: Springer Science and Business Media LLC
Date: 2016
A novel method for retinal vessel segmentation and diameter measurement using high speed video
Publisher: IEEE
Date: 07-2019
Effects of Acute and Chronic Biomechanical Strain on Human Cerebral Endothelial Cells in Altering their Proteome Profile
Publisher: Bentham Science Publishers Ltd.
Date: 15-08-2017
10.4 COMPARISON OF BLOOD PRESSURE VARIABILITY CALCULATED FROM PERIPHERAL AND DERIVED AORTIC BLOOD PRESSURE
Publisher: Springer Science and Business Media LLC
Date: 2016
Effect of vitamin D on aortic remodeling in streptozotocin-induced diabetes
Publisher: Springer Science and Business Media LLC
Date: 2012
Arterial Stiffness and Kidney Function
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2004
DOI: 10.1161/01.HYP.0000114571.75762.B0
Abstract: The vascular hallmark of subjects with end-stage renal disease undergoing hemodialysis is increased aortic stiffness, a phenomenon independent of mean arterial blood pressure, wall stress, and standard cardiovascular risk factors such as plasma glucose, cholesterol, obesity, and smoking. These observations suggest that subtle links might associate arterial stiffness and kidney function in normotensive and hypertensive populations. Recently, aortic pulse wave velocity and creatinine clearance have been shown to be statistically associated in subjects with plasma creatinine ≤130 μmol/L, again independently of mean arterial blood pressure and classical cardiovascular risk factors. This association was even shown to predominate in subjects younger than age 55 years. In addition, acceleration of aortic pulse wave velocity with age was more important in these subjects than in untreated normotensive control in iduals, and the phenomenon was consistently predicted by baseline plasma creatinine values. Among all antihypertensive drugs, angiotensin-converting enzyme inhibitors only were shown to exhibit a significant and independent effect on aortic stiffness. The use of these drugs was significantly associated with improvement of large aortic stiffness in subjects treated for hypertension. In conclusion, increased stiffness of central arteries is independently associated with reduced creatinine clearance in subjects with mild to severe renal insufficiency, indicating that kidney diseases may interact not only with small but also with large conduit arteries, independently of age, blood pressure level, and classical cardiovascular risk factors. Whether sodium, alent ionic species (calcium, phosphates), and the renin-angiotensin-aldosterone system play a role in such alterations remains to be elucidated.
10.2 EFFECTS OF INTER-ARM DIFFERENCES OF BRACHIAL SYSTOLIC BLOOD PRESSURE ON THE DERIVATION OF AORTIC SYSTOLIC PRESSURE
Publisher: Springer Science and Business Media LLC
Date: 2016
Multi-branched model of the human arterial system
Publisher: Springer Science and Business Media LLC
Date: 11-1980
DOI: 10.1007/BF02441895
VITAMIN D DEFICIENCY IS ASSOCIATED WITH ANKLE-BRACHIAL INDEX BUT NOT ARTERIAL STIFFNESS IN AN ELDERLY COMMUNITY-DWELLING CHINESE POPULATION
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2019
Reflections on determinants of augmentation index
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2012
Central Aortic Blood Pressure and Cardiovascular Risk
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2008
A novel method of artery stenosis diagnosis using transfer function and support vector machine based on transmission line model: A numerical simulation and validation study
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.CMPB.2016.03.005
Abstract: Transfer function (TF) is an important parameter for the analysis and understanding of hemodynamics when arterial stenosis exists in human arterial tree. Aimed to validate the feasibility of using TF to diagnose arterial stenosis, the forward problem and inverse problem were simulated and discussed. A calculation method of TF between ascending aorta and any other artery was proposed based on a 55 segment transmission line model (TLM) of human artery tree. The effects of artery stenosis on TF were studied in two aspects: stenosis degree and position. The degree of arterial stenosis was specified to be 10-90% in three representative arteries: carotid, aorta and iliac artery, respectively. In order to validate the feasibility of diagnosis of artery stenosis using TF and support vector machine (SVM), a database of TF was established to simulate the real conditions of artery stenosis based on the TLM model. And a diagnosis model of artery stenosis was built by using SVM and the database. The simulating results showed the modulus and phase of TF were decreasing sharply from frequency 2 to 10Hz with the stenosis degree increasing and displayed their unique and nonlinear characteristics when frequency is higher than 10Hz. The diagnosis results showed the average accuracy was above 76% for the stenosis from 10% to 90% degree, and the diagnosis accuracies of moderate (50%) and serious (90%) stenosis were 87% and 99%, respectively. When the stenosis degree increased to 90%, the accuracy of stenosis localization reached up to 94% for most of arteries. The proposed method of combining TF and SVM is a theoretically feasible method for diagnosis of artery stenosis.
Frequency dependent transmission characteristics between arterial blood pressure and intracranial pressure in rats
Publisher: IEEE
Date: 08-2012
Assessment of isoflavone and ethanolic extract of Inonotus obliquus on experimentally induced diabetes
Publisher: Springer Science and Business Media LLC
Date: 2020
9.3 FUNCTIONAL AORTIC CHANGES INDUCED BY A HIGH SALT DIET
Publisher: Springer Science and Business Media LLC
Date: 2016
[PP.23.01] EFFECT OF UNILATERAL FIELD STIMULATION OF CAROTID BARORECEPTORS ON HEMODYNAMIC PROPERTIES IN RATS ON HIGH SALT DIET
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
Heritability of functional arterial stiffness: a twin study
Publisher: Elsevier BV
Date: 03-2002
SUBSTRATE STIFFNESS AND FREQUENCY OF CYCLIC STRETCH MODULATE EXPRESSION OF ENDOTHELIAL NITRIC OXIDE SYNTHASE IN HUMAN ENDOTHELIAL CELLS
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2019
Non-invasive estimation of central aortic systolic pressure using the QKD technique: Comparison with SphygmoCor
Publisher: Elsevier BV
Date: 10-2011
Dynamic association between intraocular pressure and spontaneous pulsations of retinal veins
Publisher: Informa UK Limited
Date: 21-12-2011
DOI: 10.3109/02713683.2010.530731
Abstract: The litude of spontaneous retinal venous pulsations (SRVP) is known to be affected by intraocular pressure (IOP), retinal venous pressure, and intracranial pressure (ICP). This study characterized SRVPs adjacent to the disc and quantified changes in the litude of these pulsations during IOP manipulation in normal subjects. The study included 12 subjects (40 ± 15, 4 females, 8 males). Baseline IOP (range 10-25 mmHg) was measured and SRVP recorded using the dynamic retinal vessel analyzer (DVA). IOP was lowered using aproclonidine 0.5% and measured every 15 min, followed by dynamic recording of SRVP. Two subjects were also tested with timolol 0.5%, and three were treated with a placebo drop. Mean litude of SRVP was determined within each s le at the same site. Blood pressure and heart rate were tracked continuously. Amplitude of SRVP decreased in all subjects with reduction of IOP with aproclonidine and timolol. Mean SRVP litude was 8.5 ± 6 μm at baseline and reduced to 2.5 ± 1.8 μm after 45 min (p < 0.0001). IOP fell from 14.4 ± 2.6 mmHg to 10.2 ± 2.9 mmHg over the same period (p < 0.001). Venous diameter, blood pressure, and heart rate did not change significantly from the baseline. Analysis of waveforms showed a slight phase shift only (150 ± 78.5 ms, p = 0.93) between disc veins and adjacent retinal vein. SRVPs in the peripapillary retina have similar waveform characteristics to those at the disc. SRVP litudes are reduced by manipulation of IOP downwards with pharmacological intervention. The relationship was consistent in all in iduals tested for two classes of drugs and was independent of BP or heart rate changes.
Abnormalities associated with progressive aortic vascular dysfunction in chronic kidney disease
Publisher: Frontiers Media SA
Date: 19-05-2015
Baroreflex function: improved characterization by use of central vascular parameters compared with peripheral pressure
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2002
P136 Determinants of Arterial Stiffness in Children Using Population-indexed Anthropometric and Hemodynamic Parameters
Publisher: Springer Science and Business Media LLC
Date: 2020
P135 Assessment of Novel Blood Pressure Corrected Cardio-ankle Vascular Index in Response to Acute Blood Pressure Changes
Publisher: Springer Science and Business Media LLC
Date: 2020
Noninvasive Estimation of Aortic Stiffness Through Different Approaches
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2019
DOI: 10.1161/HYPERTENSIONAHA.119.12853
Abstract: Aortic pulse wave velocity is a worldwide accepted index to evaluate aortic stiffness and can be assessed noninvasively by several methods. This study sought to determine if commonly used noninvasive devices can all accurately estimate aortic pulse wave velocity. Pulse wave velocity was estimated in 102 patients (aged 65±13 years) undergoing diagnostic coronary angiography with 7 noninvasive devices and compared with invasive aortic pulse wave velocity. Devices evaluating carotid-femoral pulse wave velocity (Complior Analyse, PulsePen ET, PulsePen ETT, and SphygmoCor) showed a strong agreement between each other ( r .83) and with invasive aortic pulse wave velocity. The mean difference ±SD with the invasive pulse wave velocity was −0.73±2.83 m/s ( r =0.64) for Complior-Analyse: 0.20±2.54 m/s ( r =0.71) for PulsePen-ETT: −0.04±2.33 m/s ( r =0.78) for PulsePen ET and −0.61±2.57 m/s ( r =0.70) for SphygmoCor. The finger-toe pulse wave velocity, evaluated by pOpmètre, showed only a weak relationship with invasive aortic recording (mean difference ±SD =−0.44±4.44 m/s r =0.41), and with noninvasive carotid-femoral pulse wave velocity measurements ( r .33). Pulse wave velocity estimated through a proprietary algorithm by BPLab (v.5.03 and v.6.02) and Mobil-O-Graph showed a weaker agreement with invasive pulse wave velocity compared with carotid-femoral pulse wave velocity (mean difference ±SD =−0.71±3.55 m/s, r =0.23 1.04±2.27 m/s, r =0.77 and −1.01±2.54 m/s, r =0.71, respectively), revealing a negative proportional bias at Bland-Altman plot. Aortic pulse wave velocity values provided by BPLab and Mobil-O-Graph were entirely dependent on age-squared and peripheral systolic blood pressure (cumulative r 2 =0.98 and 0.99, respectively). Thus, among the methods evaluated, only those assessing carotid-femoral pulse wave velocity (Complior Analyse, PulsePen ETT, PulsePen ET, and SphygmoCor) appear to be reliable approaches for estimation of aortic stiffness.
Evaluation of the Accuracy of Cuffless Blood Pressure Measurement Devices: Challenges and Proposals
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2021
DOI: 10.1161/HYPERTENSIONAHA.121.17747
Abstract: Several novel cuffless wearable devices and smartphone applications claiming that they can measure blood pressure (BP) are appearing on the market. These technologies are very attractive and promising, with increasing interest among health care professionals for their potential use. Moreover, they are becoming popular among patients with hypertension and healthy people. However, at the present time, there are serious issues about BP measurement accuracy of cuffless devices and the 2021 European Society of Hypertension Guidelines on BP measurement do not recommend them for clinical use. Cuffless devices have special validation issues, which have been recently recognized. It is important to note that the 2018 Universal Standard for the validation of automated BP measurement devices developed by the American Association for the Advancement of Medical Instrumentation, the European Society of Hypertension, and the International Organization for Standardization is inappropriate for the validation of cuffless devices. Unfortunately, there is an increasing number of publications presenting data on the accuracy of novel cuffless BP measurement devices, with inadequate methodology and potentially misleading conclusions. The objective of this review is to facilitate understanding of the capabilities and limitations of emerging cuffless BP measurement devices. First, the potential and the types of these devices are described. Then, the unique challenges in evaluating the BP measurement accuracy of cuffless devices are explained. Studies from the literature and computer simulations are employed to illustrate these challenges. Finally, proposals are given on how to evaluate cuffless devices including presenting and interpreting relevant study results.
Personalized aortic pressure waveform estimation from brachial pressure waveform using an adaptive transfer function
Publisher: Elsevier BV
Date: 03-2023
Robust Aortic Valve Non-Opening Detection for Different Cardiac Conditions
Publisher: Wiley
Date: 15-01-2014
DOI: 10.1111/AOR.12220
Abstract: In recent years, extensive studies have been conducted in the area of pumping state detection for implantable rotary blood pumps. However, limited studies have focused on automatically identifying the aortic valve non-opening (ANO) state despite its importance in the development of control algorithms aiming for myocardial recovery. In the present study, we investigated the performance of 14 ANO indices derived from the pump speed waveform using four different types of classifiers, including linear discriminant analysis, logistic regression, back propagation neural network, and k-nearest neighbors (KNN). Experimental measurements from four greyhounds, which take into consideration the variations in cardiac contractility, systemic vascular resistance, and total blood volume were used. By having only two indices, (i) the root mean square value, and (ii) the standard deviation, we were able to achieve an accuracy of 92.8% with the KNN classifier. Further increase of the number of indices to five for the KNN classifier increases the overall accuracy to 94.6%.
P128 Accuracy of Age-appropriate Transfer Functions in Modelling Central Arterial Waveform Features
Publisher: Springer Science and Business Media LLC
Date: 2020
Propagation of pressure pulse in kangaroo arterial system
Publisher: American Physiological Society
Date: 09-1985
DOI: 10.1152/AJPREGU.1985.249.3.R335
Abstract: The pressure pulse contour in the ascending aorta of kangaroos is markedly different from that seen in other species, but the changes undergone by the pulse propagating along the aorta are quite similar. Alteration of wave contour and progressive lification of the pulse in the distal aorta and peripheral arteries of other mammals have been attributed to elastic nonuniformity of the aorta and to peripheral wave reflection. In kangaroos the aorta approximates a uniform tube with essentially constant viscoelastic properties, whereas wave reflection from the lower body appears to be unusually intense and to emanate from a single functionally discrete reflecting site this appears to be the result of arterial terminations in the muscular lower body. Intense wave reflection from the lower body is the dominant mechanism responsible for changes in the pressure pulse of kangaroos between the ascending aorta and peripheral arteries. Contour of the pulse in the ascending aorta is attributable to this and to close proximity of reflecting sites in the upper body.
Effects of gravity-induced upper-limb blood pressure changes on wave transmission and arterial radial waveform
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2016
Blood pressure-independent neurogenic effect on conductance and resistance vessels: a consideration for cuffless blood pressure measurement?
Publisher: IEEE
Date: 11-2021
Comparison Between Invasive and Noninvasive Methods to Estimate Subendocardial Oxygen Supply and Demand Imbalance
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-09-2021
Abstract: Estimation of the balance between subendocardial oxygen supply and demand could be a useful parameter to assess the risk of myocardial ischemia. Evaluation of the subendocardial viability ratio (SEVR, also known as Buckberg index) by invasive recording of left ventricular and aortic pressure curves represents a valid method to estimate the degree of myocardial perfusion relative to left ventricular workload. However, routine clinical use of this parameter requires its noninvasive estimation and the demonstration of its reliability. Arterial applanation tonometry allows a noninvasive estimation of SEVR as the ratio of the areas directly beneath the central aortic pressure curves obtained during diastole (myocardial oxygen supply) and during systole (myocardial oxygen demand). However, this “traditional” method does not account for the intra‐ventricular diastolic pressure and proper allocation to systole and diastole of left ventricular isometric contraction and relaxation, respectively, resulting in an overestimation of the SEVR values. These issues are considered in the novel method for SEVR assessment tested in this study. SEVR values estimated with carotid tonometry by "traditional” and "new” method were compared with those evaluated invasively by cardiac catheterization. The “traditional” method provided significantly higher SEVR values than the reference invasive SEVR: average of differences±SD= 44±11% (limits of agreement: 23% – 65%). The noninvasive “new” method showed a much better agreement with the invasive determination of SEVR: average of differences±SD= 0±8% (limits of agreement: ‐15% to 16%). Carotid applanation tonometry provides valid noninvasive SEVR values only when all the main factors determining myocardial supply and demand flow are considered.
AGE-RELATED EFFECTS OF POSTURAL CHANGES ON AORTIC PULSE WAVE VELOCITY
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2011
AGE, HYPERTENSION AND ARTERIAL FUNCTION
Publisher: Wiley
Date: 18-06-2007
DOI: 10.1111/J.1440-1681.2007.04657.X
Abstract: 1. Ageing exerts a marked effect on the cardiovascular system and, in particular, the large arteries. Using a variety of techniques to assess arterial stiffness, many cross-sectional studies have demonstrated a significant relationship between age and aortic stiffness, although the age-related changes observed in peripheral arteries appear to be less marked. 2. The relationship between arterial stiffness and hypertension is more complex. The distending, or mean arterial, pressure is an important confounder of measurements of arterial stiffness and, therefore, must be taken into consideration when assessing arterial stiffness in hypertensive subjects or investigating the effect of antihypertensive agents. Current methods for correcting for differences in distending pressure involve pharmacological manipulation, statistical correction or mathematical manipulation of stiffness indices. 3. Many studies have provided evidence that both peripheral (muscular) and central (elastic) arteries are stiffer in subjects with mixed (systolic/diastolic) hypertension compared with normotensive subjects. However, it is unclear to what extent differences in mean arterial pressure explain the observed differences in hypertensive subjects. In contrast, isolated systolic hypertension is associated with increased aortic, but not peripheral artery, stiffness, although the underlying mechanisms are somewhat unclear. 4. Traditional antihypertensive agents appear to reduce arterial stiffness, but mostly via an indirect effect of lowering mean pressure. Therefore, therapies that target the large arteries to reduce stiffness directly are urgently required. Agents such as nitric oxide donors and phosphodiesterase inhibitors may be useful in reducing stiffness via functional mechanisms. In addition, inhibitors or breakers of advanced glycation end-product cross-links between proteins, such as collagen and elastin, hold substantial promise.
Multi-Site Pulse Transit Times, Beat-to-Beat Blood Pressure, and Isovolumic Contraction Time at Rest and Under Stressors
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2022
CORRIGENDA
Publisher: American Physiological Society
Date: 11-2004
Magnetic resonance and applanation tonometry for noninvasive determination of left ventricular load and ventricular vascular coupling in the time and frequency domain.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2016
2.1 Derivation of Central Aortic Pressure Using the Radial Pulse Waveform Acquired by Millimetre-Wave Radar
Publisher: Springer Science and Business Media LLC
Date: 2020
ARE COMMERCIAL CUFFLESS BLOOD PRESSURE DEVICES BEING VALIDATED?
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2022
Influence of resting lung diffusion on exercise capacity in patients with COPD
Publisher: Springer Science and Business Media LLC
Date: 25-08-2017
PULSE WAVE VELOCITY IS DECREASED IN AN OVERWEIGHT CHINESE ELDERLY POPULATION
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2019
Influence of dietary nitrate supplementation on lung function and exercise gas exchange in COPD patients
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.NIOX.2018.03.009
Abstract: During exercise as pulmonary blood flow rises, pulmonary capillary blood volume increases and gas exchange surface area expands through distention and recruitment. We have previously demonstrated that pulmonary capillary recruitment is limited in COPD patients with poorer exercise tolerance. Hypoxia and endothelial dysfunction lead to pulmonary vascular dysregulation possibly in part related to nitric oxide related pathways. To determine if increasing dietary nitrate might influence lung surface area for gas exchange and subsequently impact exercise performance. Subjects had stable, medically treated COPD (n = 25), gave informed consent, filled out the St George Respiratory Questionnaire (SGRQ), had a baseline blood draw for Hgb, performed spirometry, and had exhaled nitric oxide (exNO) measured. Then they performed the intra-breath (IB) technique for lung diffusing capacity for carbon monoxide (DLCO) as well as pulmonary blood flow (Qc). Subsequently they completed a progressive semi-recumbent cycle ergometry test to exhaustion with measures of oxygen saturation (SpO Exhaled nitric oxide levels rose >200% in the nitrate group (p < 0.05) with minimal change in placebo group. The SGRQ suggested a small fall in perceived symptom limitation in the nitrate group, but no measure of resting pulmonary function differed post nitrate supplementation. With exercise, there was no influence of nitrate supplementation on peak VO Despite evidence of a rise in exhaled nitric oxide levels with nitrate supplementation, there was minimal evidence for improvement in exercise performance or pulmonary gas exchange surface area in a stable medically treated COPD population.
869 RELIABILITY OF THE MERCURY SPHYGMOMANOMETER AS A REFERENCE STANDARD FOR MEASUREMENT OF BLOOD PRESSURE
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2012
A growth model of saccular aneurysms based on hemodynamic and morphologic discriminant parameters for risk of rupture
Publisher: Elsevier BV
Date: 09-2014
DOI: 10.1016/J.JOCN.2013.12.021
Abstract: The aim of this study was to derive a model describing the evolution of bifurcation type cerebral aneurysms based on morphological and hemodynamic parameters. Idealized bifurcation models were constructed based on the two morphological parameters of aspect ratio (AR) and size ratio (SR). Aneurysm development was investigated according to the following four patterns: R1, increasing SR with constant AR R2, increasing AR with constant SR R3, increasing SR and increasing AR R4, increasing AR with constant parent artery diameter. Relationships were obtained between energy loss (EL) and morphological parameters (EL-SR and EL-AR curves). The curves were validated by mapping the growth of a ruptured patient-specific bifurcation aneurysm at three stages of follow-up. EL increased in parallel with growth patterns R1 and R3, whereas growth pattern R2 showed a decrease in EL. No significant changes were observed in EL when the growth of the aneurysm was associated only with changes in aneurysm size and independent of changes in parent artery diameter and main flow (R4). Changes in parent artery diameter of bifurcation aneurysms resulted in significant variation in EL. Mapping the growth of a follow-up aneurysm onto the EL-AR curve demonstrated that aneurysms with increasing EL during the observation period are at higher risk of rupture than aneurysms with decreasing EL. Based on the proposed growth model, assessment of morphological (AR and SR) and hemodynamic (EL) parameters may provide quantifiable information on the risk of bifurcation aneurysm rupture during clinical patient follow-up.
Fourier analysis of biological signals with a programmable calculator
Publisher: Elsevier BV
Date: 1984
DOI: 10.1016/0010-4825(84)90024-6
Abstract: A Fourier analysis program written for the Texas Instruments TI-59 programmable calculator is presented. The program determines the Fourier coefficients of any time varying periodic signal.
Blood Pressure Measurement Methodologies: Present Status and Future Prospects
Publisher: Incessant Nature Science Publishers Pvt Ltd.
Date: 2020
Non-invasive estimation of intracranial pressure by means of retinal venous pulsatility
Publisher: Springer Berlin Heidelberg
Date: 2010
Clinical Assessment of Wave Reflection
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2003
7.3 ASSESSMENT OF BLOOD PRESSURE AND HEART RATE VARIABILITY IN MULTIPLE SCLEROSIS
Publisher: Springer Science and Business Media LLC
Date: 2016
Development of Image Segmentation Methods for Intracranial Aneurysms
Publisher: Hindawi Limited
Date: 2013
DOI: 10.1155/2013/715325
Abstract: Though providing vital means for the visualization, diagnosis, and quantification of decision-making processes for the treatment of vascular pathologies, vascular segmentation remains a process that continues to be marred by numerous challenges. In this study, we validate eight aneurysms via the use of two existing segmentation methods the Region Growing Threshold and Chan-Vese model. These methods were evaluated by comparison of the results obtained with a manual segmentation performed. Based upon this validation study, we propose a new Threshold-Based Level Set (TLS) method in order to overcome the existing problems. With ergent methods of segmentation, we discovered that the volumes of the aneurysm models reached a maximum difference of 24%. The local artery anatomical shapes of the aneurysms were likewise found to significantly influence the results of these simulations. In contrast, however, the volume differences calculated via use of the TLS method remained at a relatively low figure, at only around 5%, thereby revealing the existence of inherent limitations in the application of cerebrovascular segmentation. The proposed TLS method holds the potential for utilisation in automatic aneurysm segmentation without the setting of a seed point or intensity threshold. This technique will further enable the segmentation of anatomically complex cerebrovascular shapes, thereby allowing for more accurate and efficient simulations of medical imagery.
Echocardiographic and electrocardiographic study of the normal kangaroo heart
Publisher: Wiley
Date: 04-1990
DOI: 10.1111/J.1445-5994.1990.TB01294.X
Abstract: Healthy kangaroos are prone to sudden death. To investigate possible causes of this phenomenon, echocardiographic and electrocardiographic studies were conducted in seven healthy sedated (intramuscular ketamine 20 mg/kg, xylazine 2 mg/kg) kangaroos aged 1.5-5 years weighing 5.5-48 kg. As in human hypertrophic cardiomyopathy, kangaroos showed relative left ventricular hypertrophy measured as a ratio of (internal left ventricular end-diastolic diameter)/(septal + posterior wall thickness): 1.7 (SD 0.2) in kangaroos and 1.3 (SD 0.4) in hypertrophic cardiomyopathy cf 2.6 (SD 0.6) in normal man (p less than 0.001 respectively). Peak left ventricular diastolic filling velocity was smaller in kangaroos (2.6 (SD 0.3)/sec) and hypertrophic cardiomyopathy (3.3 (SD 0.7)/sec) than in normal man (4.1 (SD 1.0)/sec) (p less than 0.01, p less than 0.05). The end of T wave occurred earlier than the closing of aortic valve. Corrected QT interval (0.20 (SD 0.02) sec) was shorter than the normal value for man (0.34-0.40 sec). In conclusion, kangaroos have cardiac hypertrophy of unknown aetiology, with impaired diastolic function, as in non-obstructive hypertrophic cardiomyopathy patients. Corrected QT interval was short. These echocardiographic and electrocardiographic findings may explain the mechanism of sudden death in kangaroos, a species which may be used as an experimental model of non-obstructive hypertrophic cardiomyopathy in man.
Heart Rate Dependency of Large Artery Stiffness
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2016
DOI: 10.1161/HYPERTENSIONAHA.116.07462
Abstract: Carotid-femoral pulse wave velocity (cfPWV) quantifies large artery stiffness, it is used in hemodynamic research and is considered a useful cardiovascular clinical marker. cfPWV is blood pressure (BP) dependent. Intrinsic heart rate (HR) dependency of cfPWV is unknown because increasing HR is commonly accompanied by increasing BP. This study aims to quantify cfPWV dependency on acute, sympathovagal-independent changes in HR, independent of BP. In iduals (n=52, age 40–93 years, 11 female) with in situ cardiac pacemakers or cardioverter defibrillators were paced at 60, 70, 80, 90, and 100 bpm. BP and cfPWV were measured at each HR. Both cfPWV (mean [95% CI], 0.31 [0.26–0.37] m/s per 10 bpm P .001) and central aortic diastolic pressure (3.78 [3.40–4.17] mm Hg/10 bpm P .001) increased with HR. The HR effect on cfPWV was isolated by correcting the BP effects by 3 different methods: (1) statistically, by a linear mixed model (2) mathematically, using an exponential relationship between BP and cross-sectional lumen area and (3) using measured BP dependency of cfPWV derived from changes in BP induced by orthostatic changes (seated and supine) in a subset of subjects (n=17). The BP-independent effects of HR on cfPWV were quantified as 0.20 [0.11–0.28] m/s per 10 bpm ( P .001, method 1), 0.16 [0.11–0.22] m/s per 10 bpm ( P .001, method 2), and 0.16 [0.11–0.21] m/s per 10 bpm ( P .001, method 3). With a mean HR dependency in the range of 0.16 to 0.20 m/s per 10 bpm, cfPWV may be considered to have minimal physiologically relevant changes for small changes in HR, but larger differences in HR must be considered as contributing to significant differences in cfPWV.
