ORCID Profile
0000-0001-8045-6873
Current Organisations
The Unversity of Adelaide
,
University of Adelaide
,
Central Adelaide Local Health Network (CALHN)
,
Central Adelaide Local Health Network
,
CARDIA-SA
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Publisher: Elsevier BV
Date: 06-2000
Abstract: Trophoblast invasion is a critical process in development of most mammals that shares similarities with the invasive behavior of tumor cells. In the present investigation, a cDNA subtraction library was constructed between invasive trophoblast at day 8 of murine development and mature noninvasive placenta at day 18 of gestation. One of the differentially expressed clones, Epcs26, was mapped to the X chromosome and revealed no homology to any known gene. It was predominantly expressed in parietal endoderm, undifferentiated cells of the ectoplacental cone, and a few trophoblast giant cells. Another gene, designated Epcs50, was mapped to chromosome 19. It exhibited homologies to the mouse Mps1 gene and, like Mps1, may have a distant relationship to the lytic protein perforin. High expression was detected in parietal endoderm cells and in a subset of secondary trophoblast giant cells. Two sequences, Epcs24 and Epcs68, exhibited an extensive open reading frame that shared the common features of the cysteine proteinase cathepsin L. Expression was confined to an undefined subpopulation of trophoblast giant cells. Both genes were mapped to chromosome 13 in close proximity to cathepsins L and J. The known functions of MPS1 and cathepsin L proteins indicate that the related proteins EPCS50, EPCS24, and EPCS68 participate in conferring invasive properties to the mouse trophoblast.
Publisher: Elsevier BV
Date: 11-2014
Publisher: Elsevier BV
Date: 07-2000
DOI: 10.1016/S0300-9572(00)00172-6
Abstract: Previous research has suggested that the physical demands of performing cardiopulmonary resuscitation (CPR) are relatively low. However, the subjects studied have generally been of a young age. The aim of this study was to test the hypothesis, in null form, that the physiological responses to the performance of single operator CPR for 10 min are independent of age. Confirmation of the hypothesis would allow the use of a period of time performing CPR as a socially non-discriminatory means of testing ability across a wide spectrum of age. 33 St. John Operations Branch members (a s le of convenience), aged between 18 and 65 years, were examined whilst performing 10 min of single operator CPR on a manikin at St. John Ambulance Headquarters, Adelaide, South Australia. Heart rate and cardiac rhythm were monitored continuously. Blood pressure was recorded at baseline and the end of the 3rd, 6th and 9th min of CPR. Subjects also rated their perceived level of activity using the 15-point Borg rating scale every 3 min and at the end of the test. The calculated rate-pressure product did not vary significantly with age, either at rest or in response to performing CPR. The rate-pressure product increased significantly (P < 0.05) whilst performing CPR. There was no effect of age on the perceived level of exertion, which also increased significantly during CPR as compared with rest. There was no significant effect of age on the physiological responses to the performance of 10 min of single operator CPR in this select group.
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.IJCARD.2018.04.077
Abstract: Coronary haemodynamic testing frequently identifies abnormal pathophysiological parameters in patients with angina and non-obstructed coronaries on angiography (NoCAD) but the clinical utility of these measures has received limited attention. This study aims to identify the clinical and coronary haemodynamic determinants of recurrent chest pain at one month in patients with NoCAD. Patients with angina, NoCAD ( 1.9. Multivariate logistic regression analysis identified frequent angina at baseline (OR: 68.9 [4.1, 1165.0], p = 0.003), previous unstable angina admission (OR: 43.9 [3.5, 547.9], p = 0.003) and a HMR > 1.9 (OR: 15.6 [2.1, 114.0], p = 0.007) as independent predictors of recurrent chest pain. In this small pilot study, an abnormal HMR was the only coronary haemodynamic parameter that was a determinant of ongoing angina at short-term follow-up.
Publisher: Wiley
Date: 13-06-2006
DOI: 10.1111/J.1445-5994.2006.01101.X
Abstract: The need for on-site cardiac surgery has been a component of guidelines for the practice of elective and emergency percutaneous coronary intervention (PCI). However, proportions of cases requiring emergency coronary artery bypass grafting (CABG) post-PCI have fallen. This audit of complications of PCI confirms the very low incidence of need for emergency CABG, despite increasingly complex PCI caseload. Although the availability of stents/antiplatelet pharmacotherapy probably has contributed to improved PCI outcomes, the avoidance of emergency CABG is not contingent on either extensive use of glycoprotein IIb/IIIa inhibitors or strategies of universal stenting.
Publisher: AMPCo
Date: 09-2016
DOI: 10.5694/MJA16.00445
Abstract: To assess differences in the rates of angiography and subsequent revascularisation for Aboriginal and non-Aboriginal South Australians who presented with an acute coronary syndrome (ACS) to explore the reasons for any observed differences. Analysis of administrative data with logistic regression modelling to assess the relationship between Aboriginal status and the decision to undertake diagnostic angiography. A detailed medical record review of Aboriginal admissions was subsequently undertaken. Emergency ACS admissions to SA cardiac catheterisation hospitals, 2007-2012. 13 701 admissions of patients with an ACS, including 274 Aboriginal patients (2.1%). Rates of coronary angiography and revascularisation documentation of justification for non-invasive management. After adjustment for age, comorbidities and remoteness, Aboriginal patients presenting with an ACS were significantly less likely than non-Aboriginal patients to undergo angiography (odds ratio [OR], 0.4 95% CI, 0.3-0.5 P < 0.001). There was no significant difference in the rates of revascularisation for Aboriginal and non-Aboriginal patients who had undergone angiography. Reasons for Aboriginal patients not undergoing angiography included symptoms being deemed non-cardiac (16%), non-invasive test performed (8%), and discharge against medical advice (11%) the reasons were unclear for 36% of Aboriginal patients. After controlling for age and other factors, the rate of coronary angiography was lower among Aboriginal patients with an ACS in SA. The reasons for this disparity are complex, including patient-related factors and their preferences, as well as the appropriateness of the intervention. Improved consideration of the hospital experience of Aboriginal patients must be a priority for reducing health care disparities.
