ORCID Profile
0000-0002-5643-5076
Current Organisations
University of New South Wales
,
University of Melbourne
,
Western Sydney Local Health District
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Publisher: Elsevier BV
Date: 05-2023
Publisher: Elsevier BV
Date: 10-2012
Publisher: JMIR Publications Inc.
Date: 11-11-2021
Abstract: trial fibrillation (AF) is common in older people and increases the risk of stroke. The feasibility and effectiveness of the implementation of a patient-led AF screening program for older people are unknown. his study aims to examine the feasibility and effectiveness of an AF screening program comprising patient-led monitoring of single-lead electrocardiograms (ECGs) with clinician-coordinated central monitoring to diagnose AF among community-dwelling people aged ≥75 years in Australia. his is a nationwide randomized controlled implementation trial conducted via the internet and remotely among 200 community-dwelling adults aged ≥75 years with no known AF. Randomization will be performed in a 1:1 allocation ratio for the intervention versus control. Intervention group participants will be enrolled in the monitoring program at randomization. They will receive a handheld single-lead ECG device and training on the self-recording of ECGs on weekdays and submit their ECGs via their smartphones. The control group participants will receive usual care from their general practitioners for the initial 6 months and then commence the 6-month monitoring program. The ECGs will be reviewed centrally by trained personnel. Participants and their general practitioners will be notified of AF and other clinically significant ECG abnormalities. his study will establish the feasibility and effectiveness of implementing the intervention in this patient population. The primary clinical outcome is the AF detection rate, and the primary feasibility outcome is the patient satisfaction score. Other outcomes include appropriate use of anticoagulant therapy, participant recruitment rate, program engagement (eg, frequency of ECG transmission), agreement in ECG interpretation between the device automatic algorithm and clinicians, the proportion of participants who complete the trial and number of dropouts, and the impact of frailty on feasibility and outcomes. We will conduct a qualitative evaluation to examine the barriers to and acceptability and enablers of implementation. Ethics approval was obtained from the human research ethics committee at the University of Sydney (project number 2020/680). The results will be disseminated via conventional scientific forums, including peer-reviewed publications and presentations at national and international conferences. y incorporating an integrated health care approach involving patient empowerment, centralized clinician-coordinated ECG monitoring, and facilitation of primary care and specialist services, it is possible to diagnose and treat AF early to reduce stroke risk. This study will provide new information on how to implement AF screening using digital health technology practicably and feasibly for older and frail populations residing in the community. ustralian New Zealand Clinical Trials Registry ACTRN12621000184875 www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=380877 ERR1-10.2196/34778
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2014
DOI: 10.1161/CIRCEP.114.001461
Abstract: Catheter ablation for ventricular tachycardia (VT) from structural heart disease has a significant risk of recurrence, but the optimal duration for in-hospital monitoring is not defined. This study assesses the timing, correlates, and prognostic significance of early VT recurrence after ablation. Of 370 patients (313 men aged 63.0±13.2 years) who underwent a first radiofrequency ablation for sustained monomorphic VT associated with structural heart disease from 2008 to 2012, sustained VT recurred in 81 patients (22%) within 7 days. In multivariable analysis, early recurrence was associated with New York Heart Association classification ≥III (odds ratio [OR] 1.90, 95% confidence interval [CI] 1.03–3.48 P =0.04), dilated cardiomyopathy (OR 1.93, 95% CI 1.03–3.57 P =0.04), prevalence of VT storm before the procedure (OR 2.62, 95% CI 1.48–4.65 P =0.001), a greater number of induced VTs (OR 1.24, 95% CI 1.07–1.45 P =0.006), and acute failure or no final induction test (OR 1.88, 95% CI 1.03–3.40 P =0.04). During a median of 2.5 (1.2, 4.0) years of follow-up, early VT recurrence was an independent correlates of mortality (hazard ratio 2.59, 95% CI 1.52–4.34 P =0.0005). Patients who have early recurrences of VT after ablation are a high risk group who may be identifiable from their clinical profile. Further study is warranted to define the optimal treatment strategies for this patient group.
Publisher: Wiley
Date: 13-01-2017
DOI: 10.1111/JCE.13127
Abstract: Women are underrepresented in clinical studies on catheter ablation (CA) for ventricular tachycardia (VT). The role of gender as a predictor for VT recurrence after CA is unclear and complication rates have not been compared in a large cohort. We analyzed data of consecutive patients undergoing CA for sustained monomorphic VT at our center between 2005 and 2015. A total of 948 patients underwent 1314 ablation procedures: 114 patients without structural heart disease (SHD) (48% female), 486 with coronary artery disease (CAD) (9% female), 301 with nonischemic cardiomyopathy (NICM) (22% female), and 46 with arrhythmogenic right ventricular cardiomyopathy (ARVC) (17% female). Women with CAD and NICM were younger than men at first ablation (63 years vs. 68 years, P = 0.05 resp. 53 years vs. 59 years, P = 0.026) with no other significant differences in baseline characteristics. Age, LVEF, NYHA-class, and VT-recurrence but not gender were independently associated with increased mortality in CAD and NICM. Mortality rates in patients with no SHD and ARVC are low in men (0%, 2.6%) and women (1.8%, 0%). Although heart disease tends to present later in women, our data do not suggest that women are referred later than men. Women with CAD or NICM and VT present for ablation at younger age with disease severity comparable to men. VT ablation in women can be accomplished with success- and complication rates comparable to male patients in both those with and without SHD.
Publisher: Wiley
Date: 11-12-2021
DOI: 10.1111/JCE.15309
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.JACEP.2017.12.008
Abstract: This was a meta-analysis of published studies to examine the impact of early referral on outcomes after catheter ablation for ventricular tachycardia (VT) in patients with structural heart disease. Patients are frequently referred for VT ablation after failure of antiarrhythmic drugs to control VT. Some studies have suggested that early referral might confer better outcomes. An electronic search was performed using major databases. The primary outcomes were long-term VT recurrence and total mortality. Secondary outcomes were acute procedural success and acute complications. Three studies were included with a total of 980 patients (mean age 64 ± 12 years, 71% males). Mean follow-up was 29 ± 27 months. Early referral for VT ablation was associated with decreased VT recurrence and acute complications compared with late referral (relative risk: 0.69 [95% confidence interval: 0.58 to 0.82], p < 0.0001 and relative risk: 0.50 [95% confidence interval: 0.27 to 0.93], p = 0.03, respectively). There was no significant difference between early and late referral for total mortality and acute success. Late referral for VT ablation was associated with worse outcomes (VT recurrence and acute complications) in patients with structural heart disease, which suggests that early referral for VT ablation might be a reasonable consideration in this patient population.
Publisher: Elsevier
Date: 2018
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 28-07-2009
Publisher: Wiley
Date: 26-09-2021
DOI: 10.1002/JOA3.12639
Abstract: We reviewed the different approaches used for central vein access during insertion of cardiac implantable electronic devices. The benefits and hazards of each approach (cephalic vein cutdown, axillary vein cannulation using venography and ultrasound) are discussed. Each approach has its advantages and hazards that need to be considered for the in idual patient and balanced against the skills of the operator. The benefits of ultrasound guided venous access in reducing radiation exposure to the patient and implanter, avoiding the need for angiographic contrast and in minimizing the risk of pneumothorax and inadvertent arterial puncture are highlighted. Trainees should be taught each approach to deal with patient variability. Ultrasound guidance should be considered as a mainstream option for most patients.
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.HRTHM.2016.07.001
Abstract: Long-term outcomes after ventricular tachycardia (VT) ablation are sparsely described. The purpose of this study was to describe long-term prognosis after VT ablation in patients with no structural heart disease (no SHD), ischemic cardiomyopathy (ICM), and nonischemic cardiomyopathy (NICM). Consecutive patients (N = 695: no SHD, 98 ICM, 358 NICM, 239) ablated for sustained VT were followed for a median of 6 years. Acute procedural parameters (complete success [noninducibility of any VT]) and outcomes after multiple procedures were reported. Compared with patients with no SHD or NICM, patients with ICM were the oldest, were more likely to be men, lowest left ventricular ejection fraction, highest drug failures, VT storms, and number of inducible VTs. Complete procedure success was highest in patients with no SHD than in patients with ICM and those with NICM (79%, 56%, 60%, respectively P < .001). At 6 years, ventricular arrhythmia (VA)-free survival was highest in patients with no SHD (77%) than in patients with ICM (54%) and those with NICM (38%) (P < .001), and overall survival was lowest in patients with ICM (48%), followed by patients with NICM (74%) and patients with no SHD (100%) (P < .001). Age, left ventricular ejection fraction, presence of SHD, acute procedural success (noninducibility of any VT), major complications, need for nonradiofrequency ablation modalities, and VA recurrence were independently associated with all-cause mortality. Long-term follow-up after VT ablation shows excellent prognosis in the absence of SHD, highest VA recurrence, and transplantation in patients with NICM and highest mortality in patients with ICM. The extremely low mortality for those without SHD suggests that VT in this population is rarely an initial presentation of a myopathic process.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2019
DOI: 10.1161/CIRCEP.119.007392
Abstract: Idiopathic ventricular arrhythmias commonly originate from the right ventricular and left ventricular outflow tracts (OTs). Advances in real-time imaging have refined our understanding of the intimate anatomic structures implicated in the genesis of OT arrhythmias, making catheter ablation for arrhythmias beyond the right ventricular OT a feasible option for cure—indeed ablation is now a class I indication in recent guidelines. The surface 12-lead ECG is routinely used to localize the anatomic site of origin before catheter ablation. However, the intimate and complex anatomy of the OT limits predictive value ECG criteria alone for localization for these arrhythmias. Multiple ECG algorithms have been developed to assist preprocedural localization, and hence predict safety and efficacy for catheter ablation of OT ventricular arrhythmias. This review will summarize all of the published 12-lead ECG algorithms used to guide localization of OT ventricular arrhythmias.
Publisher: Springer Science and Business Media LLC
Date: 09-02-2023
DOI: 10.1007/S10840-023-01483-2
Abstract: Ventricular tachycardia (VT) is associated with significantly increased morbidity and mortality. Catheter ablation (CA) in line with an implantable cardioverter-defibrillator (ICD) is highly effective in VT management however, it is unknown if CA should be considered as first-line therapy. The aim of this study is to verify the efficacy and safety of CA as first-line therapy for the first VT presentation (as adjunctive to ICD insertion), compared to initial ICD insertion and anti-arrhythmic drug (AAD) therapy. Data from patients with the first presentation for VT from January 2017 to January 2021 was reviewed. Patients were classified as “ablation first” vs “ICD first” groups and compared the clinical outcomes between groups. One hundred and eighty-four consecutive patients presented with VT 34 underwent CA as first-line therapy prior to ICD insertion, and 150 had ICD insertion/AAD therapy as first‐line. During the median follow-up of 625 days, patients who underwent CA as first-line therapy had significantly higher ventricular arrhythmia (VA)-free survival (91% vs 59%, log-rank P = 0.002) and composite of VA recurrence, cardiovascular hospitalization, transplant, and death (84% vs 54%, log-rank P = 0.01) compared to those who did not undergo CA. Multivariate analysis revealed that first-line CA was the only protective predictor of VA recurrence (hazard ratio (HR) 0.20, P = 0.003). There were 3 (9%) peri-procedural complications with no peri-procedural deaths. Real-world data supports the efficacy and safety of CA as first-line therapy at the time of the first VT hospitalization, compared to the initial ICD implant and AAD therapy.
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.HRTHM.2015.09.016
Abstract: Arrhythmias in cardiac amyloidosis (CA) result in significant comorbidity and mortality but have not been well characterized. The purpose of this study was to define intracardiac conduction, atrial arrhythmia substrate, and ablation outcomes in a group of advanced CA patients referred for electrophysiologic study. Electrophysiologic study with or without catheter ablation was performed in 18 CA patients. Findings and catheter ablation outcomes were compared to age- and gender-matched non-CA patients undergoing catheter ablation of persistent atrial fibrillation (AF). Supraventricular tachycardias were seen in all 18 CA patients (1 AV nodal reentrant tachycardia, 17 persistent atrial tachycardia [AT]/AF). The HV interval was prolonged (>55 ms) in all CA patients, including 6 with normal QRS duration (≤100 ms). Thirteen supraventricular tachycardia ablations were performed in 11 patients. Of these, 7 underwent left atrial (LA) mapping and ablation for persistent AT/AF. Compared to non-CA age-matched comparator AF patients, CA patients had more extensive areas of low-voltage areas LA (63% ± 22% vs 34% ± 22%, P = .009) and a greater number of inducible ATs (3.3 ± 1.9 ATs vs 0.2 ± 0.4 ATs, P <.001). The recurrence rate for AT/AF 1 year after ablation was greater in CA patients (83% vs 25%), and the hazard ratio for postablation AT/AF recurrence in CA patients was 5.4 (95% confidence interval 1.9-35.5, P = .007). In this group of patients with advanced CA and atrial arrhythmias, there was extensive conduction system disease and LA endocardial voltage abnormality. Catheter ablation persistent AT/AF in advanced CA was associated with a high recurrence rate and appears to have a limited role in control of these arrhythmias.
Publisher: Elsevier BV
Date: 03-2017
Publisher: Oxford University Press (OUP)
Date: 14-03-2020
Publisher: Wiley
Date: 29-11-2016
DOI: 10.1111/JCE.13117
Abstract: Catheter ablation can be lifesaving in ventricular tachycardia (VT) storm, but the underlying substrate in patients with storm is not well characterized. We sought to compare the clinical factors, substrate, and outcomes differences in patients with sustained monomorphic VT who present for catheter ablation with VT storm versus those with a nonstorm presentation. Consecutive ischemic (ICM n = 554) or nonischemic cardiomyopathy patients (NICM n = 369) with a storm versus nonstorm presentation were studied (ICM storm 186 NICM storm 101). In ICM, storm compared with nonstorm patients had significantly lower left ventricular (LV) ejection fraction (EF), greater number of antiarrhythmic drug (AAD) failures, slower VTs, greater number of scarred LV segments, higher incidence of anterior, septal, and apical endocardial LV scar (all P < 0.05). However, outcomes in follow-up were similar (12-month ventricular arrhythmia [VA]-free survival: 51% vs. 52%, P = 0.6 survival free of death/transplant 75% vs. 87%, P = 0.7). In addition to the above differences, NICM storm patients were also older however, the extent and distribution of scar was similar except for a higher incidence of lateral endocardial scar in storm patients (P = 0.05). VA-free survival (36% vs. 47%, P = 0.004) and survival free of death/transplant, however, were worse in NICM storm than nonstorm patients (72% vs. 88%, P = 0.001). NICM storm patients had worse VA-free survival than ICM storm patients. There are differences in clinical factors and scar patterns in patients undergoing VT ablation who present with VT storm versus those with a nonstorm presentation. Clinical outcomes are worse in NICM storm patients.
Publisher: Elsevier BV
Date: 09-2009
DOI: 10.1016/J.AMJCARD.2009.05.007
Abstract: Q waves can develop early in infarction and indicate infarct progression better than symptom duration. ST resolution (STR) is a predictor of reperfusion success. Our aim was to assess the prognostic impact of Q waves on presentation and STR after primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction. The combined end point was of mortality and adverse cardiovascular events (MACE death, repeat myocardial infarction, or heart failure). Q waves on presentation (Q wave, n = 332 no Q wave, n = 337) was associated with significantly less mean STR, greater incidence of akinetic, dyskinetic, or aneurysmal regional wall motion, lower left ventricular ejection fraction, and worse in-hospital and 1-year MACEs (1 year 24% vs 8.2%, p <0.001). In addition, Q waves on presentation compared to no Q waves were associated with worse 1-year MACE regardless of infarct presentation in or =70%). Q waves on presentation and inadequate STR (<70%), but not symptom duration, were independent predictors of MACE by multivariable analysis (adjusted hazard ratios of 2.7 and 2.4 for Q waves and STR, respectively). Compared to group A (no Q waves on presentation with STR), patients in group B (no Q waves with inadequate STR), group C (Q waves with STR), and group D (Q waves with inadequate STR) had hazard ratios of 3.0, 3.6, and 7.7, respectively (p <0.05) for the occurrence of MACE. In conclusion, assessment of Q-wave status on presentation and STR immediately after PPCI provides a simple and early clinical predictor of outcomes in ST-elevation myocardial infarction.
Publisher: Springer Science and Business Media LLC
Date: 22-04-2022
DOI: 10.1007/S00392-022-02020-3
Abstract: Patients with Brugada syndrome (BrS) may experience recurrent ventricular arrhythmias (VAs). Catheter ablation is becoming an emerging paradigm for treatment of BrS. To assess the efficacy and safety of catheter ablation in BrS in an updated systematic review. We comprehensively searched the databases of Pubmed/Medline, EMBASE, and Cochrane Central Register of Controlled Trials from inception to 11th of August 2021. Fifty-six studies involving 388 patients were included. A substrate-based strategy was used in 338 cases (87%), and a strategy of targeting premature ventricular complex (PVCs)/ventricular tachycardias (VTs) that triggered ventricular fibrillation (VF) in 47 cases (12%), with combined abnormal electrogram and PVC/VT ablation in 3 cases (1%). Sodium channel blocker was frequently used to augment the arrhythmogenic substrate in 309/388 cases (80%), which included a variety of agents, of which ajmaline was most commonly used. After ablation procedure, the pooled incidence of non-inducibility of VA was 87.1% (95% confidence interval [CI], 73.4–94.3 I 2 = 51%), and acute resolution of type I ECG was seen in 74.5% (95% CI [52.3–88.6] I 2 = 75%). Over a weighted mean follow up of 28 months, 7.6% (95% CI [2.1–24] I 2 = 67%) had recurrence of type I ECG either spontaneously or with drug challenge and 17.6% (95% CI [10.2–28.6] I 2 = 60%) had recurrence of VA. Catheter ablation appears to be an efficacious strategy for elimination of arrhythmias or substrate associated with BrS. Further study is needed to identify which patients stand to benefit, and optimal provocation protocol for identifying ablation targets.
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.HLC.2017.05.114
Abstract: Atrial fibrillation (AF) is the most common arrhythmia in humans and is known to be associated with an increased risk of stroke, dementia, heart failure and mortality. Non-pharmacological therapy with ablation using either surgical or percutaneous techniques is recommended in drug refractory AF. Early attempts to devise procedures to ablate AF and restore sinus rhythm culminated with the Cox-Maze procedure, the first truly successful procedure. Since then, ablation surgery has been conducted predominately as a concomitant procedure. The Cox Maze procedure is complex and technically demanding and has, therefore, been extensively modified with new techniques for creating the linear ablation lines, new lesion sets, minimally invasive surgical techniques and most recently hybrid surgical-catheter ablation techniques. Surgical ablation techniques result in a marked reduction in atrial fibrillation when compared to conventional therapy with only a small increase in procedural risk. However, further research is required to more accurately quantify those benefits and to determine the optimal lesion sets, specific to the underlying arrhythmia mechanism and the optimal energy sources for ablation.
Publisher: The Korean Society of Cardiology
Date: 2020
Publisher: Wiley
Date: 16-06-2015
DOI: 10.1111/JCE.12707
Abstract: Recurrent atrial flutter following cavotricuspid isthmus (CTI) ablation remains a significant problem. The prevalence of low contact force (CF) during CTI ablation using standard tools is unknown. Our aim was to characterize the prevalence of low CF applications when experienced operators performed CTI ablation using "traditional" markers of contact blinded to CF measurements. Average CF (grams, g) and force-time integral (FTI) was analyzed in 458 lesions in 17 patients undergoing CTI ablation. The isthmus was ided into the annular, mid and caval segments for region-specific analysis. Despite "good" contact using traditional markers, there was significant variability in CF within each isthmus segment (e.g., annular CTI 1-57 g). A high proportion of lesions had a CF <10 g (40%). Lowest CF was the annular (median 9 g), followed by the mid (12 g) and the caval CTI (18 g, P < 0.001). Sites of acute CTI re-connection had a lower average CF and FTI than nonreconnected sites (P < 0.05). Each 1 g increase in CF was associated with a 16% reduction in risk of recovered CTI conduction (95% confidence interval: 4-27%, P = 0.01). Use of surrogate markers of "good contact" during ablation by experienced operators in the absence of real-time CF sensing resulted in nearly half of all lesions being delivered with low CF with marked region-specific variability in CF. Low CF was implicated in longer time to achieve conduction block and increased risk of acute reconnection. These findings underscore the importance of real-time CF measurements for optimizing ablation of typical atrial flutter.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2021
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 16-08-2022
Abstract: Cardiac implantable electronic devices (CIEDs) include pacemakers, cardioverter defibrillators, and resynchronization therapy. This study aimed to assess CIED implantation and outcomes by sex and indication. This was a retrospective cohort study of adults with cardiovascular hospitalizations in New South Wales, Australia (2008 to 2018). CIED implantation in patients with arrhythmia, cardiomyopathy, and syncope were examined. Subcategories (complete heart block, atrial fibrillation/atrial flutter, ventricular tachycardia/ventricular fibrillation/cardiac arrest, sick sinus syndrome, and ischemic and nonischemic cardiomyopathy) were investigated. Primary outcome was implantation of CIEDs in men versus women adjusted for age and comorbidities. Secondary outcomes were trends over time, time to implant, length of stay, emergency status, and 30‐day survival. Of 1 291 258 patients with cardiovascular admissions, 287 563 had arrhythmia, cardiomyopathy, or syncope and 29 080 (2.3%) received a CIED (22 472 pacemakers, 6808 defibrillators, 3207 resynchronization therapy). Women with arrhythmia, cardiomyopathy, or syncope were less likely to have pacemakers (adjusted odds ratio [aOR], 0.78 [95% CI, 0.76–0.80]), defibrillators (aOR, 0.4, [95% CI, 0.40–0.45]) and resynchronization therapy (aOR, 0.66 [95% CI, 0.61–0.71]). Differences persisted across subcategories, including fewer pacemakers in complete heart block (aOR, 0.89 [95% CI, 0.80–0.98]) and syncope (aOR, 0.70 [95% CI, 0.63–0.79]) fewer defibrillators in ventricular tachycardia/ventricular fibrillation/cardiac arrest (aOR, 0.69 [95% CI, 0.61–0.77]) and less resynchronization therapy in cardiomyopathy (aOR, 0.62 [95% CI, 0.51–0.75]). Men and women receiving devices had higher 30‐day survival compared with those who did not receive a device, and 30‐day survival was similar between men and women receiving devices. Lower CIED implantation was seen in women versus men, across nearly all indications, including complete heart block and ventricular tachycardia/ventricular fibrillation/cardiac arrest. The underuse of cardiac devices among women may arguably reflect a sex bias and requires further research.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2015
DOI: 10.1161/CIRCEP.115.002818
Abstract: Arrhythmia origin in close proximity to the phrenic nerve (PN) can hinder successful catheter ablation. We describe our approach with epicardial PN displacement in such instances. PN displacement via percutaneous pericardial access was attempted in 13 patients (age 49±16 years, 9 females) with either atrial tachycardia (6 patients) or atrial fibrillation triggered from a superior vena cava focus (1 patient) adjacent to the right PN or epicardial ventricular tachycardia origin adjacent to the left PN (6 patients). An epicardially placed steerable sheath/4 mm-catheter combination (5 patients) or a vascular or an esophageal balloon (8 patients) was ultimately successful. Balloon placement was often difficult requiring manipulation via a steerable sheath. In 2 ventricular tachycardia cases, absence of PN capture was achieved only once the balloon was directly over the ablation catheter. In 3 atrial tachycardia patients, PN displacement was not possible with a balloon however, a steerable sheath/catheter combination was ultimately successful. PN displacement allowed acute abolishment of all targeted arrhythmias. No PN injury occurred acutely or in follow up. Two patients developed acute complications (pleuro-pericardial fistula 1 and pericardial bleeding 1). Survival free of target arrhythmia was achieved in all atrial tachycardia patients however, a nontargeted ventricular tachycardia recurred in 1 patient at a median of 13 months’ follow up. Arrhythmias originating in close proximity to the PN can be targeted successfully with PN displacement with an epicardially placed steerable sheath/catheter combination, or balloon, but this strategy can be difficult to implement. Better tools for phrenic nerve protection are desirable.