Central blood pressure, arterial waveform analysis, and vascular risk factors in glaucoma
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2013
Exercise, Vascular Stiffness, and Tissue Transglutaminase
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 24-03-2014
Abstract: Vascular aging is closely associated with increased vascular stiffness. It has recently been demonstrated that decreased nitric oxide ( NO )‐induced S‐nitrosylation of tissue transglutaminase ( TG 2) contributes to age‐related vascular stiffness. In the current study, we tested the hypothesis that exercise restores NO signaling and attenuates vascular stiffness by decreasing TG 2 activity and cross‐linking in an aging rat model. Rats were subjected to 12 weeks of moderate aerobic exercise. Aging was associated with diminished phosphorylated endothelial nitric oxide synthase and phosphorylated vasodilator‐stimulated phosphoprotein abundance, suggesting reduced NO signaling. TG 2 cross‐linking activity was significantly increased in old animals, whereas TG 2 abundance remained unchanged. These alterations were attenuated in the exercise cohort. Simultaneous measurement of blood pressure and pulse wave velocity ( PWV ) demonstrated increased aortic stiffness in old rats, compared to young, at all values of mean arterial pressure ( MAP ). The PWV ‐ MAP correlation in the old sedentary and old exercise cohorts was similar. Tensile testing of the vessels showed increased stiffness of the aorta in the old phenotype with a modest restoration of mechanical properties toward the young phenotype with exercise. Increased vascular stiffness during aging is associated with decreased TG 2 S‐nitrosylation, increased TG 2 cross‐linking activity, and increased vascular stiffness likely the result of decreased NO bioavailability. In this study, a brief period of moderate aerobic exercise enhanced NO signaling, attenuated TG cross‐linking activity, and reduced ex vivo tensile properties, but failed to reverse functional vascular stiffness in vivo, as measured by PWV .
P162 ARTERIAL STIFFNESS AND BODY COMPOSITION IN CHILDREN AND ADOLESCENTS
Publisher: Springer Science and Business Media LLC
Date: 2018
Validity and repeatability of the Vicorder apparatus: a comparison with the SphygmoCor device
Publisher: Springer Science and Business Media LLC
Date: 25-09-2009
DOI: 10.1038/HR.2009.154
Abstract: Aortic stiffness, an independent predictor of cardiovascular risk and all-cause mortality, can be estimated non-invasively by measuring carotid to femoral (aortic) pulse wave velocity (aPWV). The Vicorder device has been developed to measure aPWV with little operator training in a non-intrusive manner. The aim of this study was to assess the repeatability of aPWV measured with the Vicorder device and to compare aPWV values with those obtained using the SphygmoCor system. Vicorder and SphygmoCor aPWV was assessed in 122 subjects (53+/-18 years, 46 male) using both the manufacturers' and a standardized approach. Vicorder aPWV measurement proved to be highly repeatable (within-subject coefficient of variation 2.8%). Transit time differed significantly between the two devices (mean difference 22+/-9 ms, P<0.001), independent of the different algorithms used to calculate transit time. However, aPWV was similar between the two devices (mean difference 0.31+/-1.54 m s(-1), P<0.001) though with an inherent bias toward lower Vicorder aPWV values at high values of SphygmoCor aPWV. Bias was reduced by subtracting the additional femoral artery segment measured by the Vicorder device, also bringing the measure of transit time in closer agreement to SphygmoCor values (mean difference 5+/-9 ms, P<0.001). Transit time values significantly differed between the two devices and the Vicorder device reported lower aPWV values at higher SphygmoCor values of aPWV. This difference in transit time and inherent bias was reduced when adjustment for the additional femoral artery segment measured by the Vicorder device was made.
P165 EVALUATING CAROTID FEMORAL PULSE WAVE VELOCITY MEASURED BY CUFF-BASED APPROACH AGAINST THE TONOMETRY-BASED REFERENCE STANDARD IN A PAEDIATRIC POPULATION
Publisher: Springer Science and Business Media LLC
Date: 2018
P4.05 CHARACTERISTICS OF AORTIC STIFFNESS IN DIABETIC RATS TREATED WITH VITAMIN D
Publisher: Springer Science and Business Media LLC
Date: 2011
ISOLATED DIASTOLIC BLOOD PRESSURE AND RISK OF ATHEROSCLEROTIC CARDIOVASCULAR DISEASE IN A COMMUNITY DWELLING POPULATION
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2021
Input impedance of distributed arterial structures as used in investigations of underlying concepts in arterial haemodynamics
Publisher: Springer Science and Business Media LLC
Date: 24-10-2008
DOI: 10.1007/S11517-008-0413-0
Abstract: By definition, vascular impedance is described in the frequency domain as the ratio of sinusoidal functions of pressure and flow, yielding spectral values of impedance modulus and phase. The impedance spectrum is determined by the structure and physical properties of the vascular system, such that for a given system the relation between pressure and flow can be modified by alteration of the geometric or mechanical properties of the vascular segments. Whereas input impedance of an arterial system can be readily determined by simultaneous measurement of just two time varying signals of blood pressure and flow, the production of the same impedance spectrum from the physical properties of the system would require information of inordinate complexity and magnitude. Hence, arterial models with a tractable number of parameters or explicit mathematical description are used to approximate the physiological impedance of a vascular structure, which in all animal species consists of distributed branching arterial networks. Although models are a necessary approximation, the strong similarity between the impedance spectra of models and physiological arterial systems enables investigations of fundamental concepts. This is illustrated by examining the effect of the branching structure on the decoupling of the high peripheral resistance from the ejecting ventricles and how physical parameters derived from the impedance spectrum can be used to investigate concepts of optimal design and features related to body size across a broad range of animal species.
Minimising retinal vessel artefacts in optical coherence tomography images
Publisher: Elsevier BV
Date: 11-2011
DOI: 10.1016/J.CMPB.2011.08.005
Abstract: Optical coherence tomography (OCT) is commonly used to investigate the layers of the retina including retinal nerve fiber layer (RNFL) and retinal pigment epithelium (RPE). OCT images are altered by vessels on the retinal surface producing artefacts. We propose a new approach to compensate for these artefacts and enhance quality of OCT images. A total of 28 (20 normal and 8 glaucoma subjects) OCT images were obtained using Spectralis (Heidelberg, Germany). Shadows were detected along the image and compensated by the A-Scan intensity difference from surrounding non-affected areas. Images were then segmented and the area and thickness of RNFL and RPE were measured and compared. 10 subjects were tested twice to determine the effect of this on reproducibility of measurements. Shadow-suppressed images reflected the profile of the retinal layers more closely when assessed qualitatively, minimising distortion. The segmentation of RNFL and RPE thickness demonstrated a mean change of 2.4% ± 1 and 6% ± 1 from the original images. Much larger changes were observed in areas with vessels. Reproducibility of RNFL thickness was improved, specifically in the higher density vessel location, i.e. inferior and superior. Therefore, OCT images can be enhanced by an image processing procedure. Vessel artefacts may cause errors in assessment of RNFL thickness and are a source of variability, which has clinical implications for diseases such as glaucoma where subtle changes in RNFL need to be monitored accurately over time.
Nitric Oxide Regulates Local Arterial Distensibility In Vivo
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 15-01-2002
Abstract: Background — Arterial stiffness is an important determinant of cardiovascular risk. Several lines of evidence support a role for the endothelium in regulating arterial stiffness by release of vasoactive mediators. We hypothesized that nitric oxide (NO) acting locally regulates arterial stiffness in vivo, and the aim of this experiment was to test this hypothesis in an ovine hind-limb preparation. Methods and Results — All studies were conducted in anesthetized sheep. Pulse wave velocity (PWV) was calculated by the foot-to-foot methodology from 2 pressure waveforms recorded simultaneously with a high-fidelity dual pressure-sensing catheter placed in the common iliac artery. Intra-arterial infusion of N G -monomethyl- l -arginine (L-NMMA) increased iliac PWV significantly, by 3±2% ( P .01). Infusion of acetylcholine and glyceryl trinitrate reduced PWV significantly, by 6±4% ( P =0.03) and 5±2% ( P .01), respectively. Only the effect of acetylcholine, however, was significantly inhibited during coinfusion of L-NMMA ( P =0.03). There was no change in systemic arterial pressure throughout the studies. Importantly, infusion of L-NMMA or acetylcholine distal to the common iliac artery (via the sheath) did not affect PWV. Conclusions — These results demonstrate, for the first time, that basal NO production influences large-artery distensibility. In addition, exogenous acetylcholine and glyceryl trinitrate both increase arterial distensibility, the former mainly through NO production. This may help explain why conditions that exhibit endothelial dysfunction are also associated with increased arterial stiffness. Therefore, reversal of endothelial dysfunction or drugs that are large-artery vasorelaxants may be effective in reducing large-artery stiffness in humans, and thus cardiovascular risk.
7D.09
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
FATTY LIVER INDEX IS POSITIVELY ASSOCIATED WITH ARTERIAL STIFFNESS IN A CHINESE POPULATION
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2021
Comparison of Influence of Blood Pressure and Carotid-Femoral Pulse Wave Velocity on Target Organ Damage in Hypertension
Publisher: Frontiers Media SA
Date: 05-07-2022
Abstract: Assessment of target organ damage (TOD) is an important part of the diagnosis and evaluation of hypertension. Carotid-femoral pulse wave velocity (cf-PWV) is considered to be the gold-standard for noninvasive arterial stiffness assessment. This study aims to analyze the risk of TOD in people with different phenotypes of peripheral blood pressure and cf-PWV. The study cohort was recruited from December 2017 to September 2021 at Ruijin Hospital in Shanghai. It was ided into 4 groups according to peripheral blood pressure (pBP) and cf-PWV. TOD was assessed as carotid intima-media thickness (CIMT), chronic kidney disease (CKD), urinary albumin-creatinine ratio (ACR), estimated glomerular filtration rate (eGFR) and left ventricular mass index (LVMI). A total of 1,257 subjects (mean age 53.13 ± 12.65 years, 64.2% males) was recruited. Age, body mass index (BMI) and fasting blood glucose (FBG), as well as peripheral systolic blood pressure (pSBP), peripheral diastolic blood pressure (pDBP), peripheral pulse pressure (pPP) were significantly different in the four groups ( P & 0.01). eGFR, ACR, LVMI and CIMT were significantly different among different groups ( P & 0.01). The risk of ACR abnormality was significantly higher in the group with elevated pBP ( P = 0.005, OR 2.264, 95%CI 1.277–4.016 and in the group with elevated pBP and cf-PWV ( P = 0.003, OR 1.482, 95%CI 1.144–1.920), while left ventricular hypertrophy (LVH) was significantly higher in the group with elevated cf-PWV ( P = 0.002, OR 1.868, 95%CI 1.249–2.793). Different profiles based on the status of PBP and cf-PWV associated with different TOD. In iduals with higher pBP have an increased risk of ACR abnormality, while in iduals with only cf-PWV elevated have a higher risk of LVH.
Non-invasive Intracranial Pressure Measurement using Transcranial Doppler Sonography and Support Vector Machines
Publisher: Springer Berlin Heidelberg
Date: 2009
P4.04 CARDIOVASCULAR PARAMETERS OTHER THAN MEAN ARTERIAL PRESSURE ARE PREDICTIVE OF DYNAMIC CHANGES IN AORTIC STIFFNESS IN THE RAT
Publisher: Springer Science and Business Media LLC
Date: 2011
Arterial Flow, Pulse Pressure and Pulse Wave Velocity in Men and Women at Various Ages
Publisher: Springer International Publishing
Date: 2018
DOI: 10.1007/978-3-319-77932-4_10
Abstract: The increase in pulse pressure (PP) that occurs with advancing age is predominantly due to reduced arterial distensibility leading to decreased aortic compliance, particularly in the elderly, in whom high blood pressure mainly manifests as isolated systolic hypertension. Since age-related changes in stroke volume are minimal compared with changes in PP, PP is often considered a surrogate measure of arterial stiffness. However, since PP is determined by both cardiac and arterial function, a more precise and reliable means of assessment of arterial stiffness is arterial pulse wave velocity (PWV), a parameter that is only dependent on arterial properties. Arterial stiffness as measured by PWV has been found to be a powerful pressure-related indicator for cardiovascular morbidity and mortality. We analyzed PP and PWV in men and women of various age groups in healthy volunteers as well as cardiac patients with different types of diseases. The findings identified several striking sex-specific differences which demand consideration in guidelines for diagnostic procedures, for epidemiological analysis, and in evaluation of therapeutic interventions.
Effect of Heart Rate on Arterial Stiffness as Assessed by Pulse Wave Velocity
Publisher: Bentham Science Publishers Ltd.
Date: 08-2018
DOI: 10.2174/1573402113666170724100418
Abstract: Vascular assessment is becoming increasingly important in the diagnosis of cardiovascular diseases. In particular, clinical assessment of arterial stiffness, as measured by pulse wave velocity (PWV), is gaining increased interest due to the recognition of PWV as an influential factor on the prognosis of hypertension as well as being an independent predictor of cardiovascular and all-cause mortality. Whilst age and blood pressure are established as the two major determinants of PWV, the influence of heart rate on PWV measurements remains controversial with conflicting results being observed in both acute and epidemiological studies. In a majority of studies investigating the acute effects of heart rate on PWV, results were confounded by concomitant changes in blood pressure. Observations from epidemiological studies have also failed to converge, with approximately just half of such studies reporting a significant blood-pressure-independent association between heart rate and PWV. Further to the lack of consensus on the effects of heart rate on PWV, the possible mechanisms contributing to observed PWV changes with heart rate have yet to be fully elucidated, although many investigators have attributed heart-rate related changes in arterial stiffness to the viscoelasticity of the arterial wall. With elevated heart rate being an independent prognostic factor of cardiovascular disease and its association with hypertension, the interaction between heart rate and PWV continues to be relevant in assessing cardiovascular risk.
On Tubes, Strings, and Resonance in the Arterial System—What Makes the Beat Go on?
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2004
D-MELD, a strong and accurate tool to guide Donor-2-Recipient Matching
Publisher: International Scientific Information, Inc.
Date: 2013
DOI: 10.12659/AOT.883876
Video-Based Pulse Arrival Time can track Dynamic Blood Pressure Changes
Publisher: Avestia Publishing
Date: 08-2018
DOI: 10.11159/ICBES18.152
Progressive changes of elastic moduli of arterial wall and atherosclerotic plaque components during plaque development in human coronary arteries
Publisher: Springer Science and Business Media LLC
Date: 29-10-2018
DOI: 10.1007/S11517-018-1910-4
Abstract: Stiffness of the arterial wall and atherosclerotic plaque components is a determinant of the stress field within plaques, which has been suggested to be an indicator of plaque vulnerability. The ersity and inhomogeneous structure of atherosclerotic lesions complicate the characterization of plaque components. In the present study, stiffness of the arterial wall and atherosclerotic plaque components in human coronary arteries was examined in early and developed atherosclerotic lesions. The force-spectroscopy mode of the atomic force microscope and histological examination were used for determination of elastic moduli at specified locations within s les. Fibrous cap (E = 14.1 ± 3.8 kPa) showed lower stiffness than the fibrous tissue beneath the lipid pool (E = 17.6 ± 3.2 kPa). Calcification zones (E = 96.1 ± 18.8 kPa) and lipid pools (E = 2.7 ± 1.8 kPa) were the stiffest and softest components of atherosclerotic lesions, respectively. The increase of media stiffness (%44.8) and reduction of the elastic modulus of the internal elastic lamina (%28.9) was observed in coronary arteries. Moreover, significant differences were observed between the stiffness of medial layer in diseased parts and free-plaque segments in incomplete plaques of coronary arteries. Our results can be used for better understanding of remodeling mechanisms of the arterial wall with plaque development. Graphical abstract Stiffness alteration of the arterial wall and atherosclerotic plaque components with plaque development in coronary arteries.
NONINVASIVE MEASUREMENTS OF NORMAL VALUES OF STROKE VOLUME AND TOTAL PERIPHERAL RESISTANCE IN AN ELDERLY POPULATION ACCOUNTING FOR AGE AND SEX DIFFERENCES
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2021
Changes in the Central Arterial Pressure Pulse With Aging
Publisher: Elsevier BV
Date: 05-2010
4.1 ACUTE, SYMPATHETIC-INDEPENDENT INCREASES IN HEART RATE BY WAY OF CARDIAC PACING RAISES AORTIC AND BRACHIAL BLOOD PRESSURE WITH INCREASED CARDIAC OUTPUT AND ARTERIAL STIFFNESS
Publisher: Springer Science and Business Media LLC
Date: 2013
Arterial stiffness index beta and cardio-ankle vascular index inherently depend on blood pressure but can be readily corrected
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2017
Arterial blood pressure measurement and pulse wave analysis-–their role in enhancing cardiovascular assessment
Publisher: IOP Publishing
Date: 26-11-2009
Effect of denervation on viscoelastic properties of large arteries in polycystic kidney disease rats
Publisher: Springer Science and Business Media LLC
Date: 2013
P145 MEASUREMENT OF BLOOD PRESSURE DEPENDENCY OF CAROTID-FEMORAL PULSE WAVE VELOCITY
Publisher: Springer Science and Business Media LLC
Date: 2017
3.5 HEART RATE DEPENDENCE OF REGIONAL AND LOCAL AORTIC PULSE WAVE VELOCITY IN RATS AS A FUNCTION OF BLOOD PRESSURE
Publisher: Springer Science and Business Media LLC
Date: 2017
Accuracy of central blood pressure by Mobil-O-Graph in children and adolescents
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2020
Quantification of alterations in structure and function of elastin in the arterial media
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-1998
Abstract: Abstract —The structure of medial elastin determines arterial function and affects wall mechanical properties. The aim of this study was to (1) characterize the structure of elastin in terms of textural features, (2) relate structural parameters to total number of cardiac cycles (TC), and (3) determine the contribution of medial elastin to lumen mechanical stress. Images of pressure-fixed aortic sections stained for elastin were obtained from specimens collected postmortem from 35 animals of different species with a wide range of age, heart rate, and TC and ided into 2 groups: TC low =3.69±0.38×10 8 (n=17) and TC high =15.8±2.38×10 8 (n=18) ( P .001). A directional fractal curve was generated for each image, and image texture was characterized by directional fractal curve parameters. Elastin volume fraction and interlamellar distance were obtained by image analysis. Wall stress distribution was determined from a finite element model of the arterial wall with multiple layers simulating elastin lamellae. DFC litude was related to elastin volume fraction. Increased TC (TC low versus TC high ) was associated with lower directional fractal curve litude (0.23±0.02 versus 0.14±0.02 P .001), reduced elastin volume fraction (36.5±2.6% versus 25.7±2.1% P .01), and increased interlamellar distance (8.5±0.5 versus 11.5±1.0 μm P .05). Loss of medial elastic function increased pressure-dependent maximal circumferential stress. Structural alterations of medial elastin, quantified by fractal parameters, are associated with cumulative effects of repeated pulsations due to the combined contribution of age and heart rate. Loss of medial functional elasticity increases luminal wall stress, increasing the possibility of endothelial damage and predisposition to atherosclerosis.
Relationship between body mass index and arterial stiffness in a health assessment Chinese population
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2020
Effect of saccular aneurysm and parent artery morphology on hemodynamics of cerebral bifurcation aneurysms
Publisher: IEEE
Date: 08-2012
Central aortic blood pressure estimation in children and adolescents: results of the KidCoreBP study
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2020
Hemodynamic interactions in the eye
Publisher: S. Karger AG
Date: 2012
DOI: 10.1159/000342157
Abstract: The ocular circulation provides readily visible information about the state of the systemic circulation, as well as being potentially of relevance to the pathogenesis of ocular disorders such as glaucoma. The interaction between intraocular pressure, retinal vessels and cerebrospinal fluid pressure located at the retrolaminar portion of the eye has been of great interest for both ophthalmic and neurological clinicians and researchers. Understanding the relationship between these physiological parameters can explain phenomena such as spontaneous retinal venous pulsatility, and characterize the effects of the translaminar pressure gradient. It may be feasible to use measurable changes in venous pulsatility to enhance clinical assessment in different diseases. In this article we review recent findings on ocular hemodynamics and the relevance of these parameters in the diagnosis of ophthalmic and neurological diseases.
PP.12.05
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
Vascular Ageing in Youth: A Call to Action
Publisher: Elsevier BV
Date: 11-2021
Assessment of hemodynamic load components affecting optimization of cardiac resynchronization therapy by lumped parameter mode
Publisher: IEEE
Date: 08-2012
Is obstructive sleep apnoea causally related to arterial stiffness? A critical review of the experimental evidence
Publisher: Elsevier BV
Date: 02-2013
DOI: 10.1016/J.SMRV.2012.03.002
Abstract: Large elastic arteries and smaller muscular conduit arteries become stiffer with ageing, a process that is accelerated in the presence of cardiovascular disease (CVD). In recent years, numerous techniques have been developed to measure arterial stiffness, either in single vessels or in entire muscular arterial trees. These techniques have increasingly been shown to improve stratification of cardiovascular risk and risk reduction beyond that provided by conventional risk factors. Obstructive sleep apnoea (OSA) has been increasingly linked with excess cardiovascular morbidity and mortality however the mechanisms are still not well understood. Robustly designed studies have shown that treatment of OSA with nasal continuous positive airway pressure improves important intermediate risk factors for CVD including hypertension and endothelial function. More recently, there has been increased exploration of arterial stiffness in both cross-sectional and interventional studies in OSA patients. This review aims to give the reader a better understanding of the measurement and pathophysiology of arterial stiffness as well as providing an indication of how well a prognostic indicator are the various measures of arterial stiffness for hard cardiovascular endpoints. A critical appraisal is then provided of cross-sectional and interventional studies that have explored these same techniques in OSA populations.
Chitosan adhesive for laser tissue repair
Publisher: SPIE
Date: 09-02-2006
DOI: 10.1117/12.645155
Effect of Bifurcation Angle Configuration and Ratio of Daughter Diameters on Hemodynamics of Bifurcation Aneurysms
Publisher: American Society of Neuroradiology (ASNR)
Date: 02-08-2012
DOI: 10.3174/AJNR.A3222
Estimation of Pulse Transit Time From Radial Pressure Waveform Alone by Artificial Neural Network
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2018
OS 13-01 BRACHIAL AND CALCULATED AORTIC BLOOD PRESSURE DIFFERENCES WHEN MEASURED FROM THE DOMINANT AND NON-DOMINANT ARM
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
17β-estradiol Changes the Human Cerebral Endothelial Cell Proteome Upon Exposure to Cyclic Stretch
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 15-01-2018
Determination of central blood pressure by a noninvasive method (brachial BP and QKD interval)
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2012
A simplified method for quantifying the subject-specific relationship between blood pressure and carotid-femoral pulse wave velocity
Publisher: IEEE
Date: 08-2015
Heart and kidneys
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2017
Residual stress distribution in a lamellar model of the arterial wall
Publisher: Informa UK Limited
Date: 10-2010
DOI: 10.3109/03091902.2010.514974
Abstract: Excessive wall circumferential stress in arteries caused by luminal pressure leads to endothelial damage and clinical consequences. In addition to circumferential stress, arterial wall contains residual stress with compressive and tensile components on intima and adventitia sides. The intimal compressive component compensates part of tensile stress induced by blood pressure, hence reduces severity of endothelial tension. The opening angle caused by radial cut of arterial ring defines residual stress. In this study, finite element modelling is used to evaluate residual stress in a lamellar model of human aorta with differing opening angle and elastic modulus. Results show non-linear residual stress profiles across wall thickness, influenced by structural and mechanical parameters. Elevation of opening angle from 50° to 90° leads to increase of intimal compressive component compensating up to 32.6% of the pressure-induced tensile stress. Results may be applied in study of endothelial injury caused by excessive stress in situations such as aging, hypertension and atherosclerosis.
A2773 Impact of new hypertension guidelines on target organ damage screening in a Shanghai community-dwelling population
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2018
Easy conversion of cardio-ankle vascular index into CAVI0
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2019
Hemodynamic models of cerebral aneurysms for assessment of effect of vessel geometry on risk of rupture
Publisher: IEEE
Date: 09-2009
Evaluation of Suction Detection During Different Pumping States in an Implantable Rotary Blood Pump
Publisher: Wiley
Date: 02-05-2013
DOI: 10.1111/AOR.12079
Abstract: In recent times, the problem of noninvasive suction detection for implantable rotary blood pumps has attracted substantial research interest. Here, we compare the performance of various suction indices for different types of suction and non-suction events based on pump speed irregularity. A total of 171 different indices that consist of previously proposed as well as newly introduced suction indices are tested using regularized logistic regression. These indices can be classified as litude based (derived from the mean, maximum, and minimum values of a cycle), duration based (derived from the duration of a cycle), gradient based (derived from the first order as well as higher order differences) and frequency based (derived from the power spectral density). The non-suction event data consists of ventricular ejection with or without arrhythmia and intermittent and continuous non-opening of the aortic valve. The suction event data consists of partial ventricular collapse that occurs intermittently as well as continuously with or without arrhythmia. In addition, we also attempted to minimize the usage of multiple indices by applying the sequential forward floating selection method to find which combination of indices gives the best performance. In general, the litude-based and gradient-based indices performed quite well while the duration-based and frequency-based indices performed poorly. By having only two indices ([i] the maximum gradient change in positive slope and [ii] the standard deviation of the maximum value in a cycle), we were able to achieve a sensitivity of 98.9% and a specificity of 99.7%.