Publisher: AMPCo
Date: 06-2014
DOI: 10.5694/MJA12.11175
Abstract: Aboriginal and Torres Strait Islander patients with acute coronary syndromes (ACS) experience lower intervention rates and poorer outcomes compared with non-Indigenous patients. A broad range of geographical, cultural and systemic factors contribute to delays and suboptimal treatment for ACS. Every Indigenous ACS patient, regardless of where they live, should be able to expect a coordinated, patient-centred pathway of care provided by designated provider clinical networks and supported by Indigenous cardiac coordinators, Aboriginal liaison officers (ALOs) and health workers. These designated provider clinical networks provide: appropriate prehospital and inhospital treatment an in idualised patient care plan developed jointly with the patient and his or her family culturally appropriate education initiated within the hospital setting and involving families with support from ALOs effective follow-up care and access to relevant secondary prevention programs. We outline generic pathways to provide policymakers, health planners and health care providers with a framework for ACS diagnosis and management that can be implemented across the erse settings in which Aboriginal and Torres Strait Islander people reside and their care is delivered, in order to optimise care and assertively address the current disparities in outcomes.
Publisher: Elsevier BV
Date: 07-2017
Publisher: Cambridge University Press (CUP)
Date: 02-2008
DOI: 10.1017/S1049023X00005628
Abstract: Public safety at mass gatherings is the responsibility of multi-ple agencies. Injury surveillance and inter-agency communication are pivotal to ensure continued public safety. The principal objective of this pilot study was to improve the identification of trends and patterns of injury presentations at mass gather-ings. This was achieved through an electronic process for data gathering to support timely reporting of injury data. In addition, what evolved was the devel-opment of an inter-agency communication model to support information transfer. An Electronic Injury Surveillance System was created and piloted at two mass gatherings in South Australia. Live, real-time data were collect-ed via customized software supported by electronic report generation. The Injury Surveillance System captured data on 181 injured patients and assisted in the identification of trends and patterns of presenta-tions. The relevant injuries and patterns of injuries were reported to the appropriate organizations based on pre-defined communication models. The pilot study demonstrated that it was possible to perform “live”, portable injury surveillance during patient presentations at two mass gatherings. The Injury Surveillance System ensured immediate data capture. Well-defined communication systems established for this pilot also enabled early action to rectify hazards. Further development of electronic injury sur-veillance should be considered as an essential tool for managing public safety at mass gatherings.
Publisher: Cambridge University Press (CUP)
Date: 02-2009
DOI: 10.1017/S1049023X00006518
Abstract: Gaining an understanding of crowd behavior is important in supporting timely and appropriate crowd management principles in the planning and provision of emergency services at mass gatherings. This paper provides a review of the current understanding of the psychological factors of a crowd within the psychosocial domain as they apply to mass-gathering settings. It can be concluded from this review that there is a large theory-practice gap in relation to crowd psychology and the mass-gathering setting. The literature has highlighted two important elements of crowd behavior—there must be a “seed” and people must engage. Understanding these behaviors may provide opportunities to change crowd behavior outcomes.
Publisher: Elsevier BV
Date: 10-2013
Publisher: Cambridge University Press (CUP)
Date: 06-2005
DOI: 10.1017/S1049023X00002399
Abstract: Mass-gathering events are dynamic and challenge traditional medical management systems. To improve the system for the provision of first aid at mass-gathering events, an evaluation of two models that assist in forecasting the number of patients presenting for first-aid services was conducted. A prospective evaluation of a recurrent, mass-gathering event was undertaken comparing predicted patient presentations and ambulance transfers generated by a predictive model developed by Arbon et al and a retrospective review of seven years of historical, event data as described by Zeitz et al . Patient presentation rate (per 1,000 patrons) for this event was 1.6 and the transport to hospital rate (per 1,000 patrons) was 0.07. The retrospective review closely predicted the actual overall attendance.Both methods forecast the number of patients presenting on a daily basis. The prediction proved to be more accurate, on a day-by-day basis, using the Zeitz method. The Arbon method is particularly useful for events where there is no or limited information about previous medical work. Retrospective review of data generated from specific events (Zeitz method) considers the unique and in idual variability that can occur from event to event and is more accurate at predicting patient presentations when the data are available. Both methods have the potential to be used more frequently to adequately and efficiently plan for the resources required for specific events.
Publisher: Elsevier BV
Date: 03-2008
DOI: 10.1016/J.RESUSCITATION.2007.08.011
Abstract: St. John Ambulance Australia has used the performance of CPR for 10 min as a fitness test for its members. Recent changes in international guidelines for cardiopulmonary resuscitation caused concern that the new ILCOR protocol was more strenuous than the previous one. This study compared the two protocols to determine if there were significant differences and to allow an evidence-based decision on the continuation or modification of this practice. We studied 26 subjects performing single-rescuer cardiopulmonary resuscitation on a manikin. Every subject did 10 min cardiopulmonary resuscitation using each protocol. The study used a randomized cross-over design. The estimated maximum heart rate was calculated for each subject. Compression rate and effective ventilation (number and depth) were enforced by direct feedback. Subjective and objective measures of physical activity were recorded at regular intervals. The maximum percentage of estimated maximum heart rate achieved during 15:2 and 30:2 CPR was 76+/-2% and 79+/-2%, respectively (mean+/-standard error of mean P<0.001). The rate pressure product at the end of 10 min cardiopulmonary resuscitation was 18,999+/-891 for 15:2 and 19,204+/-757 for 30:2 (ns) while the Borg rating of perceived exertion was 13.7+/-0.5 for 15:2 and 14.8+/-0.5 for 30:2 (P<0.05). The new protocol increases both objective and subjective measures of effort. While the absolute differences in workload are small, they are statistically significant. There are significant indicators of this difference in the first 3 min of assessment. Rescuers are more likely to be operating at a high-level of physical activity. To avoid increasing the demands of its mandatory fitness test, St. John should reduce the required performance time from its present 10 min.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2003
DOI: 10.1161/01.HYP.0000054976.67487.08
Abstract: There is little information on the processes affecting selective tissue ACE inhibition and the implications in human subjects. We compared intravenously administered ACE inhibitors, perindoprilat and enalaprilat, for myocardial drug uptake and effects on angiotensin and bradykinin peptides versus hemodynamic effects in 25 patients with stable angina and well-preserved left ventricular systolic function. Myocardial uptake was rapid and more efficient for perindoprilat than for enalaprilat (peak content at 26±3 and 30±4 seconds, 0.58±0.12% and 0.27±0.07% of the administered dose for perindoprilat and enalaprilat, respectively, P =0.04 for difference). Both drugs caused a decrease in angiotensin (Ang) II level, an increase in Ang I level, and reduction in Ang II/Ang I ratio in arterial and coronary sinus blood. Bradykinin (BK)-(1-9) and BK-(1-8) levels increased in arterial blood and BK-(1-8) levels increased in coronary sinus blood after drug administration. Perindoprilat and enalaprilat caused a small decrease in mean arterial pressure (−3±1%, P .05 and −4±1%, P .01, respectively) and LV+dP/dt (−5.8±1.7%, P .01 and −4.2±2.8%, P .05, respectively), whereas systemic vascular resistance index was unchanged. Despite relatively cardioselective uptake of perindoprilat, both drugs had similar effects on the cardiac metabolism of angiotensin and bradykinin and on cardiac function. Under resting conditions, both drugs exerted small negative inotropic effects.