Publisher: MediaSphere Medical LLC
Date: 04-2021
Publisher: Wiley
Date: 31-08-2010
DOI: 10.1111/J.1540-8167.2010.01885.X
Abstract: Pulmonary veins play an important role in triggering atrial fibrillation (AF). Pulmonary vein isolation (PVI) is an effective treatment for patients with paroxysmal AF. However, the late AF recurrence rate in long-term follow-up of circumferential PV antral isolation (PVAI) is not well documented. We sought to determine the time to recurrence of arrhythmia after PVAI, and long-term rates of sinus rhythm after circumferential PVAI. One hundred consecutive patients with a mean age of 54 ± 10 years, with paroxysmal AF who underwent PVAI procedure were analyzed. Isolation of pulmonary veins was based on an electrophysiological and anatomical approach, with a nonfluoroscopic navigation mapping system to guide antral PVI. Ablation endpoint was vein isolation confirmed with a circular mapping catheter at first and subsequent procedures. Clinical, ECG, and Holter follow-up was undertaken every 3 months in the first year postablation, every 6 months thereafter, with additional prolonged monitoring if symptoms were reported. Time to arrhythmia recurrence, and representing arrhythmias, were documented. Isolation of all 4 veins was successful in 97% patients with 3.9 ± 0.3 veins isolated atient. Follow-up after the last RF procedure was at a mean of 39 ± 10 months (range 21-66 months). After a single procedure, sinus rhythm was maintained at long-term follow-up in 49% patients without use of antiarrhythmic drugs (AADs). After repeat procedure, sinus rhythm was maintained in 57% patients without the use of AADs, and in 82% patients including patients with AADs. A total of 18 of 100 patients had 2 procedures and 4 of 100 patients had 3 procedures for recurrent AF/AT. Most (86%) AF/AT recurrences occurred ≤ 1 year after the first procedure. Mean time to recurrence was 6 ± 10 months. Kaplan-Meier analysis on antiarrhythmics showed AF free rate of 87% at 1 year and 80% at 4 years. There were no major complications. PVAI is an effective strategy for the prevention of AF in the majority of patients with PAF. Maintenance of SR requires repeat procedure or continuation of AADs in a significant proportion of patients. After maintenance of sinus rhythm 1-year post-PVAI, a minority of patients will subsequently develop late recurrence of AF.
Publisher: Elsevier BV
Date: 11-2011
DOI: 10.1016/J.HRTHM.2011.05.021
Abstract: Complex fractionated atrial electrograms (CFAEs) and regions of high dominant frequency (DF) both may identify sites critical to the maintenance of atrial fibrillation (AF). CFAEs may be defined by either (1) complex multicomponent electrograms (EGMs) and/or continuous electrical activity (multicomponent/continuous EGM) or (2) discrete high-frequency EGMs. The purpose of this study was to test if the 2 definitions of CFAE identify the same arrhythmia substrate and determine the relationship of CFAE to areas of high DF. High-density epicardial mapping of the posterior left atrium was performed in 10 patients with long-lasting persistent AF. Point-by-point analysis was performed to determine the spatial distribution and correlation of CFAE defined as either (1) multicomponent/continuous-EGMs or (2) AF cycle length <120 ms. Additionally, spatial analysis was performed to determine the relationship of high DF sites to CFAE sites defined by each of the 2 definitions. The percentage of sites deemed CFAE varied markedly between patients and was different depending on the definition of CFAE adopted. There was a poor correlation between CFAE defined by multicomponent/continuous EGMs and AF cycle length <120 ms (r = 0.18). High DF sites were arranged in clusters evenly distributed throughout the posterior left atrium, with 4.2 ± 1.0 high DF clusters per patient. Although there was poor point-by-point correlation between multicomponent/continuous EGMs and high DF sites (r = 0.107), spatial analysis revealed that 96% of multicomponent/continuous EGMs were found adjacent to and partially surrounding (≤5 mm) high DF sites. There is poor anatomic overlap between CFAE defined by multicomponent/continuous EGMs and CFAE defined by AF cycle length <120 ms. Multicomponent/continuous EGMs are found adjacent to and surrounding sites of high DF. Further studies are needed to determine the mechanisms responsible for these different signals.
Publisher: Elsevier BV
Date: 04-2011
DOI: 10.1016/J.HRTHM.2010.12.017
Abstract: Omega-3 polyunsaturated fatty acids in fish oils may have antifibrillatory effects. Their mechanism of action in humans is poorly understood. The purpose of this study was to investigate the effects of chronic fish oil supplementation on human atrial electrophysiology (EP). Two groups of patients without clinical AF or structural heart disease and fish intake ≤1/week were prospectively recruited into a control group (n = 30) and a fish oil group (n = 31). The latter were prescribed 6 g/day of fish oil for ≥1 month before an EP study. The following were compared at time of EP study: serum omega-3 levels right atrial and coronary sinus effective refractory periods (ERPs) interatrial, intra-atrial, left atrial, and coronary sinus conduction at baseline and the maximal conduction delay with the shortest propagated extrastimulus and inducibility of AF (10 inductions atient). The following significant differences were noted favoring the fish oil group at time of EP: (1) twofold higher total omega-3 levels (P < .001) (2) lengthening of ERPs by 8%-14% at all measured sites and pacing cycle lengths (P < .05) (3) no effect on baseline interatrial, intra-atrial, left atrial, and coronary sinus conduction but a significant attenuation of maximal conduction delay (P < .05) (4) less inducible AF (AF ≥30 seconds: 24.2% vs. 7.9% P < .001) (5) shorter mean duration of induced AF (P = .003) and (6) prolongation of induced AF cycle length (P < .001). Chronic fish oil supplementation in humans prolongs atrial refractoriness and reduces vulnerability to inducible AF. These EP changes may explain the antifibrillatory effect of chronic fish oil ingestion.
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.HRTHM.2019.05.026
Abstract: Catheter ablation (CA) is an established therapeutic modality for ventricular tachycardia (VT). We compared the clinical outcomes of CA for VT vs medical therapy from all previously performed randomized controlled trials (RCTs) and compared these to contemporary observational studies. A comprehensive database search through to August 2018 identified 8 eligible studies enrolling 797 patients. In RCTs, VT recurrence and electrical VT storm were significantly reduced in the CA group vs medical therapy group (relative risk [RR] 0.78, 95% confidence interval [CI] 0.64-0.95, P = .01 RR 0.70, 95% CI 0.51-0.94, P = .02, respectively) at a mean follow-up of 22 months. All-cause or cardiac-specific mortality did not differ significantly (RR 0.92, 95% CI 0.67-1.27, P = .62 RR 0.82, 95% CI 0.54-1.26, P = .37, respectively). In 4 observational studies, including 3065 patients with a mean follow-up of 18.2 months, VT recurrence and mortality were significantly lower as compared to the RCTs (28.6% vs 39%, P < .001 13.2% vs 18%, P = .01, respectively) despite greater incidence of electrical storm (33.2% vs 17%, P < .001), higher prevalence of nonischemic substrate (46.4% vs 3.6%, P < .001), and lower rate of implanted ICDs (68% vs 94.7%, P < .001). Meta-analysis of RCT data shows that CA is superior to medical therapy for predominantly postinfarct, scar-related VT in terms of VT recurrence and electrical VT storm, with no reduction in mortality. Real-world observational studies also demonstrate significant reduction in VT recurrence and mortality, despite a sicker cohort, demonstrating replicability and translation of RCT data in the real world.
Publisher: Wiley
Date: 20-01-2020
DOI: 10.1111/JCE.14351
Abstract: Minimal data exist on the Advisor HD Grid (HDG) catheter and the Precision electroanatomic mapping (EAM) system for ventricular arrhythmia (VA) procedures. Using the HDG catheter, the EAM uses the high-density (HD) wave mapping and best duplicate software to compare the maximum peak-to-peak bipolar voltages within a small zone independent of wavefront direction and catheter orientation. This study aimed to summarize the procedural experience for VAs using the HDG catheter. Clinical and procedural characteristics of VA ablation procedures were retrospectively reviewed that used the HDG catheter and the Precision EAM over a 12-month period. A total of 22 patients, 18 with sustained ventricular tachycardia and 4 with premature ventricular contractions were included. Clinically indicated left and/or right ventricular (LV, RV, respectively), and aortic maps were created. LV substrate maps (n = 13) used a median 1700 points (interquartile range [IQR] HD wave mapping using the novel HDG catheter integrated with the Precision EAM is safe and feasible in VA procedures in the LV, RV, and aorta. Mapping times are consistent with other multielectrode mapping catheters.
Publisher: Wiley
Date: 11-10-2014
DOI: 10.1111/JCE.12293
Abstract: Electrogram (EGM) characteristics are used to infer catheter-tissue contact. We examined if (a) atrial EGM characteristics predicted CF and (b) compared the value of CF versus other surrogates for predicting lesion efficacy. Twelve paroxysmal AF patients underwent pulmonary vein isolation using radiofrequency (RF) ablation facilitated by a novel CF-sensing catheter. Operators were blinded to CF. EGM litude, width, and morphology were measured pre- and post-RF. At each RF site, average CF, force-time integral (FTI), impedance fall, time to impedance plateau, maximum power, catheter tip temperature, and total energy delivered were recorded. An effective lesion was defined based on previously validated EGM criteria for transmural lesions. There was a moderate correlation between CF and EGM litude (r = 0.19) and EGM width (r = -0.22). Pre-RF, EGM litude, and width had modest to poor discriminative capacity for identifying preablation CF (e.g., EGM litude identified CF>20 g with sensitivity and specificity of 67% and 60%, respectively). Preablation CF, FTI, and total energy delivered during RF were the only independent predictors of effective lesion formation. Neither pre-RF EGM litude/width nor power, temperature, and impedance changes during RF predicted effective lesion formation. An average CF >16 g or FTI >404 g*s had excellent sensitivity and specificity (>80%) for identifying an effective lesion. EGM characteristics do not reliably predict either CF before the onset of RF, nor do they predict the likelihood of an effective lesion. CF parameters were superior to power, temperature, and impedance changes during RF in predicting lesion efficacy.
Publisher: Elsevier BV
Date: 11-2017
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.CCEP.2016.10.004
Abstract: Mapping during ventricular tachycardia (VT) aims to elucidate mechanism, describe myocardial propagation, and identify the origin and critical regions of VT that can be targeted for ablation, most commonly with radiofrequency ablation. Most VTs in structural heart disease are due to macro-reentry in and around scar. A combination of mapping techniques, including mapping to identify the arrhythmia substrate, activation sequence mapping, pace-mapping, and entrainment mapping, may be used to identify putative ablation targets. This review describes the principles of entrainment mapping as it pertains to catheter ablation of scar-related VT.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2015
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.HRTHM.2017.08.002
Abstract: Atrioventricular nodal reentry tachycardia (AVNRT) is common in adults and often involves reentry through ≥2 atrioventricular nodal-atrial connections. Although AVNRT can be a trigger for atrial fibrillation (AF), we have observed new-onset AVNRT after AF ablation procedures. The purpose of this study was to determine whether ablation involving the septum or proximal coronary sinus (CS) during AF ablation may create a substrate favorable for AVNRT. Cases of ablation for persistent AF who required a repeat ablation procedure between 2009 and 2016 were reviewed for diagnosis of AVNRT. Nine patients were identified the mean age was 54 years, 7 (78%) were men, 2 with prior Cox-MAZE procedures, 5 had radiofrequency ablation (RFA) for AF, and 2 patients had both RFA and Cox-MAZE procedure. None of the patients with prior RFA had dual atrioventricular node physiology at baseline. All patients had evidence of atrial fibrosis in the septum or proximal CS, and 6 had undergone ablation either at the septum or the CS ostium/body, and the other 3 had received inferior mitral lines at a surgical MAZE procedure. All had typical AVNRT inducible that was abolished by slow pathway ablation, but 5 required ablation in the roof of the CS or on the mitral valve annulus. Ablation involving the septum or proximal CS may create a substrate favorable for AVNRT. These findings are consistent with the theory that the posteroseptal left atrium and its connections to the CS are critical for some forms of AVNRT.
Publisher: Springer Science and Business Media LLC
Date: 30-03-2022
DOI: 10.1007/S10840-022-01188-Y
Abstract: Women are under-represented in many key studies and trials examining outcomes of catheter ablation (CA) for ventricular arrhythmias (VA). We compared characteristics between men and women undergoing their first catheter ablation for VA at a single centre over 10 years. The clinical, procedural characteristics and outcomes of 287 consecutive patients (male = 182, female = 105), undergoing their first CA at our centre over 10 years were compared according to sex and underlying heart disease. In the ablation population, women were younger, had fewer co-morbidities, were less likely to have ischemic cardiomyopathy (ICM) and VA storm and were more likely to have idiopathic VA and premature ventricular complexes as the indication for ablation (P < 0.05 for all). Amongst idiopathic and non-ischemic cardiomyopathy (NICM) subgroups, baseline characteristics were similar amongst ICM, women were younger and had higher numbers of drug failure pre-ablation (P = 0.05). Women were similar to men in all procedural characteristics, acute procedural success and complications, regardless of underlying heart disease. At median follow-up of 666 days, VA-free survival, overall mortality and survival free of death or transplant were comparable in both groups. Sex was not a predictor of these outcomes, after accounting for clinical and procedural characteristics. Women represented 36% of the real-world population at our centre referred for CA of VA. There are key differences in clinical features of women versus men referred for VA ablation. Despite these differences, VA ablation in women can be accomplished with similar success and complication rates to men, regardless of underlying heart disease.
Publisher: Oxford University Press (OUP)
Date: 05-2006
Abstract: Paroxysmal atrial fibrillation (AF) is usually preceded by a premature atrial complex (PAC). We hypothesized that patients with a high frequency of atrial ectopic activity after restoration of sinus rhythm following direct current cardioversion would be more likely to experience recurrence of AF. Forty-four patients with documented persistent AF were studied. A 24 h Holter recording was performed from the day of external direct current cardioversion. Patients were reviewed at 1 week, 1 month, and 6 months. After 6 months, 59% of patients had experienced a recurrence of AF. Neither the frequency of PACs nor the frequency or duration of supraventricular tachycardia (SVT) episodes predicted AF recurrence (P=0.60, 0.30, and 0.42, respectively). There was a trend towards maximum rate of SVT predicting recurrence of AF (P=0.08). Frequency of supraventricular ectopy or the number and length of SVT runs in the 24 h after restoration of sinus rhythm are not strong predictors of recurrence of AF after electrical cardioversion. A larger study would be required to detect a small predictive effect.
Publisher: Informa UK Limited
Date: 05-0007
DOI: 10.2147/RRCC.S56549
Publisher: Elsevier BV
Date: 02-2010
DOI: 10.1016/J.AMJCARD.2009.10.017
Abstract: ST segment resolution (STR) predicts epicardial and microvascular reperfusion after primary percutaneous coronary intervention (PPCI) or thrombolysis for ST-elevation myocardial infarction. Immediate restoration of epicardial coronary flow, with improved microvascular perfusion, is much more likely with PPCI. However, the predictive value of immediate STR compared to 90 minutes after PPCI remains unknown. In 622 consecutive patients with ST-elevation myocardial infarction (mean age 59 +/- 13 years), 217 had complete STR immediately after PPCI (group A), 188 had complete STR only at 90 minutes (group B), and 217 had incomplete STR at either point (group C). The primary end point was mortality and adverse cardiovascular events ([MACE] death, nonfatal repeat myocardial infarction, and heart failure). Group A had a greater left ventricular ejection fraction (53%, 47%, and 46%, p <0.001) and lower all-cause mortality (1.8%, 3.2%, and 6%, p = 0.07), lower heart failure (1.8%, 4.3%, and 7.8%, p <0.001), and MACE (5.1%, 9.6%, and 16.1%, p = 0.001) at 30 days compared to groups B and C, respectively. The rate of MACE at 1 year was 7.6%, 17.1%, and 20.2% in groups A, B, and C, respectively (p <0.001). Immediate STR independently predicted MACE (adjusted hazard ratio 0.36, 95% confidence interval 0.21 to 0.61, p = 0.001, group A vs C), and STR at 90 minutes did not. In conclusion, STR analysis performed immediately after PPCI provided superior differentiation for adverse cardiovascular events compared to STR at 90 minutes. Immediate STR should be the contemporary goal of reperfusion with PPCI.
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.IJCARD.2017.01.131
Abstract: Atrial fibrillation (AF) and cavo-tricuspid isthmus (CTI) dependent atrial flutter (AFL) are two separate entities that coexist in a significant percentage of patients. We sought to investigate whether AF inducibility during CTI AFL ablation predicted the occurrence of AF at follow up after AFL ablation. Univariate and multivariate analyses were performed. A total of 154 patients (male: 72%, age: 61±13) with AFL and without history of AF were included. All patients underwent successful CTI dependent AFL ablation demonstrated by bidirectional block. During ablation, AF was seen or induced in 28 (18%) patients. After a mean follow up of 34±24months a total of 50 patients (32%) were noted with clinically manifest AF. From the patients who had inducible AF during AFL ablation, 50% developed post-procedural AF. From those in whom AF could not be induced, only 29% were documented with AF after ablation. Univariate and multivariate analyses revealed that only age and AF inducibility during AFL ablation were predictors of AF. Univariate analysis (age p=0.038 and inducible AF p=0.032 with odds ratio of 1.030 [95% CI (1.002-1.059)] and 2.500 [95% CI (1.084-5.765)], respectively) and multivariate analyses (age p=0.011 and inducible AF p=0.016 with adjusted odds ratio of 1.043 [95% CI (1.010-1.077)] and 3.293 [95% CI (1.250-8.676)], respectively). AF inducibility in patients undergoing CTI AFL without history of AF is a strong predictor of AF occurrence in the future. Appropriate cardiology follow-up must be encouraged in this high-risk population as stroke prevention strategies can be appropriately introduced in a timely matter especially in patients with elevated CHA
Publisher: Elsevier BV
Date: 06-2015
Publisher: Elsevier BV
Date: 09-0012
Publisher: Wiley
Date: 17-12-2012
DOI: 10.1111/JCE.12049
Abstract: The objective was to characterize the electrocardiographic and electrophysiological features of focal atrial tachycardia (FAT) originating from the left septum (LS). FAT is recognized to occur at predefined anatomic locations rather than randomly throughout the atria. We describe the ECG and EP features of ATs originating from the LS as an important site for apparent perinodal tachycardias. Nine patients presenting with LS FAT from a consecutive series of 384 underwent EP/RFA for symptomatic FAT. The mean age was 56 ± 12 years 7 female with symptoms for 36 ± 28 months. P wave morphology (PWM) was negative ositive in lead V1 and across the precordial leads and negative or negative ositive in inferior leads in all patients. Tachycardia was incessant in 6 out of 9 patients with a mean tachycardia cycle length 421 ± 56 milliseconds. His A was ahead of P wave in all patients (mean -15 ± 5 milliseconds) and earlier than CS proximal (mean 4 ± 9 milliseconds). Successful acute focal ablation achieved at a mean of 31 ± 12 milliseconds ahead of P wave with no recurrences at a mean follow-up of 30 ± 28 months. Although the left septum is an uncommon site for focal AT an awareness of this location for harboring foci is particularly important when mapping apparently right-sided septal tachycardias.
Publisher: Wiley
Date: 27-06-2016
DOI: 10.1111/JCE.13016
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2015
DOI: 10.1161/CIRCEP.115.003202
Abstract: Radiofrequency ablation (RFA) from the epicardial space for ventricular arrhythmias is limited or impossible in some cases. Reasons for epicardial ablation failure and the effect on outcome have not been systematically analyzed. We assessed reasons for epicardial RFA failure relative to the anatomic target area and the type of heart disease and assessed the effect of failed epicardial RFA on outcome after ablation procedures for ventricular arrhythmias in a large single-center cohort. Epicardial access was attempted during 309 ablation procedures in 277 patients and was achieved in 291 procedures (94%). Unlimited ablation in an identified target region could be performed in 181 cases (59%), limited ablation was possible in 22 cases (7%), and epicardial ablation was deemed not feasible in 88 cases (28%). Reasons for failed or limited ablation were unsuccessful epicardial access (6%), failure to identify an epicardial target (15%), proximity to a coronary artery (13%), proximity to the phrenic nerve (6%), and complications ( %). Epicardial RFA was impeded in the majority of cases targeting the left ventricular summit region. Acute complications occurred in 9%. The risk for acute ablation failure was 8.3× higher (4.5–15.0 P .001) after no or limited epicardial RFA compared with unlimited RFA, and patients with unlimited epicardial RFA had better recurrence-free survival rates ( P .001). Epicardial RFA for ventricular arrhythmias is often limited even when pericardial access is successful. Variability of success is dependent on the target area, and the presence of factors limiting ablation is associated with worse outcomes.
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.HLC.2022.08.001
Abstract: Cardiac arrhythmias are associated with significant morbidity, mortality and economic burden on the health care system. Detection and surveillance of cardiac arrhythmias using medical grade non-invasive methods (electrocardiogram, Holter monitoring) is the accepted standard of care. Whilst their accuracy is excellent, significant limitations remain in terms of accessibility, ease of use, cost, and a suboptimal diagnostic yield (up to ∼50%) which is critically dependent on the duration of monitoring. Contemporary wearable and handheld devices that utilise photoplethysmography and the electrocardiogram present a novel opportunity for remote screening and diagnosis of arrhythmias. They have significant advantages in terms of accessibility and availability with the potential of enhancing the diagnostic yield of episodic arrhythmias. However, there is limited data on the accuracy and diagnostic utility of these devices and their role in therapeutic decision making in clinical practice remains unclear. Evidence is mounting that they may be useful in screening for atrial fibrillation, and anecdotally, for the diagnosis of other brady and tachyarrhythmias. Recently, there has been an explosion of patient uptake of such devices for self-monitoring of arrhythmias. Frequently, the clinician is presented such information for review and comment, which may influence clinical decisions about treatment. Further studies are needed before incorporation of such technologies in routine clinical practice, given the lack of systematic data on their accuracy and utility. Moreover, challenges with regulation of quality standards and privacy remain. This state-of-the-art review summarises the role of novel ambulatory, commercially available, heart rhythm monitors in the diagnosis and management of cardiac arrhythmias and their expanding role in the diagnostic and therapeutic paradigm in cardiology.
Publisher: MDPI AG
Date: 19-10-2018
DOI: 10.3390/JCDD5040050
Abstract: Bradycardia arising from pacemaker dysfunction can be debilitating and life threatening. Electronic pacemakers serve as effective treatment options for pacemaker dysfunction. They however present their own limitations and complications. This has motivated research into discovering more effective and innovative ways to treat pacemaker dysfunction. Gene therapy is being explored for its potential to treat various cardiac conditions including cardiac arrhythmias. Gene transfer vectors with increasing transduction efficiency and biosafety have been developed and trialed for cardiovascular disease treatment. With an improved understanding of the molecular mechanisms driving pacemaker development, several gene therapy targets have been identified to generate the phenotypic changes required to correct pacemaker dysfunction. This review will discuss the gene therapy vectors in use today along with methods for their delivery. Furthermore, it will evaluate several gene therapy strategies attempting to restore biological pacing, having the potential to emerge as viable therapies for pacemaker dysfunction.