EFFECT OF PULSATLITY IN CENTRAL AORTA ON CEREBRAL BLOOD FLOW WITH ADVANCING AGE AND HYPERTENSION
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2018
P1.7 PARAMETERS OF ARTERIAL STIFFNESS DIFFER BETWEEN ATRIAL, VENTRICULAR, AND ATRIAL-VENTRICULAR CARDIAC PACING MODES
Publisher: Springer Science and Business Media LLC
Date: 2014
Reflecting on posture
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2011
Age-Related Changes in the Mechanical Properties of Large Arteries
Publisher: Springer International Publishing
Date: 09-10-2014
Increased tissue transglutaminase activity contributes to central vascular stiffness in eNOS knockout mice
Publisher: American Physiological Society
Date: 15-09-2013
DOI: 10.1152/AJPHEART.00103.2013
Abstract: Nitric oxide (NO) can modulate arterial stiffness by regulating both functional and structural changes in the arterial wall. Tissue transglutaminase (TG2) has been shown to contribute to increased central aortic stiffness by catalyzing the cross-linking of matrix proteins. NO S-nitrosylates and constrains TG2 to the cytosolic compartment and thereby holds its cross-linking function latent. In the present study, the role of endothelial NO synthase (eNOS)-derived NO in regulating TG2 function was studied using eNOS knockout mice. Matrix-associated TG2 and TG2 cross-linking function were higher, whereas TG2 S-nitrosylation was lower in the eNOS −/− compared with wild-type (WT) mice. Pulse-wave velocity (PWV) and blood pressure measured noninvasively were elevated in the eNOS −/− compared with WT mice. Intact aortas and decellularized aortic tissue scaffolds of eNOS −/− mice were significantly stiffer, as determined by tensile testing. The carotid arteries of the eNOS −/− mice were also stiffer, as determined by pressure-dimension analysis. Invasive methods to determine the PWV-mean arterial pressure relationship showed that PWV in eNOS −/− and WT erge at higher mean arterial pressure. Thus eNOS-derived NO regulates TG2 localization and function and contributes to vascular stiffness.
Reflections on systolic and diastolic augmentation
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2013
Effect of inflow on computational fluid dynamic simulation of cerebral bifurcation aneurysms
Publisher: IEEE
Date: 08-2011
Alveolar­–capillary reserve during exercise in patients with chronic obstructive pulmonary disease
Publisher: Informa UK Limited
Date: 10-2017
DOI: 10.2147/COPD.S142523
Effect of Body Habitus and Heart Rate on Accuracy of Aortic-Radial Transfer Functions for Predicting Central Hemodynamic Indices in Growing Children
Publisher: Springer Science and Business Media LLC
Date: 2020
Effects of Ventricular Premature Stimulus Coupling Interval on Blood Pressure and Heart Rate Turbulence
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-02-2003
Multi-tissue lipotoxicity caused by high-fat diet feeding is attenuated by the supplementation of Korean red ginseng in mice
Publisher: Springer Science and Business Media LLC
Date: 03-12-2019
Flow-mediated dilatation as a biomarker for cardiovascular risk in hypertension
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2008
The Relationship of Age With Regional Aortic Stiffness and Diameter
Publisher: Elsevier BV
Date: 12-2010
DOI: 10.1016/J.JCMG.2010.09.016
Abstract: The purpose of this study was to determine the impact of age on regional aortic pulse wave velocity (aPWV). aPWV is an independent predictor of cardiovascular risk and increases exponentially with age. However, it is unclear whether such changes occur uniformly along the length of the aorta or vary by region. A total of 162 subjects, aged 18 to 77 years and free of cardiovascular disease and medication, were recruited from the Anglo-Cardiff Collaborative Trial. Cine phase contrast magnetic resonance imaging was performed at 5 aortic levels. Systolic diameter and average blood flow were measured at each level and regional aPWV (regional aPWV measured by cine phase contrast magnetic resonance imaging) determined in 4 aortic segments: the arch (R1), the thoracic-descending aorta (R2), mid-descending aorta (R3), and the abdominal aorta (R4) and across the entire aorta. Regional PWV measured by cine phase contrast magnetic resonance imaging values increased from the valve to the bifurcation in the 4 segments (PWV-R1- PWV-R4: 4.6 ± 1.5 m/s, 5.5 ± 2.0 m/s, 5.7 ± 2.3 m/s, 6.1 ± 2.9 m/s, respectively) and did not differ between genders. The greatest age-related difference in stiffness occurred in the abdominal aorta (+0.9 m/s per decade, p < 0.001) followed by the thoracic-descending region (+0.7 m/s, p < 0.001), the mid-descending region (+0.6 m/s, p < 0.001) and aortic arch (+0.4 m/s, p < 0.001). The average systolic diameters decreased moving distally (L1-5: 3.1 ± 0.4 cm, 2.3 ± 0.3 cm, 2.1 ± 0.3 cm, 1.9 ± 0.2 cm, and 1.7 ± 0.2 cm, respectively). The greatest variation in systolic diameter as a function of age occurred in the ascending region (+0.96 mm/decade, p < 0.001). Values of aPWV measured across the entire aorta were strongly correlated with PWV-tonometry (R = 0.71, p < 0.001), although they were significantly lower (mean difference 1.7 ± 1.6 m/s, p < 0.001). The greatest difference in aortic stiffness occurs in the abdominal region, whereas the greatest difference in diameter occurs in the ascending aorta, which may help offset an increase in wall stiffness.
Effects of aging on changing arterial compliance and left ventricular load in a northern Chinese urban community.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-1983
Abstract: Pulse wave velocity (PWV) was measured by means of transcutaneous Doppler techniques in the aorta, right arm, and right leg of 480 normal subjects of both sexes in urban Beijing, China (age range 3 to 89 years, mean age 41 +/- 20.8 SD) supine blood pressure was recorded in the brachial artery of each subject with standard sphygmomanometric procedures. Serum cholesterol was determined in a subgroup of 79 subjects (age 17 to 85 years, mean 47 +/- 26 SD). PWV (y in cm/sec) was found to vary with age (x, years) at each of the three locations according to the following regression equations: aorta, y = 9.2x + 615, r = .673 (p less than .001) right arm, y = 4.8x + 998, r = .453 (p less than .001) right leg, y = 5.6x + 791, r = .630 (p less than .001). Systolic, diastolic, mean, and pulse pressures were found to increase with age. PWV also increased with mean supine blood pressure but was not related to serum cholesterol (average 4.49 +/- 0.11 [SEM], mmol/l). Compared with that of Western populations, serum cholesterol tended to be lower at all age groups, systolic pressure higher at ages over 35 years, and PWV higher at all ages. Because change in PWV is directly related to change in arterial compliance, these results indicate that aging and not concomitant atherosclerosis (known to be rare in Asian populations) is the dominant factor associated with reduced arterial compliance and increased left ventricular load in these subjects.
Visualization of orbital flow by means of phase contrast MRI
Publisher: IEEE
Date: 08-2012
P4.04 BARORECEPTOR SENSITIVITY IS REVERSED IN DIABETES AND IS UNAFFECTED BY ANTI-HYPERTENSIVE TREATMENT: A RODENT STUDY
Publisher: Springer Science and Business Media LLC
Date: 2013
Female Gender Is Associated with Higher Susceptibility of Weight Induced Arterial Stiffening and Rise in Blood Pressure
Publisher: MDPI AG
Date: 06-08-2021
DOI: 10.3390/JCM10163479
Abstract: Arterial stiffness is an important predictor of cardiovascular events, independent of traditional risk factors. Stiffening of arteries, though an adaptive process to hemodynamic load, results in substantial increase in the pulsatile hemodynamic forces that detrimentally affects the microcirculation perfusing the vital organs such as the brain, heart and kidneys. Studies have proposed that arterial stiffness precedes and may contribute to the development of hypertension in in iduals with obesity. Our study sought to determine the gender-based effects on arterial stiffening in obesity which may predispose to the development of hypertension. We found female sex is associated with higher susceptibility of weight-related arterial stiffening and rise in blood pressure in obesity. Women had significantly higher carotid-femoral pulse wave velocity (CF-PWV) with higher body mass index (BMI) status (normal: 7.9 ± 2 m/s overweight: 9.1 ± 2 m/s obese: 9 ± 2 m/s, p 0.001), whereas it was similar in males across all BMI categories. The linear association between arterial stiffness and BMI following adjustment for age and brachial systolic and diastolic blood pressure (BP), remained significant in females (β = 0.06 95% CI 0.01 to 0.1 p 0.05) but not in males (β = 0.04 95% CI −0.01 to 0.1 p 0.05). The mean CF-PWV values increased by 0.1 m/s for every 1 kg/m2 increase in BMI in the female subjects in the age adjusted linear model, while such effect was not seen in the male subjects. In line with arterial stiffening, the overweight and obese females demonstrated significantly higher systolic brachial BP. (BP difference: ΔBP 9−11 mmHg, p 0.01) and central systolic pressure (ΔBP 8−10 mmHg, p 0.05) compared to their lean counterparts, unlike the male subjects. Our results suggest that female gender is associated with higher susceptibility of weight-related arterial stiffening and rise in blood pressure.
P4.07 EFFECTS OF ANTI-HYPERTENSIVE TREATMENT ON FUNCTIONAL AND STRUCTURAL COMPONENTS OF LARGE ARTERY STIFFNESS IN A RODENT MODEL OF TYPE I DIABETES
Publisher: Springer Science and Business Media LLC
Date: 2013
541 VITAMIN D ATTENUATES OXIDATIVE STRESS IN A RAT MODEL OF DIABETES-INDUCED AORTIC STIFFNESS
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2012
Long-Term Angiotensin II Receptor Blockade Limits Hypertension, Aortic Dysfunction, and Structural Remodeling in a Rat Model of Chronic Kidney Disease
Publisher: S. Karger AG
Date: 2016
DOI: 10.1159/000452411
Abstract: b i Background/Aims: /i /b Chronic kidney disease (CKD) is associated with large artery remodeling, endothelial dysfunction and calcification, with angiotensin II (Ang II) a known driver of these pathologies. We investigated long-term Ang II type 1 receptor inhibition with valsartan on aortic function and structure in the Lewis polycystic kidney (LPK) rat model of CKD. b i Methods: /i /b Mixed sex LPK and Lewis control (total i n /i = 28) treated (valsartan 60 mg/kg/day p.o. from 4 to 18 weeks) and vehicle groups were studied. Functional responses to noradrenaline (NA), potassium chloride and endothelium-dependent and independent relaxations were investigated in vitro using acetylcholine hydrochloride (ACh) and sodium nitroprusside (SNP), respectively. Effects of the nitric oxide synthase (NOS) substrate smlcap L /smlcap -arginine, NOS inhibitor smlcap L /smlcap -NAME and cyclooxygenase inhibitor indomethacin on ACh responses were examined. b i Results: /i /b In the LPK, valsartan reduced systolic blood pressure and urinary protein, ameliorated exaggerated sensitivity to NA, and normalized endothelium-dependent (ACh-R sub max /sub 91 ± 7 vs. 59 ± 6%, i /i = 0.0001) and independent dysfunction (SNP-R sub max /sub 99 ± 1 vs. 82 ± 7%, i /i = 0.040), as well as improving NO-dependent relaxation (R sub max /sub -51 ± 6 vs. -26 ± 9%, i /i = 0.008). Valsartan also reduced aortic wall hypertrophy, elastin disruption/fragmentation, calcification, media cystic degeneration, and levels of matrix metalloproteinase 9. b i Conclusions: /i /b This study highlights the role of Ang II in driving vascular manifestations of CKD and indicates that early treatment can significantly limit pathological changes.
The Microsoft Research Aurora Project: Important Findings on Cuffless Blood Pressure Measurement.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2022
DOI: 10.1161/HYPERTENSIONAHA.122.20410
Abstract: Conventional blood pressure (BP) measurement devices based on an inflatable cuff only provide a narrow view of the continuous BP profile. Cuffless BP measuring technologies could permit numerous BP readings throughout daily life and thereby considerably improve the assessment and management of hypertension. Several wearable cuffless BP devices based on pulse wave analysis (applied to a photoplethysmography or tonometry waveform) with or without use of pulse arrival time are now available on the market. The key question is: Can these devices provide accurate measurement of BP? Microsoft Research recently published a complex article describing perhaps the most important and highest resource project to date (Aurora Project) on assessing the accuracy of several pulse wave analysis and pulse wave analysis-pulse arrival time devices. The overall results from 1125 participants were clear-cut negative. The present article motivates and describes emerging cuffless BP devices and then summarizes the Aurora Project. The study methodology and findings are next discussed in the context of regulatory-cleared devices, physiology, and related studies, and the study strengths and limitations are pinpointed thereafter. Finally, the implications of the Aurora Project are briefly stated and recommendations for future work are offered to finally realize the considerable potential of cuffless BP measurement in health care.
Exaggerated wave reflection in the kangaroo simulates arterial counterpulsation
Publisher: American Physiological Society
Date: 02-1984
DOI: 10.1152/AJPREGU.1984.246.2.R267
Abstract: The ascending aortic pressure wave in kangaroos is quite different from that seen in other experimental animals and in humans, despite an ascending aortic flow wave that is virtually identical. The diastolic pressure surge in the ascending aortic pressure wave of kangaroos is very prominent--so much so that peak diastolic pressure is often greater than peak systolic pressure, with the pressure wave resembling that recorded in humans during intra-aortic balloon counterpulsation. Ascending aortic impedance patterns in kangaroos indicate the presence of a single functionally discrete reflecting site in the peripheral circulation, with high reflection coefficient. All findings--of pulse contour and impedance patterns--are explicable on the basis of arterial anatomy and body shape. Wave reflection from the distant, large, and vascular lower body appears to dominate the effects of wave reflection from the short, small, and less vascular head and forelimb system.
Arterial Stiffness
Publisher: S. Karger AG
Date: 2013
DOI: 10.1159/000348620
Abstract: Stiffness of large arteries has been long recognized as a significant determinant of pulse pressure. However, it is only in recent decades, with the accumulation of longitudinal data from large and varied epidemiological studies of morbidity and mortality associated with cardiovascular disease, that it has emerged as an independent predictor of cardiovascular risk. This has generated substantial interest in investigations related to intrinsic causative and associated factors responsible for the alteration of mechanical properties of the arterial wall, with the aim to uncover specific pathways that could be interrogated to prevent or reverse arterial stiffening. Much has been written on the haemodynamic relevance of arterial stiffness in terms of the quantification of pulsatile relationships of blood pressure and flow in conduit arteries. Indeed, much of this early work regarded blood vessels as passive elastic conduits, with the endothelial layer considered as an inactive lining of the lumen and as an interface to flowing blood. However, recent advances in molecular biology and increased technological sophistication for the detection of low concentrations of biochemical compounds have elucidated the highly important regulatory role of the endothelial cell affecting vascular function. These techniques have enabled research into the interaction of the underlying passive mechanical properties of the arterial wall with the active cellular and molecular processes that regulate the local environment of the load-bearing components. This review addresses these emerging concepts.
Mechanical Characterization of the Lamellar Structure of Human Abdominal Aorta in the Development of Atherosclerosis: An Atomic Force Microscopy Study
Publisher: Springer Science and Business Media LLC
Date: 13-07-2018
DOI: 10.1007/S13239-018-0370-1
Abstract: Atherosclerosis is a major risk factor for cardiovascular disease. However, mechanisms of interaction of atherosclerotic plaque development and local stiffness of the lamellar structure of the arterial wall are not well established. In the current study, the local Young's modulus of the wall and plaque components were determined for three different groups of healthy, mildly diseased and advanced atherosclerotic human abdominal aortas. Histological staining was performed to highlight the atherosclerotic plaque components and lamellar structure of the aortic media, consisting of concentric layers of elastin and interlamellar zones. The force spectroscopy mode of the atomic force microscopy was utilized to determine Young's moduli of aortic wall lamellae and plaque components at the micron level. The high variability of Young's moduli (E) at different locations of the atherosclerotic plaque such as the fibrous cap (E = 15.5± 2.6 kPa), calcification zone (E = 103.7±19.5 kPa), and lipid pool (E = 3.5±1.2 kPa) were observed. Reduction of elastin lamellae stiffness (18.6%), as well as stiffening of interlamellar zones (50%), were detected in the diseased portion of the medial layer of abdominal aortic wall compared to the healthy artery. Additionally, significant differences in the stiffness of both elastin lamellae and interlamellar zones were observed between the diseased wall and disease-free wall in incomplete plaques. Our results elucidate the alternation of the stiffness of different lamellae in the human abdominal aortic wall with atherosclerotic plaque development and may provide new insight on the remodeling of the aortic wall during the progression of atherosclerosis.
The Human Systemic and Cerebral Circulations: Contrasts in Structure and Function
Publisher: Springer Science and Business Media LLC
Date: 2020
Angiotensin II receptor blocker telmisartan attenuates aortic stiffening and remodelling in STZ-diabetic rats
Publisher: Springer Science and Business Media LLC
Date: 20-05-2014
Persistent effect of early, brief angiotensin-converting enzyme inhibition on segmental pressure dependency of aortic stiffness in spontaneously hypertensive rats
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2012
Pathway for Elimination of Distance Measurement in Studies of Pulse Wave Velocity
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2018
Critical Closing Pressure During Intracranial Pressure Plateau Waves
Publisher: Springer Science and Business Media LLC
Date: 20-03-2013
DOI: 10.1007/S12028-013-9830-5
Abstract: Critical closing pressure (CCP) denotes a threshold of arterial blood pressure (ABP) below which brain vessels collapse and cerebral blood flow ceases. Theoretically, CCP is the sum of intracranial pressure (ICP) and arterial wall tension (WT). The aim of this study is to describe the behavior of CCP and WT during spontaneous increases of ICP, termed plateau waves, in order to quantify ischemic risk. To calculate CCP, we used a recently introduced multi-parameter method (CCPm) which is based on the modulus of cerebrovascular impedance. CCP is derived from cerebral perfusion pressure, ABP, transcranial Doppler estimators of cerebrovascular resistance and compliance, and heart rate. Arterial WT was estimated as CCPm-ICP. The clinical data included recordings of ABP, ICP, and transcranial Doppler-based blood flow velocity from 38 events of ICP plateau waves, recorded in 20 patients after head injury. Overall, CCPm increased significantly from 51.89 ± 8.76 mmHg at baseline ICP to 63.31 ± 10.83 mmHg at the top of the plateau waves (mean ± SD p < 0.001). Cerebral arterial WT decreased significantly during plateau waves by 34.3% (p < 0.001), confirming their vasodilatatory origin. CCPm did not exhibit the non-physiologic negative values that have been seen with traditional methods for calculation, therefore rendered a more plausible estimation of CCP. Rising CCP during plateau waves increases the probability of cerebral vascular collapse and zero flow when the difference: ABP-CCP (the "collapsing margin") becomes zero or negative.
Effects of pressure-dependent segmental arterial compliance and postural changes on pulse wave transmission in an arterial model of the human upper limb
Publisher: IEEE
Date: 08-2011
Peripheral “Oscillatory” Compliance Is Associated With Aortic Augmentation Index
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2001
Abstract: Abstract —The augmentation index (AIx) and “oscillatory” compliance (C 2 ) are wave contour analysis parameters for the central aorta (P ao ) and radial artery pressure wave (P rad ), respectively. Both are sensitive to cardiovascular risk factors such as aging, hypertension, and diabetes and have been proposed as prognostic markers for cardiovascular disease. In this work, we studied the relation between both. We first calculated P rad corresponding to a typical aortic A-type (AIx .15) and C-type wave (AIx ), taken from the literature, by using a generalized aorta-radial pressure transfer function. P rad corresponding to C-type waves yielded the highest C 2 value. We further used simultaneously measured aortic and radial artery pressure in 45 human subjects age 34 to 84 years (63±12 [SD]) at baseline and after administration of nitroglycerin to calculate AIx meas and C 2 , respectively. Transfer function was used to calculate reconstructed aortic pressure and AIx rec . AIx rec underestimates AIx meas by 0.03±0.16, but both values correlate well ( r =0.64 P .001). C 2 and AIx were inversely correlated ( r =−0.36 P .001 for AIx meas r =−0.30 P .01 for AIx rec ). Both AIx meas (0.06±0.17 versus 0.20±0.21 P .01) and AIx rec (0.04±0.12 versus 0.16±0.16 P .001) were lower after nitroglycerin, whereas C 2 increased only nonsignificantly (0.080±0.036 versus 0.071±0.042). C 2 is related to AIx and reflects, at least in part, hemodynamic changes affecting central aortic pressure. Nevertheless, given the model assumptions and computational steps associated with calculating C 2 , AIx could be a more appropriate parameter to use in the clinical setting because it is determined directly from the pressure wave contour.
An analysis of the relationship between central aortic and peripheral upper limb pressure waves in man
Publisher: Oxford University Press (OUP)
Date: 02-02-1993
DOI: 10.1093/EURHEARTJ/14.2.160
Abstract: Amplification of the pressure pulse between central and peripheral arteries renders pressure values in the upper limb an inaccurate measure of ascending aortic (AA) pressure. Accuracy could be improved by allowance for such lification. Transfer functions (TF) for pressures between AA and brachial artery (BA):(BATF) and between AA and radial artery (RA):(RATF) were derived from high-fidelity pressure recordings obtained at cardiac catheterization in 14 patients under control conditions, and after sublingual nitroglycerine 0.3 mg. There was no significant difference in BATF under control conditions and with nitroglycerine hence results were pooled. Control and nitroglycerine results were also pooled to obtain a single RATF. BATF and RATF moduli peaked at 5 Hz and 4 Hz, reaching 2.5 and 2.8 times the value at zero frequency respectively. Frequency-dependent changes in modulus and phase of BATF and RATF were attributable to wave travel and reflection in the upper limb. BATF and RATF were compared to published transfer functions and those derived from analysis of aortic and brachial or radial pressure waves in previous publications. Results were similar. Our BATF and RATF were used to synthesize AA pressure waves from published peripheral pulses. Correspondence was close, especially for systolic pressure which differed by 2.4 +/- 1.0 (mean +/- SEM) mmHg, whereas recorded systolic pressure differed by 20.4 +/- 2.6 (mean +/- SEM) mmHg between central and peripheral sites. Results indicate that in adult humans a single generalized TF can be used with acceptable accuracy to determine central from peripheral pressure under different conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
Of Machines and Men: Intelligent Diagnosis and the Shape of Things to Come
Publisher: Springer Science and Business Media LLC
Date: 2020
DOI: 10.1007/S11906-019-1010-3
Abstract: Artificial Intelligence (AI), although well established in many areas of everyday life, has only recently been trialed in the diagnosis and management of common clinical conditions. This editorial review highlights progress to date and suggests further improvements in and trials of AI in the management of conditions such as hypertension.
A combination of genetic, molecular and haemodynamic risk factors contributes to the formation, enlargement and rupture of brain aneurysms
Publisher: Elsevier BV
Date: 07-2013
DOI: 10.1016/J.JOCN.2012.12.003
Abstract: Many people carry cerebral aneurysms but are generally unaware of their presence until they rupture, resulting in high morbidity or mortality. The pathogenesis and aetiology of aneurysms are largely unknown however, a greater understanding, by analysing the genetic, molecular and haemodynamic risk factors involved in the initiation, enlargement, and rupture of aneurysms, could lead to effective prevention, early diagnosis and more effective treatment. The risk of aneurysm is increased by a family history of aneurysms, and amongst certain populations, namely in Japan and Finland. Several other risk factors are documented, including hypertension, smoking, alcohol consumption, and female sex. Studies indicate a higher occurrence of cerebral aneurysms in females compared to males. Oestrogen protects several components within the artery wall, and inhibits some of the inflammatory molecules that could cause aneurysms. At menopause, the oestrogen level decreases and the incidence of aneurysm increases. Haemodynamic stresses have been shown to be involved in the formation, growth and rupture of aneurysms. This is often associated with hypertension, which also increases the risk of aneurysm rupture. When an unruptured aneurysm is detected the decision to treat can be complicated, since only 1-2% of aneurysms eventually rupture. Haemodynamic simulation software offers an effective tool for the consideration of treatment options for patients who carry unruptured aneurysms. The assessment must consider the risks of interventional treatments versus non-interventional management options, such as controlling blood pressure.
Non-invasive estimation of cerebrospinal fluid pressure waveforms by means of retinal venous pulsatility and central aortic blood pressure
Publisher: Springer Science and Business Media LLC
Date: 13-04-2012
DOI: 10.1007/S10439-012-0563-Y
Abstract: Current techniques used for cerebrospinal fluid pressure (CSFp) measurements are invasive. They require a surgical procedure for placement of a pressure catheter in the brain ventricles or in the brain tissue. The human eye provides direct visualisation of its physiological structures and due to its anatomical connection with CSF via the retrolaminar optic nerve it may provide accessible information about CSFp. A total of 25 subjects were included in this study. 15 subjects were used to characterise the relationship between intraocular pressure (IOP), spontaneous retinal venous pulsatility (SRVP), and CSFp. IOP was manipulated and SRVP litudes recorded dynamically using the dynamic vessel analyzer (DVA). The relationship between IOP and SRVP litude was established to estimate CSFp. Additionally Doppler blood flow velocity of the middle cerebral artery and arterial blood pressure (ABP) were acquired for all subjects. This was to compare and validate our findings with an alternative approach (ICM+) which uses these values to estimate CSFp. A CSFp waveform was extracted from central blood pressure (CBP) waveform by removing its cardiac component frequency. Furthermore to calibrate the CSFp to CBP waveform ratio, invasive CSFp, and ABP was measured from 10 subjects with brain tumours who had a range of normal to elevated CSFp (i.e., 0-30 mmHg). Results show good agreement between the two methods (correlation r (2) = 0.55) Mean estimated CSFp for the two techniques did not show any significant difference (p > 0.05). A significant correlation between CBP pulse (CBPp) and invasive CSFp pulse (CSFpp) was observed (i.e., CSFpp = 0.0654CBBp + 3.91, p < 0.01). Estimated CSFpp was calibrated to CBPp according to this relation. In conclusion, the study demonstrated a good correlation between two different methods of estimating CSFp non-invasively and may provide a novel method to estimate CSF waveforms non-invasively.
Challenges Presented by Cuffless Measurement of Blood Pressure if Adopted for Diagnosis and Treatment of Hypertension
Publisher: S. Karger AG
Date: 2022
DOI: 10.1159/000522660
Abstract: The global health burden presented by hypertension is providing increased motivation for improved means of collection of blood pressure (BP) data. A growing area of research and commercial activity is the use of wearable devices to provide BP data using non-invasive cuffless techniques. The accelerated progress in recent years, particularly relating to connectivity of smartphone technology, has promoted the availability of consumer devices that provide values of BP. The main types of devices are wrist-worn, watch-type devices with sensors that typically record a photoplethysmography (PPG) signal, sometimes also with an electrocardiography (ECG) signal. The general underlying concept of the cuffless BP measurement in most device types is the association of BP and the travel time of the arterial pulse between two locations, determined from the time delay between the ECG and PPG signals. Other methods may involve additional analysis of the PPG waveform features. Experimental data are presented to illustrate the challenges presented by cuffless BP techniques in obtaining reliable BP measurements when the change in BP is caused by different stimuli affecting cardiac and vascular mechanisms. These effects influence the association of the measured and physiological BP change, thus presenting significant challenges and potential limitations in the use of cuffless BP devices for the diagnosis and treatment of hypertension.