Publisher: Cambridge University Press (CUP)
Date: 09-2002
DOI: 10.1017/S1049023X00000376
Abstract: St John Ambulance Operations Branch Volunteers have been providing first-aid services at the Royal Adelaide Show for 90 years. The project arose from a need to more accurately predict the workload for first-aid providers at mass gathering events. A formal analysis of workload patterns and the determinants of workload had not been performed. Casualty presentation workload would be predicted by factors including day of the week, weather, and crowd size. Collated and analyzed casualty reports over a seven-year period representing ,000 patients who presented for first-aid assistance for that period (63 show days) were reviewed retrospectively. Casualty presentations correlated significantly with crowd size, maximum daily temperature, humidity, and day of the week. Patient presentation rate had heterogeneous determinants. The most frequent presentation was minor medical problems with Wednesdays attracting higher casualty presentations and more major medical categories. In idual event analysis is a useful mechanism to assist in determining resource allocation at mass gathering events providing an evidence base upon which to make decisions about future needs. Subsequent analysis of other events will assist in supporting accurate predictor models.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2004
DOI: 10.1097/00004872-200410000-00020
Abstract: To investigate the role of angiotensin-converting enzyme-related carboxypeptidase (ACE2) in angiotensin peptide metabolism in the human coronary circulation. Angiotensin I and angiotensin II, and their respective carboxypeptidase metabolites, angiotensin-(1-9) and angiotensin-(1-7), were measured in arterial and coronary sinus blood of heart failure subjects receiving angiotensin-converting enzyme (ACE) inhibitor therapy and in normal subjects not receiving ACE inhibitor therapy. In addition, angiotensin I, angiotensin II and angiotensin-(1-7) were measured in arterial and coronary sinus blood of subjects with coronary artery disease before, and at 2, 5 and 10 min after, intravenous administration of ACE inhibitor. In comparison with normal subjects, heart failure subjects receiving ACE inhibitor therapy had a greater than 40-fold increase in angiotensin I levels, but angiotensin-(1-9) levels were low (1-2 fmol/ml), and similar to those of normal subjects. Moreover, angiotensin-(1-7) levels increased in parallel with angiotensin I levels and the angiotensin-(1-7)/angiotensin II ratio increased by 7.5-fold in coronary sinus blood. Intravenous administration of ACE inhibitor to subjects with coronary artery disease rapidly decreased angiotensin II levels by 54-58% and increased angiotensin I levels by 2.4- to 2.8-fold, but did not alter angiotensin-(1-7) levels or net angiotensin-(1-7) production across the myocardial vascular bed. The failure of angiotensin-(1-9) levels to increase in response to increased angiotensin I levels indicated little role for ACE2 in angiotensin I metabolism. Additionally, the levels of angiotensin-(1-7) were more linked to those of angiotensin I than angiotensin II, consistent with its formation by endopeptidase-mediated metabolism of angiotensin I, rather than by ACE2-mediated metabolism of angiotensin II.
Publisher: Elsevier BV
Date: 05-2010
Publisher: Springer Science and Business Media LLC
Date: 14-11-2012
Publisher: Elsevier BV
Date: 05-2010
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.HLC.2009.01.004
Abstract: The vascular health of Indigenous Australians requires urgent first aid. In concert with improved primary health care strategies, there is a need for improved access to both specialist and tertiary vascular health services. More importantly, these services must be strongly integrated to allow seemless transition in a patient focussed model of care that simultaneously addresses the need for community-based services and transition to frequently remote tertiary facilities. Education and empowerment of local health workers to identify patients requiring primary or secondary prevention and deliver evidence based therapies is as important as the need to evaluate the impact of services on disease burden. It is pivotal to the success of expanded services that clinical support is delivered in conjunction with educational and research programs.
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 03-2002
Abstract: Failed reperfusion after thrombolysis occurs in as many as 30% of patients with acute myocardial infarction (MI). Furthermore, some patients have incomplete tissue perfusion despite reperfusion of the infarct-related artery. Close assessment of the efficacy of thrombolytic administration in people with evolving acute MI is necessary, particularly with regard to myocardial perfusion status, because some patients may benefit from incremental pharmacologic or invasive reperfusion strategies. This article reviews a number of strategies to assess infarct-related artery patency and myocardial tissue perfusion. These include coronary angiography, continuous ST-segment monitoring, serial electrocardiography, obtaining serial serum biochemical markers of myocardial necrosis, monitoring for reperfusion arrhythmias, and assessment of changes in chest pain intensity. The early detection of failed reperfusion is critical if incremental strategies to enhance myocardial salvage are to be considered. Continuous ST-segment monitoring is a relatively inexpensive, reliable, and accurate tool for assessing real-time myocardial perfusion.