Publisher: Wiley
Date: 03-2022
DOI: 10.1111/IMJ.15716
Publisher: Elsevier BV
Date: 09-2021
DOI: 10.1016/J.HRTHM.2021.04.032
Abstract: Cardiac sarcoidosis (CS) with right ventricular (RV) involvement can mimic arrhythmogenic right ventricular cardiomyopathy (ARVC). Histopathological differences may result in disease-specific RV activation patterns detectable on the 12-lead electrocardiogram. Dominant subepicardial scar in ARVC leads to delayed activation of areas with reduced voltages, translating into terminal activation delay and occasionally (epsilon) waves with a small litude. Conversely, patchy transmural RV scar in CS may lead to conduction block and therefore late activated areas with preserved voltages reflected as preserved R' waves. The purpose of this study was to evaluate the distinct terminal activation patterns in precordial leads V Thirteen patients with CS affecting the RV and 23 patients with gene-positive ARVC referred for ventricular tachycardia ablation were retrospectively included in a multicenter approach. A non-ventricular-paced 12-lead surface electrocardiogram was analyzed for the presence and the surface area of the R' wave (any positive deflection from baseline after an S wave) in leads V An R' wave in leads V An easily applicable algorithm including PR prolongation and the surface area of the maximum R' wave in leads V
Publisher: Wiley
Date: 31-03-2022
DOI: 10.1111/JCE.15463
Abstract: Radiofrequency (RF) ablation has been the most widely employed energy source for catheter ablation to date. However, most of conventional RF ablation energy dissipates into the bloodstream before reaching the target tissue. Technology that conveys RF energy exclusively toward target tissue may potentially improve the quality, safety, and outcome of the RF ablation procedures. RF ablation using a novel insulated‐tip catheter (Sirona Medical Technologies [SMT]) may refine RF ablation in the future to minimize the risk of iatrogenic complications. Although it is still unclear whether the results of the SMT catheter can be translated to a human beating heart, the data for SMT catheter of this study are very promising.
Publisher: Springer Science and Business Media LLC
Date: 03-09-2020
Publisher: Elsevier
Date: 2014
Publisher: Wiley
Date: 13-05-2011
DOI: 10.1111/J.1540-8159.2011.03092.X
Abstract: Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common mechanism of supraventricular tachycardia. Slow pathway (SP) ablation is the first-line treatment approach with a high acute success rate and a low risk of inadvertent complete atrioventricular (AV) block. However, there is still some uncertainty as to the most appropriate procedural endpoints and the impact of these on risk of recurrence. We report the acute and long-term results of SP ablation in a large single-center consecutive series and analyze predictors of acute success and late recurrence. The study included 1,448 consecutive procedures in 1,419 patients with AVNRT (mean age 49 ± 17 years, 66% women) who underwent SP ablation using a combined electrophysiologic and anatomic approach. Univariate and multivariate analysis was performed for potential predictors of acute success and late recurrence. Acute success was achieved in 98.1%. Transient (first, second, or third degree) AV block occurred during the procedure in 20 (1.41%) patients. One patient (0.07%) had persistent first-degree and transient second-degree AV block after ablation and underwent pacemaker implant at day 21. Of the 1,391 patients with successful ablation, 22 patients (1.5%) developed AVNRT recurrence during a follow-up period of 63 ± 38 months. The only independent predictor of reduced procedural success was the presence of atypical AVNRT (hazard ratio 3.1, P = 0.04). Independent predictors of AVNRT recurrence were age <20 years and female gender (hazard ratios 14.1 and 3.7, respectively). No significant difference in the incidence of late recurrence was observed in patients with or without residual slow-pathway conduction, or according to use of isoproterenol testing or general anesthesia. However, patients with a single echo with recurrence had a significantly larger echo window (median 85 ms) than those without (median 30 ms, P = 0.01). This study demonstrates in a large consecutive single-center series that SP ablation using radiofrequency energy is a highly effective procedure with an extremely low risk of inadvertent AV block and a low recurrence rate. We found that single-AV nodal echo beats represented a procedural endpoint that did not predict AVNRT recurrence but that a large echo window is associated with recurrence. Recurrence rates in this series were higher in young women, possibly reflecting a more conservative approach to ablation in this age group.
Publisher: Elsevier BV
Date: 09-2014
DOI: 10.1016/J.HRTHM.2014.06.012
Abstract: The impact of diffuse atrial fibrosis detected by T1 mapping on the clinical outcome after atrial fibrillation (AF) ablation is unknown. This study aimed to validate and assess the impact of post-contrast cardiac magnetic resonance (CMR) imaging atrial T1 mapping on the clinical outcome after catheter ablation for AF. CMR imaging was performed in 3 groups by using a clinical 1.5-T scanner: controls, patients with paroxysmal AF, and patients with persistent AF. A T1 mapping sequence was used to calculate the post-contrast T1 relaxation time (T1 time) at the interatrial septum as an index of diffuse atrial fibrosis. A subset underwent left atrial endocardial bipolar voltage mapping for electrophysiologic correlation. After AF ablation, patients underwent clinical review and 7-day Holter monitoring at 6-month intervals. One hundred thirty-two patients (20 controls, 71 (63%) patients with paroxysmal AF, and 41 (37%) patients with persistent AF) underwent CMR imaging. Post-contrast atrial T1 time was significantly shorter in AF groups (237 ± 42 ms) than in controls (280 ± 37 ms) (P < .001). Post-contrast atrial T1 time correlated with mean septal voltage (R2 = .48 P < .001) and global left atrial voltage (R(2) = .41 P 230 ms was associated with freedom from AF in 85% relative to 62% with a post-contrast atrial T1 time of <230 ms (P = .01). Post-contrast atrial T1 time as measured using CMR imaging provides an index of atrial fibrosis that correlates with tissue voltage, presence of AF, and clinical outcomes after catheter ablation.
Publisher: Elsevier BV
Date: 04-2022
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2016
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2019
Publisher: Elsevier BV
Date: 02-2023
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.PBIOMOLBIO.2012.07.011
Abstract: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in human beating hearts. AF initiates self-perpetuating changes in electrophysiology, structure and functional properties of the atria, a phenomenon known as atrial remodeling. Hypertension, heart failure, valvular heart disease, sleep apnea, congenital heart disease are well known risk factors for AF that contribute to the development of atrial substrate. There is some evidence that reversal of atrial remodeling is possible with correction of antecedent conditions, however the timing of the intervention or upstream therapy may be critical. This review will describe the pathophysiology of atrial remodeling as it pertains to AF. We will describe components of remodeling including changes in atrial refractoriness, conduction and atrial structure, in addition to autonomic changes and anatomic factors that predispose to remodeling. We will discuss our current understanding of the electrophysiological changes that contribute to AF persistence. We will describe nature of atrial and pulmonary vein remodeling in the context of different forms of AF, with and without predisposing risk factors. We will describe the nature of remodeling over time following therapeutic interventions such as AF ablation in order to show that it does not necessarily improve and may worsen.
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.HRTHM.2013.06.019
Abstract: Atrial fibrillation (AF) and systolic heart failure (HF) frequently coexist. Restoration of sinus rhythm by catheter ablation may result in a variable improvement in left ventricular (LV) function. Late-gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging identifies irreversible structural change and may predict incomplete recovery of LV function. To prospectively select patients with AF and symptomatic HF but without LV LGE and report the impact of AF ablation on LV function. Patients with AF and symptomatic HF (LV ejection fraction <50%) resistant to at least 1 antiarrhythmic drug and prior electrical cardioversion underwent contrast-enhanced CMR. LGE-negative patients underwent pulmonary vein isolation and left atrial roof line with continued antiarrhythmic medications until follow-up CMR 6 months postablation. Sixteen patients (aged 52 ± 11 years mean AF duration 37 ± 39 months left atrial size 44 ± 13 mL/m(2)) underwent AF ablation. At 6 months, 15 of the 16 patients maintained sinus rhythm and underwent CMR. LV ejection fraction increased from 40% ± 10% at baseline to 60% ± 6% (P < .001) and LV end-systolic volume index decreased from 52 ± 12 to 36 ± 9 mL/m(2) (P < .001). Left atrial size decreased from 44 ± 13 to 36 ± 11 mL/m(2) (P < .01). In patients with AF and LV dysfunction in the absence of LGE on CMR, ventricular function normalizes following the restoration of sinus rhythm. CMR may assist in the selection of patients with combined AF and systolic HF most likely to benefit from catheter ablation.
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.HRTHM.2014.09.060
Abstract: Athlete ECG screening has been recommended by several international sporting bodies however, a number of controversies remain regarding the accuracy of ECG screening. An important component that has not been assessed is the reproducibility of ECG interpretation. The purpose of this study was to assess the variability of ECG interpretation among experienced physicians when screening a large number of athletes. A sports cardiologist, a sports medicine physician, and an electrophysiologist analyzed 440 consecutive screening ECGs from asymptomatic athletes and were asked to classify the ECGs according to the 2010 European Society of Cardiology criteria as normal (or demonstrating training related ECG changes) or abnormal. When an abnormal ECG was identified, they were asked to outline what follow-up investigations they would recommend. The reported prevalence of abnormal ECGs ranged from 13.4% to 17.5%. Agreement on which ECGs were abnormal ranged from poor (κ = 0.297) to moderate (κ = 0.543) between observers. Suggested follow-up investigations were varied, and follow-up costs ranged from an additional A$30-A$129 per screening episode. Neither of the 2 subjects (0.45%) in the cohort with significant pathology diagnosed as a result of screening were identified correctly by all 3 physicians. Even when experienced physicians interpret athletes' ECGs according to current standards, there is significant interobserver variability that results in false-positive and false-negative results, thus reducing the effectiveness and increasing the social and economic cost of screening.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.HLC.2018.10.007
Abstract: Non-ischaemic cardiomyopathy (NICM) encompasses a heterogeneous group of disorders that includes genetic, idiopathic, post viral and inflammatory cardiomyopathies. NICM is associated with an increased risk of ventricular arrhythmias (VAs), namely in the form of ventricular tachycardia (VT). Although implanted cardiac defibrillators (ICD) may prevent sudden death from VA, NICM patients may suffer from recurrent symptoms and ICD therapies, and anti-arrhythmic drug side effects. Catheter ablation is highly efficacious in NICM, however poses unique challenges when compared to post myocardial infarction substrates. NICM substrates are fundamentally different in scar location, extent, and transmurality which results in variable electrophysiologic properties and less apparent ablation targets during sinus rhythm, compared to ischaemic cardiomyopathy. NICM substrates can be intramural and/or epicardial, posing challenges to accessibility, which likely accounts for the observed higher rates of arrhythmia recurrence following ablation. Substrate location is influenced by the underlying aetiology (inflammatory, genetic), and can be gleaned from a combination of unique 12-lead electrocardiogram VT patterns, distribution of late gadolinium enhancement on cardiac magnetic resonance imaging, and electroanatomic voltage mapping. With the high proportion of intramural substrate in NICM, novel techniques have become increasingly common in recent years, including sequential, simultaneous or bipolar ablation on opposite myocardial surfaces to achieve greater lesion depth use of half normal saline for irrigation use of a novel retractable needle within an endocardial catheter and transcoronary/venous ethanol ablation to target more inaccessible regions. Epicardial approaches have also been improved in recent years, with advents such as the needle-in-needle technique to reduce the risk of pericardial bleeding and phrenic nerve displacement, and hybrid surgical approaches to facilitate epicardial access in the presence of adhesions. Non-invasive cardiac radiation holds promise for the future. This state-of-the-art review will summarise the incidence, mechanism, multimodal assessment and catheter ablation-based management of VA in NICM.
Publisher: Springer Science and Business Media LLC
Date: 17-11-2023
DOI: 10.1007/S10840-021-01088-7
Abstract: The purpose of this study was to compare the differences of arrhythmogenic substrate using high-density mapping in ventricular tachycardia (VT) patients with ischemic (ICM) vs non-ischemic cardiomyopathy (NICM). Data from patients presenting for VT ablation from December 2016 to December 2020 at Westmead Hospital were reviewed. Sixty consecutive patients with structural heart disease (ICM 57%, NICM 43%, mean age 66 years) having catheter ablation of scar-related VT with pre-dominant left ventricular involvement were included. ICM was associated with larger proportion of dense scar area (bipolar 19 [12-29]% vs 6 [3-10]%, P < 0.001, unipolar 20 [12-32]% vs 11 [7-19]%, P = 0.01) compared with NICM. However, the scar ratio (unipolar dense scar [%]/bipolar dense scar [%]) was significantly higher in NICM patients (1.2 [0.8-1.7] vs 1.7 [1.3-2.3], P = 0.003). Larger scar area in ICM was paralleled by higher proportion of complex electrograms (6 [2-13] % vs 3 [1-5] %, P = 0.01), longer and wider voltage based conducting channels, higher incidence of late potential-based conducting channels, longer VT cycle-length (399 ± 80 ms vs 359 ± 68 ms, P = 0.04) and greater maximal stimulation-QRS interval among sites with good pace-map correlation (75 [51-99]ms vs 48 [31-73]ms, P = 0.02). Ventricular arrhythmia (VA) storm was more highly prevalent in ICM than NICM (50% vs 23%, P = 0.03). During the follow-up period, NICM had a significantly higher cumulative incidence for the VA recurrence than ICM (P = 0.03). High-density multi-electrode catheter mapping of left ventricular arrhythmogenic substrate of NICM tends to show smaller dense scar area and higher scar ratio, compared with ICM, suggestive the extent of epicardial/intramural substrate, with paucity of substrate targets for ablation, which results in the worse outcomes with ablation.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.HLC.2018.10.005
Abstract: Cardiac electrical storm (ES) is characterised by three or more discrete episodes of ventricular arrhythmia within 24hours, or incessant ventricular arrhythmia for more than 12hours. ES is a distinct medical emergency that portends a significant increase in mortality risk and often presages progressive heart failure. ES is also associated with psychological morbidity from multiple implanted cardioverter defibrillator (ICD) shocks and exponential health resource utilisation. Up to 30% of ICD recipients may experience storm in follow-up, with the risk higher in patients with a secondary prevention ICD indication. Storm recurs in a high proportion of patients after an initial episode, and multiple storm clusters may occur in follow-up. The mechanism of storm remains elusive but is likely influenced by a complex interplay of inciting triggers (e.g., ischaemia, electrolyte disturbances), with autonomic perturbations acting on a vulnerable structural and electrophysiologic substrate. Triggers can be identified only in a minority of patients. An emergent treatment approach is warranted, if possible with emergent transfer to a high-volume centre for ventricular arrhythmia management with a multi-modality approach including ICD reprogramming, sympathetic blockade (sedation, intubation, ventilation, beta blockers), and anti-arrhythmic drugs, and adjunctive intervention techniques, such as catheter ablation and neuraxial modulation (e.g., thoracic epidural anaesthesia, stellate ganglion block). Outcomes of catheter ablation of ES are excellent with resolution of storm in over 90% of patients at 1year with a low complication rate (∼2%). ES may occur in the absence of structural heart disease in the context of channelopathies, Brugada syndrome, early repolarisation and premature ventricular contraction-induced ventricular fibrillation. There are unique treatment approaches to these conditions that must be recognised. This state-of-the-art review will summarise the incidence, mechanism, and multi-modality treatment of ES in the contemporary era.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.HLC.2018.10.006
Abstract: Mapping of scar-related ventricular tachycardia (VT) in structural heart disease is fundamentally driven by identifying the critical isthmus of conduction that supports re-entry in and around myocardial scar. Mapping can be performed using activation and entrainment techniques during VT, or by substrate mapping performed in stable sinus or paced rhythm. Activation and entrainment mapping requires the patient to be in continuous VT, which may not be haemodynamically tolerated, or, if tolerated, may lead to adverse sequelae related to impaired end organ perfusion. Mechanical circulatory support (MCS) devices may facilitate haemodynamic stability and preserve end organ perfusion during sustained VT to permit mapping for long periods. Available options for haemodynamic support include an intra-aortic balloon pump (IABP), TandemHeart left atrial to femoral artery bypass system (CardiacAssist Inc., Pittsburgh, PA, USA), Impella left ventricle (LV) to aorta flow-assist system (Abiomed, Danvers, MA, USA), and extracorporeal membrane oxygenation (ECMO) the bypass and assist devices provide far better augmentation of cardiac output than IABP. MCS has potential key advantages including maintenance of vital organ perfusion, reduction of intra-cardiac filling pressures, reduction of LV volumes, wall stress, and myocardial consumption of oxygen, and improvement of coronary perfusion during prolonged periods of VT induction and/or mapping. Observational studies show MCS allows for longer duration of mapping, and increased likelihood of VT termination, without an increased risk of peri-procedural mortality or VT recurrence in follow-up, despite being used in a significantly sicker cohort of patients. However, MCS has increased risk of complications related to vascular access, bleeding, thromboembolic risk, mapping system interference, increase procedural complexity and increased cost. Acute haemodynamic decompensation occurs in ∼11% of patients undergoing VT ablation, and is associated with increased mortality. Prospectively identifying patients at risk of acute haemodynamic decompensation in the peri-procedural period may allow prophylactic MCS. Although observational studies of MCS in patients at high risk of haemodynamic decompensation are encouraging, its benefit needs to be proven in randomised trials. This review will summarise the indication for MCS, forms of MCS, procedural outcomes, complications and utility of MCS during VT ablation.
Publisher: Oxford University Press (OUP)
Date: 02-08-2023
Abstract: There are limited data on emergency catheter ablation (CA) for ventricular arrhythmia (VA) storm. We describe the feasibility and safety of performing emergency CA in an out-of-hours setting for VA storm refractory to medical therapy at 2 tertiary hospitals. Twenty-five consecutive patients underwent out-of-hours (5pm–8am [weekday] or Friday 5pm–Monday 8am [weekend]) CA for VA storm refractory to anti-arrhythmic drugs and sedation. Baseline and procedural characteristics along with outcomes were compared to 91 consecutive patients undergoing weekday daytime-hours (8am-5pm) CA for VA storm. More patients undergoing out-of-hours CA had a left ventricular ejection fraction ≤35% (68% vs. 42%, P = 0.022), chronic kidney disease (60% vs. 20%, P & 0.001), and presented following a resuscitated out-of-hospital cardiac arrest (56% vs. 5%, P & 0.001), compared to the daytime-hours group. During median follow-up (377 [interquartile range 138-826] days), both groups experienced similar survival free from recurrent VA and VA storm. Survival free from cardiac transplant and/or mortality was lower in the out-of-hours group (44% vs. 81%, P = 0.007), but out-of-hours CA was not independently associated with increased cardiac transplant and/or mortality (hazard ratio 1.34, 95% confidence interval 0.61-2.96, P = 0.47). Of the 11 patients in the out-of-hours group who survived follow-up, VA-free survival was 91% and VA storm-free survival was 100% at 1-year after CA. Out-of-hours CA may occasionally be required to control VA storm and can be safe and efficacious in this scenario. During follow-up, cardiac transplant and/or mortality is common but undergoing out-of-hours CA was not predictive of this composite endpoint.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2012
DOI: 10.1161/CIRCEP.112.972208
Abstract: Catheter–tissue contact is critical for effective lesion creation. We characterized the contact force (CF) at different anatomic sites during antral pulmonary vein (PV) isolation for atrial fibrillation. Two experienced operators performed PV isolation in 22 patients facilitated by a novel CF-sensing ablation catheter in a blinded fashion. Average CF and force-time integral data from 1602 lesions were analyzed. The left and right PV antra were ided into the following: carina, superior, inferior, anterior, and posterior quadrants for analysis. There was significant variability in CF within and between different PV quadrants ( P .05). Lowest CF of all left PV sites was at the carina and anterior quadrant, whereas highest CF was at the superior and inferior quadrants ( P .05). Lowest CF of all right PV sites was at the carina, whereas highest CF was at the anterior and inferior quadrants ( P .05). When comparing similar PV quadrants on the left versus right (eg, left carina versus right carina), CF was always higher in the right PVs ( P .05), except at the superior quadrant where CF was similar in the left and right PVs ( P =0.19). There was no specific pattern of anatomic distribution of excess CF ( P =0.39). Monitoring of catheter–tissue CF during PV isolation demonstrates significant variability in CF within and between different PV antral sites. Sites of lowest CF were the carina and anterior left PVs and the carina of the right PVs. This information may be important for improving ablation efficacy and clinical outcomes during PV isolation.
Publisher: Wiley
Date: 02-12-2022
DOI: 10.1111/IMJ.15976
Abstract: Ventricular arrhythmias (VAs) are a group of heart rhythm disorders that can be life‐threatening and cause significant morbidity. VA in the presence of structural heart disease (SHD) has distinct prognostic implications and requires a comprehensive and multifaceted approach for investigation and management. Early specialist referral should be considered for all patients with VA. Particular urgency is recommended in patients with syncope, nonsustained/sustained VA on Holter monitor and SHD on cardiac imaging because of the heightened risk of sudden cardiac death. Comprehensive phenotyping is recommended for most patients with VA, encompassing noninvasive cardiac functional testing, multimodality imaging and genetic testing in select circumstances. Management of idiopathic VA is guided heavily by symptom burden and the presence of ventricular systolic impairment. In SHD, guideline‐directed heart failure therapy and device implantation are critical considerations. Whilst commonly used and well‐established, antiarrhythmic drugs can be h ered by toxicity and failure of adequate arrhythmia control. Catheter ablation is increasingly being considered a feasible first‐line alternative to medical therapy, where outcomes are influenced by disease aetiology and scar burden in SHD. Catheter ablation is associated with reduced arrhythmia recurrence and burden and improved quality of life at follow‐up.
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.IJCARD.2017.01.070
Abstract: Adenosine may unmask dormant PV conduction and facilitate consolidation of PV isolation. We performed a meta-analysis to determine the impact of adenosine administration on clinical outcomes in patients undergoing PVI. References and electronic databases reporting AF ablation and adenosine following PVI were searched through to 22nd November 2015. The impact of adenosine on freedom from AF was assessed in twenty publications after radiofrequency ablation (RFA), and in four publications after cryoablation to achieve PVI. Relative risks were calculated and combined in a meta-analysis using random effects modeling. In patients undergoing RFA with adenosine challenge, there was a significant reduction in freedom from AF in patients with versus without adenosine induced reconnection (RR 0.86 95%CI 0.77-0.98 p=0.02) particularly if no further ablation was performed (RR 0.66 95%CI 0.50-0.87 p<0.01). There was no difference when comparing outcomes in studies of routine adenosine challenge vs no adenosine (RR 1.07 95%CI 0.93-1.22 p=0.36). There was a non-significant trend to an increase in freedom from AF in patients receiving routine adenosine challenge (RR 1.18 95%CI 0.99-1.42 p=0.07) in non-randomized studies using cryoablation. Adenosine induced PV reconnection following PVI is associated with a significant increase in AF recurrence, particularly if the reconnection sites are not targeted for ablation. The routine use of adenosine may be beneficial in AF ablation if given early post-PVI, at sufficient dose and reconnection is ablated.