Assessment of central arterial pressure?
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2003
Systemic hemodynamic atherothrombotic syndrome (SHATS) – Coupling vascular disease and blood pressure variability: Proposed concept from pulse of Asia
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.PCAD.2019.11.002
Abstract: Hypertension (HTN) is an important risk factor for cardiovascular disease (CVD) but the association between HTN and CVD cannot be explained by average blood pressure (BP) alone. BP variability (BPV) is another important factor, along with the effects of HTN on the vasculature. The concept of systemic hemodynamic atherothrombotic syndrome (SHATS) has been proposed, describing an age-related and synergistic vicious cycle of hemodynamic stress and vascular disease. The importance of SHATS is based on the assumption that the assessment of BPV and arterial disease is likely to provide an effective opportunity to intervene early to reduce progression to HTN in younger patients or to CVD events and organ damage in older patients. In addition to providing an overview of current evidence for the mechanisms and clinical data related to SHATS, this article proposes a new SHATS score for use to diagnose and assess the severity of SHATS. The score includes two components - a BP score and a vascular score - which are multiplied to generate the SHATS score. This reflects the synergistic, rather than additive, effects of BP and vascular disease on target organ damage and CVD events. Although it requires refinement and validation in future studies, early detection of SHATS using tools such as the proposed score, combined with population-based stratification and technology-based anticipation medicine incorporating real-time in idual data, has the potential to contribute to meaningful reductions in rates of CVD events and target organ damage.
Arterial dilation and reduced wave reflection. Benefit of dilevalol in hypertension.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-1989
Abstract: We compared dilevalol (an isomer of labetalol), 200-400 mg daily, against atenolol, 50-100 mg daily, in a double-blind, crossover, placebo-controlled trial with respect to effects on arterial distensibility (measured as pulse wave velocity [PWV]) and wave reflection (assessed from carotid pressure wave contour). Twelve patients of mean age 58 years (range 44-73 years) with essential hypertension (supine diastolic blood pressure 95-114 mm Hg) took active therapy for 12 weeks, separated by a 2-4 week placebo period. Carotid pressure waveforms were recorded noninvasively by applanation tonometry with a Millar micromanometer-tipped probe. PWV was measured between carotid and femoral arteries (aortic PWV), carotid and radial arteries (arm PWV), and femoral and pedal arteries (leg PWV). Early wave reflection was calculated from the ratio of the height of the peak of the carotid wave above its shoulder to the pulse pressure and was expressed as an augmentation index. Both drugs were equally effective in reducing brachial sphygmomanometric pressure and PWV in all three regions (active vs. placebo, p less than 0.001), but there was no significant difference between the two active therapies. However, the augmentation index (averaged during the treatment period) was significantly lower with dilevalol (19%) than with atenolol (28%, p less than 0.01), corresponding to a greater decrease of 5-8 mm Hg in carotid systolic pressure compared with the brachial artery. Although both drugs were equally effective in reducing arterial distensibility, the vasodilating action of dilevalol gave added benefit in reducing wave reflection, presumably through its vasodilatory effect on peripheral conduit arteries.
Pressure wave propagation in a multibranched model of the human upper limb
Publisher: American Physiological Society
Date: 10-1995
DOI: 10.1152/AJPHEART.1995.269.4.H1363
Abstract: The influence of the large arteries and the peripheral load on pressure wave propagation in the human upper limb was investigated in an anatomically realistic multibranched model based on linear transmission theory. To mimic vascular changes seen in life, the viscoelastic properties of large arteries and the peripheral load properties (represented as modified windkessels) were altered as follows: Young's modulus (from 10.9 x 10(6) to 15.3 x 10(6) dyn/cm2) and phase (from 0 to 15 degrees) of the complex elastance, windkessel time constant (from 0 to 0.6 s), and peripheral reflection coefficient (from 0 to 0.95). The relationship between the central aortic and peripheral radial pressure waveforms was analyzed in the time and the frequency domain. Results indicate that the large arterial properties have less influence (peak systolic pressure changed by 3% and peak of transfer function changed by 29%) than the properties of the peripheral load (systolic pressure changed by 14% and peak of transfer function changed by 74%) on the pressure wave propagation in the upper limb.
Association of Haemodynamic Indices of Central and Peripheral Pressure with Subclinical Target Organ Damage
Publisher: S. Karger AG
Date: 2017
DOI: 10.1159/000484441
Abstract: b i Background: /i /b Central aortic pressure has often been shown to be more closely associated with markers of vascular function and incidence of cardiovascular events compared to peripheral pressure. However, the potential clinical use of central aortic or peripheral haemodynamic indices as markers of target organ damage (TOD) has not been fully established. b i Methods: /i /b We evaluated associations of TOD with central aortic and peripheral haemodynamic indices (central aortic [cPP] and peripheral pulse pressure [pPP], central aortic augmentation index, and central and peripheral waveform factor) in 770 hospital inpatients (age 60 ± 10 years, 473 males) with primary hypertension. TOD was quantified in terms of arterial stiffness as measured by carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (IMT), and urine albumin-to-creatinine ratio (ACR). Subclinical TOD was defined as carotid IMT .9 mm, urine ACR .5 mg/mmol in females and .5 mg/mmol in males and/or cfPWV m/s. b i Results: /i /b Both cPP and pPP showed significant correlation with cfPWV ( i r = /i .41 vs. 0.40 i /i 0.01), ACR ( i r = /i .24 vs. 0.27 i /i 0.01) and carotid IMT ( i r /i = 0.14 vs. 0.15 i /i 0.01). Each SD increase in pPP and cPP was associated with increased risk of cfPWV m/s (odds ratio [OR] = 2.7 and 2.9 for pPP and cPP, respectively), ACR .5 mg/mmol (OR = 1.2 and 1.4, respectively), and carotid IMT .9 mm (OR = 1.46 and 1.53, respectively). Compared to pPP, cPP had higher predictive power for TOD for age ≥60 years (OR = 3.07, i /i 0.001). b i Conclusions: /i /b Although both pPP and cPP show an association with TOD in a hypertensive population, cPP provides additional information beyond pPP associated with TOD in a hypertensive cohort. Central aortic haemodynamic indices as potential biomarkers of subclinical TOD need to be validated by further prospective studies.
Noninvasive determination of age-related changes in the human arterial pulse.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-1989
Abstract: Arterial pressure waves were recorded noninvasively from the carotid, radial, femoral, or all three of these arteries of 1,005 normal subjects, aged 2-91 years, using a new transcutaneous tonometer containing a high fidelity Millar micromanometer. Waves were ensemble-averaged into age-decade groups. Characteristic changes were noted with increasing age. In all sites, pulse litude increased with advancing age (carotid, 91.3% radial 67.5% femoral, 50.1% from first to eighth decade), diastolic decay steepened, and diastolic waves became less prominent. In the carotid pulse, there was, in youth, a second peak on the downstroke of the waves in late systole. After the third decade, this second peak rose with age to merge with and dominate the initial rise. In the radial pulse, a late systolic wave was also apparent, but this occurred later with age, this second peak rose but not above the initial rise in early systole, even at the eighth decade. In the femoral artery, there was a single systolic wave at all ages. Aging changes in the arterial pulse are explicable on the basis of both an increase in arterial stiffness with increased pulse-wave velocity and progressively earlier wave reflection. These two factors may be separated and effects of the latter measured from pressure wave-contour analysis using an "augmentation index," determined by a computer algorithm developed from invasive pressure and flow data. Changes in peak pressure in the central (carotid) artery show increasing cardiac afterload with increasing age in a normal population this can account for the cardiac hypertrophy that occurs with advancing age (even as other organs atrophy) and the predisposition to cardiac failure in the elderly. Identification of mechanisms responsible offers a new approach to reduction of left ventricular afterload.
Cuffless blood pressure measuring devices: review and statement by the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 16-06-2022
Arterial viscoelasticity: role in the dependency of pulse wave velocity on heart rate in conduit arteries
Publisher: American Physiological Society
Date: 06-2017
DOI: 10.1152/AJPHEART.00849.2016
Abstract: Experimental investigations have established that the stiffness of large arteries has a dependency on acute heart rate (HR) changes. However, the possible underlying mechanisms inherent in this HR dependency have not been well established. This study aimed to explore a plausible viscoelastic mechanism by which HR exerts an influence on arterial stiffness. A multisegment transmission line model of the human arterial tree incorporating fractional viscoelastic components in each segment was used to investigate the effect of varying fractional order parameter (α) of viscoelasticity on the dependence of aortic arch to femoral artery pulse wave velocity (afPWV) on HR. HR was varied from 60 to 100 beats/min at a fixed mean flow of 100 ml/s. PWV was calculated by intersecting tangent method (afPWV Tan ) and by phase velocity from the transfer function (afPWV TF ) in the time and frequency domain, respectively. PWV was significantly and positively associated with HR for α ≥ 0.6 for α = 0.6, 0.8, and 1, HR-dependent changes in afPWV Tan were 0.01 ± 0.02, 0.07 ± 0.04, and 0.22 ± 0.09 m/s per 5 beats/min HR-dependent changes in afPWV TF were 0.02 ± 0.01, 0.12 ± 0.00, and 0.34 ± 0.01 m/s per 5 beats/min, respectively. This crosses the range of previous physiological studies where the dependence of PWV on HR was found to be between 0.08 and 0.10 m/s per 5 beats/min. Therefore, viscoelasticity of the arterial wall could contribute to mechanisms through which large artery stiffness changes with changing HR. Physiological studies are required to confirm this mechanism. NEW & NOTEWORTHY This study used a transmission line model to elucidate the role of arterial viscoelasticity in the dependency of pulse wave velocity on heart rate. The model uses fractional viscoelasticity concepts, which provided novel insights into arterial hemodynamics. This study also provides a means of assessing the clinical manifestation of the association of pulse wave velocity and heart rate.
Effects of pacing modality on noninvasive assessment of heart rate dependency of indices of large artery function
Publisher: American Physiological Society
Date: 09-2016
DOI: 10.1152/JAPPLPHYSIOL.00445.2016
Abstract: Studies investigating the relationship between heart rate (HR) and arterial stiffness or wave reflections have commonly induced HR changes through in situ cardiac pacing. Although pacing produces consistent HR changes, hemodynamics can be different with different pacing modalities. Whether the differences affect the HR relationship with arterial stiffness or wave reflections is unknown. In the present study, 48 subjects [mean age, 78 ± 10 (SD), 9 women] with in situ cardiac pacemakers were paced at 60, 70, 80, 90, and 100 beats per min under atrial, atrioventricular, or ventricular pacing. At each paced HR, brachial cuff-based pulse wave analysis was used to determine central hemodynamic parameters, including ejection duration (ED) and augmentation index (AIx). Wave separation analysis was used to determine wave reflection magnitude (RM) and reflection index (RI). Arterial stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV). Pacing modality was found to have significant effects on the HR relationship with ED ( P = 0.01), central aortic pulse pressure ( P = 0.01), augmentation pressure ( P 0.0001), and magnitudes of both forward and reflected waves ( P = 0.05 and P = 0.003, respectively), but not cfPWV ( P = 0.57) or AIx ( P = 0.38). However, at a fixed HR, significant differences in pulse pressure lification ( P 0.001), AIx ( P 0.0001), RM ( P = 0.03), and RI ( P = 0.03) were observed with different pacing modalities. These results demonstrate that although the HR relationships with arterial stiffness and systolic loading as measured by cfPWV and AIx were unaffected by pacing modality, it should still be taken into account for studies in which mixed pacing modalities are present, in particular, for wave reflection studies.
Does Replacing Sodium Excreted in Sweat Attenuate the Health Benefits of Physical Activity?
Publisher: Human Kinetics
Date: 08-2016
Abstract: International guidelines suggest limiting sodium intake to 86–100 mmol/day, but average intake exceeds 150 mmol/day. Participants in physical activities are, however, advised to increase sodium intake before, during and after exercise to ensure euhydration, replace sodium lost in sweat, speed rehydration and maintain performance. A similar range of health benefits is attributable to exercise and to reduction in sodium intake, including reductions in blood pressure (BP) and the increase of BP with age, reduced risk of stroke and other cardiovascular diseases, and reduced risk of osteoporosis and dementia. Sweat typically contains 40–60 mmol/L of sodium, leading to approximately 20–90 mmol of sodium lost in one exercise session with sweat rates of 0.5–1.5 L/h. Reductions in sodium intake of 20–90 mmol/day have been associated with substantial health benefits. Homeostatic systems reduce sweat sodium as low as 3–10 mmol/L to prevent excessive sodium loss. “Salty sweaters” may be in iduals with high sodium intake who perpetuate their “salty sweat” condition by continual replacement of sodium excreted in sweat. Studies of prolonged high intensity exercise in hot environments suggest that sodium supplementation is not necessary to prevent hyponatremia during exercise lasting up to 6 hr. We examine the novel hypothesis that sodium excreted in sweat during physical activity offsets a significant fraction of excess dietary sodium, and hence may contribute part of the health benefits of exercise. Replacing sodium lost in sweat during exercise may improve physical performance, but may attenuate the long-term health benefits of exercise.
Characterizing dynamic properties of retinal vessels in the rat eye using high speed imaging
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.MVR.2013.12.006
Abstract: The dynamic properties of retinal vessels including pulse wave propagation and pulsatility index provide new perspective in retinal hemodynamic analysis. In this study we utilize a high speed imaging system to capture these characteristics in the rat eye for the first time. Retinal video images of 9 Wistar-Kyoto (WKY) rats were captured at a rate of 250 frames per second for 10s with a 50° field of view using a high speed camera (Optronis, Kehl, Germany). Two recordings were taken from each rat at the same sites for repeatability analysis. The electrocardiogram (ECG) was measured simultaneously with retinal images. Arterial retinal pulse wave velocity (rPWV) and arterial/venous pulse litude were calculated from recorded images. Arterial measurements were repeated in another normotensive strain of the same age (Sprague-Dawley, n=4). The average WKY rPWV was 11.4 ± 6.1 cm/s. The differences between repeated measures were not significant (-2.8 ± 2.9 cm/s, p=0.2). Sprague-Dawley animals had a similar rPWV (9.8 ± 2.2 cm/s, p=0.61). The average arterial and venous pulse litude was 7.1 ± 1.5 μm and 8.2 ± 2.0 μm respectively. There was a positive correlation between rPWV and heart rate in the WKY groups (r(2)=0.32). A positive correlation was also obtained between arterial and venous diameter and their pulse litude (r(2)=0.67 and r(2)=0.37 respectively). rPWV was associated with heart rate. Higher pulsation litude was also correlated with larger vessel diameter. High speed imaging of retinal vessels in the rat eye provides an accurate and robust method to study dynamic characteristics of these vessels and their relationship with ocular and systemic abnormalities.
[OP.1C.01] HIGH SALT DIET INCREASES AORTIC STIFFNESS AND PRESSURE PULSE AMPLIFICATION IN RAT
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
542 542 CHARACTERISATION OF THE PRESSURE DEPENDENCY OF PULSE WAVE VELOCITY IN THE MOUSE AORTA
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2012
Pulsatile flow and pressure in human systemic arteries. Studies in man and in a multibranched model of the human systemic arterial tree.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-1980
Abstract: Substantial research indicates that fluid and crystallized abilities are highly correlated throughout the adult life span. However, recent proposals suggest that a large discrepancy between these two abilities, defined as crystallized performance minus fluid performance, indicates heightened risk for Alzheimer's disease (AD). In 266 cognitively healthy older adults, the present study tested linear and quadratic relationships between an ability discrepancy score and early AD neuropathology indexed via in vivo measures of beta-amyloid deposition and cortical thickness in AD-vulnerable regions. We also tested the extent that alternative forms of this ability discrepancy measure (e.g., subdomain discrepancies, verbal-visual discrepancies) and an episodic memory composite might also be sensitive markers of early AD pathology. An overall ability discrepancy was linearly and positively correlated with beta- amyloid. A quadratic relationship was found between the overall ability discrepancy score and cortical thickness such that a small positive correlation was found at lower discrepancy levels (fluid > crystallized), but at higher discrepancy levels (crystallized > fluid) a negative relationship was found (i.e., an inverted-U pattern). Similar patterns were found across each subdomain of cognition, but the effects were weaker than the overall ability discrepancy score. Importantly, inclusion of episodic memory (the gold standard) did not alter any of the effects, suggesting that an ability discrepancy confers unique predictiveness of AD biomarkers. These findings replicate previous findings and increase the confidence in their usefulness to predict AD biomarkers. Longitudinal validation is needed to clearly relate an ability discrepancy to specific stages of preclinical AD. (PsycINFO Database Record (c) 2020 APA, all rights reserved).
Field stimulation of the carotid baroreceptor complex does not compromise baroreceptor function in spontaneously hypertensive rats
Publisher: IEEE
Date: 08-2014
Dynamic Stress Analysis of the Arterial Wall Utilizing Physiological Pressure Waveforms
Publisher: Science Publications
Date: 10-2008
Methods and devices for measuring arterial compliance in humans
Publisher: Oxford University Press (OUP)
Date: 08-2002
DOI: 10.1016/S0895-7061(02)02962-X
Abstract: This review analyses methods and devices used worldwide to evaluate the arterial stiffness. Three main methodologies are based upon analysis of pulse transit time, of wave contour of the arterial pulse, and of direct measurement of arterial geometry and pressure, corresponding to regional, systemic and local determination of stiffness. They are used in clinical laboratory and/or in clinical departments. Particular attention is given to the reproducibility data in literature for each device. This article summarizes the discussion of the dedicated Task Force during the first Conference of Consensus on Arterial Stiffness held in June 2000 (Paris, France).
Snoring-related energy transmission to the carotid artery in rabbits
Publisher: American Physiological Society
Date: 05-2006
DOI: 10.1152/JAPPLPHYSIOL.01439.2005
Abstract: Epidemiological studies link habitual snoring and stroke, but mechanisms involved are poorly understood. One previously advanced hypothesis is that transmitted snoring vibration energy may promote carotid atheromatous plaque formation or rupture. To test whether vibration energy is present in carotid artery walls during snoring we developed an animal model in which we examined induced snoring (IS)-associated tissue energy levels. In six male, supine, anesthetized, spontaneously breathing New Zealand White rabbits, we surgically inserted pressure transducer-tipped catheters (Millar) to monitor tissue pressure at the carotid artery bifurcation (P CT ) and within the carotid sinus lumen (P CS artery ligated). Snoring was induced via external compression (sandbag) over the pharyngeal region. Data were analyzed using power spectral analysis for frequency bands above and below 50 Hz. For frequencies below 50 Hz, P CT energy was 2.2 (1.1–12.3) cmH 2 O 2 [median (interquartile range)] during tidal breathing (TB) increasing to 39.0 (2.5–95.0) cmH 2 O 2 during IS ( P = 0.05, Wilcoxon's signed-rank test). For frequencies Hz, P CT energy increased from 9.2 (8.3–10.4) × 10 −4 cmH 2 O 2 during TB to 172.0 (118.0–569.0) × 10 −4 cmH 2 O 2 during IS ( P = 0.03). Concurrently, P CS energy was 13.4 (8.5–18.0) × 10 −4 cmH 2 O 2 during TB and 151.0 (78.2–278.8) × 10 −4 cmH 2 O 2 during IS ( P 0.03). The P CS energy was greater than P CT energy for the 100–275 Hz bandwidth. In conclusion, during IS there is increased energy around and within the carotid artery, including lower frequency lification for P CS . These findings may have implications for carotid atherogenesis and/or plaque rupture.
Physiological and pathophysiological implications of ventricular/vascular coupling
Publisher: Springer Science and Business Media LLC
Date: 03-1984
DOI: 10.1007/BF02584226
Abstract: Metabolic surgery ameliorates insulin resistance and is associated with long-term, effective weight loss, but the mechanisms involved remain unknown. Here, the duodenal-jejunal omega switch (DJOS) surgery in combination with high-fat, high-carbohydrate diet was performed on diet obese rats and joint effects of bariatric surgery and different dietary patterns on heat shock protein 70 (HSP70) and HSP90 plasma and liver concentrations were measured. We found that plasma and liver levels of HSP70 were lower after DJOS surgery in comparison to the control in the groups of animals kept on control diet (CD) and high-fat, high-sugar diet (HFS) but the postoperative change of the diet led to the increase in HSP70 in plasma and liver concentration in DJOS-operated animals. A high-calorie meal, rich in carbohydrates and fats, significantly increased circulating levels of HSP90, reducing the normalising effect of DJOS. The HFS diet applied during all stages of the experiment led to the higher levels of liver HSP90 concentration. The combination of CD and DJOS surgery was the most efficient in the lowering of the HSP90 liver concentration. The normalisation of circulating levels and liver concentrations of HSP70 and HSP90 may be achieved in a combination of DJOS procedure with a proper dietary plan.
Central pulsatile pressure and flow relationship in the time and frequency domain to characterise hydraulic input to the brain and cerebral vascular impedance
Publisher: Springer International Publishing
Date: 2016
Arterial Pulse Wave Velocity and Heart Rate
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2002
Endothelin-1 regulates arterial pulse wave velocity in vivo
Publisher: Elsevier BV
Date: 12-2003
DOI: 10.1016/J.JACC.2003.06.016
Abstract: The aim of this study was to investigate whether endothelin-1, acting locally, regulates arterial distensibility, assessed by measuring pulse-wave velocity in vivo. Arterial stiffness is a key determinant of cardiovascular risk. Several lines of evidence support a role for the endothelium in regulating arterial stiffness by release of vasoactive mediators. However, the role of endothelin-1 (ET-1) in the regulation of arterial stiffness has not been investigated. All studies were conducted in anesthetized sheep. Pulse wave velocity (PWV) was calculated using the foot-to-foot methodology from two pressure waveforms simultaneously recorded with a high-fidelity, dual pressure-sensing catheter placed in the common iliac artery. Intra-arterial infusion of ET-1 significantly increased iliac PWV by 12 +/- 5% (mean +/- STD p < 0.001), whereas infusion of the endothelin-A (ET(A)) receptor antagonist BQ-123 significantly reduced PWV by 12 +/- 4% (p < 0.001). After BQ-123 infusion, exogenously infused ET-1 did not significantly change PWV compared with infusion of saline (change of -0.08 +/- 0.11% vs. -0.01 +/- 0.07% p = 0.53). Importantly, infusion of BQ-123 or ET-1 distal to the common iliac artery did not affect PWV. These results demonstrate, for the first time, that endogenous ET-1 production directly regulates large artery PWV in vivo. In addition, exogenous ET-1 increases PWV, and this can be blunted by ET(A) receptor blockade. These observations explain, in part, why conditions that exhibit up-regulation of ET-1 are also associated with arterial stiffening. Therefore, drugs that block ET(A) receptors may be effective in reducing large artery stiffness in humans, and thus cardiovascular risk.
Does increase in arterial stiffness and wave reflection precede development of placental-mediated complications in pregnancy?
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2018
A modified postural drainage position produces less cardiovascular stress than a head-down position in patients with severe heart disease: A quasi-experimental study
Publisher: Elsevier BV
Date: 2006
DOI: 10.1016/S0004-9514(06)70029-0
Abstract: Does a modified postural drainage position (horizontal) produce less cardiovascular and respiratory stress than a head-down postural drainage position (30 degrees) in people with severe heart disease? A quasi-experimental study. Thirty-one patients (mean age 69 years, SD 13) with severe left ventricular systolic dysfunction (mean ejection fraction 23%, SD 7) who were stable, receiving regular medication and free of acute respiratory illness. Two manoeuvres were performed--one from long sitting to a modified (horizontal) postural drainage position, and one from long sitting to a head-down (30 degrees) postural drainage position. Cardiovascular responses examined were blood pressure, sphygmocardiographic indices, and cardiac rhythm. Respiratory responses examined were respiratory rate, transcutaneous arterial oxyyhaemoglobin saturation, and dyspnoea. Three participants were intolerant to the postural drainage positions--two during head-down and one during modified positioning. The remaining 28 participants maintained their resting cardiac rhythm and did not complain of chest pain or dyspnoea. The changes in cardiovascular responses during the sitting to head-down postural drainage manoeuvre in the tolerant participants were significantly greater (p < 0.05) than the changes during the sitting to the modified postural drainage manoeuvre for most of the sphygmocardiographic indices. In contrast, there were no significant respiratory responses to either postural drainage manoeuvre. Modified positioning is associated with less cardiovascular stress than head-down positioning, yet for most patients with severe heart disease, both positions are generally well tolerated. For a subset of these patients, either position may be inappropriate. This suggests that modified positioning should be attempted first but that a head-down position may be attempted if the modified position proves ineffective.
Ascending aortic impedance patterns in the kangaroo: their explanation and relation to pressure waveforms.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-1986
Abstract: This study seeks to explain mechanisms responsible for the peculiar ascending aortic pressure waveform and impedance spectral pattern in kangaroos. Pulsatile pressure and blood flow velocity were measured and input impedance calculated in the ascending aorta, descending thoracic aorta, and brachiocephalic artery of 15 rock kangaroos. Pressure and velocity waveforms and impedance spectral patterns were interpreted with the aid of an asymmetric uniform T-tube model of the systemic arterial tree. The ascending aortic pressure waveform displayed a very large secondary wave that began in late systole or early diastole and continued throughout most of diastole. The peak of this secondary wave (which almost always occurred in diastole) was often greater than peak systolic pressure and results from apparently intense wave reflections from peripheral vascular beds. This contention is supported by the configuration of the impedance spectral pattern that is explained on the basis of a single (or dominant) functionally discrete reflecting site in the lower part of the body. These findings are explicable on the basis of body size and shape and the extreme eccentric location of the heart within the body. Wave reflections from the diminutive upper body are so small that they are totally dominated by intensive wave reflections from the large muscular lower body. These conclusions are supported by results obtained from the asymmetric T-tube model.