Publisher: Elsevier BV
Date: 03-2014
Publisher: Elsevier BV
Date: 10-2012
Publisher: Elsevier BV
Date: 2003
DOI: 10.1016/S0300-9572(02)00282-4
Abstract: Non-traditional and lay first responders increasingly are being trained in the skill of defibrillation. With simplification of new devices, there is a need to determine optimal first responder selection and training and maintenance of this important skill. These issues are of prime importance for the St John Ambulance Australia Operations Branch which already has a substantial first response defibrillation programme. We trained 12 trainers (3 h and 30 min), who subsequently instructed 41 further first responders (2 h and 30 min), a total group with a broad range of pre-existing experience and skill level, in the use of an automated external defibrillator (AED). Acquisition and maintenance of the AED skill was determined by four criteria at three monthly intervals. St John first responders with higher qualification levels were more likely to acquire the skill of defibrillation successfully (r=0.37, P<0.05). However, once acquired, the skill was easily maintained by virtually all (98%) members. A positive correlation was noted between the overall score achieved at the 6-month re-assessment and the number of times members had taken an AED 'on duty' (r=0.31, P<0.05). For St John first responders proficient in cardiopulmonary resuscitation (CPR), the skill of defibrillation with an AED is readily acquired and maintained. While less experienced members may be less likely to acquire the skill initially, once acquired the skill is equally maintained by all, provided ongoing 'on duty' exposure is available.
Publisher: Wiley
Date: 07-2005
DOI: 10.1111/J.1440-1681.2005.04225.X
Abstract: 1. Nitric oxide (NO) is an important mediator of contractile function in the heart. However, isolated papillary muscle preparations appear to lack NO responsiveness in certain animal species. Although cat, guinea-pig and ferret models have been NO responsive, there have been mixed results in the rat papillary muscle. In null form, we tested three separate hypotheses in rat papillary muscle, specifically that the NO donor sodium nitroprusside (SNP) would not affect the contractility of: (i) the isolated papillary muscle (ii) papillary muscle prestimulated with the beta-adrenoceptor agonist isoprenaline and (iii) papillary muscle subjected to 15 min anoxia followed by 45 min reoxygenation. 2. Male Sprague-Dawley rats were used. The left ventricular papillary muscle was mounted and maintained at 30 degrees C and was stimulated at 10 b.p.m. Each experiment was performed in parallel with a control papillary muscle from the same animal. Papillary muscles were exposed to increasing concentrations of SNP (10(-9) to 10(-5) mol/L) either alone or following pretreatment with 10(-7) mol/L isoprenaline. Anoxia/reoxygenation was simulated by 15 min anoxia followed by 60 min reoxygenation in the presence or absence of 10(-7) mol/L SNP. 3. Both isometric and isotonic parameters were assessed. As expected, isoprenaline had a significant positive inotropic response. Similarly, contractility was impaired during anoxia and partially recovered during reoxygenation. Nitric oxide did not alter either isotonic or isometric parameters in the three experimental protocols. 4. The rat isolated papillary muscle has no measurable response to exogenous NO. The inotropic effects of beta-adrenoceptor stimulation and anoxia/reoxygenation are NO independent.
Publisher: Wiley
Date: 02-2016
DOI: 10.1111/IMJ.12949
Abstract: Using Australian guidelines for management of acute coronary syndromes, we assessed the probability of an Indigenous patient receiving interventional and therapeutic care after presenting in two metropolitan hospitals. A retrospective case note review of patients admitted through two Adelaide public tertiary hospital emergency departments from December 2007 to December 2009. The study cohort was 488 patients with high-risk clinical features without ST-segment elevation. Indigenous patients were significantly younger, present later in the disease process and have a higher burden of cardiovascular risk factors when compared with non-Indigenous patients. Indigenous patients were 54% more likely to receive angiography (Risk ratios (RR) = 1.54 95% CI 1.31 1.81) than non-Indigenous patients, however, this difference disappeared after adjustment for age, sex and propensity score. Indigenous patients were 20% more likely to receive the recommended medications (RR = 1.19, 95% CI 1.01 1.40) compared with non-Indigenous patients. Patients over 65 years were 53% less likely to receive an angiogram (RR = 0.47, 95% CI 0.38 0.56) and were 35% less likely to receive the recommended medications (RR = 0.65, 95% CI 0.54 0.78) than a patient at the ages of 18-49. Women were almost 20% less likely to receive an angiogram (RR = 0.81, 95% CI 0.66 0.99) and 20% less likely to receive the recommended medications (RR = 0.80, 95% CI 0.71 0.91) when compared with men. The likelihood of receiving medications on discharge was significantly influenced by age, gender, ethnicity, comorbid burden and revascularisation. The younger age and significantly higher-risk profile of Indigenous adults presenting to SA hospitals with acute coronary syndromes appears to lead to different management decisions, which may well be led by patient factors. Many of these risk conditions can be better managed in the primary care setting.
Publisher: Elsevier BV
Date: 08-2015
Publisher: Cambridge University Press (CUP)
Date: 12-2010
DOI: 10.1017/S1049023X00008700
Abstract: Sudden, out-of-hospital cardiac arrest (OHCA) has an annual incidence of approximately 50 per 100,000 population. Public access defibrillation is seen as one of the key strategies in the chain-of-survival for OHCA. Positioning of these devices is important for the maximization of public health outcomes. The literature strongly advocates widespread public access to automated external defibrillatiors (AEDs). The most efficient placement of AEDs within in idual communities remains unclear. A retrospective case review of OHCAs attended by the South Australia Ambulance Service in metropolitan and rural South Australia over a 30-month period was performed. Data were analyzed using Utstein-type indicators. Detailed demographics, summative data, and clinical data were recorded. A total of 1,305 cases of cardiac arrest were reviewed. The annual rate of OHCA was 35 per 100,000 population. Of the cases, the mean value for the ages was 66.3 years, 517 (39.6%) were transported to hospital, 761 (58.3%) were judged by the paramedic to be cardiac, and 838 (64.2%) were witnessed. Bystander cardiopulmonary resuscitation (CPR) was performed in 495 (37.9%) of cases. The rhythm on arrival was ventricular fibrillation (VF) or ventricular tachycardia (VT) in 419 (32.1%) cases, and 315 (24.1%) of all arrests had return of spontaneous circulation (ROSC) before or on arrival at the hospital. For cardiac arrest cases that were witnessed by the ambulance service (n = 121), the incidence of ROSC was 47.1%. During the 30-month period, there only was one location that recorded more than one cardiac arrest. No other location recorded recurrent episodes. This study did not identify any specific location that would justify defibrillator placement over any other location without an existing defibrillator. The impact of bystander CPR and the relatively low rate of bystander CPR in this study points to an area of need. The relative potential impact of increasing bystander CPR rates versus investing in defibrillators in the community is worthy of further consideration.