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.JACEP.2016.05.013
Abstract: The aim of this study was to categorize arrhythmia mechanisms and to summarize ablation strategies in patients with persistent pulmonary vein isolation (PVI) at the time of redo procedures. Persistent PVI is more frequently seen in patients undergoing redo procedures for recurrent atrial arrhythmias after catheter ablation for atrial fibrillation (AF). Consecutive patients who underwent their first AF ablation procedures at Brigham and Women's Hospital were screened and included if they had persistent isolation of all pulmonary veins at the time of redo procedures. Of 300 consecutive patients undergoing first AF ablation procedures, redo procedures were performed in 63 (21%), and 26 patients (9%) had persistent PVI. Of those, 11 had recurred with AF and 15 with organized atrial tachycardia (AT). During the index procedure, linear ablation was performed in 46% of patients with recurrent AF and 93% with recurrent organized AT (p = 0.020). At the time of last follow-up, 2 of 10 patients (20%) in the AF group and 10 of 15 patients (67%) in AT group were in sinus rhythm, without class I or III antiarrhythmic drugs (p = 0.022). Patients with recurrence of atrial arrhythmia despite persistent PVI frequently present with organized AT. Linear ablation during the index procedure is associated with recurrence of organized AT. Recurrence rates after redo procedures were higher if patients had recurrent AF after the index procedure, and these patients often presented with AF again. Patients with recurrent AF despite persistent PVI may represent a population with lower success rates of catheter ablation.
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.JACEP.2019.09.013
Abstract: This study sought to summarize the procedural characteristics and outcomes of patients with structural heart disease (SHD) who have focal ventricular tachycardia (VT). Scar-mediated re-entry is the predominant mechanism of VT in SHD. Some SHD patients may have a focal VT mechanism that remains poorly described. An extended induction protocol incorporating programmed electrical stimulation, right ventricular burst pacing and isoprenaline was used to elucidate both re-entrant and focal VT mechanisms. Eighteen of 112 patients (16%) with SHD undergoing VT ablation over 2 years had a focal VT mechanism elucidated (mean age 66±13 years ejection fraction 46±14% nonischemic cardiomyopathy 10). Repetitive failure of termination with antitachycardia pacing (ATP) (69% of patients) or defibrillator shocks (56%) was a common feature of focal VTs. A median of 3 VTs per patient were inducible (28 focal VTs, 34 re-entrant VTs 53% of patients had both focal and re-entrant VT mechanism). Focal VTs more commonly originated from the right ventricle (RV) than the left ventricle (LV) (67% vs. 33%, respectively). In the RV, the RV outflow tract was the most common site (33% of all focal VTs), followed by the RV moderator band (22%), apical septal RV (6%), and lateral tricuspid annulus (6%). The lateral LV (non-Purkinje) was the most common LV focal VT site (16%), followed by the papillary muscles (17%). After median follow-up of 289 days, 78% of patients remained arrhythmia-free no patients had recurrence of focal VT at repeat procedure. In patients with recurrence, defibrillator therapies were significantly reduced from a median of 53 ATP episodes pre-ablation to 10 ATP episodes post-ablation. During follow-up, 2 patients (11%) underwent repeat VT ablation none had recurrence of focal VT. Focal VTs are common in patients with SHD and often coexist with re-entrant forms of VT. High failure rate of defibrillator therapies was a common feature of focal VT mechanisms. Uncovering and abolishing focal VT may further improve outcomes of catheter ablation in SHD.
Publisher: Springer Science and Business Media LLC
Date: 02-06-2022
DOI: 10.1007/S00392-022-02038-7
Abstract: The original article has been corrected.
Publisher: Elsevier BV
Date: 05-2011
DOI: 10.1016/J.HRTHM.2011.01.014
Abstract: Atrial mechanical stunning is a form of tachycardia-mediated atrial cardiomyopathy that manifests after reversion of persistent atrial arrhythmias to sinus rhythm. This study sought to examine whether chronic omega-3 polyunsaturated fatty acid supplementation with fish oils can reverse atrial mechanical stunning. Patients undergoing reversion of persistent atrial fibrillation (AF) or atrial flutter (AFL) to sinus rhythm were randomized to a control group (n = 26) or an omega-3 group (n = 23). The latter were prescribed 6 g/day of fish oil for ≥1 month prior to the procedure. Parameters of left atrial appendage function were compared immediately before and immediately after reversion. After fish oil intake for a mean of 70 days, the following were noted favoring the omega-3 group among both AF and AFL patients: (1) 2-fold higher serum omega-3 levels (P < .001), (2) less mean decrease in emptying velocity (e.g., AF: 8% vs. 32%, P = .02), (3) less mean decrease in appendage emptying fraction (e.g., AFL: 7% vs. 60%, P = .002), (4) lower incidence of new or increased spontaneous echocardiographic contrast (e.g., AF: 11% vs. 62.5%, P = .003), and (5) lower incidence of atrial mechanical stunning (e.g., AFL: 20% vs. 100%, P = .001). Omega-3 intake conferred protection against stunning in a multivariable analysis (odds ratio 0.18, P = .02). Chronic fish oil ingestion in humans attenuates atrial mechanical stunning after reversion of atrial arrhythmias to sinus rhythm. This suggests that fish oils may target or even reverse underlying cellular and/or structural remodeling that occurs in response to persistent atrial arrhythmias.
Publisher: Oxford University Press (OUP)
Date: 24-05-2017
Abstract: A commonly held notion is that patients with a family history of atrial fibrillation (AF) have worse atrial substrate and higher rates of arrhythmia recurrence following ablation. We sought to examine differences in atrial substrate and catheter ablation outcomes in patients with a 1st degree family member with paroxysmal or persistent AF (PeAF) compared to those without. A total of 256 consecutive patients undergoing their 1st ablation for AF (123 paroxysmal, 133 persistent) with >1 year follow up were included. The presence of one 1st-degree family relative was defined as a 'positive family history'. Clinical characteristics, electroanatomic map findings, ablation characteristics and outcomes were compared in patients with and without a positive family history of AF. Patients with paroxysmal fibrillation with a positive family history (n = 57 46%) had similar clinical characteristics and arrhythmia recurrence after catheter ablation as those without. Of those that recurred, patients with a positive family history were more likely to have progressed to PeAF (P = 0.05). Patients with PeAF with a positive family history (n = 75 56%) had similar clinical characteristics, electroanatomic mapping findings and ablation characteristics, but worse long term arrhythmia free survival (P = 0.04). The presence of a 1st-degree family member with AF does not impact the clinical outcomes of catheter ablation for paroxysmal AF. However, a positive family history is associated with worse arrhythmia free survival in patients with PeAF. This finding is not explained by differences in clinical characteristics, atrial substrate assessed by voltage maps or ablation characteristics.
Publisher: Wiley
Date: 02-2017
DOI: 10.1111/PACE.13013
Abstract: Patients on rivaroxaban have variable international normalized ratios (INRs) but it is uncertain if INR impacts procedural heparin requirement during left atrial ablation. We sought to examine the determinants of heparin dosing in this patient population. We reviewed consecutive patients who received rivaroxaban within 24 hours of left atrial ablation and compared them to patients on uninterrupted warfarin. The determinants of heparin requirement were evaluated using regression analysis. We then tested a weight-based heparin dose prospectively in rivaroxaban patients. There were 258 patients on rivaroxaban and 213 on warfarin. The mean INR was 1.4 in the rivaroxaban group and 2.3 in the warfarin group (P 350 seconds, rivaroxaban patients required significantly more heparin (166.9 vs. 78.3 units/kg, P 300 seconds. There were seven and three cases of pericardial effusion in rivaroxaban and warfarin patients, respectively (P = 0.41). The average volume drained in the rivaroxaban group was elevated (988.6 vs. 275.0 mL, P = 0.21). Body weight is the strongest predictor of procedural heparin requirement during left atrial ablation in patients on uninterrupted rivaroxaban, even in those with an elevated INR. A heparin dose of 120 units/kg achieves an ACT > 300 seconds in the majority of patients. In cases of pericardial effusion, bleeding may be prolonged.
Publisher: Elsevier BV
Date: 10-2020
Publisher: JMIR Publications Inc.
Date: 13-04-2022
DOI: 10.2196/34470
Abstract: Atrial fibrillation (AF) is an increasingly common chronic health condition for which integrated care that is multidisciplinary and patient-centric is recommended yet challenging to implement. The aim of Coordinating Health Care With Artificial Intelligence–Supported Technology in AF is to evaluate the feasibility and potential efficacy of a digital intervention (AF-Support) comprising preprogrammed automated telephone calls (artificial intelligence conversational technology), SMS text messages, and emails, as well as an educational website, to support patients with AF in self-managing their condition and coordinate primary and secondary care follow-up. Coordinating Health Care With Artificial Intelligence–Supported Technology in AF is a 6-month randomized controlled trial of adult patients with AF (n=385), who will be allocated in a ratio of 4:1 to AF-Support or usual care, with postintervention semistructured interviews. The primary outcome is AF-related quality of life, and the secondary outcomes include cardiovascular risk factors, outcomes, and health care use. The 4:1 allocation design enables a detailed examination of the feasibility, uptake, and process of the implementation of AF-Support. Participants with new or ongoing AF will be recruited from hospitals and specialist-led clinics in Sydney, New South Wales, Australia. AF-Support has been co-designed with clinicians, researchers, information technologists, and patients. Automated telephone calls will occur 7 times, with the first call triggered to commence 24 to 48 hours after enrollment. Calls follow a standard flow but are customized to vary depending on patients’ responses. Calls assess AF symptoms, and participants’ responses will trigger different system responses based on prespecified protocols, including the identification of red flags requiring escalation. Randomization will be performed electronically, and allocation concealment will be ensured. Because of the nature of this trial, only outcome assessors and data analysts will be blinded. For the primary outcome, groups will be compared using an analysis of covariance adjusted for corresponding baseline values. Randomized trial data analysis will be performed according to the intention-to-treat principle, and qualitative data will be thematically analyzed. Ethics approval was granted by the Western Sydney Local Health District Human Ethics Research Committee, and recruitment started in December 2020. As of December 2021, a total of 103 patients had been recruited. This study will address the gap in knowledge with respect to the role of postdischarge digital care models for supporting patients with AF. Australian New Zealand Clinical Trials Registry ACTRN12621000174886 www.australianclinicaltrials.gov.au/anzctr/trial/ACTRN12621000174886 DERR1-10.2196/34470
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 04-2011
DOI: 10.1016/J.HRTHM.2010.11.046
Abstract: Prompt thrombolytic reperfusion reduces postinfarct ventricular electrical instability after ST elevation myocardial infarction (STEMI). The purpose of this study was to examine the relationship between reperfusion time and inducible ventricular tachycardia (VT) early and spontaneous ventricular arrhythmias (VAs) late after primary percutaneous coronary intervention (PCI) for STEMI. Consecutive patients were recruited if they (1) had no prior coronary disease, (2) had been reperfused with primary PCI, (3) had postinfarct ejection fraction ≤40%, and (4) had undergone cardiac electrophysiologic study (n = 128). Three groups were compared according to reperfusion time: early (≤3 hours, n = 26), intermediate (>3-5 hours, n = 45), or delayed reperfusion (>5 hours, n = 57). Spontaneous VA was a composite endpoint of sudden death or defibrillator-treated VA. Mean ejection fraction (33% ± 5%, 31% ± 6%, and 31% ± 7%, P = .41) and peak creatinine kinase (P = .37) were similar between groups. VT was inducible in 11.5%, 17.8%, and 36.8% of patients in the early, intermediate, and delayed reperfusion groups, respectively (P = .003). At 2 years, the incidence of spontaneous VA was 0%, 8.9%, and 14% in the early, intermediate, and delayed reperfusion groups, respectively (P = .025). By multivariable analysis, delayed reperfusion conferred a sixfold increase in the odds of inducible VT (P = .01). Although inducible VT was the strongest predictor of spontaneous VA (hazard ratio 14.31, P = .001), delayed reperfusion conferred a threefold increase in risk when inducible VT was excluded from the multivariable model (P = .035). Reperfusion time is a critical determinant of postinfarct ventricular electrical instability early and late after STEMI treated with primary PCI.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.JACEP.2018.03.014
Abstract: Adequate catheter-tissue contact facilitates efficient heat energy transfer to target tissue. Tissue contact is thus critical to achieving lesion transmurality and success of radiofrequency (RF) ablation procedures, a fact recognized more than 2 decades ago. The availability of real-time contact force (CF)-sensing catheters has reinvigorated the field of ablation biophysics and optimized lesion formation. The ability to measure and display CF came with the promise of dramatic improvement in safety and efficacy however, CF quality was noted to have just as important an influence on lesion formation as absolute CF quantity. Multiple other factors have emerged as key elements influencing effective lesion formation, including catheter stability, lesion contiguity and continuity, lesion density, contact homogeneity across a line of ablation, spatiotemporal dynamics of contact governed by cardiac and respiratory motion, contact directionality, and anatomic wall thickness, in addition to traditional ablation indices of power and RF duration. There is greater appreciation of surrogate markers as a guide to lesion formation, such as impedance fall, loss of pace capture, and change in unipolar electrogram morphology. In contrast, other surrogates such as tactile feedback, catheter motion, and electrogram litude are notably poor predictors of actual contact and lesion formation. This review aims to contextualize the role of CF sensing in lesion formation with respect of the fundamental principles of biophysics of RF ablation and summarize the state-of-the-art evidence behind the role of CF in optimizing lesion formation.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.HLC.2018.10.013
Abstract: Arrhythmogenic cardiomyopathy (ACM) is now commonly used to describe any form of non-hypertrophic, progressive cardiomyopathy characterised by fibrofatty infiltration of the ventricular myocardium. Right ventricular (RV) involvement refers to the classical arrhythmogenic right ventricular cardiomyopathy, but left ventricular, or bi-ventricular involvement are now recognised. ACM is mostly hereditary and associated with mutations in genes encoding proteins of the intercalated disc. ACM classically manifests as ventricular arrhythmias, and sudden death may be the first presentation of the disease. Heart failure is seen with advanced stages of the disease. Diagnosis can be challenging due to variable expressivity and incomplete penetrance, and is guided by established Taskforce criteria that incorporate electrical features (12-lead electrocardiography (ECG), features of ventricular arrhythmias), structural features (on imaging via echo and cardiac magnetic resonance imaging [MRI]), tissue characteristics (via biopsy), and familial/genetic evaluation. Electrical abnormalities may precede structural alterations, which also make diagnosis challenging, especially in differentiating ACM from other conditions such as benign right ventricular arrhythmias, channelopathies such as Brugada, or the Athlete's Heart. Genetic testing is critical in identifying familial mutations and initiating cascade testing, but finds a pathogenic mutation in only ∼50% of patients. Some critical genotype-phenotype correlations do exist and may help guide risk stratification and give clues to disease progression. Therapeutic strategies include restriction from high endurance and competitive sports, ß-blockers, antiarrhythmic drugs, heart failure medications, implantable cardioverter-defibrillators and combined endocardial/epicardial catheter ablation. Ablation has emerged as the treatment of choice for recurrent ventricular arrhythmias in ACM. This state-of-the-art review outlines the pathogenesis, diagnosis and treatment of ACM in the contemporary era.
Publisher: Oxford University Press (OUP)
Date: 18-08-2012
Abstract: Increasing age is a significant risk factor for developing atrial fibrillation (AF). Pulmonary vein (PV) triggers are critical in the mechanism of AF, but little is known of the substrate changes that occur within the PVs with ageing. Therefore, we sought to identify whether ageing is associated with electroanatomic changes within the pulmonary veins. Twenty-five patients undergoing ablation for left-sided supraventricular tachycardia had high-density 3D electroanatomic maps of all four PVs created. Patients were ided into two groups: group 1 aged 50 years. Mean-voltage (MV), % low-voltage (LV < 0.5 mV), conduction, signal complexity, and PV muscle sleeve length and diameter were assessed. Age was 33 ± 8 vs. 66 ± 8 years for groups 1 and 2, respectively (P < 0.001). Group 2 demonstrated: (i) lower MV within the PVs (1.66 ± 1.1 vs. 1.88 ± 1.1 mV, P < 0.001) (ii) increased % LV (5.0 vs. 1.1%, P < 0.001), and increased voltage heterogeneity within the PVs (65 ± 14 vs. 55 ± 8%, P < 0.05) (iii) regional and global conduction slowing in the PVs and (iv) increased % complex signals within the PVs (1.4 vs. 0.4%, P = 0.009). There was no difference in PV sleeve length or diameter. Increasing age is associated with PV electroanatomic changes characterized by a significant reduction in PV voltage, conduction slowing, and increasing signal complexity. These observations provide new insights into the potential mechanisms behind the increased prevalence of AF with advancing age.
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.CCEP.2015.03.005
Abstract: Patients with dilated cardiomyopathies (DCM) face a significant burden of arrhythmias, including conduction defects such as atrioventricular block and interventricular delay in the form of left bundle branch block, resulting in altered electromechanical coupling that can exacerbate heart failure. Atrial fibrillation is common and carries an adverse prognosis. Ventricular arrhythmias and sudden cardiac death generally occur late in the disease course. Sustained monomorphic ventricular tachycardia accounts for most of the sustained ventricular arrhythmias in DCM. This article summarizes common forms of arrhythmias encountered in patients with DCM, and reviews the relevant electrophysiologic basis of these arrhythmias and their management.
Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.AMJCARD.2011.03.082
Abstract: Omega-3 polyunsaturated fatty acids in fish oils may have antifibrillatory effects however, their electrophysiologic effects in paroxysmal atrial fibrillation (PAF) remain unknown. The aim of this study was to investigate the effects of chronic fish oil supplementation on human pulmonary vein (PV) and left atrial electrophysiology in PAF. Patients with PAF undergoing PV isolation were randomized ≥1 month before their procedure into a control group (n = 18) or a fish oil group (n = 18) in an unblinded fashion. The latter were supplemented with fish oil 6 g/day for a mean of 40 ± 12 days. Pulmonary venous and left atrial effective refractory periods (ERPs), PV conduction, and susceptibility to AF initiated within PVs were assessed. Compared to the control group, the fish oil group had (1) longer left-sided (p = 0.002) and right-sided (p = 0.001) pulmonary venous ERPs (2) less dispersion of pulmonary venous ERPs (left PVs p = 0.001, right PVs p = 0.07) (3) longer left atrial ERPs (p = 0.02) (4) no difference in pulmonary venous conduction (5) lower incidence of AF initiated from PVs during ERP testing (77% vs 31%, p = 0.02) and (6) prolongation of mean AF cycle length (p = 0.009) and shortest AF cycle length in PVs (p = 0.04). In conclusion, patients with PAF chronically supplemented with fish oils exhibit distinctive electrophysiologic properties including prolonged pulmonary venous and left atrial ERPs and decreased susceptibility to initiation AF from within PVs. These changes may in part explain the antifibrillatory effect of chronic omega-3 polyunsaturated fatty acid supplementation in patients with PAF.
Publisher: Wiley
Date: 24-07-2014
DOI: 10.1111/JCE.15487
Abstract: Multielectrode mapping (MEM) and automated point collection are important enhancements to substrate mapping in ventricular tachycardia ablation. The effects of tissue contact and respiration on electrogram voltage with differing depolarization wavefronts with MEM catheters are unclear. Bipolar and unipolar voltages were collected from control (n = 5) and infarcted (n = 7) animals with a multispline MEM catheter. Electro-anatomic maps were created in sinus rhythm, and right and left ventricular pacing. Analysis was performed across three collections: standard settings (SS), respiratory-phase gating (RG), and electrode-tissue proximity (TP). Comparison was made to scar detected by cardiac MRI (cMRI). Compared to SS and RG acquisition, median bipolar and unipolar voltages were higher using TP, regardless of the depolarization wavefront. In infarct animals, bipolar voltages were 30.7%-50.5% higher for bipolar and 8.7%-13.8% higher on unipolar voltages with TP, compared to SS. The effect of RG on bipolar and unipolar voltages was minimal. Percentage of local abnormal ventricular activities was not impacted by acquisition settings or wavefront direction in infarct animals. Compared with cMRI defined scar, all three acquisition settings overestimated scar area using standard voltage-based cutoffs. RG improved the low voltage area concordance with MRI by 1.6%-5.1% whereas TP improved by 5.9%-8.4%. High density voltage mapping with a MEM catheter is influenced by point collection settings. Tissue contact filters reduced low voltage areas and improved agreement with cMRI fibrosis in infarcted ovine hearts. These findings have critical implications for optimizing filter settings for high density substrate mapping in the left ventricle.
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.IJCARD.2013.03.053
Abstract: Intravenous omega-3 polyunsaturated fatty acids (ω-3 PUFAs) may prevent atrial fibrillation (AF) inducibility and perpetuation in animal models. We examined the effect of high dose IV ω-3 PUFAs on human atrial electrophysiology. We randomised 88 patients with no structural heart disease to receive saline (control group) or high dose IV ω-3 PUFA infusion prior to detailed atrial electrophysiologic evaluation. Biologically active components, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were measured in total lipids, free fatty acid and phospholipid (membrane incorporated) fraction pre and post infusion. Compared to pre-infusion values, EPA and DHA increased significantly in the total lipids and free fatty acid but were unchanged in the phospholipid fraction. IV ω-3 did not alter atrial refractory periods, however it slowed right, left and global atrial conduction (P<.05). Inducible AF was significantly less likely in ω-3 patients compared to controls (AF ≥ 5 min, 20% vs. 58%, P = .02) and was non-sustained (mean AF duration: 14s vs. 39 s, P<.001), however inducible and sustained atrial flutter was more common (≥ 5 min: 28% vs. 0%, P = .01). Organisation of AF into flutter was observed in a greater proportion of inductions in the ω-3 group (8.5% vs. 0.6%, P<.001). IV ω-3 PUFAs (as free fatty acids) cause acute atrial conduction slowing, suppress AF inducibility, organise AF into atrial flutter and enhance atrial flutter inducibility. These findings provide a novel insight into potential anti and pro-arrhythmic mechanisms of fish oils in human AF.
Publisher: Elsevier BV
Date: 03-2016
DOI: 10.1016/J.CCEP.2015.10.009
Abstract: Ventricular arrhythmias arising from the region of the left ventricular summit can be challenging for catheter-based percutaneous ablation. A detailed knowledge of the anatomy of this region and the need of high-density mapping of surrounding structures are critical in ensuring safe and effective ablation. This case-based review focuses on the particular challenges with ablation in this region.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.HLC.2018.10.022
Abstract: Catheter ablation (CA) is highly efficacious for symptomatic atrial fibrillation (AF) but data predominantly comes from patients with preserved ventricular function. We performed an updated systematic review and meta-analysis of randomised controlled trials (RCT) comparing CA versus medical therapy for AF associated with heart failure (HF). Medline, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for RCTs reporting clinical outcomes of CA versus medical therapy for AF in HF patients with ≥6 months' follow-up (atrioventricular-node ablation/device therapy studies excluded). Primary endpoint was change in left ventricular ejection fraction (LVEF). Secondary endpoints were 6-minute walk test (6MWT) distance, quality of life (QoL measured by the Minnesota Living with Heart Failure Questionnaire [MLHFQ]), peri-procedural mortality, major peri-procedural complications and mid-term (≥1-year) survival. Six RCTs (n=772 patients mean age 62±11years, LVEF 30±9%) were included. Catheter ablation, compared to medical therapy was associated with: greater improvement in LVEF (mean difference [MD] 5.67% 95% Confidence Interval [CI], 3-8 I Catheter ablation is superior to medical therapy for AF in patients with heart failure resulting in greater improvement in LVEF, quality of life and functional status, with a survival benefit.