Stimulatory Effects of Computer-Rendered Artificial Virtual Environment on Heart Rate Variability and Baroreceptor Sensitivity
Publisher: Elsevier BV
Date: 2018
Serum 25-Hydroxyvitamin D Deficiency and Insufficiency are Associated with Ankle-Brachial Index but not Arterial Stiffness in an Elderly Community-dwelling Chinese Population
Publisher: Springer Science and Business Media LLC
Date: 2019
Noninvasive estimation of baroreflex sensitivity using pressure pulse amplification
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2001
DOI: 10.1109/51.917724
Assessment of baroreflex sensitivity by continuous noninvasive monitoring of peripheral and central aortic pressure
Publisher: IEEE
Date: 08-2014
Age-Specific Acute Changes in Carotid–Femoral Pulse Wave Velocity With Head-up Tilt
Publisher: Oxford University Press (OUP)
Date: 07-07-2020
DOI: 10.1093/AJH/HPAA101
Abstract: Aortic stiffness as measured by carotid–femoral pulse wave velocity (cfPWV) is known to depend on blood pressure (BP), and this dependency may change with age. Therefore, the hydrostatic BP gradient resulting from a change in body posture may elicit a cfPWV change that is age-dependent. We aimed to analyze the relationship between BP gradient—induced by head-up body tilting—and related changes in cfPWV in in iduals of varying age. cfPWV and other hemodynamic parameters were measured in 30 healthy in iduals at a head-up tilt of 0° (supine), 30°, and 60°. At each angle, the PWV gradient and resulting cfPWV were also estimated (predicted) by assuming a global nonlinear, exponential, pressure–diameter relationship characterized by a constant β0, and taking into account that (diastolic) foot-to-foot cfPWV acutely depends on diastolic BP. cfPWV significantly increased upon body tilting (8.0 ± 2.0 m/s supine, 9.1 ± 2.6 m/s at 30°, 9.5 ± 3.2 m/s at 60°, P for trend & .01) a positive trend was also observed for heart rate (HR P & 0.01). When the observed, tilt-induced cfPWV change measured by applanation tonometry was compared with that predicted from the estimated BP hydrostatic gradient, the difference in observed-vs.-predicted PWV change increased nonlinearly as a function of age (R2 for quadratic trend = 0.38, P & 0.01, P vs. linear = 0.04). This result was unaffected by HR tilt-related variations (R2 for quadratic trend = 0.37, P & 0.01, P vs. linear = 0.04). Under a hydrostatic pressure gradient, the pulse wave traveling along the aorta undergoes an age-related, nonlinear PWV increase exceeding the increase predicted from BP dependency.
RELATIONSHIP BETWEEN ARTERIAL STIFFNESS AND CHRONIC KIDNEY DISEASE IN PATIENTS WITH HYPERTENSION
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2019
Interarm Differences in Brachial Blood Pressure and their Effect on the Derivation on Central Aortic Blood Pressure
Publisher: Springer Science and Business Media LLC
Date: 2020
P135 SYSTEMIC CARDIOVASCULAR INPUTS IN MODELS ESTIMATING INTRACRANIAL PRESSURE MAGNITUDE AND WAVEFORM
Publisher: Springer Science and Business Media LLC
Date: 2018
Older age is associated with greater central aortic blood pressure following the exercise stress test in subjects with similar brachial systolic blood pressure
Publisher: Springer Science and Business Media LLC
Date: 21-08-2015
DOI: 10.1007/S00380-015-0733-6
Abstract: Brachial systolic pressure (BSP) is often monitored during exercise by the stress test however, central systolic pressure (CSP) is thought to be a more direct measure of cardiovascular events. Although some studies reported that exercise and aging may play roles in changes of both BSP and CSP, the relationship between BSP and CSP with age following the exercise stress test remains unclear. The aim of this study was to evaluate the effect of age on the relationship between BSP and CSP measured after exercise. Ninety-six subjects underwent the diagnostic treadmill exercise stress test, and we retrospectively ided them into the following 3 groups by age: the younger age group (43 ± 4 years), middle age group (58 ± 4 years), and older age group (70 ± 4 years). Subjects exercised according to the Bruce protocol, to achieve 85 % of their age-predicted maximum heart rate or until the appearance of exercise-associated symptoms. BSP, CSP, and pulse rate (PR) were measured using a HEM-9000AI (Omron Healthcare, Japan) at rest and after exercise. BSP, CSP, and PR at rest were not significantly different among the 3 groups (p = 0.92, 0.21, and 0.99, respectively). BSP and PR immediately after exercise were not significantly different among the groups (p = 0.70 and 0.38, respectively). However, CSP immediately after exercise was 144 ± 18 mmHg (younger age), 149 ± 17 mmHg (middle age), and 158 ± 19 mmHg (older age). CSP in the older age group was significantly higher than that in the younger age group (p < 0.01). Despite similar BSPs in all age groups after exercise, CSP was higher in the older age group. Therefore, older subjects have a higher CSP after exercise, which is not readily assessed by conventional measurements of BSP.
Reply
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2018
Inhibition of Glycosphingolipid Synthesis Ameliorates Atherosclerosis and Arterial Stiffness in Apolipoprotein E −/− Mice and Rabbits Fed a High-Fat and -Cholesterol
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-06-2014
DOI: 10.1161/CIRCULATIONAHA.113.007559
Abstract: Glycosphingolipids, integral components of the cell membrane, have been shown to serve as messengers, transducing growth factor–initiated phenotypes. Here, we have examined whether inhibition of glycosphingolipid synthesis could ameliorate atherosclerosis and arterial stiffness in transgenic mice and rabbits. Apolipoprotein E −/− mice (12 weeks of age n=6) were fed regular chow or a Western diet (1.25% cholesterol, 2% fat). Mice were fed 5 or 10 mg/kg of an inhibitor of glycosphingolipid synthesis, D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), solubilized in vehicle (5% Tween-80 in PBS) the placebo group received vehicle only. At 20 and 36 weeks of age, serial echocardiography was performed to measure aortic intima-media thickening. Aortic pulse-wave velocity measured vascular stiffness. Feeding mice a Western diet markedly increased aortic pulse-wave velocity, intima-media thickening, oxidized low-density lipoprotein, Ca 2+ deposits, and glucosylceramide and lactosylceramide synthase activity. These were dose-dependently decreased by feeding D-PDMP. In liver, D-PDMP decreased cholesterol and triglyceride levels by raising the expression of SREBP2, low-density lipoprotein receptor, HMGCo-A reductase, and the cholesterol efflux genes (eg, ABCG5 , ABCG8 ). D-PDMP affected very-low-density lipoprotein catabolism by increasing the gene expression for lipoprotein lipase and very-low-density lipoprotein receptor. Rabbits fed a Western diet for 90 days had extensive atherosclerosis accompanied by a 17.5-fold increase in total cholesterol levels and a 3-fold increase in lactosylceramide levels. This was completely prevented by feeding D-PDMP. Inhibition of glycosphingolipid synthesis ameliorates atherosclerosis and arterial stiffness in apolipoprotein E −/− mice and rabbits. Thus, inhibition of glycosphingolipid synthesis may be a novel approach to ameliorate atherosclerosis and arterial stiffness.
Quantification of peripheral and central blood pressure variability using a time-frequency method
Publisher: IEEE
Date: 08-2016
Comparison of Risk of Target Organ Damage in Different Phenotypes of Arterial Stiffness and Central Aortic Blood Pressure
Publisher: Frontiers Media SA
Date: 14-04-2022
Abstract: The aim of this study was to explore the risk of target organ damage (TOD) in different groups based on carotid-femoral pulse wave velocity (cfPWV) and central aortic blood pressure (CBP) in different populations. The study cohort was ided into four groups according to the status of cfPWV and CBP [Group ( cfPWV/CBP ): high cfPWV and high CBP Group ( cfPWV ): high cfPWV and normal CBP Group ( CBP ): normal cfPWV and high CBP Group ( control ): normal cfPWV and normal CBP]. TOD was determined by the assessment of carotid intima-media thickness (CIMT) abnormality, chronic kidney disease (CKD), microalbuminuria, and left ventricular hypertrophy (LVH). A total of 1,280 patients (mean age 53.14 ± 12.76 years, 64.1% male patients) were recruited in this study. Regarding Group ( control ) as reference, LVH was significantly higher in Group ( cfPWV ) and Group ( CBP ) [OR 2.406, 95% CI (1.301–4.452), P & 0.05 OR 2.007, 95% CI (1.335–3.017), P & 0.05] microalbuminuria was significantly higher in Group ( cfPWV/CBP ) and Group ( CBP ) [OR 3.219, 95% CI (1.630–6.359), P & 0.05 OR 3.156, 95% CI (1.961–5.079), P & 0.05]. With age stratified by 60 years, the risk of CKD was significantly higher in Group ( cfPWV/CBP ) [OR 4.019, 95% CI (1.439–11.229), P & 0.05]. Different phenotypes based on the status of cfPWV and CBP were associated with different TOD. In iduals with both cfPWV and CBP elevated have a higher risk of microalbuminuria.
Use of Arterial Transfer Functions for the Derivation of Central Aortic Waveform Characteristics in Subjects With Type 2 Diabetes and Cardiovascular Disease
Publisher: American Diabetes Association
Date: 10-2004
Dependence of arterial stiffness on pressure quantified in the realm of the cardiac cycle
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2015
An investigation of the individualized, two-point calibration method for cuffless blood pressure estimation using pulse arrival time: an historical perspective using the Casio BP-100 digital watch
Publisher: IEEE
Date: 11-2021
Electrical Activity of the Heart Under Pressure
Publisher: Oxford University Press (OUP)
Date: 05-10-2017
DOI: 10.1093/AJH/HPX175
Effect of glyceryl trinitrate on peripheral arteries alters left ventricular hydraulic load in man
Publisher: Oxford University Press (OUP)
Date: 02-1986
DOI: 10.1093/CVR/20.2.153
Abstract: Effects of sublingual glyceryl trinitrate (GTN) were studied in ten patients without heart failure during diagnostic cardiac catheterisation following angiography. GTN caused substantial reduction in peak left ventricular and aortic pressure (19 mmHg) with lesser reduction in mean aortic pressure (9 mmHg) and no change in diastolic aortic pressure. Reduction in stroke volume (by 15%), associated with fall in left ventricular end diastolic pressure (by 4 mmHg) was insufficient to explain the marked (17 mmHg - 34%) reduction in pulse pressure. Decrease in pulse pressure was associated with loss of the late systolic peak on both the aortic and left ventricular pressure wave. This peak is caused by pulse wave reflection. GTN caused no change in peripheral resistance or in indices of aortic compliance (characteristic impedance, total arterial compliance) but was associated with reduction in fluctuations of both modulus and phase of aortic impedance. All these changes in pressure waves and in impedance spectra are explicable on the basis of decreased peripheral wave reflection. This can be attributed to the known vasodilatory effect of GTN on the peripheral arteries. Simulation of arterial vasodilatation in a multi-branched model of the systemic arterial system confirmed this interpretation. Dilatation of peripheral arteries explains in part the beneficial effects of GTN in adult man.
Are Korotkoff Sounds Reliable Markers for Accurate Estimation of Systolic and Diastolic Pressure Using Brachial Cuff Sphygmomanometry?
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2021
Relationship between Arterial Stiffness and Renal Function Determined by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) Equations in a Chi
Publisher: Hindawi Limited
Date: 14-03-2022
DOI: 10.1155/2022/8218053
Abstract: Background. The association between arterial stiffness and cardiovascular risk in CKD and ESRD patients is well established. However, the relationship between renal function estimation and properties of large arteries is unclear due to the four different methods used to quantify glomerular filtration. This study investigated the relationship between carotid-femoral pulse wave velocity (c-fPWV), as a measure of arterial stiffness, and accepted metrics of renal function. Methods. This cross-sectional study was conducted in 431 health examination in iduals in China, enrolled from January 2017 to June 2019. c-fPWV and blood pressure were measured, and blood s les were obtained for all participants. Four different methods were used to determine the estimated glomerular filtration rate (eGFR) as described by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) equations: (i) CKD-EPISCr formula based on SCr, (ii) CKD-EPICysC formula based on CysC, (iii) CKD-EPISCr/CysC formula based on Cr and CysC, and (iv) MDRD. Results. Of all of the study participants (average age 53.1 ± 13.0 years, 68.1% male), 23.7% had diabetes mellitus and 66.6% had hypertension. The average eGFR values determined by the CKD-EPISCr, CKD-EPICysC, CKD-EPISCr/CysC, and MDRD equations were 91.9 ± 15.6 , 86.8 ± 21.4 , 89.6 ± 18.3 , and 90.7 ± 16.6 ml/min/1.73m2, respectively. c-fPWV was significantly and negatively correlated with eGFR determined by CKD-EPISCr ( r = − 0.336 , P 0.001 ), CKD-EPICysC ( r = − 0.385 , P 0.001 ), CKD-EPISCr/CysC ( r = − 0.378 , P 0.001 ), and MDRD ( r = − 0.219 , P .001 ) equations. After adjusting for confounding factors, c-fPWV remained significantly and negatively correlated with eGFR determined by the CKD-EPICysC equation ( β = − 0.105 , P = 0.042 ) and significantly and positively correlated with age ( β = 0.349 , P ≤ 0.01 ), systolic pressure ( β = 0.276 , P ≤ 0.01 ), and hypoglycemic drugs ( β = 0.101 , P = 0.019 ). Conclusion. In a health examination population in China, c-fPWV is negatively correlated with eGFR determined by four different equations however, only the metric of eGFR determined by the equation for CKD-EPICysC showed an independent relation with c-fPWV.
Relationship between Obesity Phenotypes and Cardiovascular Risk in a Chinese Cohort
Publisher: Springer Science and Business Media LLC
Date: 2020
Cuffless Blood Pressure Measurement
Publisher: Annual Reviews
Date: 06-06-2022
DOI: 10.1146/ANNUREV-BIOENG-110220-014644
Abstract: Cuffless blood pressure (BP) measurement has become a popular field due to clinical need and technological opportunity. However, no method has been broadly accepted hitherto. The objective of this review is to accelerate progress in the development and application of cuffless BP measurement methods. We begin by describing the principles of conventional BP measurement, outstanding hypertension/hypotension problems that could be addressed with cuffless methods, and recent technological advances, including smartphone proliferation and wearable sensing, that are driving the field. We then present all major cuffless methods under investigation, including their current evidence. Our presentation includes calibrated methods (i.e., pulse transit time, pulse wave analysis, and facial video processing) and uncalibrated methods (i.e., cuffless oscillometry, ultrasound, and volume control). The calibrated methods can offer convenience advantages, whereas the uncalibrated methods do not require periodic cuff device usage or demographic inputs. We conclude by summarizing the field and highlighting potentially useful future research directions.
Validation of non-invasive central blood pressure devices: ARTERY Society task force consensus statement on protocol standardization
Publisher: Oxford University Press (OUP)
Date: 30-01-2017
Blood pressure waveform analysis by means of wavelet transform
Publisher: Springer Science and Business Media LLC
Date: 30-09-2008
DOI: 10.1007/S11517-008-0397-9
Abstract: The assessment of cardiovascular function by means of arterial pulse wave analysis (PWA) is well established in clinical practice. PWA is applied to study risk stratification in hypertension, with emphasis on the measurement of the augmentation index as a measure of aortic pressure wave reflections. Despite the fact that the prognostic power of PWA, in its current form, still remains to be demonstrated in the general population, there is general agreement that analysis and interpretation of the waveform might provide a deeper insight in cardiovascular pathophysiology. We propose here the use of wavelet analysis (WA) as a tool to quantify arterial pressure waveform features, with a twofold aim. First, we discuss a specific use of wavelet transform in the study of pressure waveform morphology, and its potential role in ascertaining the dynamics of temporal properties of arterial pressure waveforms. Second, we apply WA to evaluate a database of carotid artery pressure waveforms of healthy middle-aged women and men. Wavelet analysis has the potential to extract specific features (wavelet details), related to wave reflection and aortic valve closure, from a measured waveform. Analysis showed that the fifth detail, one of the waveform features extracted applying the wavelet decomposition, appeared to be the most appropriate for the analysis of carotid artery pressure waveforms. What remains to be assessed is how the information embedded in this detail can be further processed and transformed into quantitative data, and how it can be rendered useful for automated waveform classification and arterial function parameters with potential clinical applications.
Method of calibration of measurement of central aortic pressure and prediction of all-cause mortality in chronic kidney disease
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2015
Tissue Transglutaminase Modulates Vascular Stiffness and Function Through Crosslinking‐Dependent and Crosslinking‐Independent Functions
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-02-2017
Abstract: The structural elements of the vascular wall, namely, extracellular matrix and smooth muscle cells ( SMC s), contribute to the overall stiffness of the vessel. In this study, we examined the crosslinking‐dependent and crosslinking‐independent roles of tissue transglutaminase ( TG 2) in vascular function and stiffness. SMC s were isolated from the aortae of TG 2−/− and wild‐type ( WT ) mice. Cell adhesion was examined by using electrical cell–substrate impedance sensing and PicoGreen assay. Cell motility was examined using a Boyden chamber assay. Cell proliferation was examined by electrical cell–substrate impedance sensing and EdU incorporation assays. Cell micromechanics were studied using magnetic torsion cytometry and spontaneous nanobead tracer motions. Aortic mechanics were examined by tensile testing. Vasoreactivity was studied by wire myography. SMC s from TG 2−/− mice had delayed adhesion, reduced motility, and accelerated de‐adhesion and proliferation rates compared with those from WT . TG 2−/− SMC s were stiffer and displayed fewer cytoskeletal remodeling events than WT . Collagen assembly was delayed in TG 2−/− SMC s and recovered with adenoviral transduction of TG 2. Aortic rings from TG 2−/− mice were less stiff than those from WT stiffness was partly recovered by incubation with guinea pig liver TG 2 independent of crosslinking function. TG 2−/− rings showed augmented response to phenylephrine‐mediated vasoconstriction when compared with WT . In human coronary arteries, vascular media and plaque, high abundance of fibronectin expression, and colocalization with TG 2 were observed. TG 2 modulates vascular function/tone by altering SMC contractility independent of its crosslinking function and contributes to vascular stiffness by regulating SMC proliferation and matrix remodeling.
Letter: Aldosterone Antagonism and Arterial Stiffness
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2004
Ultrasound measurement of central pulse pressure from carotid diameter
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2018
2.4 RELATIONSHIP BETWEEN ADULT TRANSFER FUNCTION DERIVED CENTRAL AORTIC SYSTOLIC PRESSURE AND MEASURED SYSTOLIC PRESSURE IN THE HEALTHY CHILDREN POPULATION
Publisher: Springer Science and Business Media LLC
Date: 2014
CALCULATION OF ARTERIAL PATH LENGTH FOR CAROTID-FEMORAL PULSE WAVE VELOCITY DETERMINATION USING AN ESTABLISHED FORMULA
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2019
Cuffless Estimation of Blood Pressure: Importance of Variability in Blood Pressure Dependence of Arterial Stiffness Across Individuals and Measurement Sites
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2018
Arterial Stiffness as a Predictor of the Index of Atherosclerotic Cardiovascular Disease in Hypertensive Patients
Publisher: MDPI AG
Date: 06-02-2023
Abstract: Objective: The aim of this study was to evaluate the predictive value of carotid-femoral pulse wave velocity (cfPWV) and cardiovascular disease in the hypertensive population in China and to determine the specific cfPWV cut-off value for assessing future cardiovascular disease (CVD) risk. Methods: This cross-sectional study included 630 hospital patients with primary hypertension and multiple cardiovascular risk factors or complications involving damage to clinical target organs. The study was conducted between July 2007 and October 2008. Atherosclerotic cardiovascular disease (ASCVD) risk calculations were computed according to criteria presented by the American College of Cardiology and the American Heart Association. Patients were stratified by a predefined risk threshold of 10% and ided into two groups: ASCVD ≥ 10% or ASCVD 10%. cfPWV was used as a marker of arterial stiffness. A receiver operating characteristics (ROC) curve was applied to establish the optimal cfPWV cut-off point to differentiate between participants with and without ASCVD risk. Results: In the study cohort of 630 patients (age 63.55.2 ± 8.6 years, 61.7% male) with primary hypertension, the pressure indices (augmented pressure, augmentation index [AIx], aortic pulse pressure, aortic systolic pressure [SBP]) and Framingham Risk Scores (FRS) were greater in females than in males (p 0.001) ASCVD risk scores and peripheral diastolic pressure (DBP) were higher in males (p 0.05). All hemodynamic indices showed a significant positive correlation with ASCVD risk scores and FRS AIx was not correlated with ASCVD risk scores. In multivariate logistic analysis, cfPWV was significantly associated with ASCVD risk (OR: 1.324, 95% confidence interval: 1.119–1.565, p 0.001) after adjusting for age, gender, smoking, body mass index, total cholesterol, fasting blood glucose, antihypertensive treatment, statin treatment, and DBP. In the ROC analysis, the area under the curve was 0.758 and 0.672 for cfPWV and aortic SBP (p 0.001 and p 0.001, respectively) the optimal critical value of cfPWV and aortic SBP was 12.45 m/s (sensitivity 63.2%, specificity 77.8%) and 124.5 mmHg (sensitivity 63.9%, specificity 65.3%). Conclusions: cfPWV is significantly correlated with the risk of ASCVD. The best cut-off value of cfPWV for assessing future CVD risk in the hypertensive population in China is 12.45 m/s.
Discrepancy between in-vivo measure and ex-vivo calculation of pulse wave velocity in retinal arteries
Publisher: Springer Science and Business Media LLC
Date: 2018
[BP.08.03] HEART RATE DEPENDENCY OF REGIONAL AND LOCAL AORTIC PULSE WAVE VELOCITY IN RATS AS A FUNCTION OF BLOOD PRESSURE
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2017
Lumped parameter model of cardiovascular-respiratory interaction
Publisher: IEEE
Date: 07-2013
Nitroglycerin has more favourable effects on left ventricular afterload than apparent from measurement of pressure in a peripheral artery
Publisher: Oxford University Press (OUP)
Date: 02-1990
DOI: 10.1093/OXFORDJOURNALS.EURHEARTJ.A059669
Abstract: Nitroglycerin (0.3 mg) was administered sublingually to 14 patients undergoing cardiac catheterization, and pressure waves compared in the ascending aorta and brachial artery. After nitroglycerin, ascending aortic systolic pressure fell in all cases (by 6-44, average 22 mmHg) whereas brachial systolic pressure remained unchanged (in three) or fell to a lesser degree (4-33, average 12 mmHg). Diastolic pressure did not change significantly. Alterations in pressure and in wave contour were explained on the basis of arterial dilation, with reduction in wave reflection. Nitroglycerin reduces left ventricular afterload through arterial dilation as well as preload through venous dilation. This effect on afterload is not apparent from measurement of pressure in the brachial artery.
Vascular Health Assessment of The Hypertensive Patients (VASOTENS) Registry: Study Protocol of an International, Web-Based Telemonitoring Registry for Ambulatory Blood Pressure and Arterial Stiffness
Publisher: JMIR Publications Inc.
Date: 29-06-2016
DOI: 10.2196/RESPROT.5619
A novel method for retinal vessel segmentation and diameter measurement in high speed fundus videos
Publisher: Avestia Publishing
Date: 08-2018
DOI: 10.11159/ICBES18.134
Noninvasive characterization of the effect of aortic impedance on left ventricular structure
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2015
Determination of central blood pressure by a noninvasive method (brachial blood pressure and QKD interval)
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2013
Salt sensitivity and arterial structure and function
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2003
N-Point Moving Average: A Special Generalized Transfer Function Method for Estimation of Central Aortic Blood Pressure
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2018
Contactless video-based photoplethysmography technique comparison investigating pulse transit time estimation of arterial blood pressure
Publisher: IEEE
Date: 11-2021
Reply
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2017
Of cats and dogs and matters of the heart
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2017
Role of natriuretic peptides in regulation of conduit artery distensibility
Publisher: American Physiological Society
Date: 09-2004
DOI: 10.1152/AJPHEART.00101.2004
Abstract: Arterial distensibility, assessed by the pulse-wave velocity (PWV), is an independent predictor of cardiovascular risk. We investigated whether natriuretic peptides, acting locally, modify conduit artery distensibility in vivo. All studies were conducted in anesthetized sheep ( n = 18) by using a validated ovine hindlimb model. In brief, the PWV was calculated, with the use of the foot-to-foot methodology, from two pressure waveforms recorded simultaneously with a high-fidelity dual pressure-sensing catheter placed in the common iliac artery. Drugs were infused either proximally, via the catheter to perfuse the segment of artery under study, or distally, via the sheath to control for any reflex changes in flow or sympathetic activation. First, the effects of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and c-type natriuretic peptide (CNP) were studied. Second, the role of endogenous ANP was investigated by infusing the natriuretic peptide receptor type A (NPR A )-selective receptor antagonist A71915. Third, A71915 was coinfused with ANP. Fourth, the NPR C -selective agonist cANF was infused. Infusion of CNP or des-[Gln 18 Ser 19 Gly 20 Leu 21 Gly 22 ]-ANF-(4-23)-NH 2 (cANF) had no effect on iliac PWV. However, infusion of ANP, and to a lesser degree BNP, resulted in a reduction in PWV (−9% P 0.01 and −6% P 0.05, respectively). A71915 increased iliac PWV from 2.97 ± 0.13 to 3.06 ± 0.13 m/s P 0.01. Coinfusion of A71915 with ANP completely abolished the effects of ANP ( P 0.01). Importantly, ANP-BNP infusion via the sheath did not alter PWV. In conclusion, ANP, and to a lesser extent BNP, modify large artery distensibility via the NPR A receptor. Neither CNP nor cANF altered PWV, suggesting that the NPR B and NPR C receptors do not acutely influence distensibility in vivo.
Cardiovascular responses to short-term head-down positioning in healthy young and older adults
Publisher: Wiley
Date: 03-2005
DOI: 10.1002/PRI.22
Abstract: Isolated head-down postural drainage is assumed to acutely load the cardiovascular system. Consequently, it is considered a relative contraindication in the presence of severe cardiovascular disease. Evidence demonstrating that the head-down manoeuvre as used by physiotherapists does significantly load the cardiovascular system is lacking. The present study documents the cardiovascular responses t short-term 30 degrees head-down positioning in healthy subjects. The results are a point of reference for respiratory patients with and without cardiovascular disease. A quasi-experimental research design was used, with multiple measurements obtained at rest (long sitting and in the head-down position. Twenty-one young subjects (mean age 25 years (standard deviation, (SD) 3 years)) and 19 older subjects (mean age 66 years (SD 6 years)) were studied. Applanation tonometry and sphygmocardiography were used to measure temporal and pressure variables, and indices that estimate myocardial work and coronary blood flow. Absolute differences existed between the two age groups for all variables at rest (p 0.05). Serial measures in the head-down position did not vary across time (p > 0.05). Small (<9%) but significant (p < or = 0.02) decreases in heart rate, relative diastolic duration, mean arterial blood pressure and diastolic time indices, and small (<12%) but significant (p < or = 0.002) increases in cardiac cycle time, ejection duration (relative and absolute) and absolute diastolic duration were observed in the head-down position compared with rest. A small (9%) but significant (p < 0.001) fall in the sub-endocardial viability ratio occurred in the head down position. The findings have little consequence in health, but they suggest that head-down postural drainage may be of concern for chest physiotherapy recipients with reduced cardiac reserve or impaired barorefilex function.