Publisher: Elsevier BV
Date: 2007
DOI: 10.1016/J.JACC.2006.08.053
Abstract: This study sought to assess the determinants of platelet nitric oxide (NO) responsiveness in diabetic patients admitted with acute coronary syndromes (ACS) and the short-term effects of aggressive glycemic control on these factors. Hyperglycemia is an independent risk factor for mortality in both diabetic patients and nondiabetic patients with ACS. The mechanism(s) underlying this observation and potential benefit from its correction remain uncertain. Although a reduction in NO bioavailability has been proposed, this remains untested in the ACS setting. A total of 76 diabetic patients with ACS were studied. Putative correlations between admission blood sugar level (BSL), inhibition of platelet aggregation by the NO donor sodium nitroprusside (SNP), and superoxide (O2-) were assessed. Hyperglycemic patients (n = 60) were randomized to acute glycemic control with intravenous versus subcutaneous insulin, and changes in the aforementioned parameters were compared. Plasma levels of the endogenous inhibitor of NO synthase asymmetric dimethylarginine (ADMA) were also monitored. There was an inverse correlation between admission BSL and both platelet SNP response (p = 0.007) and ADMA levels (p = 0.045), and a positive correlation with O2- generation (p < 0.001). Intravenous insulin infusion resulted in a greater reduction (p < 0.001) in BSL, differentially improved platelet responsiveness to SNP (p = 0.049), and decreased O2- (p < 0.001) and ADMA levels (p = 0.049). A component of platelet dysfunction in diabetic patients with ACS is impaired responsiveness to the anti-aggregatory effects of NO, probably reflecting increased NO clearance by O2-. This phenomenon is reversed by acute aggressive glycemic control. These findings provide a further rationale for use of insulin therapy in acute myocardial infarction and suggest its extension to ACS patients.
Publisher: Wiley
Date: 27-02-2013
DOI: 10.1111/IMJ.12050
Abstract: Using Australian guidelines for management of acute coronary syndromes, we investigated the proportion of high-risk patients enrolled in the Acute Coronary Syndromes Prospective Audit registry who received a coronary angiogram. A prospective nationwide multicentre registry involving 39 Australian hospitals was used. The study cohort were patients with high-risk clinical features without ST segment elevation (n = 1948) admitted from emergency departments between 1 November 2005 and 31 July 2007. Eighty nine per cent of patients with ST segment elevation myocardial infarction and only 53% of eligible patients with high-risk acute coronary syndromes with no ST elevation received a diagnostic angiogram. Increasing age was associated with lower rates of angiography a high-risk patient at the age of ≥ 70 years was 19% less likely to receive an angiogram than one at the age of <70 years (risk ratio (RR) = 0.81 95% confidence interval (CI) 0.76, 0.76). Women were 26% less likely than men to receive an angiogram (RR = 0.74 95% CI = 0.65, 0.83). The adjusted RR from the multivariate analysis suggests that a patient at the age of ≥ 70 years was 35% less likely to receive an angiogram than one at the age of <70 years (RR = 0.65, 95% CI = 0.60, 0.73), and that women were 13% less likely than men to receive an angiogram (RR = 0.87, 95% CI = 0.80, 0.96). Indigenous patients were as likely to access angiography as eligible non-indigenous patients (RR = 1.03, 95% CI 0.85, 1.25). There is underinvestigation of high-risk patients without ST segment elevation in Australian hospitals, particularly for women and older patients. Indigenous patients are younger and have poorer risk profiles, and represent a group that would benefit from greater investment in prevention strategies.
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.HLC.2010.02.015
Abstract: The challenges and opportunities for provision of, and access to, reliable chronic cardiovascular health care for Indigenous people were addressed by expert speakers from New Zealand and Australia. It is well recognised that cardiovascular disease is a life-long concern, requiring reliable follow-up, early transition of clinical research into practice and ongoing support of patients. The clinical outcomes and long-term prognosis of in iduals with cardiovascular disease are critically dependent upon the quality and availability of follow-up and chronic care facilities. This paper summarises the principal issues identified by the expert speakers for the provision of chronic cardiovascular health care to Indigenous peoples in Australia and New Zealand identifies common challenges and describes important initiatives which the Cardiac Society of Australia and New Zealand (CSANZ), in partnership with health care professionals, communities and governments, can undertake in order to achieve the goals of uniform and equitable health care for chronic cardiovascular disease in all the Indigenous peoples, relevant to the needs of these peoples, in New Zealand and Australia. The issues addressed by the meeting include: 1) Determination of appropriate models for effective delivery of cardiovascular health care. (2) Who should deliver cardiovascular health care and what are the workforce requirements. (3) What support systems and infrastructure are required. (4) How can primary care and secondary specialist services be effectively integrated.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2000
DOI: 10.1097/00005344-200003000-00013
Abstract: The effects of inotropically active agents on the left ventricular force-interval relation are a potential determinant of their clinical utility and safety. However, little information is available concerning the effects of noncatecholamine positive inotropic agents on this relation. Therefore this study compared the short-term effects of digoxin and milrinone on resting hemodynamics, frequency potentiation (FP), and mechanical restitution (MR) in patients undergoing nonemergency cardiac catheterization. Both digoxin and milrinone produced similar increases in LV + dP/dt at rest (12.2 +/- 1.3%, p < 0.000001 and 11.4 +/- 3.2%, p < 0.01, respectively). The positive inotropic effects of digoxin were marginally attenuated during FP (by 8.5 +/- 4.2% and 4.6 +/- 2.9% at 10 and 60 s, respectively, both p = NS compared with baseline). Similarly, on MRC analysis, the parameter c (a measure of sensitivity of contractile performance to reductions in cycle length) increased by 3.6 +/- 3.7% (p = NS). Whereas the positive inotropic effects of milrinone were not significantly attenuated during FP, they were abolished and possibly reversed at short cycle lengths on MR curve construction (6.8 +/- 5.9% negative inotropic effect at 60% of resting cycle length p = NS p < 0.05 vs. resting cycle length). In conclusion, in patients with well-preserved left ventricular systolic function, the positive inotropic effects of milrinone but not of digoxin are markedly dependent on heart rate. These properties may influence both relative safety and efficacy of both agents.