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.IJCARD.2018.03.055
Abstract: There is little known about the influence of obesity on ventricular electrical remodelling after myocardial infarction. The aim of our study was to assess the relationship between body mass index (BMI) and the primary outcome of inducible-VT and the secondary outcome of all-cause mortality in consecutive patients who presented with ST elevation myocardial infarction (STEMI) and LV-dysfunction (LVEF ≤ 40%). Consecutive patients (n = 380) with STEMI and LV-dysfunction (LVEF ≤ 40%) underwent electrophysiological (EP) studies for risk-stratification. Inducible-VT ≥200 ms cycle-length (CL) with one to four extra-stimuli (ES) was considered abnormal. Patients were classified according their body mass index (BMI) to be normal (18.5-24.9), overweight (25-29.9) or obese (>30). The primary outcome of inducible-VT occurred in 42.7%, 21.5% and 21% of normal weight, overweight and obese patients respectively (p < 0.001). When adjusting for ejection-fraction, hypertension and triple-vessel-disease, normal BMI remained a significant predictor for inducible-VT. All-cause mortality was higher in patients with normal weight (12.8%) when compared to overweight (3.2%) and obese (3.8%) patients (p = 0.002) and was mainly driven by increased cardiac-death (6.8%, 1.9% and 1.9% in normal, overweight and obese patients respectively, p = 0.05). After adjusting for age, EF, and hypertension, normal BMI remained a significant predictor of mortality. In patients presenting with STEMI and LV-dysfunction, BMI appears to be a significant predictor of inducible-VT and all-cause mortality, with worse outcomes for those with normal weight, when compared to overweight or obese in iduals. These findings are consistent with the obesity-paradox.
Publisher: MediaSphere Medical LLC
Date: 2021
Publisher: Elsevier BV
Date: 02-2019
Publisher: Elsevier BV
Date: 06-2010
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.JACEP.2018.08.009
Abstract: This is a systematic review summarizing the procedural characteristics and outcomes of ventricular assist device (VAD)-related ventricular tachycardia (VT) ablation. Drug-refractory VT refractory commonly develops post-VAD implantation. Procedural and outcome data come from small series or case reports. An electronic search was performed using major databases. Primary outcomes were VT recurrence, mortality, and cardiac transplantation. Secondary endpoints were acute procedural success and procedural complications. Eighteen studies were included, with a total of 110 patients (mean age 59.6 ± 11 years, 89% men VT storm 34%). Scar-related re-entry was the predominant mechanism of VT (90.3%) and cannula-related VT in 19.3% cases. Electroanatomical mapping interference occurred in 1.8% of cases there were no reports of catheter entrapment. Noninducibility of clinical VT was achieved in 77.9% procedural complications occurred in 9.4%. At a mean follow-up of 263.5 ± 267.0 days, VT recurred in 43.6%, 23.4% underwent cardiac transplant, and 48.1% died. There were no procedural-related deaths and no death was directly related to ventricular arrhythmia. In follow-up, there was a significant reduction in implantable cardioverter-defibrillator therapies or shocks (57.1% vs. 23.8%). Ablation allowed VT storm termination in 90% of patients. VAD-related VT is predominantly related to pre-existing intrinsic myocardial scar rather than inflow cannula site insertion. Catheter ablation is a reasonable treatment strategy, albeit with expectedly high rate of recurrence, transplantation, and mortality related to severe underlying disease.
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 06-2023
Publisher: Oxford University Press (OUP)
Date: 02-04-2015
Abstract: In patients presenting with spontaneous sustained ventricular tachycardia (VT) from the outflow-tract region without overt structural heart disease ablation may target premature ventricular contractions (PVCs) when VT is not inducible. We aimed to determine whether inducibility of VT affects ablation outcome. Data from 54 patients (31 men age, 52 ± 13 years) without overt structural heart disease who underwent catheter ablation for symptomatic sustained VT originating from the right- or left-ventricular outflow region, including the great vessels. A single morphology of sustained VT was inducible in 18 (33%, SM group) patients, and 11 (20%) had multiple VT morphologies (MM group). VT was not inducible in 25 (46%) patients (VTni group). After ablation, VT was inducible in none of the SM group and in two (17%) patients in the MM group. In the VTni group, ablation targeted PVCs and 12 (48%) patients had some remaining PVCs after ablation. During follow-up (21 ± 19 months), VT recurred in 46% of VTni group, 40% of MM inducible group, and 6% of the SM inducible group (P = 0.004). Analysis of PVC morphology in the VTi group further supported the limitations of targeting PVCs in this population. Absence of inducible VT and multiple VT morphologies are not uncommon in patients with documented sustained outflow-tract VT without overt structural heart disease. Inducible VT is associated with better outcomes, suggesting that attempts to induce VT to guide ablation are important in this population.
Publisher: JMIR Publications Inc.
Date: 26-08-2021
DOI: 10.2196/21186
Abstract: Cardiac arrhythmias are a leading cause of death. The mainstay method for diagnosing arrhythmias (eg, atrial fibrillation) and cardiac conduction disorders (eg, prolonged corrected QT interval [QTc]) is by using 12-lead electrocardiography (ECG). Handheld 12-lead ECG devices are emerging in the market. In tandem with emerging technology options, evaluations of device usability should go beyond validation of the device in a controlled laboratory setting and assess user perceptions and experiences, which are crucial for successful implementation in clinical practice. This study aimed to evaluate clinician and patient perceptions and experiences, regarding the usability of a handheld 12-lead ECG device compared to a conventional 12-lead ECG machine, and generalizability of this user-centered approach. International Organization for Standardization Guidelines on Usability and the Technology Acceptance Model were integrated to form the framework for this study, which was conducted in outpatient clinics and cardiology wards at Westmead Hospital, New South Wales, Australia. Each patient underwent 2 ECGs (1 by each device) in 2 postures (supine and standing) acquired in random sequence. The times taken by clinicians to acquire the first ECG (efficiency) using the devices were analyzed using linear regression. Electrocardiographic parameters (QT interval, QTc interval, heart rate, PR interval, QRS interval) and participant satisfaction surveys were collected. Device reliability was assessed by evaluating the mean difference of QTc measurements within ±15 ms, intraclass correlation coefficient, and level of agreement of the devices in detecting atrial fibrillation and prolonged QTc. Clinicians’ perceptions and feedback were assessed with semistructured interviews based on the Technology Acceptance Model. A total of 100 patients (age: mean 57.9 years, SD 15.2 sex: male: n=64, female n=36) and 11 clinicians (experience acquiring ECGs daily or weekly 10/11, 91%) participated, and 783 ECGs were acquired. Mean differences in QTc measurements of both handheld and conventional devices were within ±15 ms with high intraclass correlation coefficients (range 0.90-0.96), and the devices had a good level of agreement in diagnosing atrial fibrillation and prolonged QTc (κ=0.68-0.93). Regardless of device, QTc measurements when patients were standing were longer duration than QTc measurements when patients were supine. Clinicians’ ECG acquisition times improved with usage (P .001). Clinicians reported that device characteristics (small size, light weight, portability, and wireless ECG transmission) were highly desired features. Most clinicians agreed that the handheld device could be used for clinician-led mass screening with enhancement in efficiency by increasing user training. Regardless of device, patients reported that they felt comfortable when they were connected to the ECG devices. Reliability and usability of the handheld 12-lead ECG device were comparable to those of a conventional ECG machine. The user-centered evaluation approach helped us identify remediable action to improve the efficiency in using the device and identified highly desirable device features that could potentially help mass screening and remote assessment of patients. The approach could be applied to evaluate and better understand the acceptability and usability of new medical devices.
Publisher: Wiley
Date: 13-09-2019
DOI: 10.1111/JCE.14143
Abstract: Major technological and procedural advancements have reinvigorated catheter ablation as adjunctive therapy for drug-refractory ventricular tachycardia (VT). We examined temporal trends in VT ablations as compared to other interventional cardiovascular procedures namely, percutaneous coronary intervention (PCI) and atrial fibrillation (AF) ablation in Australia. A retrospective review of procedural numbers for VT ablations, AF ablations, and PCI was performed from 2008/09-2016/17 the Australian Institute of Health, Welfare and Aging (AIHW), and Medicare Australia (MA) databases. Linear regression models were fitted to compare the trends in population-adjusted procedural numbers over the 10-year period. Data from the AIHW and MA sources respectively showed that (a) PCI had a 1.3% (AIHW data P = .15) and 1.8% (MA data P < .001) population-adjusted increment per year, (b) AF ablations had a 12.7% (P < .001) and 11.7% (P < .001) per year population-adjusted increment, and (c) VT ablations showed an 18% (P < .001) and 12.7% (P < .001) per year population-adjusted increment. Growth of PCI was increasing at a lower rate than AF ablations (P < .001 for both AIHW and MA sources). Growth of VT ablation was significantly higher than AF ablations and PCI (AIHW: 18% vs 12.7% [P = .004] and 1.3% per year [P < .001]). Catheter-based VT ablation has increased significantly in Australia over the last decade, consistent with worldwide trends, and now surpassing all ablation procedures, including AF ablation and PCI for CAD. This data highlight the provision of additional resources to match the increasing demand for VT ablation procedures in Australia.
Publisher: Elsevier BV
Date: 12-2021
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2013
DOI: 10.1161/CIRCEP.113.000213
Abstract: Electrophysiological study (EPS) after myocardial infarction may have a role in identifying patients at risk of sudden cardiac death. It has been shown previously that inducible very fast ventricular tachycardia (VT cycle length [CL], 200–230 ms) is predictive of arrhythmia recurrence however, its significance early after reperfusion in ST-segment–elevation myocardial infarction is unknown. Consecutive patients with ST-segment–elevation myocardial infarction treated with primary percutaneous coronary intervention with a left ventricular ejection fraction ≤40% underwent early EPS with an implantable-cardioverter defibrillator implanted for inducible VT, but not for a negative EPS. The end point was the cumulative incidence of death or first arrhythmic event (defined as resuscitated cardiac arrest or spontaneous ventricular tachyarrhythmia). A total of 1721 patients with ST-segment–elevation myocardial infarction underwent early left ventricular ejection fraction assessment (median, 4 days after myocardial infarction) with a left ventricular ejection fraction ≤40% in 24%. EPS was performed in 290 eligible patients with no arrhythmia or ventricular fibrillation/flutter (CL ms) induced in 203 patients (EPS negative, group 1), monomorphic VT induced in 87 patients, consisting of very fast VT in 67% (group 2 n=58), and standard VT (CL ms) in 33% (group 3 n=29). Kaplan–Meier 4-year cumulative incidence of death or arrhythmia was 8.2±2.3%, 33.1±7.1%, and 37.0±10.2% in groups 1, 2, and 3, respectively ( P .001). The majority of inducible VT in patients who have been reperfused early after ST-segment–elevation myocardial infarction is very fast VT (CL, 200–230 ms). This very fast VT incurs at least a similar risk of arrhythmia or death as inducible standard VT (CL ms) and a significantly higher risk than patients with a negative EPS.
Publisher: Elsevier BV
Date: 06-2014
Publisher: Springer Science and Business Media LLC
Date: 18-02-2022
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2016
DOI: 10.1161/CIRCEP.116.004357
Abstract: Lamin A/C ( LMNA ) cardiomyopathy is a genetic disease with a proclivity for ventricular arrhythmias. We describe the multicenter experience with percutaneous catheter ablation of sustained monomorphic ventricular tachycardia (VT) in LMNA cardiomyopathy. Twenty-five consecutive LMNA mutation patients from 4 centers were included (mean age, 55±9 years ejection fraction, 34±12% VT storm in 36%). Complete atrioventricular block was present in 11 patients 3 patients were on mechanical circulatory support for severe heart failure. A median of 3 VTs were inducible per patient in 82%, mapping was consistent with origin from scar in the basal left ventricle, particularly the septum, but also basal inferior wall and subaortic mitral continuity. After multiple procedures (median 2 atient transcoronary alcohol in 6 and surgical cryoablation in 2 patients), acute success (noninducibility of any VT) was achieved in only 25% of patients. Partial success (inducibility of a nonclinical VT only: 50%) and failure (persistent inducibility of clinical VT: 12.5%) was attributed to intramural septal substrate in 13 of 18 patients (72%). Complications occurred in 25% of patients. After a median follow-up of 7 months after the last procedure, 91% experienced ≥1 VT recurrence, 44% received or were awaiting mechanical circulatory support or transplant for end-stage heart failure, and 26% died. Catheter ablation of VT associated with LMNA cardiomyopathy is associated with poor outcomes including high rate of arrhythmia recurrence, progression to end-stage heart failure, and high mortality. Basal septal scar and intramural VT origin makes VT ablation challenging in this population.
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 06-2021
Publisher: The Korean Society of Cardiology
Date: 2021
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.JACEP.2018.08.010
Abstract: This study sought to determine whether combined endocardial-epicardial (endo-epi) ablation was superior to endocardial only ablation in patients with scar-related ventricular tachycardia (VT). Limited single-center studies suggest that combined endo-epi ablation strategy may be superior to endocardial ablation (endo) alone in patients with nonischemic cardiomyopathy (NICM) and arrhythmogenic right ventricular cardiomyopathy (ARVC), and ischemic cardiomyopathy (ICM). A systematic review of Medline, Cochrane, and Embase databases was performed for studies that reported outcomes comparing endo-epi with endo VT ablation alone. Seventeen studies consisting of 975 patients were included (mean 56 ± 10 years of age 79% male NICM in 36.6% ICM in 32.8% and ARVC in 30.6%). After a mean follow-up of 27 ± 21 months, endo-epi ablation was associated with a 35% reduction in risk of VT recurrence compared with endocardial ablation alone (risk ratio [RR]: 0.65 95% confidence interval [CI]: 0.55 to 0.78 p < 0.001). Sensitivity analysis showed lower risk of VT recurrence in ICM (RR: 0.43 95% CI: 0.28 to 0.67 p = 0.0002) and ARVC (RR: 0.59 95% CI: 0.43 to 0.82 p = 0.0002), with a nonsignificant trend in NICM (RR: 0.87 95% CI: 0.70 to 1.08 p = 0.20). Endo-epi, compared with endo ablation, was associated with reduced all-cause mortality (RR: 0.56 95% CI: 0.32 to 0.97 p = 0.04). Acute procedural complications were higher with the endo-epi approach (RR: 2.62 95% CI: 0.91 to 7.52 p = 0.07). This meta-analysis suggests that a combined endo-epi ablation is associated with a lower risk of VT recurrence and subsequent mortality than endo only VT ablation in patients with scar-related VT. Procedural complications, however, are higher with the endo-epi approach.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 17-06-2014
DOI: 10.1161/CIRCULATIONAHA.113.008494
Abstract: Entrainment criteria for macroreentrant arrhythmias are based on detecting fusion between tachycardia and paced wavefronts, but this is often difficult for atrial tachycardias (AT) after ablation of atrial fibrillation. With the use of a multipolar catheter, pacing was performed from electrodes within the coronary sinus showing activation later than adjacent electrodes (downstream overdrive pacing) during 66 ATs in 62 patients: 20 cavotricuspid isthmus–dependent ATs, 20 perimitral ATs, 13 focal ATs with sequential coronary sinus activation, and 13 other macroreentrant left atrial ATs. The paced cycle length was 10 to 30 milliseconds below the tachycardia cycle length (TCL), and activation at the neighboring upstream electrodes was assessed. Downstream overdrive pacing at 48 sites close to a macroreentrant circuit (PPI−TCL milliseconds, where PPI is postpacing interval) produced constant fusion demonstrated by a long stimulus to upstream atrial electrogram interval (S-A u ) % TCL and was consistent with orthodromic activation of the upstream site despite its close proximity to the pacing site. In contrast, downstream overdrive pacing at 18 sites during focal AT or remote from the macroreentrant AT circuit (PPI−TCL milliseconds) always demonstrated a comparatively short S-A u % of TCL (12±4% versus 89±4% of TCL P .001), consistent with direct activation. Selection of a downstream activation site for overdrive pacing can facilitate rapid recognition of macroreentry and proximity to the reentry circuit using a single multielectrode catheter by recognizing a PPI–TCL milliseconds and S-A u % of TCL. Recognition of intracardiac constant fusion with this method is a novel criterion for transient entrainment.
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.JACC.2016.08.058
Abstract: Mutations in LMNA are variably expressed and may cause cardiomyopathy, atrioventricular block (AVB), or atrial arrhythmias (AAs) and ventricular arrhythmias (VA). Detailed natural history studies of LMNA-associated arrhythmic and nonarrhythmic outcomes are limited, and the prognostic significance of the index cardiac phenotype remains uncertain. This study sought to describe the arrhythmic and nonarrhythmic outcomes of LMNA mutation carriers and to assess the prognostic significance of the index cardiac phenotype. The incidence of AVB, AA, sustained VA, left ventricular systolic dysfunction (LVD) (= left ventricular ejection fraction ≤50%), and end-stage heart failure (HF) was retrospectively determined in 122 consecutive LMNA mutation carriers followed at 5 referral centers for a median of 7 years from first clinical contact. Predictors of VA and end-stage HF or death were determined. The prevalence of clinical manifestations increased broadly from index evaluation to median follow-up: AVB, 46% to 57% AA, 39% to 63% VA, 16% to 34% and LVD, 44% to 57%. Implantable cardioverter-defibrillators were placed in 59% of patients for new LVD or AVB. End-stage HF developed in 19% of patients, and 13% died. In patients without LVD at presentation, 24% developed new LVD, and 7% developed end-stage HF. Male sex (p = 0.01), nonmissense mutations (p = 0.03), and LVD at index evaluation (p = 0.004) were associated with development of VA, whereas LVD was associated with end-stage HF or death (p < 0.001). Mode of presentation (with isolated or combination of clinical features) did not predict sustained VA or end-stage HF or death. LMNA-related heart disease was associated with a high incidence of phenotypic progression and adverse arrhythmic and nonarrhythmic events over long-term follow-up. The index cardiac phenotype did not predict adverse events. Genetic diagnosis and subsequent follow-up, including anticipatory planning for therapies to prevent sudden death and manage HF, is warranted.
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.CCL.2015.07.007
Abstract: Cardiac arrhythmias are a major source of morbidity and mortality in adults with CHD. A multidisciplinary approach in a center specializing in the care of ACHD is most likely to have the expertise needed provide this care. Knowledge of the underlying anatomy, mechanism of arrhythmia, and potential management strategies is critical, as well as access and expertise in the use of advanced imaging and ablative technologies. Future challenges in management include refining the underlying mechanism and putative ablation targets for catheter ablation of AF, an arrhythmia rapidly rising in prevalence in this population.
Publisher: Elsevier BV
Date: 06-2020
Publisher: Wiley
Date: 12-04-2021
DOI: 10.1111/JCE.15026
Publisher: Wiley
Date: 08-02-2022
DOI: 10.1111/JCE.15388
Abstract: Ventricular tachycardia (VT) can occur following valvular interventions. There are limited data describing substrate and ablation approaches in such patients. We sought to describe the clinical, electrophysiologic, electroanatomic features and catheter ablation outcomes of patients with VT following aortic and/or mitral valve intervention. Over 12-years, consecutive patients with aortic valve replacement (AVR) and/or mitral valve replacement (MVR) or repair, undergoing VT ablation, were identified from two centers. Clinical and procedural parameters and outcomes are described. Twenty-three patients (age 66 ± 14years, 78% male, left ventricular ejection fraction 37 ± 16%), with prior AVR (mechanical n = 6, bioprosthetic n = 2, transcatheter n = 1), MVR (mechanical n = 5, bioprosthetic n = 1), mitral valve repair (n = 6) and both mechanical AVR and MVR (n = 2), underwent VT ablation. Sixteen had concurrent ischemic cardiomyopathy, 10 with prior bypass surgery. Left ventricular access was obtained in 21/23 (91%) patients (transseptal n = 14, retrograde aortic n = 5, transapical n = 2), with perivalvular scar identified in 17/21 (81%). Re-entrant VT isthmi involved the perivalvular regions in 12/23 (52%) patients, and regions remote from the valve in the remainder 9% had nonscar-related VT. Intramural substrate was ablated from adjacent chambers in 5/23 (22%) patients and with half-normal saline irrigation in 8/23 (35%) patients. There were no instances of catheter entrapment. Following final ablation, VA-free survival was 78% at 13-months. Only half of VT circuits following valvular interventions involve the valve regions themselves, while the remainder involves unrelated regions. Catheter ablation is safe and efficacious at treating VT following valvular intervention, but novel strategies may be required.