CUFFLESS BLOOD PRESSURE DEVICES AND INCONSISTENT TRACKING OF BLOOD PRESSURE CHANGES
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2021
Alterations in central hemodynamic in patients with COPD after acute high intensity exercise
Publisher: Elsevier BV
Date: 05-2021
Systolic time intervals assessed from analysis of the carotid pressure waveform
Publisher: IOP Publishing
Date: 20-08-2018
Abstract: The timing of mechanical cardiac events is usually evaluated by conventional echocardiography as an index of cardiac systolic function and predictor of cardiovascular outcomes. We aimed to measure the systolic time intervals, namely the isovolumetric contraction time (ICT) and pre-ejection period (PEP), by arterial tonometry. Sixty-two healthy volunteers (age 47 ± 17 years) and 42 patients with heart failure and reduced ejection fraction were enrolled (age 66 ± 14 years). Pulse waves were recorded at the carotid artery by arterial tonometry together with simultaneous aortic transvalvular flow by Doppler-echocardiography, synchronized by electrocardiographic gating. The ICT was determined from the time delay between the electrical R wave and the carotid pressure waveform, after adjustment for the pulse transit time from the aortic valve to the carotid artery site, estimated by an algorithm based on the carotid-femoral pulse wave velocity. The PEP was evaluated by adding the electrical QR duration to the ICT. The ICT derived from carotid pulse wave analysis was closely related to that measured by echocardiography (r = 0.90, p < 0.0001), with homogeneous distribution in Bland-Altman analysis (mean difference and 95% confidence interval = 0.2 from -14.2 to 14.5 ms). ICT and PEP were higher in cardiac patients than in healthy volunteers (p < 0.0001). The ratio between PEP and left ventricular ejection time was related to the ejection fraction measured with echocardiography (r = 0.555, p < 0.0001). The timing of electro-mechanical cardiac events can be reliably obtained from the carotid pulse waveform and carotid-femoral PWV, evaluated using arterial tonometry. Systolic time intervals assessed with this approach showed good agreement with measurements performed with conventional echocardiography and may represent a promising additional application of arterial tonometry.
Transfer Function Between Intracranial Pressure and Aortic Blood Pressure and Carotid Blood Flow
Publisher: IEEE
Date: 07-2018
Significant venous flow alterations following brain arteriovenous malformation Surgery
Publisher: Elsevier BV
Date: 05-2022
DOI: 10.1016/J.JOCN.2022.03.023
Abstract: Brain arteriovenous malformation (bAVM) resection imposes several post-operative clinical challenges including intracranial haemorrhage (ICH). Daily non-invasive monitoring of haemodynamic measurements may be useful in predicting post-operative ICH. This prospective study used transcranial colour duplex (TCCD) and central aortic pressure (CAP) measurements to evaluate 15 bAVM patients pre-operatively and daily ≤ 14 days post-operatively. TCCD measurements of middle cerebral artery and veins included peak systolic (PSV), end diastolic (EDV), and pulsatility indices (PI). Parameters were compared with 7 craniotomy patients (non-bAVM craniotomy/surgical group). Normal reference values included 20 healthy volunteers. Significant middle cerebral vein MCV changes in bAVM patients occurred Maximal PSV was significantly higher (median 47 cm/s) compared to non-bAVM craniotomy/surgical controls (median 17 cm/s, p = 0.0123) maximal PI was significantly higher (median 0.99, p = 0.005) compared to the non-bAVM craniotomy/surgical controls (median 0.49). In 8 of 15 patients, increased MCV velocity and pulsatility "stabilised" within 14 days post-operatively. Mean number of days for the 8 patients to reach stable state was 5.9 days, (range 0-9 days). To our knowledge, this is the first imaging study demonstrating significant venous changes post bAVM resection. Significant increased venous flow occurs in pial veins bilaterally. Increased pressure of venous flow is evidenced by a significant increase in diameter and pulsatility. Subsequently, haemorrhagic complications may be due distal constriction of the pial veins causing venous hypertension. The cause of the dilated vascular bed is unknown.
Retinal vascular and structural changes are associated with amyloid burden in the elderly: Ophthalmic biomarkers of preclinical Alzheimer's disease
Publisher: Springer Science and Business Media LLC
Date: 03-2017
Assessment of Central Arterial Hemodynamics in Children: Comparison of Noninvasive and Invasive Measurements
Publisher: Oxford University Press (OUP)
Date: 09-09-2020
DOI: 10.1093/AJH/HPAA148
Abstract: In adults, central systolic blood pressure (cSBP) and augmentation index (cAIx) are independently associated with cardiovascular events and mortality. There is increasing interest in central hemodynamic indices in children. We aimed to assess the accuracy of current techniques against invasive intra-aortic measurements in children. Intra-aortic pressure waveforms were recorded with simultaneous brachial, radial, and carotid waveforms in 29 children (6.7 ± 3.9 years old) undergoing cardiac catheterization. Adult and age-appropriate transfer functions (TFs) (brachial adult: b-aTF radial adult: r-aTF radial for 8-year-old children: TF8 and radial for 14-year-old children: TF14) were used to synthesize central aortic waveforms from peripheral waveforms calibrated either to invasively or noninvasively recorded BP. Central hemodynamic indices were measured by pulse wave analysis. cSBP measured from invasively calibrated r-aTF (β = 0.84 intraclass correlation coefficient = 0.91 mean error ± SDD = −1.0 ± 5.0 mm Hg), TF8 (β = 0.78 intraclass correlation coefficient = 0.84 mean error ± SDD = 4.4 ± 5.6 mm Hg), and TF14 (β = 0.82 intraclass correlation coefficient = 0.90 mean error ± SDD = 2.0 ± 4.7 mm Hg)-synthesized central waveforms correlated with and accurately estimated intra-aortic cSBP measurements, while noninvasively calibrated waveforms did not. cAIx derived from TF-synthesized central waveforms did not correlate with intra-aortic cAIx values, and degree of error was TF-dependent. The currently available r-aTF accurately estimates cSBP with invasive pulse pressure calibration, while age-appropriate TFs do not appear to provide additional benefit. Accuracy of cAIx estimation appears to be TF dependent.
Association between Brachial-Ankle Pulse Wave Velocity as a Marker of Arterial Stiffness and Body Mass Index in a Chinese Population
Publisher: MDPI AG
Date: 03-03-2022
DOI: 10.3390/JCDD9030075
Abstract: Objectives: Arterial stiffness is widely accepted as an important predictor of cardiovascular disease (CVD) development. While obesity is generally associated with increased CVD risk, there is evidence that overweight patients with existing CVD may have better clinical outcomes than their lean counterparts. Our study sought to observe any potential association between brachial–ankle pulse wave velocity (BAPWV), a marker of arterial stiffness related to CVD risk, and Body Mass Index (BMI), a crude and widely used measure of obesity. Methods: Adult in iduals (n = 857) assessed for routine CV risk were included and grouped according to their BMI ( kg/m2: normal 25–30 kg/m2: overweight, ≥30 kg/m2: obese). Their anthropometric parameters, brachial cuff pressures, and BAPWV were measured. Results: Brachial pressure was significantly higher as BMI increased. BAPWV showed a positive linear association with systolic (r = 0.66, p 0.01), mean (r = 0.60, p 0.01), diastolic (r = 0.51, p 0.01), and pulse (r = 0.53, p 0.01) pressures. However, a linear relationship between BMI and BAPWV was only apparent in males aged years (p = 0.01) and in females aged ≥50 years (p 0.01). In in iduals with similar brachial systolic pressure, BAPWV was higher in normal-weight subjects compared to overweight–obese ones. Conclusions: This conflicting finding is attributed to an overestimation of the degree of arterial stiffness as a measure of CVD risk in in iduals with a less ‘healthy’ BMI. This suggests that BMI may not the appropriate obesity indicator to assess CV risk. Our finding emphasizes the importance of establishing a non-linear relationship between CVD risk, age, and BMI, taking into account apparent sex differences, to predict future CV events. While this finding may suggest a lower degree of stiffness in large arteries of overweight–obese subjects compared to their normal-weight counterparts, the potential implications for in iduals with higher BMI need be explored further.
Application of cardiovascular models in comparative physiology and blood pressure variability
Publisher: IEEE
Date: 07-2013
Brachioradial delay
Publisher: Elsevier BV
Date: 12-1990
DOI: 10.1016/0140-6736(90)92928-B
Abstract: Abnormalities in language processing and the related brain structures have been reported in people with schizophrenia. It has been proposed that the brain pathways for language processing are anomalous in these in iduals and form the underlying basis for the positive symptoms of the illness. If language pathway abnormalities can be detected early in people at high-risk for schizophrenia prior to the onset of symptoms, early treatment can ensue. Fifteen young adults at high genetic risk for developing schizophrenia were compared with 15 of their siblings with schizophrenia or schizoaffective disorder and 15 age and sex matched in iduals at low risk for schizophrenia using a visual lexical decision task during fMRI. The data were analyzed by contrasting activation obtained during a real word-pseudoword discrimination task to activation obtained during a nonlinguistic discrimination task, and the differential activations were examined. Patterns of brain activation while reading and discriminating between real and pseudowords differed across groups, with more bilateral activation in schizophrenia patients and their high-risk siblings than controls. In control subjects discrimination of words from psuedowords significantly activated Brodmann's area 44 more strongly than when non-linguistic symbols were discriminated. However, high-risk subjects and their siblings with schizophrenia activated this region similarly for both language and non-language tasks. Normal in iduals can be distinguished from subjects at high genetic risk for schizophrenia and patients with schizophrenia by their more lateralized and stronger activation of Brodmann's area 44 to word compared with symbol discrimination tasks. Thus, evaluation of language processing by fMRI may be a valuable tool for use in the prediction of in idual risk for developing schizophrenia.
[OP.5B.01] QUANTIFICATION OF HEART RATE DEPENDENCY OF AORTIC PULSE WAVE VELOCITY
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
OS 13-07 DISPARATE EFFECT OF EARLY WAVE REFLECTION IN AORTIC PRESSURE AND AORTIC FLOW VELOCITY WAVEFORM
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
Estimation of central aortic systolic pressure using late systolic inflection of radial artery pulse and its application to vasodilator therapy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2012
Cardiovascular Effects of Long-Term Vitamin D Supplementation: Summarised by Many but Studied by Few
Publisher: S. Karger AG
Date: 2016
DOI: 10.1159/000452939
Ventricular/vascular interaction in patients with mild systemic hypertension and normal peripheral resistance.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-1986
Abstract: Total left ventricular external power and aortic input impedance spectra were calculated from recordings of pulsatile pressure and flow in the ascending aorta of 22 human subjects undergoing cardiac catheterization. Eleven subjects had increased aortic pressure (systolic 153 +/- 3.8[SEM] mm Hg, p less than .001 diastolic 91 +/- 2.4 mm Hg, p less than .03 mean 118 +/- 2.4 mm Hg, p less than .001) and constituted the group with mild hypertension (average age 50 +/- 1.9 years). The other 11 (age-matched) subjects had normal arterial pressures and constituted the control group. Cardiac output in the hypertensive group was abnormally high (6.9 +/- 0.3 liters/min, p less than .04) compared with that in control subjects (6.1 +/- 0.2 liters/min), so that peripheral resistance was similar. Characteristic aortic impedance (index of aortic elastance) was increased in the hypertensive group (142 +/- 19 vs 72 +/- 4.5 dyne-sec-cm-5, p less than .002), as was the fluctuation of impedance moduli and phase. These elevated pulsatile components of arterial load were associated with a significant (p less than .002) increase in pulsatile left ventricular external power (89%), and the increased cardiac output was associated with a significant (p less than .001) increase in steady flow power (31%). The ratio of pulsatile to total power was also increased (38%) in the hypertensive group (p less than .001). Increased characteristic aortic impedance in the hypertensive group suggests that the human aorta is stiffer, and fluctuations in the impedance spectra suggest increased or less dispersed wave reflections.(ABSTRACT TRUNCATED AT 250 WORDS)
Estimation of cardiac stroke volume from radial pulse waveform by artificial neural network
Publisher: Elsevier BV
Date: 05-2022
DOI: 10.1016/J.CMPB.2022.106738
Abstract: Stroke volume (SV) and cardiac output (CO) are the key indicators for the evaluation of cardiac function and hemodynamic status during the perioperative period, which are very important in the detection and treatment of cardiovascular diseases. Traditional CO and SV measurement methods have problems such as complex operation, low precision and poor generalization ability. In this paper, a method for estimating stroke volume based on cascade artificial neural network (ANN) and time domain features of radial pulse waveform (SV Experimental results showed that the Pearson correlation coefficients and mean difference between SV A method is proposed to estimate cardiac stroke volume by the ANN with time domain features of radial pulse wave. It avoids the complicated modeling process based on hemodynamics within traditional models, improves the estimation accuracy of SV, and has a good generalization ability.
Change in Pulsatile Cerebral Arterial Pressure and Flow Waves as a Therapeutic Strategy?
Publisher: Springer International Publishing
Date: 2016
DOI: 10.1007/978-3-319-22533-3_34
Abstract: While intracranial pressure (ICP), arterial pressure and transcranial middle cerebral artery flow velocity (MCAFV) are often monitored in unconscious patients following stroke or head injury, the value of waveform indices has not been fully established. We retrospectively analysed the data of eight adults (aged 19-36 years) with closed head injury who had spontaneous and repeated episodes of elevated ICP (i.e. "plateau waves"). MCAFV was measured using transcranial Doppler, ICP using a Codman catheter and radial artery pressure using cannulation. Ascending aortic pressure (AAP) was generated from the radial artery using SphygmoCor(TM). Cerebral perfusion pressure (CPP) was calculated as AAP - ICP in the time domain.During the period of increased ICP, ICP and cerebral flow velocity litude increased significantly compared with the basal condition, while cerebral mean flow decreased. Amplitude of the secondary peak in ICP, AAP and MCAFV waveform became apparent.An increase in the litude of ICP, AAP and MCAFV waves can be attributed to the greater prominence of reflected waves from the lower body, which was apparent in pulse waveform analysis. Arterial vasodilators such as nitrates reduce reflected pressure waves from the lower body and, by decreasing the litude of AAP, ICP and MCAFV, may be as beneficial for the cerebral circulation as they are for the left ventricle of the heart.
P2.03 AORTIC, BUT NOT RADIAL PRESSURE GIVES A MODEL INDEPENDENT ESTIMATE OF CEREBRAL ARTERY CRITICAL CLOSING PRESSURE
Publisher: Springer Science and Business Media LLC
Date: 2013
Estimation of aortic systolic blood pressure from radial systolic and diastolic blood pressures alone using artificial neural networks
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2017
Normal cerebral vascular pulsations in humans: changes with age and implications for microvascular disease
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2017
6A.07
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
Effects of aging on arterial distensibility in populations with high and low prevalence of hypertension: comparison between urban and rural communities in China.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-1985
Abstract: Arterial pulse wave velocity, an established index of arterial distensibility, was measured together with arterial pressure in a group of 524 normal subjects of both sexes 2 months to 94 years old (mean age 45.6 +/- 15.3 years [SD]) in rural Guangzhou, China, an area with known low prevalence of hypertension. Fasting serum lipid levels and overnight Na+ and K+ urinary excretion levels were determined in a subgroup of 104 subjects (ages 8 to 88 years). Comparisons were made with data obtained similarly from normal subjects in urban Beijing, an area with known high prevalence of hypertension. Serum cholesterol levels were similar and low in each group (Guangzhou, 4.34 +/- 0.12 mmol/liter [SE] BEijing, 4.49 +/- 0.11 mmol/liter). Prevalence of hypertension (WHO criteria) was 4.9% (Guangzhou) and 15.6% (Beijing). In Guangzhou subjects pulse wave velocity was consistently lower in the aorta, arm, and leg, and increased to a lesser degree with age compared with Beijing subjects. Regression equations (x = pulse wave velocity [cm/sec], y = age [years]) were as follows: (1) aorta, Guangzhou: y = 5.1x + 533, r = .552, p less than .05 Beijing: y = 9.2x + 615, r = .673, p less than .001 (2) arm, Guangzhou: y = 0.61x + 817, r = .121, p less than .05 Beijing: y = 4.8x + 998, r = .453, p less than .001 (3) leg, Guangzhou: y = 4.43x + 718, r = .512, p less than .05 Beijing: y = 5.6x + 791, r = .630, p less than .001.(ABSTRACT TRUNCATED AT 250 WORDS)
Albumin-genipin solder for laser tissue repair
Publisher: Wiley
Date: 2004
DOI: 10.1002/LSM.20081
Abstract: Laser tissue soldering (LTS) is an alternative technique to suturing for tissue repair that avoids foreign body reaction and provides immediate sealing of the wound. One of the major drawbacks of LTS, however, is the weak tensile strength of the solder welds when compared to sutures. In this study, a crosslinking agent of low cytotoxicity was investigated for its ability to enhance the bond strength of albumin solders with sheep intestine. Solder strips were welded onto rectangular sections of sheep small intestine using a diode laser. The laser delivered in continuous mode a power of 170 +/- 10 mW at lambda = 808 nm, through a multimode optical fiber (core size = 200 microm) to achieve a dose of 10.8 +/- 0.5 J/mg. The solder thickness and surface area were kept constant throughout the experiment (thickness = 0.15 +/- 0.01 mm, area = 12 +/- 1.2 mm2). The solder was composed of 62% bovine serum albumin (BSA), 0.38% genipin, 0.25% indocyanin green dye (IG), and water. Tissue welding was also performed with a BSA solder without genipin, as a control group. The repaired tissue was tested for tensile strength by a calibrated tensiometer. Murine fibroblasts were also cultured in extracted media from heat-denatured genipin solder to assess cell growth inhibition in a 48 hours period. The tensile strength of the genipin solder was doubled that of the BSA solder (0.21 +/- 0.04 N and 0.11 +/- 0.04 N, respectively P = 10(-15) unpaired t-test, N = 30). Media extracted from crosslinked genipin solder showed negligible toxicity to fibroblast cells under the culture conditions examined here. Addition of a chemical crosslinking agent, such as genipin, significantly increased the tensile strength of adhesive-tissue bonds. A proposed mechanism for this enhanced bond strength is the synergistic action of mechanical adhesion with chemical crosslinking by genipin.
Heart Rate, Synchrony and Arterial Hemodynamics
Publisher: Springer London
Date: 2014
Central blood pressure in children and adolescents: Non-invasive development and testing of novel transfer functions
Publisher: Springer Science and Business Media LLC
Date: 24-08-2017
DOI: 10.1038/JHH.2017.59
Pulse Pressure Amplification and Arterial Stiffness in Middle Age
Publisher: Springer London
Date: 2014
Improved arterial distensibility in normotensive subjects on a low salt diet.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-1986
Abstract: Arterial pulse wave velocity (PWV), a noninvasive index of arterial distensibility, was measured in 57 normotensive subjects who followed a voluntary low salt diet for a period ranging from 8 months to 5 years (mean, 24.8 months). Subjects who followed a regular diet were matched for age and mean arterial pressure with the low salt (LS) s le and were used as controls (C). For both s les, subjects were ided into three age groups: Group 1 (aged 2 to 19 years, n = 16), Group 2 (29 to 44 years, n = 26), and Group 3 (45 to 66 years, n = 15). There was a marked increase in aortic PWV with age in the control s le but not in the LS s le. There was no significant difference in aortic PWV for Group 1, but in Groups 2 and 3, the LS subjects showed a decrease of 21.8% and 22.7%, respectively, compared to C subjects. Aortic PWV (cm/sec) was: Group 1: C = 581 (SE44), LS = 614 (SE31) Group 2: C = 942 (SE46) LS = 737 (SE27) (p less than 0.001) Group 3: C = 958 (SE77), LS = 741 (SE25) (p less than 0.05]. Arm and leg PWV were also significantly lower in the older age groups. These findings suggest that normotensive adult subjects who follow a low salt diet (mean intake, 44 mmol Na/24 hours) have reduced arterial stiffness and that the effect is independent of blood pressure. This is prima facie evidence that reduced salt intake has a beneficial effect in improving distensibility of the central aorta and large peripheral arteries, which is independent of its antihypertensive action.
Arterial hemodynamics and wave analysis in the frequency and time domains: an evaluation of the paradigms
Publisher: Springer Science and Business Media LLC
Date: 02-2009
RELATIONSHIP BETWEEN ARTERIAL STIFFNESS AND RENAL FUNCTION DETERMINED BY CKD-EPI AND MDRD EQUATIONS IN A CHINESE COHORT UNDERGOING HEALTH ASSESSMENT
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2021
Osteoporosis is inversely associated with arterial stiffness in the elderly: An investigation using the Osteoporosis Self‐assessment Tool for Asians index in an elderly Chinese cohort
Publisher: Wiley
Date: 07-02-2019
DOI: 10.1111/JCH.13493
The finger volume pulse and assessment of arterial properties
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2002
MODELING AND HEMODYNAMIC SIMULATION OF HUMAN ARTERIAL STENOSIS VIA TRANSMISSION LINE MODEL
Publisher: World Scientific Pub Co Pte Lt
Date: 08-2016
DOI: 10.1142/S0219519416500676
Abstract: Arterial stenosis plays a key role in the development and formation of cardiovascular diseases. The effects of arterial stenosis on the global hemodynamic characteristics of human artery tree were studied based on a previously proposed transmission line model of 55 segment arterial tree. Different position, degree and length of the arterial stenosis were simulated to discuss the changes of blood pressure and flow waveform in human arterial tree. The stenosis degree of 50% to 90% were specified to represent a mild, moderate or severe stenosis. Three representative stenosis positions: aorta, carotid and iliac artery were selected. The stenosis length was specified to be 1[Formula: see text]cm to 4[Formula: see text]cm. The results of simulation were compared with the literature data. And ankle branchial index (ABI) was calculated to show its relationship with the stenosis position. The results showed that the influence of aorta stenosis on the blood pressure and flow waveforms of upstream artery is more obvious than those of downstream artery branch artery stenosis has more influence on the blood pressure and flow waveforms of downstream artery than those of upstream artery. When the stenosis degree increased to 80%, the blood pressure and flow waveforms are affected significantly. The stenosis length causes a obvious change in the pressure and flow waveforms of stenosis inlet and outlet. The comparisons of literature and ABI demonstrated that the modeling method is a feasible tool to simulate and study the hemodynamics of the human artery stenosis.
Improved assessment of arterial stiffness using corrected cardio-ankle vascular index (CAVI0) in overweight adolescents with white-coat and essential hypertension
Publisher: Informa UK Limited
Date: 06-11-2017
DOI: 10.1080/00365513.2017.1397286
Abstract: Arterial stiffness is a marker of vascular damage. Although adiposity increases cardiovascular risk, the relationship between paediatric overweight and arterial stiffness is unclear. The study aimed to evaluate the simultaneous effect of hypertension and overweight on arterial stiffness using cardio-ankle vascular index (CAVI) and related novel, theoretically blood pressure (BP)-independent, index CAVI
Prediction of incident hypertension with the coronary artery calcium score based on the 2017 ACC/AHA high blood pressure guidelines
Publisher: Springer Science and Business Media LLC
Date: 04-08-2020
P2.14 COMPARISON OF AGE-RELATED CENTRAL AORTIC BLOOD PRESSURE PARAMETERS USING TWO SPHYGMOCOR TECHNIQUES
Publisher: Springer Science and Business Media LLC
Date: 2013
Genetic and Environmental Factors in the Function and Structure of the Arterial Wall
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-1995
Abstract: Abstract In large arteries the structure of the arterial wall determines pulsatile hemodynamics of pressure and flow. Mechanical wall stiffness, wall thickness, and elastin and collagen content vary along the arterial tree. The contribution of genetic and environmental factors to such structural properties is not yet known, but some data are available on possible functional correlates. In hypertensive rats diastolic and pulse pressure have been shown to be linked to two different genes on separate chromosomes. Although a genetic component contributes to intimal calcification, medial hypertrophy is not associated with genetic factors. A study of French West Indies families showed a preferential genetic determinant for pulse pressure in contrast to systolic or diastolic pressure. Environmental and geographic factors are associated with markedly different prevalences of hypertension and age-related increases in arterial stiffening in urban and rural communities in China. Salt consumption has also been implicated in modifications of pulse wave velocity. Recent data on structural parameters of the aortic trunk in oriental (Chinese) and occidental (American and Australian) subjects have shown that the ascending aorta in oriental subjects is of a relatively larger diameter and thinner media. This suggests that in this population a relatively higher primary pressure pulse would be generated because of increased stiffness of the proximal aorta. This suggests that factors other than arterial pressure are responsible for structural differences in the aortic wall and that oriental populations may have a predisposition to increased arterial pressure based on structural factors that affect the interaction between ventricular ejection and arterial load.
Angiotensin-converting enzyme inhibitor limits pulse-wave velocity and aortic calcification in a rat model of cystic renal disease
Publisher: American Physiological Society
Date: 11-2011
DOI: 10.1152/AJPRENAL.00393.2011
Abstract: The effect of angiotensin-converting enzyme inhibition on function and structure of the aorta was studied in the Lewis polycystic kidney (LPK) rat model of cystic renal disease and Lewis controls. Pulse-wave velocity (PWV) was recorded under urethane anesthesia (1.3 g/kg ip) in mixed-sex animals aged 6 and 12 wk and in 12-wk-old animals treated with perindopril (3 mg·kg −1 ·day −1 po) from age 6–12 wk. Tail-cuff systolic pressures were recorded over the treatment period. After PWV measurements, animals were euthanized and the aorta was removed for histomorphological and calcium analysis. Hypertension in LPK at 6 and 12 wk was associated with a shift of the PWV curve upward and to the right, indicating a decrease in aortic compliance, which was significantly reduced by perindopril. LPK demonstrated greater aortic calcification (6 wk: 123 ± 19 vs. 65 ± 7 and 12 wk: 406 ± 6 vs. 67 ± 6 μmol/g, P 0.001, LPK vs. Lewis, respectively). This was reduced by treatment with perindopril (172 ± 48 μmol/g, 12 wk LPK P 0.001). Medial cross-sectional area and elastic modulus/wall stress of the aorta were greater in LPK vs. Lewis control animals at 6 and 12 wk of age and showed an age-related increase that was prevented by treatment with perindopril ( P 0.001). Perindopril also ameliorated the degradation of elastin, increase in collagen content, and medial elastocalcinosis seen in 12-wk LPK. Overall, perindopril improved the structural and functional indices of aortic stiffness in the LPK rats, demonstrating a capacity for angiotensin-converting enzyme inhibition to limit vascular remodeling in chronic kidney disease.