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.HLC.2010.02.017
Abstract: Cardiovascular disease (CV) is an important problem among the 400 million Indigenous Populations around the world, and has been included in the World Health Organization (WHO) "2008-2013 Action Plan for Non-Communicable Diseases". Our understanding of the causes of CV disease in the Indigenous populations of Australia and New Zealand will be facilitated by better understanding the causes of CV disease in Indigenous populations around the world. The opening scientific presentations of the Inaugural CSANZ Conference on Indigenous Cardiovascular Health were from two international speakers notable for their commitment to Indigenous Health as a global problem.
Publisher: Elsevier BV
Date: 05-0004
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.HLC.2010.02.019
Abstract: Rates of acute rheumatic fever and chronic rheumatic heart disease in Aboriginal people, Torres Strait Islanders and Māori continue to be unacceptably high. The impact of rheumatic heart disease is inequitable on these populations as compared with other Australians and New Zealanders. The associated cardiac morbidity, including the development of rheumatic valve disease, and cardiomyopathy, with possible sequelae of heart failure, development of atrial fibrillation, systemic embolism, transient ischaemic attacks, strokes, endocarditis, the need for interventions including cardiac surgery, and impaired quality of life, and shortened life expectancy, has major implications for the in idual. The adverse health and social effects may significantly limit education and employment opportunities and increase dependency on welfare. Additionally there may be major adverse impacts on family and community life. The costs in financial terms and missed opportunities, including wasted young lives, are substantial. Prevention of acute rheumatic fever is dependent on the timely diagnosis and treatment of sore throats and skin infections in high-risk groups. Both Australia and New Zealand have registries for acute rheumatic fever but paradoxically neither includes all cases of chronic rheumatic heart disease many of whom would benefit from close surveillance and follow-up. In New Zealand and some Australian States there are programs to give secondary prophylaxis with penicillin, but these are not universal. Surgical outcomes for patients with rheumatic valvular disease are better for valve repair than for valve replacement. Special attention to the selection of the appropriate valve surgery and valve choice is required in pregnant women. It may be necessary to have designated surgical units managing Indigenous patients to ensure high rates of surgical repair rather than valve replacement. Surgical guidelines may be helpful. Long-term follow-up of the outcomes of surgery in Indigenous patients with rheumatic heart disease is required. Underpinning these strategies is the need to improve poverty, housing, education and employment. Cultural empathy with mutual trust and respect is essential. Involvement of Indigenous people in decision making, design, and implementation of primary and secondary prevention programs, is mandatory to reduce the unacceptably high rates of rheumatic heart disease.
Publisher: Informa UK Limited
Date: 2008
Publisher: Wiley
Date: 25-12-2001
Publisher: Elsevier BV
Date: 02-2011
Publisher: Elsevier BV
Date: 07-2013
Publisher: Informa UK Limited
Date: 02-2012
DOI: 10.1586/ERC.11.190
Abstract: Takotsubo cardiomyopathy (TTC) is a form of reversible acute cardiac dysfunction of uncertain pathogenesis, which occurs predominantly in postmenopausal women, often with antecedent severe stress. Systolic dysfunction most commonly affects the apex of the left ventricle. There is considerable uncertainty regarding the pathogenesis of TTC and the optimal diagnostic methodology. Acute catecholamine release may play a component role, but the regional hypokinesis is associated with an acute inflammatory process, with resultant early release of brain natriuretic peptide (BNP) and N-terminal pro-BNP. As the diagnosis of TTC has largely been a process of exclusion, there has been considerable underdiagnosis. The combination of demographics, preceding history, ECG appearances and N-terminal pro-BNP elevation may provide the basis for improved early diagnosis. Complete recovery takes at least several months, with a risk of recurrent episodes. Efforts to delineate pathogenesis, expedite diagnosis and evaluate residual disability may assist in the development of appropriate treatment regimens.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2008
Publisher: Elsevier BV
Date: 12-1998
DOI: 10.1016/S1071-9164(98)90232-9
Abstract: Nitrates are superior to furosemide in the management of acute pulmonary edema associated with myocardial infarction however, their role in the absence of infarction is unclear. A randomized comparison was undertaken of the relative effectiveness of primary therapy with either intravenous morphine/furosemide (men/women n = 32) or nitroglycerin/N-acetylcysteine (NTG/NAC n = 37) in consecutive patients with acute pulmonary edema. The primary end point was change in PaO2/FIO2 over the first 60 minutes of therapy. Secondary end points were needed for mechanical respiratory assistance (ie, continuous positive airway pressure via mask or intubation and ventilation) and changes in other gas exchange parameters. Both treatment groups showed improvement in oxygenation after 60 minutes of therapy however, this reached statistical significance only with NTG/NAC therapy. There was no significant difference between groups in the assessed parameters (95% CI for differences in Pao2/FIO2: furosemide/morphine -12 to 23 and NTG/NAC 4 to 44), a finding also confirmed in 32 patients presenting with respiratory failure. Only 11% of the study group required mechanical ventilatory assistance (continuous positive airway pressure in 4 patients and intubation and ventilation in 3 patients). NTG/NAC therapy is as effective as furosemide/morphine in the initial management of acute pulmonary edema, regardless of the presence or absence of respiratory failure. The necessity for mechanical ventilatory assistance is infrequent in these patients, regardless of the initial medical treatment regimen.