Publisher: Wiley
Date: 09-07-2021
DOI: 10.1111/JCE.15146
Publisher: Wiley
Date: 06-10-2016
DOI: 10.1111/JCE.13088
Abstract: Substrate-based ablation for scar-related ventricular tachycardia (VT) has gained prominence: however, there is limited data comparing it to ablation guided predominantly by activation and entrainment mapping of inducible and hemodynamically tolerated VTs. We compared the acute procedural efficacy and outcomes of predominantly substrate-based ablation versus ablation guided predominantly by activation and entrainment mapping. Database searches through April 2016 identified 6 eligible studies (enrolling 403 patients, with 1 randomized study) comparing the 2 strategies. The relative risk of VT recurrence at follow-up was assessed as the primary outcome using a random-effects meta-analysis. Secondary endpoints of acute success (based on noninducibility of VT), procedural complications, and mortality were assessed using weighted mean difference with the random effects model. At a median follow-up of 18 months, the relative risk (RR) of VT recurrence was not significantly different with substrate-based versus activation/entrainment guided VT ablation (0.72, 95% confidence interval [CI] 0.44-1.18), P = 0.2). Acute success (RR 1.02, 95% CI 0.95-1.1, P = 0.6), procedural complications (RR 0.8, 95% CI 0.35-1.82, P = 0.5) cardiovascular mortality and total mortality did not differ significantly (RR 0.83, 95% CI 0.38-1.79, P = 0.6 and RR 0.76, 95% CI 0.36-1.59, P = 0.5, respectively). This meta-analysis demonstrates similar acute procedural efficacy, and complications, VT recurrence and mortality rates when comparing a predominantly substrate-based ablation strategy to a strategy guided predominantly by activation and entrainment mapping of inducible and hemodynamically tolerated VTs.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2015
DOI: 10.1161/CIRCEP.114.002145
Abstract: Cardiac sarcoid–related ventricular tachycardia (VT) is a rare disorder the underlying substrate and response to ablation are poorly understood. We sought to examine the ventricular substrate and outcomes of catheter ablation in this population. Of 435 patients with nonischemic cardiomyopathy referred for VT ablation, 21 patients (5%) had cardiac sarcoidosis. Multiple inducible VTs were observed with mechanism consistent with scar-mediated re-entry in all VTs. Voltage maps showed widespread and confluent right ventricular scarring. Left ventricular scarring was patchy with a predilection for the basal septum, anterior wall, and perivalvular regions. Epicardial right ventricular scar overlay and exceeded the region of corresponding endocardial scar. After ≥1 procedures, ablation abolished ≥1 inducible VT in 90% and eliminated VT storm in 78% of patients however, multiple residual VTs remained inducible. Failure to abolish all inducible VTs was because of septal intramural circuits or extensive right ventricular scarring. Multiple procedure VT-free survival was 37% at 1 year, but VT control was achievable in the majority of patients with fewer antiarrhythmic drugs compared with preablation (2.1±0.8 versus 1.1±0.8 P .001). Patients with cardiac sarcoidosis and VT exhibit ventricular substrate characterized by confluent right ventricular scarring and patchy left ventricular scarring capable of sustaining a large number of re-entrant circuits. Catheter ablation is effective in terminating VT storm and eliminating ≥1 inducible VT in the majority of patients, but recurrences are common. Ablation in conjunction with antiarrhythmic drugs can help palliate VT in this high-risk population.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2009
DOI: 10.1097/ALN.0B013E3181AAEB11
Abstract: The prognostic role of brain natriuretic peptide (BNP) measurement before noncardiac surgery is unclear. The authors therefore performed a meta-analysis of studies in patients undergoing noncardiac surgery to assess the prognostic value of elevated BNP or N-terminal pro-BNP (NT-proBNP) levels in predicting mortality and major adverse cardiovascular events (MACE) (cardiac death or nonfatal myocardial infarction). Unrestricted searches of MEDLINE and EMBASE bibliographic databases were performed using the terms "brain natriuretic peptide," "b-type natriuretic peptide," "BNP," "NT-proBNP," and "surgery." In addition, review articles, bibliographies, and abstracts of scientific meetings were manually searched. The meta-analysis included prospective studies that reported on the association of BNP or NT-proBNP and postoperative major adverse cardiovascular event (MACE) or mortality. The study endpoints were MACE, all-cause mortality, and cardiac mortality at short-term (less than 43 days after surgery) and longer-term (more than 6 months) follow-up. A random-effects model was used to pool study results funnel-plot inspection was done to evaluate publication bias Cochrane chi-square test and I testing was used to test for heterogeneity. Data from 15 publications (4,856 patients) were included in the analysis. Preoperative BNP elevation was associated with an increased risk of short-term MACE (OR 19.77 95% confidence interval [CI] 13.18-29.65 P & 0.0001), all-cause mortality (OR 9.28 95% CI 3.51-24.56 P & 0.0001), and cardiac death (OR 23.88 95% CI 9.43-60.43 P & 0.00001). Results were consistent for both BNP and NT-proBNP. Preoperative BNP elevation was also associated with an increased risk of long-term MACE (OR 17.70 95% CI 3.11-100.80 P & 0.0001) and all-cause mortality (OR 4.77 95% CI 2.99-7.46 P & 0.00001). Elevated BNP and NT-proBNP levels identify patients undergoing major noncardiac surgery at high risk of cardiac mortality, all-cause mortality, and MACE.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2014
DOI: 10.1161/CIRCEP.114.001615
Abstract: Catheter ablation for ventricular arrhythmia (VA) near the distal great cardiac vein (GCV) is often challenging, and data are limited. Analysis was performed in 30 patients (19 men age, 52.8±15.5 years) who underwent catheter ablation for focal VA (11 ventricular tachycardia and 19 premature contractions) with early activation in the GCV (36.7±8.0 ms pre-QRS). Angiography in 27 patients showed earliest GCV site within 5 mm of a coronary artery in 20 (74%). Ablation was performed in the GCV in 15 patients and abolished VA in 8. Ablation was attempted at adjacent non-GCV sites in 19 patients and abolished VA in 5 patients (4 from the left ventricular endocardium and 1 from the left coronary cusp) all success had VA with an initial r wave in lead I and activation ≤7 ms after the GCV (GCV–non-GCV interval). In 13 patients, percutaneous epicardial mapping was performed, but because of adjacent coronaries only 2 received radiofrequency application with VA elimination in 1. Surgical cryoablation was performed in 3 patients and abolished VA in 2. Overall acute success was achieved in 16 (53%) patients. After a median of 2.8 months, 13 patients remained free of VA. Major complications occurred in 4 patients, including coronary injury requiring stenting. Ablation for this arrhythmia is challenging and often limited by the adjacent coronary vessels. Success of anatomically guided endocardial ablation may be identified by a short GCV–non-GCV interval and r wave in lead I.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2012
DOI: 10.1161/CIRCEP.112.970624
Abstract: Esophageal hematoma recently has been reported as a form of esophageal injury after atrial fibrillation (AF) ablation, attributed to the use of transesophageal echocardiography (TEE). We sought to determine the incidence, clinical features, and sequelae of this form of esophageal injury. This was a prospective series of 1110 AF ablation procedures performed under general anesthesia (GA) over 9 years. TEE was inserted after induction of GA to exclude left atrial appendage thrombus, define cardiac function, and guide transseptal puncture. The procedural incidence of esophageal hematoma was 0.27% (3/1110 procedures, mortality 0%). Odonyphagia, regurgitation, and hoarseness were the predominant symptoms, with an onset within 12 hours. There was absence of fever and neurological symptoms. Chest computed tomography excluded atrio-esophageal fistula and was diagnostic of esophageal hematoma localized to either the upper esophagus or extending the length of the mid and lower esophagus endoscopy confirmed the diagnosis. Management was conservative in all cases comprising of ceasing oral intake and anticoagulation. Long term sequelae included esophageal stricture formation requiring dilatation, persistent esophageal dysmotility (mid esophageal hematoma), and vocal cord paralysis, resulting in hoarse voice (upper esophageal hematoma). Esophageal hematoma is a rare but important differential diagnosis for esophageal injury after TEE-guided AF ablation under GA, and can result in significant patient morbidity. Key clinical features differentiate presentation of esophageal hematoma from that of an atrio-esophageal fistula.
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.HRTHM.2021.09.026
Abstract: Patients with idiopathic nonischemic cardiomyopathy (NICM) and near-normal left ventricular ejection fraction (LVEF) may develop ventricular tachycardia (VT). The purpose of this study was to describe procedural characteristics and outcomes in patients requiring ablation for NICM-related VT with near-normal LVEF compared to impaired LVEF. Over 8 years, 77 consecutive patients with NICM-related VT underwent catheter ablation. Of these patients, 47 had idiopathic NICM (20 near-normal LVEF, 27 impaired LVEF). Procedural characteristics and outcomes were compared. Mean age was 64 ± 12years, mean LVEF was 40% ± 14%, and 75% were male. In the near-normal LVEF group compared to the impaired LVEF group, LVEF was higher (54% ± 5% vs 30 ± 8% P <.001), scar was predominantly located in the perivalvular left ventricle (LV) and basal septum (15/20 [75%]), was smaller in size [bipolar: 9.7 (6.2-32.4) cm Idiopathic NICM-related VT with near-normal LVEF was associated with discrete areas of arrhythmogenic, predominantly intramural, scar in the perivalvular LV and basal septum. Despite smaller scar, patients required similar ablation amounts and experienced comparable long-term outcomes compared to patients with idiopathic NICM-related VT and impaired LVEF. These findings underscore the "three-dimensionality" of substrate, whereby the intramural basal septum forms the third dimension and impacts ablation outcomes.
Publisher: Wiley
Date: 25-08-2022
DOI: 10.1111/IMJ.15891
Abstract: Ventricular arrhythmia (VA) is the most common cause of sudden cardiac death post‐ST elevation myocardial infarction (STEMI). Ventricular tachycardia (VT) may be inducible in electrophysiology studies (EPS) early ( days) post‐STEMI. Whether it originates from the infarct site remains unknown. We examined the correlation between inducible VT and infarct location post‐STEMI. To investigate the correlation between inducible VT and infarct location post‐STEMI. We retrospectively analysed 46 patients from 2005 to 2017 with STEMI who underwent early programmed ventricular stimulation through EPS ( h post‐STEMI and days from admission). Gated heart pool scans were used to visualise infarct scar regions, and VT exit sites were derived from induction 12‐lead electrocardiography. Patients were followed up for primary outcomes of recurrent VA and all‐cause mortality. Forty‐six patients were included for analysis, with 50 uniquely induced VT exit sites. Mean left ventricular ejection fraction was 30 ± 8.7% and 22% had impaired right ventricular ejection fraction. Mean time from presentation to EPS was 16 ± 31.3 days. Of the induced VT, 44 (88%) were from within scar and scar‐border regions, whereas 6 (12%) of the induced VT were found to be remote to imaging‐derived scar. Over a median follow‐up period of 75 months, 6 (13%) patients died, and 7 (15%) patients had recurrent VA. No deaths occurred in patients with remote VT. The majority of early inducible post‐infarct VT arises from acute myocardial scar however, a small portion arises from sites remote from scars with a possible focal aetiology.
Publisher: Wiley
Date: 06-08-2020
DOI: 10.1111/PACE.14025
Publisher: Elsevier BV
Date: 08-2021
Publisher: Oxford University Press (OUP)
Date: 17-02-2021
Abstract: There are conflicting data as to the impact of procedural volume on outcomes with specific reference to the incidence of major complications after catheter ablation for atrial fibrillation. Questions regarding minimum volume requirements and whether these should be per centre or per operator remain unclear. Studies have reported ergent results. We performed a systematic review and meta-analysis of studies reporting the relationship between either operator or hospital atrial fibrillation (AF) ablation volumes and incidence of complications. Databases were searched for studies describing the relationship between operator or hospital AF ablation volumes and incidence of complications which were published prior to 12 June 2020. Of 1593 articles identified, 14 (315 120 patients) were included in the meta-analysis. Almost two-thirds of the procedures were performed in low-volume centres. Both hospital volume of ≥50 and ≥100 procedures/year were associated with a significantly lower incidence of complications compared to & /year (4.2% vs. 5.5%, OR = 0.58, 95% CI 0.50–0.66, P & 0.001) or & /year (5.5% vs. 6.2%, OR = 0.62, 95% CI 0.53–0.73, P & 0.001), respectively. Hospitals performing ≥50 procedures/year demonstrated significantly lower mortality compared with those performing & procedures/year (0.16% vs. 0.55%, OR = 0.33, 95% CI 0.26–0.43, P & 0.001). A similar relationship existed between proceduralist volume of & /year and incidence of complications [3.75% vs. 12.73%, P & 0.001 OR = 0.27 (0.23–0.32)]. There is an inverse relationship between both hospital and proceduralist AF ablation volume and the incidence of complications. Implementation of minimum hospital and operator AF ablation volume standards should be considered in the context of a broader strategy to identify AF ablation Centers of Excellence.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2015
DOI: 10.1161/CIRCEP.114.002714
Abstract: Mapping to identify scar-related ventricular tachycardia re-entry circuits during sinus rhythm focuses on sites with abnormal electrograms or pace-mapping findings of QRS morphology and long stimulus to QRS intervals. We hypothesized that (1) these methods do not necessarily identify the same sites and (2) some electrograms are far-field potentials that can be recognized by pacing. From 12 patients with coronary disease and recurrent ventricular tachycardia undergoing catheter ablation, we retrospectively analyzed electrograms and pacing at 546 separate low bipolar voltage ( .5 mV) sites. Electrograms were characterized as showing evidence of slow conduction if late potentials (56%) or fractionated potentials (76%) were present. Neither was present at (13%) sites. Pacing from the ablation catheter captured 70% of all electrograms. Higher bipolar voltage and fractionation were independent predictors for pace capture. There was a linear correlation between the stimulus to QRS duration during pacing and the lateness of a capturing electrogram ( P .001), but electrogram and pacing markers of slow conduction were discordant at 40% of sites. Sites with far-field potentials, defined as those that remained visible and not captured by pacing stimuli, were identified at 48% of all pacing sites, especially in areas of low bipolar voltage and late potentials. Initial radiofrequency energy application rendered 74% of targeted sites electrically unexcitable. Far-field potentials are common in scar areas. Combining analysis of electrogram characteristics and assessment of pace capture may refine identification of substrate targets for radiofrequency ablation.
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.HRTHM.2019.04.038
Abstract: Access to the epicardial space is fundamental to several cardiac procedures. While traditional indications include catheter ablation of ventricular arrhythmias and accessory pathways, novel indications include left atrial appendage occlusion, esophageal protection, mapping and ablation during atrial fibrillation procedures, implantation of epicardial pacing leads, and phrenic nerve displacement to facilitate safe ablation of atrial and ventricular arrhythmias. Accessing the epicardial space safely is a major challenge requiring intimate knowledge of cardiac anatomy, extensive training, and expertise. Over the past years, multiple technological advances have led to significant improvements in epicardial access success and safety. Important ex les of such advances include CO
Publisher: Elsevier BV
Date: 05-2017
DOI: 10.1016/J.JACC.2017.02.044
Abstract: In patients referred for radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in the setting of structural heart disease, early post-procedural mortality (EM) has not been previously investigated. The purpose of this study was to evaluate EM after catheter ablation of scar-related VT. Associations between clinical and procedural variables and EM (within 31 days of the procedure) were tested in patients with structural heart disease undergoing RFCA of VT at 12 international centers. Of 2,061 patients (mean age 62 ± 13 years left ventricular ejection fraction [LVEF] 34 ± 13% 53% ischemic etiology), EM occurred in 100 (5% 95% confidence interval [CI]: 4% to 6%). A total of 54 (3%) patients died before hospital discharge (median 9 days after the procedure 25% for refractory VT), including 12 (0.6%) after a major procedure-related complication. In multivariable analysis, the following factors were found to be significantly associated with EM: LVEF (odds ratio [OR] per percent decrease: 1.12 95% CI: 1.05 to 1.20 p < 0.001), chronic kidney disease (OR: 2.73 95% CI: 1.10 to 6.80 p = 0.030), presentation with VT storm (OR: 3.61 95% CI: 1.37 to 9.48 p = 0.009), and presence of unmappable VTs (OR: 5.69 95% CI: 1.37 to 23.69 p = 0.017). Recurrent VT was also associated with an increased risk of subsequent death (hazard ratio: 7.19 95% CI: 5.57 to 9.28 p < 0.001) and EM (hazard ratio: 11.45 95% CI: 7.47 to 17.59 p < 0.001). In a contemporary cohort of patients with scar-related VT undergoing RFCA, EM occurred in 5% of cases. Clinical and procedural variables indicating poorer clinical status (low LVEF, chronic kidney disease, VT storm, and unmappable VTs) and post-procedural VT recurrence may predict EM. Identification of such features may prompt early consideration for hemodynamic support or other care to help mitigate later potential complications.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2021
Publisher: The Korean Society of Cardiology
Date: 2021
Publisher: Elsevier BV
Date: 07-2015
Publisher: Oxford University Press (OUP)
Date: 13-12-2019
Abstract: Despite widespread adoption of contact force (CF) sensing technology in atrial fibrillation (AF) ablation, randomized data suggests lack of improvement in clinical outcomes. We aimed to assess the safety and efficacy of CF-guided vs. non CF-guided AF ablation. Electronic databases were searched for randomized controlled trials (RCTs) and controlled observational studies (OS) comparing outcomes of AF ablation performed with vs. without CF guidance. The primary efficacy endpoint was freedom from AF at follow-up. The primary safety endpoint was major peri-procedural complications. Secondary endpoints included procedural, fluoroscopy, and ablation duration. Subgroup analyses were performed by AF type and study design. Nine RCTs (n = 903) and 26 OS (n = 8919) were included. Overall, CF guidance was associated with improved freedom from AF [relative risk (RR) 1.10 95% confidence interval (CI) 1.02-1.18], and reduced total procedure duration [mean difference (MD) 15.33 min 95% CI 6.98-23.68], ablation duration (MD 3.07 min 95% CI 0.29-5.84), and fluoroscopy duration (MD 5.72 min 95% CI 2.51-8.92). When restricted to RCTs however, CF guidance neither improved freedom from AF (RR 1.03 95% CI 0.95-1.11), independent of AF type, nor did it reduce procedural, fluoroscopy, or ablation duration. Contact force guidance did not reduce the incidence of major peri-procedural complications (RR 0.89 95% CI 0.64-1.24). Meta-analysis of randomized data demonstrated that CF guidance does not improve the safety or efficacy of AF ablation, despite initial observational data showing dramatic improvement. Rigorous evaluation in randomized trials is needed before widespread adoption of new technologies.
Publisher: Elsevier BV
Date: 04-2015
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.JACEP.2017.09.001
Abstract: The authors sought to investigate the effect of low irrigation flow rate on lesion characteristics and ablation outcomes in a clinicopathological study. Irrigated ablation produces deeper lesions compared with nonirrigated ablation, which may not be desirable in the thin-walled posterior left atrium (LA), where collateral esophageal injury is possible. Lesions were placed on the smooth posterior right atrium in 20 swine and posterior LA in 60 patients at a maximum power of 20 to 25 W with either: 1) power-controlled ablation at an irrigation flow rate of 17 ml/min (high-flow group 10 swine n = 40) or 2) temperature-controlled ablation at an irrigation flow rate of 2 ml/min (low-flow group 10 swine n = 20). Safety and efficacy was also compared in 326 patients undergoing AF ablation using high-flow (n = 160) or low-flow settings (n = 166) for posterior LA ablation. Low-flow, compared with high-flow, lesions in swine had a higher incidence of lesions with: impedance fall ≥10 Ω, loss of pace capture, electrograms characteristic of transmural lesions, and visible lesions on anatomic inspection (p < 0.05 for all). Low-flow lesions had a maximal diameter at the endocardial surface, whereas high-flow lesions had a maximal diameter at the epicardial surface. In humans, impedance, pace capture, and transmurality data also strongly favored low-flow lesions. There was no difference in acute pulmonary vein isolation, complications, or 12-month arrhythmia-free survival between the groups. Low-flow irrigated ablation provides favorable lesion characteristics for posterior LA ablation without increasing the risk of adverse events.
Publisher: JMIR Publications Inc.
Date: 25-10-2021
Abstract: trial fibrillation (AF) is an increasingly common chronic health condition for which integrated care that is multidisciplinary and patient-centric is recommended yet challenging to implement. he aim of Coordinating Health Care With Artificial Intelligence–Supported Technology in AF is to evaluate the feasibility and potential efficacy of a digital intervention ( i AF-Support /i ) comprising preprogrammed automated telephone calls (artificial intelligence conversational technology), SMS text messages, and emails, as well as an educational website, to support patients with AF in self-managing their condition and coordinate primary and secondary care follow-up. oordinating Health Care With Artificial Intelligence–Supported Technology in AF is a 6-month randomized controlled trial of adult patients with AF (n=385), who will be allocated in a ratio of 4:1 to AF-Support or usual care, with postintervention semistructured interviews. The primary outcome is AF-related quality of life, and the secondary outcomes include cardiovascular risk factors, outcomes, and health care use. The 4:1 allocation design enables a detailed examination of the feasibility, uptake, and process of the implementation of AF-Support. Participants with new or ongoing AF will be recruited from hospitals and specialist-led clinics in Sydney, New South Wales, Australia. AF-Support has been co-designed with clinicians, researchers, information technologists, and patients. Automated telephone calls will occur 7 times, with the first call triggered to commence 24 to 48 hours after enrollment. Calls follow a standard flow but are customized to vary depending on patients’ responses. Calls assess AF symptoms, and participants’ responses will trigger different system responses based on prespecified protocols, including the identification of red flags requiring escalation. Randomization will be performed electronically, and allocation concealment will be ensured. Because of the nature of this trial, only outcome assessors and data analysts will be blinded. For the primary outcome, groups will be compared using an analysis of covariance adjusted for corresponding baseline values. Randomized trial data analysis will be performed according to the intention-to-treat principle, and qualitative data will be thematically analyzed. thics approval was granted by the Western Sydney Local Health District Human Ethics Research Committee, and recruitment started in December 2020. As of December 2021, a total of 103 patients had been recruited. his study will address the gap in knowledge with respect to the role of postdischarge digital care models for supporting patients with AF. ustralian New Zealand Clinical Trials Registry ACTRN12621000174886 www.australianclinicaltrials.gov.au/anzctr/trial/ACTRN12621000174886 ERR1-10.2196/34470
Publisher: Oxford University Press (OUP)
Date: 17-02-2018
Abstract: Atrial tachycardia (AT) related to atrial fibrillation (AF) ablation frequently poses a diagnostic challenge. Downstream overdrive pacing (DOP) can be used to rapidly detect reentry and assess proximity of a pacing site to an AT circuit or focus. We hypothesized that systematic DOP using multielectrode catheters would facilitate AT mapping. DOP identified constant fusion when the post-pacing interval (PPI)-tachycardia cycle length (TCL) 75% of TCL. Mapping was performed as follows: (i) CS DOP, (ii) DOP at left atrial (LA) roof, (iii) DOP at selected LA sites based on prior DOP attempts, and (iv) mapping and ablation at regions of fractionated electrograms in region of AT. Activation mapping was performed at operator discretion. AT diagnosis was confirmed by successful ablation or additional mapping when ablation was unsuccessful. Fifty consecutive patients with sustained AT underwent mapping of 68 ATs, of whom 42 (62%) were macroreentrant, 19 were locally reentrant (28%), and 7 (10%) were focal. AT was correctly identified with a median of three DOP attempts. All macroreentrant ATs were identified with ≤6 DOP attempts. One AT (1.6%) was terminated by DOP, and three ATs (4.8%) required activation mapping. Intracardiac concealed fusion was seen in 26 ATs (38%), each of which was successfully ablated. Reentry could be demonstrated in a substantial majority of AF ablation-related AT. A stepwise diagnostic approach using DOP and recognition of intracardiac concealed fusion can be used to rapidly identify and ablate reentrant AT.
Publisher: Massachusetts Medical Society
Date: 05-03-2020
DOI: 10.1056/NEJMC1916858
Publisher: Springer Science and Business Media LLC
Date: 24-04-2019
DOI: 10.1007/S10840-019-00548-5
Abstract: Targets for substrate-based catheter ablation of scar-related ventricular tachycardia (VT) include sites with fractionated and late potentials (LPs). We hypothesized that in patients with cardiac resynchronization therapy (CRT), the pacing mode may influence the timing of abnormal electrograms (EGMs) relative to the surface QRS complex. We assessed bipolar EGM characteristics in left ventricular low bipolar voltage areas (< 1.5 mV) from 10 patients with coronary disease and a CRT device undergoing catheter ablation for VT. EGMs at 81 sites were analyzed during three different pacing modes (biventricular (BiV), right ventricular (RV)-only, and left ventricular (LV)-only) pacing. Stimulus to end of local electrogram duration (Stim-to-eEGM) depended significantly on the stimulation site (BiV, LV, or RV, p = 0.032). Single-chamber pacing unmasked LPs, not present during BiV pacing, in three patients. In another three patients, a concomitant increase in stimulus to end of surface QRS duration caused by single-site pacing compensated for the increase in Stim-to-eEGM duration, thereby prohibiting LP unmasking. The sequence of ventricular activation, as determined by the pacing site in patients with CRT devices, has a major influence on the detection of late potentials during substrate-guided ablation. Further study is warranted to define the optimal approaches, including the rhythm, for substrate mapping, but our findings suggest that BiV pacing may be most likely to obscure detection of late potentials as compared to single-site pacing.
Publisher: Elsevier BV
Date: 07-2012
DOI: 10.1016/J.HRTHM.2012.02.015
Abstract: Catheter-tissue contact is important for effective lesion creation. To assess the effect of respiration on contact force (CF) during atrial fibrillation and cavotricuspid isthmus (CTI)-dependent atrial flutter ablation. Patients undergoing CTI ablation alone (n = 15) and pulmonary vein (PV) isolation alone (n = 12) under general anesthesia were recruited. Lesions were delivered under ventilation (30 seconds) alternating with lesions delivered under apnea (30 seconds) at an adjacent anatomical site at CTI or PV antra. The average force (F(av)), force-time integral (FTI), and force variability were measured in a region-specific manner by using a novel CF-sensing ablation catheter. Operators were blinded to CF data. F(av) and FTI were higher with apnea than with ventilation in all CTI and PV segments (P <.05), an effect attributed to drop in CF with each respiratory swing, resulting in greater force variability during ventilation (P <.05). Low FTI lesions (<500 g) were strongly associated with longer ablation time to achieve bidirectional CTI block (r(2) = .81 P <.001), left PVI (r(2) = .65 P = .009), and right PVI (r(2) = .41 P = .05). Sites with transient CTI block were associated with lower F(av) and FTI than were sites with persistent CTI block (P <.05). Sites of acute PV reconnection were associated with lower F(av) and FTI compared with non-reconnected sites (P <.001). Catheter-tissue CF is critically influenced by respiration greater CF is observed with ablation during apnea. Poor CF is implicated in longer ablation time to achieve CTI block or PV isolation and in acute reconnection.