Haemoglobin
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2013
Critical Closing Pressure Determined with a Model of Cerebrovascular Impedance
Publisher: SAGE Publications
Date: 14-11-2012
Abstract: Critical closing pressure (CCP) is the arterial blood pressure (ABP) at which brain vessels collapse and cerebral blood flow (CBF) ceases. Using the concept of impedance to CBF, CCP can be expressed with brain-monitoring parameters: cerebral perfusion pressure (CPP), ABP, blood flow velocity (FV), and heart rate. The novel multiparameter method (CCPm) was compared with traditional transcranial Doppler (TCD) calculations of CCP (CCP1). Digital recordings of ABP, intracranial pressure (ICP), and TCD-based FV from previously published studies of 29 New Zealand White rabbits were reanalyzed. Overall, CCP1 and CCPm showed correlation across wide ranges of ABP, ICP, and PaCO2 ( R = 0.93, P 0.001). Three physiological perturbations were studied: increase in ICP ( n = 29) causing both CCP1 and CCPm to increase ( P 0.001 for both) reduction of ABP ( n = 10) resulting in decrease of CCP1 ( P = 0.006) and CCPm ( P = 0.002) and controlled increase of PaCO2 ( n = 8) to hypercapnic levels, which decreased CCP1 and CCPm, albeit insignificantly ( P = 0.123 and P = 0.306 respectively), caused by a spontaneous significant increase in ABP ( P = 0.025). Multiparameter mathematical model of critical closing pressure explains the relationship of CCP on brain-monitoring variables, allowing the estimation of CCP during cases such as hypercapnia-induced hyperemia, where traditional calculations, like CCP1, often reach negative non-physiological values.
P2.11 THE IMPACT OF ATRIAL FIBRILLATION AND PACEMAKERS ON ACCURACY OF CENTRAL BLOOD PRESSURE MEASURED BY A NOVEL CUFF-BASED TECHNIQUE
Publisher: Springer Science and Business Media LLC
Date: 2013
Measuring Ascending Aortic Stiffness <em>In Vivo</em> in Mice Using Ultrasound
Publisher: MyJove Corporation
Date: 02-12-2014
DOI: 10.3791/52200
Non-symmetrical double-logistic analysis of 24 hour arterial stiffness profile in normotensive and hypertensive subjects
Publisher: IEEE
Date: 08-2008
The effect of interval sprinting exercise on vascular function and aerobic fitness of post‐menopausal women
Publisher: Wiley
Date: 05-11-2019
DOI: 10.1111/SMS.13574
Abstract: Menopausal transition accelerates an age-associated decrease in vascular function and a decline in aerobic fitness. The purpose of this study was to examine the effect of 8 weeks of interval sprinting cycle ergometer exercise on arterial stiffness, basal forearm blood flow, and aerobic fitness of post-menopausal women. Sixty overweight post-menopausal women were randomized into either exercise (Ex, n = 30) or control (C, n = 30) groups. Ex participants completed 24 interval sprinting exercise (ISE) sessions over 8 weeks. Each 20-minute ISE session comprised of alternating 8 seconds sprints and 12 seconds of light pedaling. Arterial stiffness assessed through ankle-brachial pulse wave velocity (baPWV) and augmentation index (AIx), basal forearm blood flow (FBF) assessed using venous occlusion, and aerobic fitness were assessed before and after the intervention. baPWV was significantly decreased in the Ex group by 7.2%, P = .03, whereas AIx demonstrated a 10% decrease, P = .002. No changes were found in basal FBF. Aerobic fitness was significantly increased, P = .002, in the Ex group (14%) with no change occurring in the control group.ISE training, despite minimal exercise commitment time (8 hours over 8 weeks), significantly lowered the arterial stiffness and increased the aerobic fitness of post-menopausal women. These results suggest that ISE positively influences the negative change in arterial stiffness and aerobic fitness that typically accompanies menopause.
[PP.37.13] INHERENT BLOOD PRESSURE DEPENDENCE OF ARTERIAL STIFFNESS INDEX BETA AND CARDIO-ANKLE VASCULAR INDEX
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
Reply to Comments: Using the Cardio-Ankle Vascular Index (CAVI) or the Mathematical Correction Form (CAVI0) in Clinical Practice
Publisher: MDPI AG
Date: 10-04-2020
DOI: 10.3390/IJMS21072647
Abstract: We read with great interest Alizargar et al [...]
Effect of large arteries on blood pressure variability
Publisher: IEEE
Date: 07-2013
Cuffless Blood Pressure Monitoring and the Advent of a New Era in Medicine and Society
Publisher: Springer International Publishing
Date: 2019
Intracranial pressure waveforms are more closely related to central aortic than radial pressure waveforms: Implications for pathophysiology and therapy
Publisher: Springer International Publishing
Date: 2016
Chitosan adhesive for laser tissue repair: In vitro characterization
Publisher: Wiley
Date: 2005
DOI: 10.1002/LSM.20145
Abstract: Laser tissue repair usually relies on hemoderivate protein solders, based on serum albumin. These solders have intrinsic limitations that impair their widespread use, such as limited tensile strength of repaired tissue, poor solder solubility, and brittleness prior to laser denaturation. Furthermore, the required activation temperature of albumin solders (between 65 and 70 degrees C) can induce significant thermal damage to tissue. In this study, we report on the design of a new polysaccharide adhesive for tissue repair that overcomes some of the shortcomings of traditional solders. Flexible and insoluble strips of chitosan adhesive (elastic modulus approximately 6.8 Mpa, surface area approximately 34 mm2, thickness approximately 20 microm) were bonded onto rectangular sections of sheep intestine using a diode laser (continuous mode, 120 +/- 10 mW, lambda = 808 nm) through a multimode optical fiber with an irradiance of approximately 15 W/cm2. The adhesive was based on chitosan and also included indocyanin green dye (IG). The temperature between tissue and adhesive was measured using a small thermocouple (diameter approximately 0.25 mm) during laser irradiation. The repaired tissue was tested for tensile strength by a calibrated tensiometer. Murine fibroblasts were cultured in extracted media from chitosan adhesive to assess cytotoxicity via cell growth inhibition in a 48 hours period. Chitosan adhesive successfully repaired intestine tissue, achieving a tensile strength of 14.7 +/- 4.7 kPa (mean +/- SD, n = 30) at a temperature of 60-65 degrees C. Media extracted from chitosan adhesive showed negligible toxicity to fibroblast cells under the culture conditions examined here. A novel chitosan-based adhesive has been developed, which is insoluble, flexible, and adheres firmly to tissue upon infrared laser activation.
Direct means of obtaining CAVI0—a corrected cardio-ankle vascular stiffness index (CAVI)—from conventional CAVI measurements or their underlying variables
Publisher: IOP Publishing
Date: 21-09-2017
Abstract: Cardio-ankle vascular index (CAVI) as measured using the VaSera device (CAVI From data of 497 subjects, eight candidate CAVI parameters were defined and calculated, containing all combinations of left or right tb/tba/blood pressure. Candidates were evaluated through correlation with measured left and right CAVI Left and right CAVI Our results permit straightforward calculation of [Formula: see text] during a study, as well as retrospective estimation of [Formula: see text] from CAVI
POA 02-2 ATHEROGENIC VASCULAR STIFFNESS AND HYPERTENSION
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
Opposing changes in thoracic and abdominal aortic biomechanical properties in rodent models of vascular calcification and hypertension
Publisher: American Physiological Society
Date: 15-07-2014
DOI: 10.1152/AJPHEART.00139.2014
Abstract: This study investigated the effects of hypertension on regional aortic biomechanical and structural properties in three rat models of vascular calcification: the hypertensive Lewis polycystic kidney (LPK n = 13) model of chronic kidney disease, spontaneously hypertensive rats (SHRs n = 12), and calcification in normotensive Lewis rats induced by vitamin D 3 and nicotine (VDN n = 8). Lewis and Wistar-Kyoto rats were controls. Thoracic and abdominal aortic stiffness parameters were assessed by tensile testing. In models where aortic stiffness differences compared with controls existed in both thoracic and abdominal segments, an additional cohort was quantified by histology for thoracic and abdominal aortic elastin, collagen, and calcification. LPK and VDN animals had higher thoracic breaking strain than control animals ( P 0.01 and P 0.05, respectively) and lower energy absorption within the tensile curve of the abdominal aorta ( P 0.05). SHRs had a lower abdominal breaking stress than Wistar-Kyoto rats. LPK and VDN rats had more elastic lamellae fractures than control rats ( P 0.001), which were associated with calcium deposition (thoracic R = 0.37, P = 0.048 abdominal: R = 0.40, P = 0.046). LPK rats had higher nuclear density than control rats ( P 0.01), which was also evident in the thoracic but not abdominal aorta of VDN rats ( P 0.01). In LPK and VDN rats, but not in control rats, media thickness and cross-sectional area were at least 1.5-fold greater in thoracic than abdominal regions. The calcification models chronic kidney disease and induced calcification in normotension caused differences in regional aortic stiffness not seen in a genetic form of hypertension. Detrimental abdominal aortic remodeling but lower stiffness in the thoracic aorta with disease indicates possible compensatory mechanisms in the proximal aorta.
A comparative study of pulsatile arterial hemodynamics in rabbits and guinea pigs
Publisher: American Physiological Society
Date: 04-1976
DOI: 10.1152/AJPLEGACY.1976.230.4.868
Abstract: Pulsatile pressure and flow were measured in the ascending aorta and other arteries of 22 anesthetized rabbits and 16 anesthetized guinea pigs. Pressure/flow relationships were expressed as vascular impedance. Aortic flow waves were almost identical in the two species, but pressure waves were quite different. Reflected pressure waves returned earlier from the periphery in guinea pigs, augmenting pressure during late systole and resulting in relatively high external left ventricular work, an inappropriately larger difference between mean systolic and mean diastolic pressure and absence of any aortic diastolic pressure wave. Values of impedance modulus and phase were similar but differed in the frequency at which maxima and minima occurred. In both species, impedance curves were interpreted to indicate a functionally discrete reflecting site in the lower body whose position corresponded to the region of the aortic bifurcation. In addition, rabbits showed evidence of an upper body reflecting site approximately one-third as far distant from the heart. As in dogs, the arterial system in both species can be represented by an asymmetrical T-shaped model of realistic dimensions.
Central Aortic Blood Pressure and Pulse Wave Velocity as Tools in the Hemodynamic Assessment of Hypertension
Publisher: Incessant Nature Science Publishers Pvt Ltd.
Date: 2020
Arteriosclerosis and Atherosclerosis Assessment in Clinical Practice: Methods and Significance
Publisher: S. Karger AG
Date: 2023
DOI: 10.1159/000530616
Abstract: Alongside cancer, cardiovascular disease (CVD) exhibits the highest rates of morbidity and mortality globally, in western society as well as in Asian countries. Aging is a serious problem for the Asian population as progression toward a super-aged society is moving at a remarkably high rate. This increased rate of aging leads to increased CVD risk and, consequently, high CVD incidence. However, aging is not the only deleterious factor of vascular problems hypertension, hypercholesterolemia, diabetes mellitus, and kidney disease may induce atherosclerosis and arteriosclerosis (i.e., arterial stiffening), and the progression of these diseases ultimately leads to cardiovascular, cerebrovascular, chronic kidney, or peripheral artery disease. Despite the existence of several guidelines on the treatment of risk factors such as hypertension and CVD, there is still an ongoing debate regarding the clinical need for assessment of arteriosclerosis and atherosclerosis, which act as a bridge between cardiovascular risk factors and CVD. In other words, although arteriosclerosis and atherosclerosis are essential to our understanding of vascular diseases, the need for additional tests beyond the conventional diagnosis method remains disputed. This is presumably due to insufficient discussion on how to apply such tests in clinical practice. This study aimed to fill this gap.
Progressive vascular remodelling, endothelial dysfunction and stiffness in mesenteric resistance arteries in a rodent model of chronic kidney disease
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.VPH.2015.12.004
Abstract: Chronic kidney disease (CKD) and hypertension are co-morbid conditions both associated with altered resistance artery structure, biomechanics and function. We examined these characteristics in mesenteric artery together with renal function and systolic blood pressure (SBP) changes in the Lewis polycystic kidney (LPK) rat model of CKD. Animals were studied at early (6-weeks), intermediate (12-weeks), and late (18-weeks) time-points (n=21), relative to age-matched Lewis controls (n=29). At 12 and 18-weeks, LPK arteries exhibited eutrophic and hypertrophic inward remodelling characterised by thickened medial smooth muscle, decreased lumen diameter, and unchanged or increased media cross-sectional area, respectively. At these later time points, endothelium-dependent vasorelaxation was also compromised, associated with impaired endothelium-dependent hyperpolarisation and reduced nitric oxide synthase activity. Stiffness, elastic-modulus/stress slopes and collagen/elastin ratios were increased in 6 and 18-week-old-LPK, in contrast to greater arterial compliance at 12weeks. Multiple linear regression analysis highlighted SBP as the main predictor of wall-lumen ratio (r=0.536, P<0.001 n=46 pairs). Concentration-response curves revealed increased sensitivity to phenylephrine but not potassium chloride in 18-week-LPK. Our results indicate that impairment in LPK resistance vasculature is evident at 6weeks, and worsens with hypertension and progression of renal disease.
Proceedings of the High Blood Pressure Research Council of Australia 2007 Annual Scientific Meeting
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2008
Effects of cardiac timing and peripheral resistance on measurement of pulse wave velocity for assessment of arterial stiffness
Publisher: Springer Science and Business Media LLC
Date: 20-07-2017
DOI: 10.1038/S41598-017-05807-X
Abstract: To investigate the effects of heart rate (HR), left ventricular ejection time (LVET) and wave reflection on arterial stiffness as assessed by pulse wave velocity (PWV), a pulse wave propagation simulation system (PWPSim) based on the transmission line model of the arterial tree was developed and was applied to investigate pulse wave propagation. HR, LVET, arterial elastic modulus and peripheral resistance were increased from 60 to 100 beats per minute (bpm), 0.1 to 0.45 seconds, 0.5 to 1.5 times and 0.5 to 1.5 times of the normal value, respectively. Carotid-femoral PWV (cfPWV) and brachial-ankle PWV (baPWV) were calculated by intersecting tangent method (cfPWV tan and baPWV tan ), maximum slope (cfPWV max and baPWV max ), and using the Moens-Korteweg equation ( $${\\bf{cfPW}}{{\\bf{V}}}_{{{\\bf{c}}}_{{\\bf{0}}}}$$ cfPW V c 0 and $${\\bf{baPW}}{{\\bf{V}}}_{{{\\bf{c}}}_{{\\bf{0}}}}$$ baPW V c 0 ). Results showed cfPWV and baPWV increased significantly with arterial elastic modulus but did not increase with HR when using a constant elastic modulus. However there were significant LVET dependencies of cfPWV tan and baPWV tan (0.17 ± 0.13 and 0.17 ± 0.08 m/s per 50 ms), and low peripheral resistance dependencies of cfPWV tan , cfPWV max , baPWV tan and baPWV max (0.04 ± 0.01, 0.06 ± 0.04, 0.06 ± 0.03 and 0.09 ± 0.07 m/s per 10% peripheral resistance), respectively. This study demonstrated that LVET dominates the effect on calculated PWV compared to HR and peripheral resistance when arterial elastic modulus is constant.
4A.06
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
Correction
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2011
Endothelial Function and Arterial Stiffness in OSA Using Pulse Wave Analysis
Publisher: American Thoracic Society
Date: 15-05-2009
Comparison of frequency-based techniques for assessment of baroreceptor sensitivity and heart rate variability
Publisher: IEEE
Date: 07-2017
Weight Loss, Blood Pressure Reduction, and Aortic Stiffness: An Old Dilemma Revisited
Publisher: Wiley
Date: 03-2011
DOI: 10.1038/OBY.2010.304
Central aortic pressure improves prediction of cardiovascular events compared to peripheral blood pressure in short-term follow-up of a hypertensive cohort
Publisher: Informa UK Limited
Date: 16-12-2018
P9.14 INCREASED CAROTID ARTERY STIFFNESS DECREASES MEASURED CAROTID-FEMORAL PULSE WAVE VELOCITY AND EFFECTS THE ESTIMATION OF AGE DEPENDENCY OF AORTIC STIFFNESS
Publisher: Springer Science and Business Media LLC
Date: 2014
The rhythm of running: can the heart join in?
Publisher: Wiley
Date: 12-1993
Improvements on cuff measurement of arterial pressure
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2013
Response to Central Pressure and Pulse Wave Amplification in the Upper Limb
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2010
Non-invasive cerebrospinal fluid pressure estimation using multi-layer perceptron neural networks
Publisher: IEEE
Date: 08-2012
Heart Rate Dependence of Aortic Pulse Wave Velocity at Different Arterial Pressures in Rats
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2012
DOI: 10.1161/HYPERTENSIONAHA.112.194225
Abstract: Arterial stiffness, as measured by aortic pulse wave velocity (PWV), is an independent marker of cardiovascular disease and events in both healthy and diseased populations. Although some cardiovascular risk factors, such as age and blood pressure, show a strong association with PWV, the association between heart rate (HR) and PWV is not firmly established. Furthermore, this association has not been investigated at different arterial blood pressures. To study effects of HR on aortic PWV at different mean arterial pressures (MAPs), adult (12 weeks n=7), male, anesthetized Sprague-Dawley rats were randomly paced at HRs of between 300 and 450 bpm, at 50-bpm steps. At each pacing step, aortic PWV was measured across a physiological MAP range of 60 to 150 mmHg by infusing sodium nitroprusside and phenylephrine. When compared at the same MAP, increases in HR resulted in significant increases in PWV at all of the MAPs mmHg (ANOVA, P .05), with the greatest significant change of 6.03±0.93% observed in the range 110 to 130 mmHg. The positive significant association between HR and PWV remained when PWV was adjusted for MAP (ANOVA, P .001). These results indicate that HR dependency of PWV is different at higher pressures than at lower pressures and that HR may be a confounding factor that should be taken into consideration when performing analysis based on PWV measurements.
Nebivolol Increases Arterial Distensibility In Vivo
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2004
DOI: 10.1161/01.HYP.0000137983.45556.6E
Abstract: Arterial stiffness is a key determinant of cardiovascular risk in hypertensive patients. β-Blockers appear to be less effective than other drugs in improving outcome in hypertensive patients, and a potential explanation may be that β-blockers are less effective in reducing arterial stiffness. The aim of this study was to assess the direct effect of β-blockade on pulse wave velocity (PWV), a robust measure of arterial distensibility, using a local, ovine, hind-limb model. In addition, we hypothesized that the vasodilating β-blocker nebivolol, but not atenolol, would increase arterial distensibility in vivo. All studies were conducted in anesthetized sheep. PWV was recorded in vivo using a dual pressure-sensing catheter placed in the common iliac artery. Intraarterial infusion of nebivolol reduced PWV by 6±3% at the higher dose ( P .001), but did not alter mean arterial pressure (change of −1±3 mm Hg, P =0.1). In contrast, atenolol had no effect on PWV ( P =0.11) despite a small drop in mean pressure (change of −5±3 mm Hg, P .01). Infusion of glyceryl trinitrate led to a dose-dependent fall in PWV, and 2 nmol/min produced a similar reduction in PWV to the higher dose of nebivolol (500 nmol/min). The effect of nebivolol on PWV was significantly attenuated during coinfusion of N G -monomethyl- l -arginine ( P =0.003) and also during coinfusion of butoxamine ( P =0.02). These results demonstrate that nebivolol, but not atenolol, increases arterial distensibility. This effect of nebivolol is mediated through the release of NO via a β 2 adrenoceptor–dependent mechanism. Thus, nebivolol may be of benefit in conditions of increased large artery stiffness, such as isolated systolic hypertension.
Effects of instructed meditation augmented by computer-rendered artificial virtual environment on heart rate variability
Publisher: IEEE
Date: 07-2018
Basal NO Locally Modulates Human Iliac Artery Function In Vivo
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2005
DOI: 10.1161/01.HYP.0000164581.39811.BD
Abstract: We demonstrated previously that endogenous NO influences large-artery distensibility in the ovine hindlimb. However, the role of basal NO in larger human conduit arteries is controversial. The aim of this study was to investigate whether basal production of NO, acting locally, influences iliac artery distensibility in humans. Distensibility was assessed by intra-arterial measurement of the pulse wave velocity. Eighteen subjects, free of significant coronary or iliac artery disease, were studied after diagnostic cardiac catheterization. Simultaneous pressure waveforms were recorded with a high-fidelity dual-pressure sensing catheter, placed in the common iliac artery during intra-arterial infusion of saline (baseline), glyceryl trinitrate (4 nmol/min), or N G -monomethyl- l -arginine (8 and 16 μmol/min). Drugs were infused proximally, via the catheter to perfuse the segment of artery under study, or distally, via the sheath, to control for any reflex changes in flow or sympathetic activation. Velocity was calculated using the foot-to-foot methodology. Six subjects received glyceryl trinitrate and 12 N G -monomethyl- l -arginine. There was no change in velocity after infusion of glyceryl trinitrate or N G -monomethyl- l -arginine via the sheath. However, infusion of glyceryl trinitrate via the catheter significantly reduced velocity by 31.43±5.80% (mean±SEM P .01 P =0.02 for comparison). Likewise, infusion of the highest dose of N G -monomethyl- l -arginine via the catheter significantly increased velocity by 27.25±8.20% ( P =0.001 P =0.02 for comparison). Importantly, there was no change in mean arterial blood pressure throughout the studies. These data indicate that under resting conditions, local NO production modulates human iliac artery distensibility and that exogenous NO increases arterial distensibility.
Transcranial colour duplex reveals haemodynamically significant venous flow alterations following resection of arteriovenous malformation of the brain
Publisher: Springer Science and Business Media LLC
Date: 2020
Determination of Aortic Pulse Wave Velocity From Waveform Decomposition of the Central Aortic Pressure Pulse
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2008
DOI: 10.1161/HYPERTENSIONAHA.107.092676
Abstract: Aortic pulse wave velocity (PWV), calculated from pulse transit time (PTT) using 2 separate pulse recordings over a known distance, is a significant biomarker of cardiovascular risk. This study evaluates a novel method of determining PTT from waveform decomposition of central aortic pressure using a single pulse measurement. Aortic pressure was estimated from a transformed radial pulse and decomposed into forward and backward waves using a triangular flow wave. Pulse transit time was determined from cross-correlation of forward and backward waves. Pulse transit time, representing twice the PTT between 2 specific sites, was compared with independent measurements of carotid-femoral PTT in a cohort of 46 subjects (23 females age 57±14 years). Linear regression between measured PTT (y milliseconds) and calculated PTT (x milliseconds) was y=1.05x−2.1 ( r =0.67 P .001). This model was tested in a separate group of 44 subjects (21 females age 55±14 years) by comparing measured carotid-femoral PWV (y meters per second) and PWV calculated using the estimated value of PTT (eTR/2) and carotid femoral distance (x meters per second y=1.21x−2.5 r =0.82 P .001). Findings indicate that the time lag between the forward and backward waves obtained from the decomposition of aortic pressure wave can be used to determine PWV along the aortic trunk and shows good agreement with carotid-femoral PWV. This technique can be used as a noninvasive and nonintrusive method for measurement of aortic PWV using a single pressure recording.
[OP.8A.06] PULSATILE STRETCH ALTERS AMYLOID PRECURSOR PROTEIN EXPRESSION AND NITRIC OXIDE SIGNALLING IN HUMAN CEREBRAL ENDOTHELIAL CELLS PRE-EXPOSED TO GLYCOSPHINGOLIPID INHIBITION
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2017
WHOLE-BODY IONIZING IRRADIATION INCREASES AORTIC STIFFNESS AND STIFFNESS SENSITIVITY TO HIGH BLOOD PRESSURE IN RATS: PP.10.402
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2010
Increased aortic impedance.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-1994
Arterial transfer functions: background, applications and reservations
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2008
76 COMPARISON OF THE USE OF CENTRAL AND PERIPHERAL PRESSURE WAVEFORMS FOR OPTIMIZATION OF CARDIAC RESYNCHONIZATION THERAPY
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2012
[PP.19.27] APPLICATION OF NEURAL NETWORKS FOR ESTIMATION OF AORTIC SYSTOLIC PRESSURE FROM PERIPHERAL SYSTOLIC AND DIASTOLIC PRESSURE
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2017
TRACKING OF CENTRAL AORTIC SYSTOLIC BLOOD PRESSURE OVER THE ENTIRE LIFE COURSE
Publisher: Elsevier BV
Date: 04-2014
Automated ‘oscillometric’ blood pressure measuring devices: how they work and what they measure
Publisher: Springer Science and Business Media LLC
Date: 30-05-2022
DOI: 10.1038/S41371-022-00693-X
Abstract: Automated ‘oscillometric’ blood pressure (BP) measuring devices (BPMDs) were developed in the 1970s to replace manual auscultatory BP measurement by mercury sphygmomanometer. Automated BPMDs that have passed accuracy testing versus a reference auscultatory sphygmomanometer using a scientifically accepted validation protocol are recommended for clinical use globally. Currently, there are many thousands of unique automated BPMDs manufactured by hundreds of companies, with each device using proprietary algorithms to estimate BP and using a method of operation that is largely unchanged since inception. Validated automated BPMDs provide similar BP values to those recorded using manual auscultation albeit with potential sources of error mostly associated with using empirical algorithms to derive BP from waveform pulsations. Much of the work to derive contemporary BP thresholds and treatment targets used to manage cardiovascular disease risk was obtained using automated BPMDs. While there is room for future refinement to improve accuracy for better in idual risk stratification, validated BPMDs remain the recommended standard for office and out-of-office BP measurement to be used in hypertension diagnosis and management worldwide.
Methodology and technology for peripheral and central blood pressure and blood pressure variability measurement
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
Evidence of early degenerative changes in large arteries in human essential hypertension.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-1985
Abstract: Noninvasive evaluation of brachial artery diameter (pulsed Doppler velocimetry) and pulse wave velocity (strain gauge mechanography) was performed in 23 normal subjects and 49 patients with uncomplicated essential hypertension. Pulsatile arterial function was described in terms of derived characteristic impedance and arterial compliance. Compared with normal controls, hypertensive patients had greater arterial diameter (p less than 0.01) and pulse wave velocity (p less than 0.001). Two nomograms obtained from normal subjects relating the product of age and diastolic pressure to diameter and pulse wave velocity were used for analysis of the hypertensive group 35 patients were inside the 95% confidence limits of the diameter and pulse wave velocity nomograms (Group 1), while 14 patients were outside the pulse wave velocity nomogram (Group 2). Age and mean pressure were similar, but pulse wave velocity was higher (p less than 0.001), arterial compliance lower (p less than 0.001), and characteristic impedance higher (p less than 0.001) in Group 2 than in Group 1. The litude of pulse pressure was higher in Group 2 than in Group 1 (p less than 0.001), and a negative correlation was found between pulse pressure and arterial compliance in Group 2, but not in Group 1. Thus, in the majority of hypertensive patients, arterial modifications could be related to the normal influence of age and pressure. In contrast, other patients exhibited features suggesting excessive arterial stiffness, manifested by abnormally high pulse wave velocity, decreased arterial compliance, and increased characteristic impedance.