Publisher: BMJ
Date: 11-07-2012
DOI: 10.1136/HEARTJNL-2011-301481
Abstract: Tako-Tsubo cardiomyopathy (TTC) is associated with regional left ventricular dysfunction, independent of the presence of fixed coronary artery disease. Previous studies have used T2-weighted cardiac MRI to demonstrate the presence of periapical oedema. The authors sought to determine the distribution, resolution and correlates of oedema in TTC. 32 patients with TTC were evaluated at a median of 2 days after presentation, along with 10 age-matched female controls. Extent of oedema was quantified both regionally and globally scanning was repeated in patients with TTC after 3 months. Correlations were sought between oedema and the extent of hypokinesis, catecholamine release, release of N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), and markers of systemic inflammatory activation (high-sensitivity C-reactive protein and platelet response to nitric oxide). In the acute phase of TTC, T2-weighted signal intensity was greater at the apex than at the base (p<0.0001) but was nevertheless significantly elevated at the base (p<0.0001), relative to control values. Over 3 months, T2-weighted signal decreased substantially, but remained abnormally elevated (p<0.02). The regional extent of oedema correlated inversely with radial myocardial strain (except at the apex). There were also direct correlations between global T2-weighted signal and (1) plasma normetanephrine (r=0.39, p=0.04) and (2) peak NT-proBNP (r=0.39, p=0.03), but not with systemic inflammatory markers. TTC is associated with slowly resolving global myocardial oedema, the acute extent of which correlates with regional contractile disturbance and acute release of both catecholamines and NT-proBNP.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
DOI: 10.1161/CIRCOUTCOMES.115.002488
Abstract: High-sensitivity troponin T (hs-TnT) assays promise greater discrimination of evolving myocardial infarction, but the impact of unguided implementation on the effectiveness of care is uncertain. We evaluated the impact of hs-TnT reporting on care and outcome among chest pain patients presenting to 5 emergency departments within a multicenter randomized trial. Patients were allocated to hs-TnT reporting (hs-report) or standard reporting (std-report Roche Elecys). The primary end point was death and new or recurrent acute coronary syndrome by 12 months. A total of 1937 patients without ST-segment elevation were enrolled between July 2011 and March 2013. The median age was 61 (interquartile range, 48–74) years, and 46.3% were women. During the index hospitalization, 1466 patients (75.7%) had maximal troponin ng/L within 24 hours. Randomization to hs-report format did not alter the admission rate (hs-report: 57.7% versus std-report: 58.0% P =0.069). There was no difference in angiography (hs-report: 11.9% versus std-report: 10.9% P =0.479). The hs-reporting did not reduce 12-month death or new/recurrent acute coronary syndrome in the overall population (hs-report: 9.7% versus std-report: 7.2% [hazard ratio, 0.83 (0.57–1.22) P =0.362]). However, among those with troponin levels ng/L, a modest reduction in the primary end point was observed (hs-report: 2.6% versus std-report: 4.4%, [hazard ratio, 0.58 95% confidence interval, 0.34–0.1.00 P =0.050). High-sensitivity troponin reporting alone is associated with only modest changes in practice. Clinical effectiveness in the adoption of high-sensitivity troponin may require close coupling with protocols that guide interpretation and care. URL: www.ANZCTR.org.au . Unique identifier: ACTRN12611000879965.
Publisher: Elsevier BV
Date: 10-2015
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 17-11-2015
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.IJCARD.2013.12.026
Abstract: This study assessed the burden and determinants of cardiovascular and metabolic risk in a community s le of high risk Indigenous Australians. Indigenous Australians are over-represented in the most disadvantaged strata of Australian society. The role of psychosocial and socioeconomic factors in patterning cardiometabolic disease in this population is unclear. The Heart of the Heart Study was a cross sectional study of 436 Aboriginal adults from remote, urban and peri-urban communities around Alice Springs (Northern Territory, Australia). Participants underwent detailed assessments of socio-demographic, psychosocial, cardiovascular and metabolic status. In iduals with depression were twice as likely to have cardiovascular disease (OR 2.03 1.07-3.88 p<0.05). Chronic kidney disease (39.7%, 37.2% and 18.2%) and diabetes (28.4%, 34.0% and 19.2%) were more common in peri-urban and remote compared to urban communities. Cardiovascular disease did not vary across locations (p=0.069), but coronary artery disease did (p=0.035 for trend). Unemployed in iduals were more likely to have cardiovascular disease (OR 2.32 1.33-4.06 p<0.001). Socioeconomic gradients in coronary artery disease, all cardiovascular disease and diabetes, as measured by income, operated differentially across locations (p for location/socioeconomic status interactions 0.002 0.01 and 0.04 respectively). Participants had high rates of pre-existing cardiovascular disease, diabetes and chronic kidney disease. Cardiovascular risk in these communities was associated with psychosocial factors and socioeconomic indicators. However, gradients operated differentially across location. These data provide a strong foundation for better understanding key drivers of increased levels of cardiovascular and other common forms of non-communicable disease in Indigenous people.
Publisher: Elsevier BV
Date: 09-2006
DOI: 10.1016/J.JACC.2006.04.092
Abstract: This study sought to compare the influence of changes in systolic interval on the negative inotropic effects of metoprolol, sotalol, and verapamil in patients with ischemic heart disease. The long-term symptomatic and prognostic effects of antiarrhythmic agents are not easily predicted on the basis of acute hemodynamic actions at rest, but may be unmasked during tachycardia. However, this has not been studied extensively in vivo. The force-interval relationship of the intact human left ventricle was examined before and 10 min after intravenous bolus administration of the negatively inotropic agents metoprolol, sotalol, or verapamil in patients undergoing diagnostic cardiac catheterization. All three drugs similarly reduced maximal rate of increase of left ventricular pressures (LV+dP/dt(max)) by approximately 10%, but ersely modified the force-interval relationship. The parameter c (the reduction in LV+dP/dt(max) of a fixed premature stimulus on mechanical restitution) was significantly reduced by metoprolol (by 9+/- 4%, p < 0.05), was increased by verapamil (by 6 +/- 2%, p < 0.05), and was not significantly changed by sotalol. Similarly, metoprolol had a minimal effect on the extent of frequency potentiation, whereas sotalol and verapamil attenuated frequency potentiation (the relative response to 10 s of rapid pacing was 1.19 +/- 0.58-fold, 0.07 +/- 0.35-fold, and 0.03 +/- 0.17-fold of the baseline response after 10 min of metoprolol, sotalol, or verapamil, respectively). These results show that the negative inotropic effects of metoprolol are attenuated and those of verapamil are accentuated at short cycle lengths sotalol is intermediate between the two. These properties may contribute to the relative safety of these agents in patients prone to hemodynamic deterioration during sustained tachycardia.