Publisher: Wiley
Date: 21-12-2015
DOI: 10.1111/JCE.12575
Abstract: The transesophageal echo probe (TEE) is commonly used before and during atrial fibrillation (AF) ablation under general anesthesia (GA). We sought to determine the potential contribution of the TEE probe to esophageal injury after pulmonary vein isolation (PVI) alone for paroxysmal AF. Seventy-six patients undergoing PVI with TEE, PVI/TEE, 16 undergoing PVI without TEE (PVI/No TEE), and 27 undergoing TEE without any left atrial ablation (TEE/No LA ablation) under GA were included. Posterior wall ablation was power (20-25 W) and time limited (electrogram attenuation or ≤30 s). Esophageal capsule endoscopy (n = 206) was performed pre- and post-procedure and at 2 weeks. Esophageal lesions were seen in 30% of PVI/TEE, 0% of patients in the PVI/No TEE (P = 0.009), and 22% of TEE/No LA ablation groups (P = 0.47 vs. PVI/TEE). There were no instances of esophageal bleeding, perforation, or need for gastrointestinal intervention. Self-resolving dysphagia was the only reported symptom (5%). All lesions healed within 2 weeks. There was no significant difference in the location or morphological appearance of esophageal lesions seen in the PVI/TEE versus TEE/No LA ablation groups. Esophageal lesions were seen in 30% of patients undergoing PVI alone under GA with use of TEE and in a similar proportion (22%) of patients undergoing TEE in the absence of left atrial ablation. This study makes the preliminary observation that one must be cognizant of the TEE probe as a potential contributor to esophageal injury after AF ablation. Larger studies are needed to confirm these findings.
Publisher: Oxford University Press (OUP)
Date: 15-02-2021
Abstract: Ventricular tachycardia (VT) in ischaemic cardiomyopathy (ICM) originates from scar, identified as low-voltage areas with invasive high-density electroanatomic mapping (EAM). Abnormal myocardial deformation on speckle tracking strain echocardiography can non-invasively identify scar. We examined if regional and global longitudinal strain (GLS) can localize and quantify low-voltage scar identified with high-density EAM. We recruited 60 patients, 40 ICM patients undergoing VT ablation and 20 patients undergoing ablation for other arrhythmias as controls. All patients underwent an echocardiogram prior to high-density left ventricular (LV) EAM. Endocardial bipolar and unipolar scar location and percentage were correlated with regional and multilayer GLS. Controls had normal GLS and normal bipolar and unipolar voltages. There was a strong correlation between endocardial and mid-myocardial longitudinal strain and endocardial bipolar scar percentage for all 17 LV segments (r = 0.76–0.87, P & 0.001) in ICM patients. Additionally, indices of myocardial contraction heterogeneity, myocardial dispersion (MD), and delta contraction duration (DCD) correlated with bipolar scar percentage. Endocardial and mid-myocardial GLS correlated with total LV bipolar scar percentage (r = 0.83 0.82, P & 0.001 respectively), whereas epicardial GLS correlated with epicardial bipolar scar percentage (r = 0.78, P & 0.001). Endocardial GLS −9.3% or worse had 93% sensitivity and 82% specificity for predicting endocardial bipolar scar & % of LV surface area. Multilayer strain analysis demonstrated good linear correlations with low-voltage scar by invasive EAM. Validation studies are needed to establish the utility of strain as a non-invasive tool for quantifying scar location and burden, thereby facilitating mapping and ablation of VT.
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.HRTHM.2018.10.016
Abstract: The comparative efficacy of antiarrhythmic drug (AAD) therapy vs ventricular tachycardia (VT) ablation in arrhythmogenic right ventricular cardiomyopathy (ARVC) is unknown. We compared outcomes of AAD and/or β-blocker (BB) therapy with those of VT ablation (with AAD/BB) in patients with ARVC who had recurrent VT. In a multicenter retrospective study, 110 patients with ARVC (mean age 38 ± 17 years 91[83%] men) with a minimum of 3 VT episodes were included 77 (70%) were initially treated with AAD/BB and 32 (29%) underwent ablation. Subsequently, 43 of the 77 patients treated with AAD/BB alone also underwent ablation. Overall, 75 patients underwent ablation. When comparing initial AAD/BB therapy (n = 77) and VT ablation (n = 32) after ≥3 VT episodes, a single ablation procedure rendered 35% of patients free of VT at 3 years compared with 28% of AAD/BB-only-treated patients (P = .46). Of the 77 AAD/BB-only-treated patients, 43 subsequently underwent ablation. For all 75 patients who underwent ablation, 56% were VT-free at 3 years after the last ablation procedure. Epicardial ablation was used in 40/75 (53%) and was associated with lower VT recurrence after the last ablation procedure (endocardial/epicardial vs endocardial-only 71% vs 47% 3-year VT-free survival P = .05). Importantly, there was no difference in survival free of death or transplantation between the ablation- and AAD/BB-only-treated patients (P = .61). In patients with ARVC and a high VT burden, mortality and transplantation-free survival are not significantly different between drug- and ablation-treated patients. These patients have a high risk of recurrent VT despite drug therapy. Combined endocardial/epicardial ablation is associated with reduced VT recurrence as compared with endocardial-only ablation.
Publisher: Elsevier BV
Date: 04-2016
Publisher: Elsevier BV
Date: 04-2016
DOI: 10.1016/J.JACEP.2015.10.013
Abstract: This study sought to assess the incidence, operator demographics, clinical characteristics, procedural factors, and prognosis of esophageal perforation and fistula after atrial fibrillation ablation. Esophageal injury is a feared complication of atrial fibrillation ablation. An Internet-based global survey soliciting anonymous information regarding esophageal perforation and fistula was emailed to 3,080 physicians. Detailed information regarding physician, patient, and procedural characteristics related to esophageal perforation with or without fistula was collected. The survey was completed by 405 of 3,080 physicians (13%). Responding physicians performed 191,215 atrial fibrillation ablations and esophageal perforation with or without fistula occurred in 31 patients (0.016%) with multiple ablation catheter types despite monitoring of esophageal position or temperature during ablation in 90% of patients. Among patients who present with esophageal perforation, death, or severe neurologic injury occurred more frequently in patients with greater body mass index (30.9 ± 6.8 kg/m Esophageal perforation is rare but continues to occur with multiple catheter types despite esophageal monitoring during ablation. The prognosis of esophageal perforation is substantially improved if diagnosed and treated before development of atrial-esophageal fistula. An early surgical approach to esophageal perforation should be strongly considered regardless of evidence of fistula.
Publisher: Wiley
Date: 03-2010
DOI: 10.1111/J.1540-8167.2009.01624.X
Abstract: The long-term outcomes of patients with inducible very fast ventricular tachycardia (VFVT) of cycle length (CL) 200 to 250 ms have not been well studied. Consecutive patients with ischemic cardiomyopathy with a left ventricular ejection fraction (LVEF) of <or=40% (n = 300) underwent programmed ventricular stimulation (PVS) and were ided into 4 groups based on results of the study. Group A were noninducible, had induced ventricular fibrillation (VF), or polymorphic VT (CL 320 ms). The primary endpoint was spontaneous ventricular arrhythmia or sudden death. The mean age was 63 +/- 12 years and mean LVEF was 29 +/- 7%. At mean follow-up of 38 +/- 25 months (median 30 months), the primary endpoint rate was 6.6%, 34%, 44%, and 71% in groups A, B C, and D, respectively (P < 0.001). Neither mode of induction of VT nor LVEF altered the observed pattern in the primary endpoint. There was no significant difference in the primary endpoint among implanted cardioverter defibrillator recipients in groups B and C (38% vs 45%, P = 0.43). Adjusted hazard ratios for the primary endpoint compared to group A were 3.2, 3.5, and 7.0 in groups B, C, and D, respectively (P < 0.05). Inducible VFVT (200-250 ms) is a clinically significant arrhythmia with adverse long-term outcomes and should not be considered a nonspecific finding of PVS.
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.IJCARD.2013.06.030
Abstract: Sino-atrial node disease and aging increase AF risk. We investigated if long-term fish oil supplementation reduces paroxysmal atrial tachycardia/fibrillation (AT/AF) burden in patients aged ≥60 years with sinoatrial node disease and dual chamber pacemakers. Following a run-in period of 6 months (p1) where AT/AF burden was logged,78 patients were randomised to control or fish oil group (total omega-3 6 g/d) and AT/AF burden evaluated after 6 months (p2 39 controls, 39 fish oil) and 12 months (p3 39 controls 18 fish oil). A subset of 21 fish oil patients crossed over to controls in the final 6 months (crossover group). Median AT/AF burden increased significantly in controls (1.5%, 3.2%, 4.3%, P 1 min was not significantly different between the groups (P=.9). There was a rebound increase in AT/AF burden in p3 in cross over patients (2.2% to 5.8%, P=.01) reaching a level similar to controls (crossover vs. controls, 5.8% vs. 4.3%, P=.63) and higher than those who continued fish oil for 12 months (crossover vs. continued intake 5.8% vs. 1.2%, P=.02). Fish oil patients had shorter duration episodes of AT/AF with no difference in frequency compared to controls. Long-term fish oil supplementation did not suppress AT/AF burden but may have attenuated its temporal progression related to aging and sinus node disease.
Publisher: Oxford University Press (OUP)
Date: 29-06-2018
Abstract: To assess the incremental benefit of uninterrupted direct oral anticoagulants (DOACs) vs. uninterrupted vitamin K antagonists (VKA) for catheter ablation (CA) of non-valvular atrial fibrillation (NVAF) on three primary outcomes: major bleeding, thrombo-embolic events, and minor bleeding. A secondary outcome was post-procedural silent cerebral infarction (SCI) as detected by brain magnetic resonance imaging. A systematic review of Medline, Cochrane, and Embase was done to find all randomized controlled trials (RCTs) in which uninterrupted DOACs were compared against uninterrupted VKA for CA of NVAF. A fixed-effect model was used, with the exception of the analysis regarding major bleeding events (I2 > 25), for which a random effects model was used. The benefit of uninterrupted DOACs over VKA was analysed from four RCTs that enrolled a total of 1716 patients (male: 71.2%) with NVAF. Of these, 1100 patients (64.1%) had paroxysmal atrial fibrillation. No significant benefit was seen in major bleeding events [risk ratio (RR) 0.54, 95% confidence interval (95% CI) 0.29-1.00 P = 0.05]. No significant differences were found in minor bleeding events (RR 1.11, 95% CI 0.82-1.52 P = 0.50), thrombo-embolic events (RR 0.74, 95% CI 0.26-2.11 P = 0.57), or post-procedural SCI (RR 1.06, 95% CI 0.74-1.53 P = 0.74). An uninterrupted DOACs strategy for CA of NVAF appears to be as safe as uninterrupted VKA without a significantly increased risk of minor or major bleeding events. There was a trend favouring DOACs in terms of major bleeding. Given their ease of use, fewer drug interactions and a similar security and effectiveness profile, DOACs should be considered first line therapy in patients undergoing CA for NVAF.
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.HLC.2018.09.010
Abstract: Cardiac arrhythmias are frequently seen in patients with dilated cardiomyopathy (DCM) and can precipitate heart failure and death. In patients with non-ischaemic DCM, evidence for the benefit of an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden cardiac death has recently been questioned. Algorithms devised to identify high-risk in iduals who might benefit most from ICD implantation have focussed on clinical criteria with little attention paid to the underlying aetiology of DCM. Malignant ventricular arrhythmias often occur as a nonspecific consequence of DCM but can also be a primary manifestation of disease in heritable forms of DCM and may precede DCM onset. We undertook a literature search and identified 11 genes that have been associated with DCM and ventricular arrhythmias in multiple kindreds. Many of these genes fall into a diagnostic grey zone between left-dominant arrhythmogenic right ventricular cardiomyopathy and arrhythmic DCM. Genes associated predominantly with arrhythmic DCM included LMNA and SCN5A, as well as the more recently-reported DCM disease genes, RBM20, FLNC, and TTN. Recognition of arrhythmic DCM genotypes is important, as this may impact on clinical management. In particular, prophylactic ICD implantation and early referral for heart transplantation may be indicated in genotype-positive in iduals. Collectively, these findings argue in favour of including genetic testing in standard-of-care management of familial DCM. Further studies in genotyped patient cohorts are required to establish the long-term health and economic benefits of this strategy.
Publisher: Wiley
Date: 03-10-2016
DOI: 10.1111/JCE.13095
Abstract: To correlate impedance decrease during atrial fibrillation (AF) ablation with lesion durability and PV conduction recovery demonstrated during redo procedures. Markers of successful ablation beyond acute conduction block are needed to improve durability of pulmonary vein (PV) isolation (PVI). Local impedance decrease resulting from ablation is a real-time marker of tissue heating and is correlated with lesion creation. Impedance changes associated with point-by-point radiofrequency ablation in the PV antra were recorded during 167 consecutive first-time AF ablations. During clinically indicated redo procedures, sites of recovered PV conduction were identified, and were correlated with the impedance change achieved during ablation at these locations during the initial procedure. Redo procedures were performed in 28 patients, in whom 19 sites of recovered PV conduction were documented. Most sites of PV reconnection (58%) occurred along the posterior PV antra. Ablation resulting in impedance decrease <10 ohms during the initial procedure was present in 89% (17/19) of sites with conduction recovery. Regions with adjacent ablation resulting in impedance decrease <10 ohms were associated with a higher rate of conduction recovery (37% vs. 1.5%, P < 0.001). Likewise, patients with PV conduction recovery demonstrated during redo procedure (Group 1) had larger regions where ablation resulted in <10 ohm impedance decrease than patients without PV conduction recovery (Group 2) (21.9 ± 15.5 mm vs. 11.5 ± 2.1 mm, P < 0.01). Recovered PV conduction occurs predominantly in regions where adjacent ablation applications result in impedance decreases <10 ohms. Impedance-guided ablation strategies may improve durability of PVI.
Publisher: Wiley
Date: 16-09-2020
DOI: 10.1111/JCE.14740
Publisher: Oxford University Press (OUP)
Date: 28-04-2015
Abstract: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation of atrial fibrillation (AF). The intervenous ridge (IVR) may be incorporated into ablation strategies to achieve PVI however, randomized trials are lacking. We performed a randomized multi-centre international study to compare the outcomes of (i) circumferential antral PVI (CPVI) alone (minimal) vs. (ii) CPVI with IVR ablation to achieve in idual PVI (maximal). Two hundred and thirty-four patients with paroxysmal AF underwent CPVI and were randomized to a minimal or maximal ablation strategy. The primary outcome of recurrent atrial arrhythmia was assessed with 7-day Holter monitoring at 6 and 12 months. PVI was achieved in all patients. Radiofrequency ablation time was longer in the maximal group (46.6 ± 14.6 vs. 41.5 ± 13.1 min P < 0.01), with no significant differences in procedural or fluoroscopy times. At mean follow-up of 17 ± 8 months, there was no difference in freedom from AF after a single procedure between a minimal (70%) and maximal ablation strategy (62% P = 0.25). In the minimal group, ablation was required on the IVR to achieve electrical isolation in 44%, and was associated with a significant reduction in freedom from AF (57%) compared with the minimal group without IVR ablation (80% P < 0.01). There was no statistically significant difference in freedom from AF between a minimal and maximal ablation strategy. Despite attempts to achieve PVI with antral ablation, IVR ablation is commonly required. Patients in whom antral isolation can be achieved without IVR ablation have higher long-term freedom from AF (the Minimax study ACTRN12610000863033).
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2022
Publisher: Elsevier BV
Date: 2011
Publisher: Elsevier BV
Date: 04-2020
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2019
DOI: 10.1161/CIRCHEARTFAILURE.118.005371
Abstract: Variants in the cardiomyocyte-specific RNA splicing factor RBM20 have been linked to familial cardiomyopathy, but the causative genetic architecture and clinical consequences of this disease are incompletely defined. To define the genetic architecture of RBM20 cardiomyopathy, we first established a database of RBM20 variants associated with cardiomyopathy and compared these to variants observed in the general population with respect to their location in the RBM20 coding transcript. We identified 2 regions significantly enriched for cardiomyopathy-associated variants in exons 9 and 11. We then assembled a registry of 74 patients with RBM20 variants from 8 institutions across the world (44 index cases and 30 from cascade testing). This RBM20 patient registry revealed highly prevalent family history of sudden cardiac death (51%) and cardiomyopathy (72%) among index cases and a high prevalence of composite arrhythmias (including atrial fibrillation, nonsustained ventricular tachycardia, implantable cardiac defibrillator discharge, and sudden cardiac arrest, 43%). Patients harboring variants in cardiomyopathy-enriched regions identified by our variant database analysis were enriched for these findings. Further, these characteristics were more prevalent in the RBM20 registry than in large cohorts of patients with dilated cardiomyopathy and TTNtv cardiomyopathy and not significantly different from a cohort of patients with LMNA -associated cardiomyopathy. Our data establish RBM20 cardiomyopathy as a highly penetrant and arrhythmogenic cardiomyopathy. These findings underline the importance of arrhythmia surveillance and family screening in this disease and represent the first step in defining the genetic architecture of RBM20 disease causality on a population level.
Publisher: JMIR Publications Inc.
Date: 19-01-2021
Abstract: ardiac arrhythmias are a leading cause of death. The mainstay method for diagnosing arrhythmias (eg, atrial fibrillation) and cardiac conduction disorders (eg, prolonged corrected QT interval [QTc]) is by using 12-lead electrocardiography (ECG). Handheld 12-lead ECG devices are emerging in the market. In tandem with emerging technology options, evaluations of device usability should go beyond validation of the device in a controlled laboratory setting and assess user perceptions and experiences, which are crucial for successful implementation in clinical practice. his study aimed to evaluate clinician and patient perceptions and experiences, regarding the usability of a handheld 12-lead ECG device compared to a conventional 12-lead ECG machine, and generalizability of this user-centered approach. nternational Organization for Standardization Guidelines on Usability and the Technology Acceptance Model were integrated to form the framework for this study, which was conducted in outpatient clinics and cardiology wards at Westmead Hospital, New South Wales, Australia. Each patient underwent 2 ECGs (1 by each device) in 2 postures (supine and standing) acquired in random sequence. The times taken by clinicians to acquire the first ECG (efficiency) using the devices were analyzed using linear regression. Electrocardiographic parameters (QT interval, QTc interval, heart rate, PR interval, QRS interval) and participant satisfaction surveys were collected. Device reliability was assessed by evaluating the mean difference of QTc measurements within ±15 ms, intraclass correlation coefficient, and level of agreement of the devices in detecting atrial fibrillation and prolonged QTc. Clinicians’ perceptions and feedback were assessed with semistructured interviews based on the Technology Acceptance Model. total of 100 patients (age: mean 57.9 years, SD 15.2 sex: male: n=64, female n=36) and 11 clinicians (experience acquiring ECGs daily or weekly 10/11, 91%) participated, and 783 ECGs were acquired. Mean differences in QTc measurements of both handheld and conventional devices were within ±15 ms with high intraclass correlation coefficients (range 0.90-0.96), and the devices had a good level of agreement in diagnosing atrial fibrillation and prolonged QTc (κ=0.68-0.93). Regardless of device, QTc measurements when patients were standing were longer duration than QTc measurements when patients were supine. Clinicians’ ECG acquisition times improved with usage ( i P /i & .001). Clinicians reported that device characteristics (small size, light weight, portability, and wireless ECG transmission) were highly desired features. Most clinicians agreed that the handheld device could be used for clinician-led mass screening with enhancement in efficiency by increasing user training. Regardless of device, patients reported that they felt comfortable when they were connected to the ECG devices. eliability and usability of the handheld 12-lead ECG device were comparable to those of a conventional ECG machine. The user-centered evaluation approach helped us identify remediable action to improve the efficiency in using the device and identified highly desirable device features that could potentially help mass screening and remote assessment of patients. The approach could be applied to evaluate and better understand the acceptability and usability of new medical devices.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2012
DOI: 10.1161/CIRCEP.111.968859
Abstract: Inducibility of atrial fibrillation (AF) after pulmonary vein isolation has been used to guide additional left atrial ablation in paroxysmal AF. The sensitivity and specificity of AF induction in this setting remains uncertain. We examined the incidence and characteristics of inducible AF in patients without structural heart disease or clinical AF and the effect of different induction protocols on AF inducibility. In 44 patients with supraventricular tachycardia with no history of AF or risk factors for AF, atrial refractoriness and conduction were measured, followed by AF induction attempts (10 atient). Each induction was performed after a waiting time that exceeded twice the duration of induced AF from the preceding induction. AF ≥1 minute was considered inducible, and ≥5 minutes as sustained. Burst pacing (at 200 ms for 10 seconds) was compared to decremental pacing (from 200 ms to shortest cycle length, resulting in 1:1 atrial capture for 10 seconds). After 10 inductions, AF was inducible in 49.5%, and sustained in 29.5% of patients. The incidence of both inducible and sustained AF increased with each induction. Apart from male gender, no clinical or electrophysiological features were associated with sustained AF. Decremental pacing was associated with a higher incidence of sustained AF (41.2% versus 14.8%, P =0.049), longer duration of AF ( P =0.006), and shorter mean AF cycle length ( P .001) compared with burst pacing. Inducible and sustained AF is common in patients in the absence of structural heart disease or clinical AF, and its incidence varies according to gender, method of induction, and number of inductions. There is a direct relationship between AF persistence and number of inductions, which has not reached a plateau after 10 inductions.
Publisher: Wiley
Date: 09-2022
DOI: 10.1111/IMJ.15900
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2022
DOI: 10.1161/CIRCEP.122.011129
Abstract: Ventricular tachycardia (VT) storm is associated with significantly increased morbidity, mortality, and exponential healthcare utilization. Although catheter ablation (CA) may be curative, there are limited data directly comparing outcomes of early CA with initial medical therapy. We compared outcomes of patients presenting with VT storm treated with initial CA versus those treated with initial medical therapy during their first storm presentation in an observational study. Retrospective data from the host institution from January 2014 to April 2020 of 129 patients with their first VT storm presentation were analyzed (58 underwent initial CA, 71 underwent treatment with initial medical therapy). Outcomes were compared in follow-up. Median time to initial CA was 6 days. Over a median follow-up of 702 days, patients who underwent initial CA compared with those treated with initial medical therapy had significantly less: (i) VA recurrence (43% versus 92% P =0.002) (ii) VT storm recurrence (28% versus 73% P .001) (iii) composite end point of death, heart transplant, VT storm recurrence, and VT-related hospitalization (47% versus 89% P =0.002) (iv) iatrogenic complications (at 12 months: 17% versus 45% P .001) (v) cardiovascular-related hospitalizations (50% versus 89% P =0.01) (vi) total number of hospitalizations (median 1 versus 4 P .001) and (vi) cumulative days in hospital (median 0.5 versus 18 P .001). There were no intraprocedural deaths in patients treated with early CA. In an observational setting in which patients presenting with storm, early CA appears superior to initial medical therapy in terms of VT recurrence, storm recurrence, iatrogenic complications, cardiovascular hospitalizations, and cumulative days in hospital in follow-up.