Effect of Ambient Lighting and Skin Tone on Estimation of Heart Rate and Pulse Transit Time from Video Plethysmography
Publisher: IEEE
Date: 07-2020
Systemic arterial hemodynamics in the diamond python Morelia spilotes
Publisher: American Physiological Society
Date: 09-1982
DOI: 10.1152/AJPREGU.1982.243.3.R205
Abstract: Studies of pulsatile systemic arterial hemodynamics were conducted in 10 diamond python snakes to test the hypothesis that body shape--through spatial dispersion of peripheral reflecting sites--is an important determinant of impedance patterns and of pulse wave contour. Findings support the hypothesis. Flow patterns in the aortic roots were similar to those in humans, sheep, dogs, rabbits, and guinea pigs, but in contrast to larger animals, little change in flow contour was seen in other arteries. Pressure wave contour was similar in all systemic arteries from which records were taken with no secondary diastolic wave under any circumstances. Impedance patterns at different sites showed none of the fluctuations that in other animals are attributable to discrete wave reflection. Discrete proximal wave reflection at the confluence of aortic arches was minimal. Data are explicable on the basis of widely distributed peripheral reflecting sites--a consequence of the snake's long and tapered body.
SYMPATHETIC ACTIVITY CONTRIBUTES TO ABDOMINAL AORTIC COMPLIANCE AND WALL DISTENSIBILITY IN RATS
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2011
P1.31 DETERMINING PULSE WAVE VELOCITY USING MRI: A COMPARISON AND REPEATABILITY OF RESULTS USING SEVEN TRANSIT TIME ALGORITHMS
Publisher: Springer Science and Business Media LLC
Date: 2008
Effects of age on ventricular-vascular coupling
Publisher: Elsevier BV
Date: 04-1985
DOI: 10.1016/0002-9149(85)90659-9
Abstract: The effects of age on the interrelation between the physical properties of the arterial tree (aortic input impedance) and left ventricular performance (cardiac output) were studied in 45 subjects, aged 19 to 62 years, without apparent cardiovascular disease. Ascending aortic pulsatile pressure and blood flow velocity were measured with a multisensor catheter and cardiac output by green dye or the Fick method. Heart rate and end-diastolic aortic pressure remained unchanged with age, whereas aortic systolic, mean and pulse pressures and aortic radius increased. In subjects younger than 30 years, early systolic pressure usually exceeded late systolic pressure (type C beat) in subjects older than 50 years, late systolic pressure usually exceeded early systolic pressure (type A beat). In 55% of subjects aged 30 to 50 years, early and late systolic pressures were essentially equal (type B beat). The impedance spectra from all subjects showed fluctuations about the characteristic impedance (index of elastance) that were greater in the older subjects. Peripheral resistance increased 37% (r = 0.47, p less than 0.001) over the age range of 20 to 60 years, whereas characteristic impedance increased 137% (r = 0.66, p less than 0.001). The fundamental impedance modulus increased, and the impedance modulus minimum shifted to a higher frequency. These changes in the impedance spectral pattern indicate that the ascending aorta becomes stiffer and the cross section of the peripheral vascular bed decreases with age, causing increased pulse wave velocity and wave reflection.(ABSTRACT TRUNCATED AT 250 WORDS)
Expert Consensus on the Clinical Use of Pulse Wave Velocity in Asia
Publisher: S. Karger AG
Date: 2022
DOI: 10.1159/000528208
Abstract: Arterial stiffness is a progressive aging process that predicts cardiovascular disease. Pulse wave velocity (PWV) has emerged as a noninvasive, valid, and reliable measure of arterial stiffness and an independent risk predictor for adverse outcomes. However, up to now, PWV measurement has mostly been used as a tool for risk prediction and has not been widely used in clinical practice. This consensus paper aims to discuss multiple PWV measurements currently available in Asia and to provide evidence-based assessment together with recommendations on the clinical use of PWV. For the methodology, PWV measurement including the central elastic artery is essential and measurements including both the central elastic and peripheral muscular arteries, such as brachial-ankle PWV and cardio-ankle vascular index, can be a good alternative. As Asian populations are rapidly aging, timely detection and intervention of “early vascular aging” in terms of abnormally high PWV values are recommended. More evidence is needed to determine if a PWV-guided therapeutic approach will be beneficial to the prevention of cardiovascular diseases beyond current strategies. Large-scale randomized controlled intervention studies are needed to guide clinicians.
Smooth muscle cell and arterial aging: basic and clinical aspects
Publisher: Oxford University Press (OUP)
Date: 05-03-2018
DOI: 10.1093/CVR/CVY009
Abstract: Arterial aging engages a plethora of key signalling pathways that act in concert to induce vascular smooth muscle cell (VSMC) phenotypic changes leading to vascular degeneration and extracellular matrix degradation responsible for alterations of the mechanical properties of the vascular wall. This review highlights proof-of-concept ex les of components of the extracellular matrix, VSMC receptors which connect extracellular and intracellular structures, and signalling pathways regulating changes in mechanotransduction and vascular homeostasis in aging. Furthermore, it provides a new framework for understanding how VSMC stiffness and adhesion to extracellular matrix contribute to arterial stiffness and how interactions with endothelial cells, platelets, and immune cells can regulate vascular aging. The identification of the key players of VSMC changes operating in large and small-sized arteries in response to increased mechanical load may be useful to better elucidate the causes and consequences of vascular aging and associated progression of hypertension, arteriosclerosis, and atherosclerosis.
Blood pressure phenotypes in youth
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2016
P.37 An Assessment of Potential Sources of Error that May Arise in the Measurement of Carotid-Femoral Pulse Wave Velocity
Publisher: Springer Science and Business Media LLC
Date: 2020
Impact of new hypertension guidelines on target organ damage screening in a Shanghai community‐dwelling population
Publisher: Wiley
Date: 18-09-2019
DOI: 10.1111/JCH.13677
The prevalence and impact of orthostatic intolerance in young women across the hypermobility spectrum
Publisher: Wiley
Date: 27-02-2022
DOI: 10.1002/AJMG.A.62705
Abstract: Orthostatic intolerance (OI) is frequently reported in young women with generalized hypermobility spectrum disorder (G‐HSD) and hypermobile EDS (hEDS). However, it remains currently unclear whether OI is a comorbidity or fundamental part of the pathophysiology of G‐HSD or hEDS. This study investigated the prevalence and impact of OI in young women across the hypermobility spectrum. Forty‐five women (14–30 years, 15 controls, 15 G‐HSD, and 15 hEDS) undertook a head‐up tilt (HUT) and active stand test. Postural Orthostatic Tachycardia Syndrome (POTS) and Orthostatic Hypotension (OH) were assessed using age‐related criteria. Autonomic dysfunction and quality‐of‐life questionnaires were also completed. The prevalence of POTS was higher in women with G‐HSD than hEDS and control groups during HUT (43% vs. 7% and 7%, respectively, p 0.05), but similar between groups during the active stand (47%, 27%, and 13% for G‐HSD, hEDS, and control, respectively). No participants had OH. hEDS and G‐HSD participants reported more severe orthostatic symptoms and poorer quality of life than controls. Although POTS was observed in hypermobile participants, there is no conclusive evidence that its prevalence differed between groups due to differences between the HUT and active stand assessments. Nevertheless, OI and broader autonomic dysfunction impacted on their quality of life.
The Physiological Measurement Handbook
Publisher: CRC Press
Date: 11-12-2014
DOI: 10.1201/B17831
Heart rate and blood pressure dependence of aortic distensibility in rats: comparison of measured and calculated pulse wave velocity
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-08-2020
Relationship between arterial stiffness and chronic kidney disease in patients with primary hypertension
Publisher: Springer Science and Business Media LLC
Date: 29-10-2019
DOI: 10.1038/S41371-019-0275-Y
Abstract: To investigate the association of noninvasive indices of arterial stiffness with chronic kidney disease (CKD) in patients with primary hypertension, 547 (mean age 60 years, 63% males) hypertensive hospital inpatients were recruited, comprising 337 hypertensives without CKD and 210 hypertensives with CKD. Noninvasive arterial stiffness indices were obtained, including central arterial haemodynamics derived from the radial artery waveform using SphygmoCor V8.0 system, carotid-femoral pulse wave velocity (cfPWV), large and small artery elasticity indices (C1, C2 respectively). Intima-media thickness (IMT) was evaluated by ultrasonography. The diagnosis of CKD was assessed by the estimated glomerular filtration rate (eGFR) or urinary albumin creatinine ratio (ACR). Compared with hypertension without CKD, hypertensive patients with CKD were older, had higher central systolic blood pressure, cfPWV, and IMT (all P < 0.01). With decreasing eGFR, cfPWV and augmentation index adjusted to heart rate of 75 bpm increased progressively whereas C2 decreased (P < 0.05) in subjects with CKD. In the overall population, cfPWV showed a significant trend of a negative association with eGFR (P = 0.04) after adjusting for age, gender, and brachial systolic blood pressure. Multiple logistic analysis showed that 1 SD (3 m/s) increase in cfPWV entailed a 1.35 (95% Cl: 1.018-1.790) times higher likelihood of the presence of CKD even after adjustment for confounding factors. The association of arterial stiffness and CKD suggests that cfPWV may be a potential hemodynamic index to evaluate cardiovascular risk in CKD patients with primary hypertension.
Disparate Associations of 24-h Central Aortic and Brachial Cuff Blood Pressure With Hypertension-Mediated Organ Damage and Cardiovascular Risk
Publisher: Frontiers Media SA
Date: 22-02-2022
Abstract: Aim of this study was to evaluate the associations of non-invasive central aortic and peripheral (brachial) blood pressure (BP) for Hypertension-mediated organ damage (HMOD) and atherosclerotic cardiovascular disease (ASCVD) risk. We evaluated associations of HMOD with 24-h ambulatory blood pressure monitoring (ABPM) of central aortic and peripheral BP indices in patients with primary hypertension and presence of several cardiovascular risk factors. BP measurements were performed by means of a non-invasive automated oscillometric device (Mobil-O-Graph). HMOD was defined as the presence of carotid intima-media thickness (IMT) above normal values and/or carotid plaque, left ventricular hypertrophy (LVH), and/or renal abnormalities as assessed by urine albumin/creatinine ratio above normal values and/or estimated glomerular filtration rate (eGFR) & ml/min per 1.73 m 2 . In the study cohort of 273 (age 55.2 ± 13.4 years, 71.8% male) patients with primary hypertension, documented HMOD was present in 180 (65.9%), LVH in 70 (25.6%), increased IMT in 129 (47.3%). Fifty-six patients (20.5%) had kidney organ damage (20.5% albuminuria and 2.6% impaired eGFR). When accounting for confounding factors (age, sex, body-mass-index, antihypertensive treatment, smoking, triacylglycerol, statin treatment, glucose, hypoglycemic therapy, or heart rate) only peripheral 24-h pulse pressure (PP) maintained statistical significance with HMOD indices (OR: 1.126, 95% CI: 1.012~1.253 p = 0.029). Using ASCVD risk score as the independent continuous variable in multiple linear regression, 24-h central systolic pressure (SBP) (β = 0.179 95% CI:0.019~0.387 p = 0.031), daytime central PP (β = 0.114 95% CI:0.070~0.375 p = 0.005, night-time central SBP (β = 0.411 95% CI:0.112~0.691 p = 0.007) and night-time PP (β = 0.257 95% CI:0.165~0.780 p = 0.003) were all positively associated with ASCVD risk. Blood pressure obtained by 24-h ABPM was better correlated with HMOD than office BP. Whilst 24-h peripheral BP showed a stronger association with HMOD than 24-h central BP, the prognostic value of 24-h central BP for the 10-year ASCVD risk was superior to 24-h peripheral BP.
PP.06.14
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
Carotid-femoral pulse wave velocity assessment using novel cuff-based techniques
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2013
Importance of Pressure Pulse Amplification in the Association of Resting Heart Rate and Arterial Stiffness
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2013
[OP.2D.03] PULSATILE STRETCH ALTERS EXPRESSION AND PROCESSING OF AMYLOID PRECURSOR PROTEIN IN HUMAN CEREBRAL ENDOTHELIAL CELLS
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
The Severity of Obstructive Sleep Apnea Increases the Risk of Arteriosclerosis
Publisher: IMR Press
Date: 09-03-2022
Abstract: Obstructive sleep apnea (OSA) is a common disorder worldwide. It is associated with myocardial remodeling and arteriosclerosis in patients with hypertension. Our study investigated the relationship between OSA severity and arteriosclerosis and blood pressure in an Asian population. We enrolled 365 subjects from July 2018 to December 2020 at Ruijin Hospital. We recorded data from the medical history and collected blood s les from all participants. We performed 24-hour ambulatory Blood Pressure (BP) monitoring and Carotid-femoral pulse wave velocity (cf-PWV) measurements. Overnight polysomnography (PSG) was performed using Respironics Alice PDxSleepware. PSG was performed in a total of 365 subjects mean age of 49.1 ± 12.8 years and Body Mass Index (BMI) 28.1 ± 3.8 kg/m2. The majority (89.3%) were male. The office systolic BP was significantly higher in the moderate to severe group than mild OSA group (148 ± 21 mmHg vs 139 ± 19 mmHg, The severity of OSA was positively correlated with pulse wave velocity. AHI, office BP and age were independent risk factors for arteriosclerosis.
Prevention of cardiac hypertrophy by the use of a glycosphingolipid synthesis inhibitor in ApoE−/− mice
Publisher: Elsevier BV
Date: 09-2015
Improved Measurement of Blood Pressure by Extraction of Characteristic Features from the Cuff Oscillometric Waveform
Publisher: MDPI AG
Date: 16-06-2015
DOI: 10.3390/S150614142
The pressure field as a methodology for fluid management and red cell preservation during cardiac surgery
Publisher: Springer Science and Business Media LLC
Date: 18-01-2023
DOI: 10.1186/S13019-023-02134-3
Abstract: Anemia and red cell transfusion contribute to morbidity and mortality of surgery. The concept of patient blood management to mitigate preoperative anemia, optimize coagulation, conserve red cells intraoperatively and accept lower post-operative transfusion thresholds has recently gained widespread acceptance across a range of surgical disciplines. Fluid administration is likely to contribute significantly to perioperative anemia and red-cell transfusion requirements, yet a robust basis for managing fluid administration in this context has not been articulated. There is an urgent need for this. We developed ‘the pressure field method’ as a novel approach to guiding the administration of fluid and drugs to optimize tissue perfusion. The pressure field method was used for the intraoperative management of 67 patients undergoing semi-elective cardiac surgery. We compared intraoperative anemia and transfusion requirements in this cohort with a conventional group of 413 patients undergoing cardiac surgery. In the pressure field group, no patients required transfusion whereas in the conventional group, 16% required transfusion during bypass and these patients received an average of 2.4 units of packed red cells (P 0.0001). The average decrease in hemoglobin in the pressure field group was only 13 g/L, whereas in the conventional group it was 52 g/L (P 0.0001). 80% of the pressure field group received no intravenous fluid during cardiac surgery, and the average intraoperative fluid load was 115 mL. The pressure field method appears to reduce transfusion requirements due to decreased intraoperative fluid loading.
Finite Element Modeling and Dynamic Stress Analysis of the Arterial Wall With Physiological Arterial Pressure Waveforms
Publisher: ASMEDC
Date: 2004
Abstract: Arterial diseases, promoted by modification of arterial wall properties, are among the main causes of morbidity and mortality. Biomechanical parameters, including mechanical wall stress, are important factors determining arterial function in normal and pathological conditions. This investigation aims to determine dynamic stress distribution in the arterial wall 7subjected to physiological pressure waveforms. Finite element models of a typical artery were developed to evaluate Von Mises stress in the arterial wall due to physiological pressure waveforms and with differing mechanical parameters, including Young’s modulus of elasticity, non-linear stress-strain relationship and visco-elastic parameter, and appropriate boundary conditions allowing radial expansion. Results showed marked effects by mentioned parameters on maximum, minimum and litude of the stress wave and stress waveform. This study suggest to analyse fatigue effects of the arterial wall due to differing stress waveforms and values.
Fatty Liver Index is Positively Associated with Arterial Stiffness in a Chinese Cohort Undergoing Health Assessment
Publisher: Springer Science and Business Media LLC
Date: 15-10-2021
DOI: 10.1007/S44200-021-00003-9
Abstract: Nonalcoholic fatty fiver disease (NAFLD) is a metabolic liver injury closely related to insulin resistance. Fatty liver index (FLI) can be used as a surrogate marker and is a validated index for NAFLD. This study aimed to explore the relationship between FLI and arterial stiffness in a Chinese population. From December 2017 to March 2019, 402 inpatients (mean age 51.12 ± 11.95 years) were recruited for cardiovascular disease screening at Ruijin Hospital North, Shanghai. Measurement of brachial systolic, diastolic, mean, and pulse pressure was done with cuff sphygmomanometry and carotid-femoral pulse wave velocity (cfPWV) was measured (SphygmoCor) to assess arterial stiffness. Subjects were ided into three groups according to their FLI 30, normal 30–59, intermediate fatty liver index ≥ 60, NAFLD. The proportion of subjects with hepatic steatosis (FLI ≥ 60), intermediate FLI (30–59), and no steatosis (FLI 30) was 34.4%, 31.8%, and 33.8%, respectively. The male population (53.9%) had significantly higher FLI levels ( p 0.05). Subjects with FLI ≥ 60 had higher cfPWV (8.41 ± 1.77 m/s) than those with FLI 30 (7.81 ± 1.83 m/s p = 0.006). cfPWV was positively correlated with logFLI ( r = 0.168, p = 0.001). After adjusting for age, sex, body mass index, mean arterial blood pressure, glucose, cholesterol, heart rate, and glomerular filtration rate (eGFR), FLI remained positively associated with cfPWV ( β = 0.097, p = 0.024). cfPWV, as a measure of arterial stiffness, is higher in the NAFLD group when compared to that in normal groups. Fatty liver index is positively associated with arterial stiffness in a Chinese population.
Image segmentation methods for intracranial aneurysm haemodynamic research
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.JBIOMECH.2013.12.035
Abstract: Patient-specific haemodynamic technology is being increasingly utilised in clinical applications. Under normal circumstances, computational haemodynamic simulation is performed using geometric results obtained via medical image segmentation. However, even when employed upon the same set of medical imaging data, both the geometry and volume of intracranial aneurysm models are highly dependent upon varying insufficiently validated vascular segmentation methods. In this study, we compared three segmentation methods to segment the geometry of the aneurysm. These include: the Region Growing Threshold (RGT), Chan-Vese model (CV) and Threshold-Based Level Set (TLS). The results obtained were evaluated via measurement of arterial volume differences (VD), local geometric shapes, and haemodynamic simulation results. In total, 45 patient-specific aneurysm cases with three different anatomy locations were assessed in this study. From this, we discovered that the average VD of all three segmentation methods lay in the vicinity of 9.3% (SD= ± 4.6%). The computational haemodynamic simulation was performed via the use of the vessel geometries. Analyses produced an average of 23.2% (SD= ± 8.7%) difference in energy loss (EL) between the varying segmentation methods, with the difference in Wall Shear Stress (WSS) averaging 24.0% (SD= ± 8.5%) and 126.4% (SD= ± 124.4%) for the highest and lowest volumes of WSS respectively. The results of the lowest WSS, was seen to be significantly dependent upon the geometry of the aneurysm surface. It is therefore essential, in order to confirm the quality of segmentation processes in the application of patient-specific analyses of cerebrovascular haemodynamics - to validate these in idual segmentation methods.
PWPSim: A new simulation tool of pulse wave propagation in the human arterial tree
Publisher: IEEE
Date: 07-2017
Role of Pulse Pressure Amplification in Arterial Hypertension
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2009
Potential effects of systematic errors in intraocular pressure measurements on screening for ocular hypertension
Publisher: Springer Science and Business Media LLC
Date: 22-02-2013
DOI: 10.1038/EYE.2013.7
OS 13-06 GENERATION OF AORTIC FLOW VELOCITY FROM DERIVED AORTIC PRESSURE WAVEFORMS USING AGE-SPECIFIC AORTIC IMPEDANCE MODELLING
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
Principles of cerebral hemodynamics when intracranial pressure is raised
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
2.1 A METHOD FOR THE MEASUREMENT OF PRESSURE SENSITIVITY OF CAROTID-FEMORAL PULSE WAVE VELOCITY IN HUMANS
Publisher: Springer Science and Business Media LLC
Date: 2015
Microvascular function
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2015
Indices of central aortic pressure waveform and ventricular function
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2016
Equipotential earthing study: equipotential wiring is unnecessary
Publisher: Springer Science and Business Media LLC
Date: 09-2004
DOI: 10.1007/BF03178675
Central arterial pulse wave augmentation is greater in girls than boys, independent of height
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2010
Mechanical stretch: physiological and pathological implications for human vascular endothelial cells
Publisher: Publiverse Online S.R.L
Date: 18-09-2015
Pulse wave velocity is decreased with obesity in an elderly Chinese population
Publisher: Wiley
Date: 30-08-2019
DOI: 10.1111/JCH.13659
Peripheral and central pressure waveform parameters are associated with normal tension and primary open-angle glaucoma
Publisher: Springer Science and Business Media LLC
Date: 2008
Characterisation of cardiac autonomic function in multiple sclerosis based on spontaneous changes of heart rate and blood pressure
Publisher: Elsevier BV
Date: 05-2018
DOI: 10.1016/J.MSARD.2018.03.018
Abstract: Prevalence of cardiovascular autonomic dysfunction (CAD) in multiple sclerosis (MS) varies between studies. Cardiac autonomic function is usually assessed by cardiovascular reflex tests. We hypothesized that MS is associated with CAD, quantifiable by non-invasive means including quantification of baroreceptor sensitivity (BRS) and heart rate variability. In this study a comprehensive suite of cardiovascular autonomic tests based only on the spontaneous changes of heart rate and blood pressure was applied to 23 MS patients and age and gender-matched controls. From 5-min continuous non-invasive recording of the electrocardiogram and blood pressure, heart-rate, blood pressure, and autonomic function variables were calculated. Analysis included heart rate variability in the time domain, heart rate and blood pressure variability in the frequency domain, and baroreceptor sensitivity in both the time and frequency domain. BRS measured by the frequency technique in high frequency band was found to be significantly lower in MS (16 ± 9 ms/mmHg) compared to controls (29 ± 17 ms/mmHg) (p < 0.05). Also mean of BRS modulus in MS averaged 15 ± 8 ms/mmHg which is significantly lower compared to controls (25 ± 15 ms/mmHg) (p < 0.05). Systolic blood pressure variability in the high frequency band (0.15-0.5 Hz) was found to be significantly higher in the MS compared to controls (5.8 ± 16.7 mmHg The results, using techniques novel to MS investigation, showed diminished baroreceptor reflex and impaired sympathetic function using frequency domain systolic blood pressure variability analysis.
Interventional Cardiology and Cardiac Catheterisation
Publisher: CRC Press
Date: 24-04-2019
The ebbing tide of the reservoir-wave model.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2015
Central Aortic Blood Pressure and Management of Hypertension
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2013
EFFECTS OF SKIN TONE AND AMBIENT LIGHTING ON ACCURACY OF CONTACTLESS MEASUREMENT OF HEART RATE AND PULSE TRANSIT TIME: AN INVESTIGATION TOWARD IMAGE-BASED BLOOD PRESSURE ESTIMATION
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2021
A7254 Prediction of cardiovascular events in short-term follow-up
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2018
Vascular biomarker measurement using wrist-worn tonometer technology
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2018
Isolated systolic hypertension in the young
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2018
Viewpoint: The Case for Non-Invasive Central Aortic Pressure Monitoring in the Management of Hypertension
Publisher: Springer Science and Business Media LLC
Date: 20-10-2022
DOI: 10.1007/S44200-022-00023-Z
Abstract: Elevated central aortic pressure indices (e.g., systolic pressure and pulse pressure) predict cardiovascular (CV) events and mortality in addition to structural changes (e.g., left ventricular hypertrophy, carotid intima-media thickness and reduced glomerular filtration rate). These elevated risks have been shown in multiple studies to be superior to, and in others, at least as high as that associated with brachial pressures. Threshold values for the diagnosis of elevated central arterial pressures have been defined and can be considered target goals of treatment. Measurements of central arterial pressures can be incorporated into the current approaches to hypertension management utilizing currently available non-invasive devices that measure central pressures during the measurement of brachial BP. The objective of this review is to outline the rationale and evidence supporting incorporation of central aortic pressure monitoring into the care of patients with hypertension.
Effect of increasing heart rate on finger photoplethysmography fitness index (PPGF) in subjects with implanted cardiac pacemakers
Publisher: Public Library of Science (PLoS)
Date: 28-11-2018
Analysis of the Radial Pulse Wave and its Clinical Applications: A Survey
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2021
Recommendations for Improving and Standardizing Vascular Research on Arterial Stiffness
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2015
Use of arterial transfer function for the derivation of aortic waveform characteristics
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2004
ASSESSMENT OF SUBCLINICAL TARGET ORGAN DAMAGE BY COMPONENTS OF BLOOD PRESSURE
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2018
The kangaroo as a model for the study of hypertrophic cardiomyopathy in man
Publisher: Oxford University Press (OUP)
Date: 06-1986
DOI: 10.1093/CVR/20.6.398
Abstract: In experiments in 14 anaesthetised kangaroos, 10 developed unexpected ventricular fibrillation and died. In seeking a cause for this, similarities were noted with hypertrophic cardiomyopathy (HC) in man. Like patients with this condition, kangaroos have unexplained left ventricular hypertrophy and are known to be susceptible to sudden death with excitement and exertion. Retrospective analysis of all data showed other features of hypertrophic cardiomyopathy: unusually rapid left ventricular pressure development in systole (peak dP/dt: kangaroo 3602 (SEM472) HC 1947(SEM172) mmHg X s-1), unusually slow left ventricular relaxation (exponential time constant: kangaroo 54(SEM7) HC 63 (SEM5) ms relaxation time: kangaroo 128(SEM7) HC 112(SEM7) ms), and inappropriately long duration of mechanical systole in relation to ventricular depolarisation (393(SEM21) ms and 214(SEM15) ms respectively). A disparity between the duration of mechanical systole and electrical activation caused a type of incomplete tetanus to develop with ventricular extrasystoles, a phenomenon previously seen in patients with hypertrophic cardiomyopathy. These findings suggest that the kangaroo may be a useful experimental model for studying the fatal rhythm disturbances and abnormal ventricular dynamics in human hypertrophic cardiomyopathy.
Central Aortic Blood Pressure Waveform Estimation with a Temporal Convolutional Network
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2023
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