Publisher: Elsevier BV
Date: 11-2011
DOI: 10.1016/J.AMJCARD.2011.06.047
Abstract: Takotsubo cardiomyopathy (TTC) is characterized by reversible left ventricular (LV) systolic dysfunction independent of fixed coronary disease or coronary spastic pathogenesis. A number of investigators have documented marked elevation of natriuretic peptide levels at presentation in such patients. We sought to determine the pattern, extent, and determinants of the release of N-terminal pro-B type natriuretic peptide/B type natriuretic peptide (NT-proBNP/BNP) in patients with TTC. We evaluated NT-proBNP/BNP release acutely and during the first 3 months in 56 patients with TTC (96% women, mean age 69 ± 11 years). The peak plasma NT-proBNP levels were compared to the pulmonary capillary wedge pressure and measures of regional and global LV systolic dysfunction (systolic wall stress, wall motion score index, and LV ejection fraction) as potential determinants of NT-proBNP/BNP release. In patients with TTC, the plasma concentrations of NT-proBNP (median 4,382 pg/ml, interquartile range 2,440 to 9,019) and BNP (median 617 pg/ml, interquartile range 426 to 1,026) were substantially elevated and increased significantly during the first 24 hours after the onset of symptoms (p = 0.001), with slow and incomplete resolution during the 3 months thereafter. The peak NT-proBNP levels exhibited no significant correlation with either pulmonary capillary wedge pressure or systolic wall stress. However, the peak NT-proBNP level correlated significantly with the simultaneous plasma normetanephrine concentrations (r = 0.53, p = 0.001) and the extent of impairment of LV systolic function, as measured by the wall motion score index (r = 0.37, p = 0.008) and LV ejection fraction (r = -0.39, p = 0.008). In conclusion, TTC is associated with marked and persistent elevation of NT-proBNP/BNP levels, which correlated with both the extent of catecholamine increase and the severity of LV systolic dysfunction.
Publisher: Oxford University Press (OUP)
Date: 08-2002
DOI: 10.1016/S0008-6363(02)00401-7
Abstract: In dilated cardiomyopathy and in athlete's heart, progressive LV dilatation is accompanied by rightward displacement of the diastolic LV pressure-volume relation. In dilated cardiomyopathy, an increase in diastolic LV stiffness can limit this rightward displacement thereby decreasing LV systolic performance. Because nitric oxide (NO) reduces diastolic LV stiffness, the present study relates diastolic LV stiffness and LV systolic performance to intensity of endomyocardial NO synthase (NOS) gene expression in dilated cardiomyopathy and in athlete's heart. Microtip LV pressures, conductance-catheter or angiographic LV volumes, echocardiographic LV wall thicknesses and snap-frozen LV endomyocardial biopsies were obtained in 33 patients with dilated cardiomyopathy and in three professional cyclists referred for sustained ventricular tachycardia. Intensity of LV endomyocardial inducible NOS (NOS2) and constitutive NOS (NOS3) gene expression was determined using quantitative reverse transcription-polymerase chain reaction (RT-PCR). Dilated cardiomyopathy patients with higher diastolic LV stiffness-modulus and lower LV stroke work had lower NOS2 and NOS3 gene expression at any given level of LV end-diastolic wall stress. The intensity of NOS2 and NOS3 gene expression observed in athlete's heart was similar to dilated cardiomyopathy with low LV diastolic stiffness-modulus and preserved LV stroke work. High LV endomyocardial NOS gene expression is observed in athlete's heart and in dilated cardiomyopathy with low diastolic LV stiffness and preserved LV stroke work. Favourable effects on the hemodynamic phenotype of high LV endomyocardial NOS gene expression could result from a NO-mediated decrease in diastolic LV stiffness and a concomitant rise in LV preload reserve.
Publisher: Oxford University Press (OUP)
Date: 02-2002
Publisher: BMJ
Date: 11-08-2012
DOI: 10.1136/HEARTJNL-2012-302229
Abstract: Limited strategies have been developed to evaluate and address the alarming discrepancy in early mortality between Indigenous and non-Indigenous populations. To assess heart failure (HF), HF risk factors and document cardiac characteristics in an Australian Aboriginal population. Adults were enrolled across six Aboriginal communities in Central Australia. They undertook comprehensive cardiovascular assessments, including echocardiography, to determine HF status, asymptomatic ventricular dysfunction and underlying risk factor profile. Of 436 participants (mean age 44±14 years 64% women) enrolled, 5.3% (95% CI 3.2% to 7.5%) were diagnosed with HF, only 35% of whom had a pre-existing HF diagnosis. Asymptomatic left ventricular dysfunction (ALVD) was seen in 13% (95% CI 9.4% to 15.7%) of the population. Estimates of HF risk factor prevalence were as follows: body mass index (BMI) ≥30 kg/m(2) 42%, hypertension 41%, diabetes mellitus 40%, coronary artery disease (CAD) 7% and history of acute rheumatic fever or rheumatic heart disease 7%. In logistic regression analysis (after adjustment for age and gender), HF was associated with CAD (OR=9.6, p<0.001), diabetes (OR=5.4, p=0.002), hypertension (OR=4.8, p=0.006), BMI ≥30 kg/m(2) (OR=2.9, p=0.02), acute rheumatic fever or rheumatic heart disease (OR=5.6, p=0.001) and B-type natriuretic peptide (OR=1.02, p<0.001). The burden of HF, ALVD and risk factors in this population was extremely high. This study highlights potentially modifiable targets on which to focus resources and screening strategies to prevent HF in this high-risk Indigenous population.
Start Date: 2012
End Date: 2013
Funder: National Health and Medical Research Council
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End Date: 2018
Funder: National Health and Medical Research Council
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End Date: 2021
Funder: National Health and Medical Research Council
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End Date: 2016
Funder: National Health and Medical Research Council
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