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.HLC.2022.02.014
Abstract: There are differences in substrate and ablation approaches for ventricular tachycardia (VT) in ischaemic (ICM) and non-ischaemic cardiomyopathy (NICM). To perform a systematic review and meta-analysis comparing clinical and procedural characteristics/outcomes of VT ablation in ICM versus NICM. Electronic databases were searched for comparative studies reporting outcomes of VT ablation in patients with ICM and NICM. Primary outcomes were acute procedural success, VT recurrence and long-term mortality. Meta-analyses were performed using random-effects modelling. Thirty-one (31) studies (7,473 patients 4,418 ICM and 3,055 NICM) were included. Patients with ICM were significantly older (67.0 vs 55.3 yrs), more commonly male (89% vs 79%), had lower left ventricular ejection fraction (29% vs 38%) were less likely to undergo epicardial access (11% vs 36%) and were more likely to require haemodynamic support during ablation (relative risk [RR] 1.30 95% CI 1.01-1.69). Acute procedural success (i.e. non-inducibility of VT) was higher in the ICM cohort (RR 1.10, 95% CI 1.05-1.15). Recurrence of VT at follow-up was significantly lower in the ICM cohort (RR 0.77 95% CI 0.70-0.84). Peri-procedural mortality, incidence of procedural complications and long-term mortality were not significantly different between the cohorts. NICM and ICM patients undergoing VT ablation are fundamentally different in their clinical characteristics, ablation approaches, acute procedural outcomes and likelihood of VA recurrence. VT ablation in NICM has a lower likelihood of procedural success with increased risk of VA recurrence, consistent with known challenging arrhythmia substrate.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2017
Publisher: Wiley
Date: 23-05-2011
DOI: 10.1111/J.1540-8159.2011.03129.X
Abstract: Prolonged right ventricular (RV) apical pacing produces dysynchronous ventricular contraction, which may result in left ventricular (LV) dysfunction, whereas septal pacing sites might reflect a more synchronous LV activation. This study examined a method of evaluating alternate RV pacing sites using a template scoring system based on measuring the angle of lead attachment in the 40° left anterior oblique (LAO) fluoroscopic view and its effect on altering the loop of lead in the RV. Twenty-three consecutive patients for RV pacing were enrolled. Conventional active fixation leads were positioned in either the RV outflow tract (RVOT) or mid RV using a stylet designed for septal placement (Model 4140, St. Jude Medical, St. Paul, MN, USA). Using LAO cine fluoroscopy, a generous loop of lead was inserted into the RV chamber and the change in angle of attachment determined. Successful positioning of pacing leads at the RVOT septum (18 patients) and mid-RV septum (five patients) was achieved. With introduction of more lead into the RV chamber, the angle of attachment in the LAO projection altered over a range of 6°-32° for all patients with a mean of 14.6 ± 6.6°. In 87% of patients, the range was predominantly within the same template score with only minor overlap into another zone. This study shows that the angle of lead attachment in the RV is altered by introducing more lead, but in most cases, the template score remains the same. Further studies are required to determine the accuracy and efficacy of the templates.
Publisher: Oxford University Press (OUP)
Date: 08-08-2014
Abstract: To characterize the nature of atrial fibrillation (AF) activation in human persistent AF (PerAF) using modern tools including activation, directionality analyses, complex-fractionated electrogram, and spectral information. The mechanism of PerAF in humans is uncertain. High-density epicardial mapping (128 electrodes/6.75 cm(2)) of the posterior LA wall (PLAW), LA and RA appendage (LAA, RAA), and RSPV-LA junction was performed in 18 patients with PerAF undergoing open heart surgery. Continuous 10 s recordings were analysed offline. Activation patterns were characterized into four subtypes (i) wavefronts (broad or multiple), (ii) rotational circuits (≥2 rotations of 360°), (iii) focal sources with centrifugal activation of the entire mapping area, or (iv) disorganized activity [isolated chaotic activation(s) that propagate ≤3 bipoles or activation(s) that occur as isolated beats dissociated from the activation of adjacent bipole sites]. Activation at a total of 36 regions were analysed (14 PLAW, 3 RSPV-LA, 12 LAA, and 7 RAA) creating a database of 2904 activation patterns. In the majority of maps, activation patterns were highly heterogeneous with multiple unstable activation patterns transitioning from one to another during each recording. A mean of 3.8 ± 1.6 activation subtypes was seen per map. The most common patterns seen were multiple wavefronts (56.2 ± 32%) and disorganized activity (24.2 ± 30.3%). Only 2 of 36 maps (5.5%) showed a single stable activation pattern throughout the 10-s period. These were stable planar wavefronts. Three transient rotational circuits were observed. Two of the transient circuits were located in the posterior left atrium, while the third was located on the anterior surface of the LAA. Focal activations accounted for 11.3 ± 14.2% of activations and were all short-lived (≤2 beats), with no site demonstrating sustained focal activity. Human long-lasting PerAF is characterized by heterogeneous and unstable patterns of activation including wavefronts, transient rotational circuits, and disorganized activity.
Publisher: Springer Science and Business Media LLC
Date: 25-07-2014
DOI: 10.1007/S11886-014-0522-3
Abstract: Ventricular arrhythmias (VA) are a significant contributor to morbidity and mortality in patients with heart failure (HF). Implantable cardioverter defibrillators are effective in reducing mortality, but do not prevent arrhythmia recurrence. There is increasing recognition that frequent premature ventricular contractions or repetitive ventricular tachycardia may also lead to new onset ventricular dysfunction or deterioration of ventricular function in patients with pre-existing HF. Suppression of the arrhythmia may lead to recovery of ventricular function. Catheter ablation has emerged as a safe and effective treatment option for reducing arrhythmia recurrence and for suppression of PVCs but its efficacy is governed by the nature of the arrhythmias, the underlying HF substrate and the accessibility of the arrhythmia substrates to ablation.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2020
Publisher: Elsevier BV
Date: 04-2012
DOI: 10.1016/J.HRTHM.2011.11.034
Abstract: Persistent atrial fibrillation (AF) is associated with a high risk of recurrence after electrical cardioversion. We examined if long-term supplementation with omega-3 polyunsaturated fatty acids in fish oils commenced >1 month prior to electrical cardioversion and continued thereafter reduces recurrence of persistent AF. This was an open-label, randomized study of 178 patients with persistent AF >1-month duration. Participants were assigned to control group (n = 87) or omega-3 group (6 g/d fish oil n = 91) and underwent cardioversion 1 month later. Concurrent antiarrhythmic use of sotalol or amiodarone was permitted. Fish oil was continued till return of persistent AF or a maximum of 1 year. Intention-to-treat analysis was performed for the primary end point defined as the recurrence of persistent AF. Mean duration of fish oil intake was 56 days precardioversion and a total of 242 days in follow-up. Eicosapentaenoic acid and docosahexaenoic acid, the active components of fish oils, were 1.8-fold and 2.1-fold higher, respectively, in the omega-3 group compared with controls at the time of cardioversion (P <.001). At 90 days, 38.5% of the patients receiving omega-3 fatty acid supplement had AF recurrence compared with 77.5% of the controls (hazard ratio [omega-3 vs control] 0.38 95% confidence interval 0.27-0.56 P 1 month prior to electrical cardioversion and continued thereafter reduces the recurrence of persistent AF. Randomized controlled trials on long-term fish oil supplementation are needed to confirm these findings.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Public Library of Science (PLoS)
Date: 10-02-2020
Publisher: Elsevier BV
Date: 10-2018
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-05-2016
DOI: 10.1161/CIRCULATIONAHA.116.018011
Abstract: Although sinus node dysfunction (SND) and atrial arrhythmias frequently coexist and interact, the putative mechanism linking the 2 remain unclear. Although SND is accompanied by atrial myocardial structural changes in the right atrium, atrial fibrillation (AF) is a disease of variable interactions between left atrial triggers and substrate most commonly of left atrial origin. Significant advances have been made in our understanding of the genetic and pathophysiologic mechanism underlying the development and progression of SND and AF. Although some patients manifest SND as a result of electric remodeling induced by periods of AF, others develop progressive atrial structural remodeling that gives rise to both conditions together. The treatment strategy will thus vary according to the predominant disease phenotype. Although catheter ablation will benefit patients with predominantly AF and secondary SND, cardiac pacing may be the mainstay of therapy for patients with predominant fibrotic atrial cardiomyopathy. This contemporary review summarizes current knowledge on sinus node pathophysiology with the broader goal of yielding insights into the complex relationship between sinus node disease and atrial arrhythmias.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 09-2010
Publisher: Elsevier BV
Date: 08-2019
Publisher: Springer Science and Business Media LLC
Date: 09-01-2017
DOI: 10.1007/S10840-016-0211-9
Abstract: Atrial fibrillation (AF) and cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) are two separate entities that coexist in a significant percentage of patients. We sought to investigate whether AF inducibility during CTI AFL ablation predicted the occurrence of AF at follow-up after successful AFL ablation. A systemic review of Medline, Cochrane, and Embase was done for all the clinical studies in which assessment of AF inducibility in patients undergoing ablation for CTI AFL was performed. Given the low heterogeneity (i.e., I A total of 10 studies (4 prospective and 6 retrospective) with a total of 1299 patients (male, 73% mean age 59 ± 11 years) fulfilled the inclusion criteria. During a mean follow-up period of 23 ± 7.6 months, 407 patients (31%) developed AF during AFL ablation. The overall incidence for new-onset AF during follow-up was 29% (47% in the group with inducible AF vs. 21% in the non-inducible group). The odds ratio (OR) for developing AF after AFL ablation in patients with AF inducibility for all studies combined was 3.72, 95% CI 2.83-4.89 [prospective studies (OR 5.52, 95% CI 3.23-9.41) vs. retrospective studies (OR 3.23, 95% CI 2.35-4.45)]. Although ablation for CTI AFL is highly effective, AF continues to be a long-term risk for in iduals undergoing this procedure. AF induced by pacing protocols in patients undergoing CTI AFL predicts for future AF. Inducible AF is a clinically relevant finding that may help guide decisions for long-term anticoagulation after successful typical AFL ablation especially in patients with elevated CHADS-VASc scores (≥2) and in considering prophylactic PVI during CTI AFL ablation.
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.HRTHM.2013.08.022
Abstract: It has been reported that cardiological screening and genetic evaluation in relatives of families with sudden unexplained death syndrome and unexplained cardiac arrest (UCA) may uncover a heritable etiology in a significant proportion of families. To evaluate the yield of a comprehensive evaluation protocol of a large unselected cohort of consecutive families with autopsy-negative sudden unexplained death syndrome (termed sudden arrhythmic death syndrome [SADS]) and UCA. We studied (1) 109 consecutive families (411 relatives) referred with 1 or more sudden deaths in the family and (2) 52 consecutive probands with UCA (91 relatives) referred by cardiologists between January 2007 and December 2012. A comprehensive cardiological screening was performed followed by targeted genetic evaluation if a clinical phenotype was proven or suspected. Diagnosis was made by a multidisciplinary team using published clinical criteria. A diagnosis was made in 19 of 109 families with SADS (yield 18%), with the majority having long QT syndrome (LQTS). Diagnosis varied according to proband age, with LQTS most common in the very young (≤20 years) and Brugada syndrome in the older age probands (≥40 years) (P = .03). In contrast, a diagnosis was made in 32 of 52 families with UCA (yield 62%), the majority of which had LQTS and Brugada syndrome. No clinical or circumstantial factors increased the likelihood of diagnosis in families with either SADS or UCA. In contrast to previously published series, a comprehensive strategy of cardiological evaluation and targeted genetic testing in more than 100 families with SADS was found to have a lower diagnostic yield (18%). Diagnostic yield in families with UCA was approximately 4 times higher (62%), which is consistent with the published literature.
Publisher: Elsevier BV
Date: 07-2015
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.JACEP.2015.09.010
Abstract: This study sought to assess loss of pulmonary vein (PV) excitability to pacing relative to the development of entrance block and the anatomic completion of the circumferential radiofrequency ablation (RFA) line. During encircling RFA for PV isolation (PVI), entrance block develops before anatomic completion of encirclement (early) in some patients. We hypothesized that early entrance block may be associated with loss of PV excitability to pacing. In 30 patients undergoing PV isolation (age 61 ± 10 years, 21 men), excitability to pacing was assessed at predefined PV sites when entrance block developed and after completion of the RFA line. Of 60 PV pairs, 37 developed entrance block early, with a gap ≥10 mm in the RFA line. In only 35% of PV pairs in this subgroup, both PV sleeves captured, and all of the capturing PV pairs showed exit block (no conduction from PV to atrium) despite the presence of an excitable gap. In the remaining 23 PV pairs, entrance block did not occur until encircling RFA was anatomically complete. In 83% of these PV pairs, both sleeves captured with exit block (p < 0.001 compared with early block PVs). The majority of PV pairs develops entrance and exit block before complete anatomic encircling by RFA lesions. Early entrance block is frequently associated with loss of PV sleeve excitability, consistent with a spreading wave of injury or edema rather than a permanent conduction barrier. This may help to explain the significant rate of PV conduction recovery associated with the acute endpoints of entrance and exit block.
Publisher: AMPCo
Date: 31-07-2020
DOI: 10.5694/MJA2.50714
Publisher: Wiley
Date: 02-2010
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 10-2021
DOI: 10.1016/J.JACEP.2021.06.001
Abstract: This study describes the clinical and electrophysiological characteristics of basal-septal ventricular tachycardias (VTs) in patients with structural heart disease (SHD). The basal septum is a common source of VT in patients with SHD. Data from 312 consecutive patients with SHD undergoing catheter ablation of ventricular arrhythmias were reviewed. Thirty-three basal-septal VTs in 31 patients (mean age 67.4 ± 14.2 years, mean left ventricular ejection fraction [LVEF] 42% ± 15%) were identified. Patients with VTs with left ventricular basal-septal breakthrough were more likely to have ischemic cardiomyopathy and lower LVEF patients with right ventricular basal-septal VT were more likely to have sarcoidosis or right ventricular cardiomyopathy of unknown significance, with higher LVEF. Atrioventricular block was present in 45% of patients and intraventricular block including persistent biventricular pacing in 77%. Unipolar scar was larger than bipolar scar (area 18.8% ± 19.4% vs 12.7% ± 14.6% P < 0.001). VTs with right bundle branch block configuration and S wave in lead V Basal-septal VTs in patients with SHD have a distinct clinical, electrocardiographic, and electrophysiological profile depending on the breakthrough site, accompanied by a deep intramural septal substrate that limits procedural success after catheter ablation.
Publisher: Oxford University Press
Date: 07-2018
DOI: 10.1093/MED/9780198784906.003.0530
Abstract: Advances in surgery and clinical care have resulted in a progressive increase in life expectancy of patients with congenital heart disease (CHD). Cardiac arrhythmias are a common and onerous complication in CHD, of which atrial fibrillation (AF) is rapidly increasing in prevalence. AF frequents coexists with intra-atrial reentrant tachycardias. AF onset and prevalence may vary as a function of the congenital lesion as well as the operative repair. AF progression to a persistent or permanent form may be rapid. Cardioembolic risks in this population are higher compared to those without CHD. Common cardioembolic risk predictors lack validation in this population. Rhythm control with antiarrhythmic drugs can be challenging due to low efficacy and toxicity. Rate control is critical as AF with rapid ventricular rates may be poorly tolerated in patients with complex CHD and may be associated with an increased risk of sudden cardiac death. There is limited evidence for the role of percutaneous catheter ablation for AF. Concurrent atrial arrhythmia surgery should be considered in patients with a prior history of AF scheduled to undergo open cardiac surgery primarily to address an underlying cardiac lesion. Much further work is needed to expand our understanding of the mechanism of AF in CHD and improve efficacy of catheter ablation in this population.
Publisher: Elsevier BV
Date: 06-2020
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2017
DOI: 10.1161/CIRCEP.117.005005
Abstract: Noninducibility of sustained monomorphic ventricular tachycardia (SMVT) postablation does not insure absence of later recurrence in patients with ischemic cardiomyopathy. This study aims to determine the relation between inducible nonsustained VT postablation and VT recurrences. One hundred sixty-five consecutive patients (156 male age 68±9 years) underwent ablation for SMVT because of ischemic cardiomyopathy 44 patients who did not have induction testing or in whom only ventricular fibrillation was induced after ablation were excluded. In 38 patients (23%), SMVT was inducible (group C). Of the 83 patients without inducible SMVT after ablation, nonsustained VT defined as ≥5 beats lasting for s, was induced in 34 patients (group B, 21%), whereas the remaining 49 patients had no VT induced by the induction test (group A, 30%). Over a median follow-up of 18.7 months, freedom from recurrent VT at 24 months was 60% in group A, 45% in group B ( P =0.017 versus group A), and 38% in group C ( P =0.005 versus group A). In patients without inducible SMVT, inducible nonsustained VT and left ventricular ejection fraction was independently associated with VT recurrence (hazard ratio, 3.66 and 1.07 95% CI, 1.3–11.1 and 1.01–1.14). Inducible nonsustained VT postablation suggests the continued presence of functional arrhythmia substrate. Further trials are needed to assess whether additional ablation would improve outcome in this group.
Publisher: Wiley
Date: 02-01-2014
DOI: 10.1111/PACE.12331
Abstract: Direct His bundle capture may negate ventricular electrical dyssynchrony induced by right ventricular (RV) apical pacing. We sought to evaluate if direct His bundle pacing is possible with conventional pacemaker lead implantation at various sites in the RV. Consecutive patients underwent RV pacing using standard implantable active fixation pacing leads in a random order in the RV outflow tract, middle RV, and RV apex at stimulation threshold and at increasing voltages of 2.5, 5, 7.5, and 10 volts (V). At each location, QRS width and morphology on 12-lead electrocardiograph (ECG) were compared in sinus and paced rhythm at the different voltages. Twelve patients underwent a total of 2,160 paced QRS measurements. Progressive increases in stimulation voltage did not change QRS morphology or duration regardless of site of pacing (RV outflow tract, middle RV, and RV apex) in any of the 12 ECG leads. In addition, apart from the stimulation threshold between the RV outflow tract and RV apex, there was no statistically significant difference in QRS duration between the three pacing sites. In patients with a baseline normal QRS duration, none of the three conventional RV pacing sites were able to produce QRS narrowing and capture the His-Purkinje system. Furthermore, based on paced QRS duration as an indirect surrogate of electrical LV dyssynchrony, there was no clear advantage of one pacing site over another.
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.HRTHM.2015.01.003
Abstract: Distinguishing orthodromic atrioventricular reciprocating tachycardia (ORT) using a retrograde septal accessory pathway (AP) from atypical atrioventricular nodal reentrant tachycardia (AVNRT) may be challenging. Specifically, excluding the presence and participation of an AP may require multiple diagnostic maneuvers. The purpose of this study was to assess the relative value of commonly used right ventricular (RV) pacing maneuvers, including identification of anterograde His-bundle activation with entrainment, to differentiate ORT using a retrograde septal AP from atypical AVNRT. From March 2009 to June 2014, 56 patients (28 female age 43.9 ± 17.4 years) who underwent electrophysiologic study and ablation for supraventricular tachycardia (26 ORT using septal AP and 30 atypical AVNRT) that exhibited a concentric atrial activation pattern and a septal ventriculoatrial interval >70 ms were analyzed. Overdrive pacing maneuvers or ventricular extrastimuli failed on at least 1 occasion to correctly identify a septal AP. Overall, 16 ORT patients and 26 AVNRT patients had successful RV entrainment, and 12 (75%) ORT patients showed anterograde His capture (11 patients) and/or anterograde septal ventricular capture (3 patients). None of the patients with atypical AVNRT showed anterograde conduction to the His bundle with entrainment. RV pacing maneuvers are useful to exclude an AP in patients with AVNRT having concentric atrial activation sequence and a septal ventriculoatrial interval >70 ms however, none are consistently diagnostic. When observed in this patient population, anterograde His-bundle or septal ventricular capture during RV entrainment was diagnostic for ORT using a septal AP.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 23-07-2019
DOI: 10.1161/CIRCULATIONAHA.118.039410
Abstract: An accurate estimation of the risk of life-threatening (LT) ventricular tachyarrhythmia (VTA) in patients with LMNA mutations is crucial to select candidates for implantable cardioverter-defibrillator implantation. We included 839 adult patients with LMNA mutations, including 660 from a French nationwide registry in the development s le, and 179 from other countries, referred to 5 tertiary centers for cardiomyopathies, in the validation s le. LTVTA was defined as (1) sudden cardiac death or (2) implantable cardioverter defibrillator–treated or hemodynamically unstable VTA. The prognostic model was derived using the Fine-Gray regression model. The net reclassification was compared with current clinical practice guidelines. The results are presented as means (SD) or medians [interquartile range]. We included 444 patients, 40.6 (14.1) years of age, in the derivation s le and 145 patients, 38.2 (15.0) years, in the validation s le, of whom 86 (19.3%) and 34 (23.4%) experienced LTVTA over 3.6 [1.0–7.2] and 5.1 [2.0–9.3] years of follow-up, respectively. Predictors of LTVTA in the derivation s le were: male sex, nonmissense LMNA mutation, first degree and higher atrioventricular block, nonsustained ventricular tachycardia, and left ventricular ejection fraction (lmna-risk-vta.fr). In the derivation s le, C-index (95% CI) of the model was 0.776 (0.711–0.842), and the calibration slope 0.827. In the external validation s le, the C-index was 0.800 (0.642–0.959), and the calibration slope was 1.082 (95% CI, 0.643–1.522). A 5-year estimated risk threshold ≥7% predicted 96.2% of LTVTA and net reclassified 28.8% of patients with LTVTA in comparison with the guidelines-based approach. In comparison with the current standard of care, this risk prediction model for LTVTA in laminopathies significantly facilitated the choice of candidates for implantable cardioverter defibrillators. URL: www.clinicaltrials.gov . Unique identifier: NCT03058185.
Publisher: Wiley
Date: 03-11-2017
DOI: 10.1111/JCE.13346
Abstract: Right ventricular (RV)-scar related ventricular tachycardia (VT) is often due to arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) or cardiac sarcoidosis (CS), but some patients whose clinical course has not been described do not fulfill diagnostic criteria for these diseases. We sought to characterize the electrophysiologic substrate and catheter ablation outcomes of such patients, termed RV cardiomyopathy of unknown source (RCUS). Data of 100 consecutive patients who presented with RV cardiomyopathy and/or RV-related VT for ablation were reviewed (51 ARVC/D, 22 CS 27 RCUS). Compared to ARVC/D, RCUS patients were older (P = 0.001), less commonly had RV dilatation (P = 0.001) or dysfunction (P = 0.01) and fragmented QRS, parietal block, and T-wave inversion. Compared to CS, R-CUS patients had less severe LV dysfunction. Extent and distribution of endocardial/epicardial scar and inducible VTs in RCUS patients were comparable with ARVC/D and CS patients. At a median follow-up of 23 months, RCUS patients had more favorable VT-free survival (RCUS 71%, ARVC/D 60%, CS 41%, P = 0.03) and survival free of death or cardiac transplant (RCUS 92%, ARVC/D 92%, CS 62%, P = 0.01). No RCUS patients developed new criteria for ARVC/D or CS in follow-up. Up to one-third of patients with RV scar-related VT are not classifiable as ARVC/D or CS. These patients had a somewhat better prognosis than ARVC/D or sarcoid and did not develop evidence of these diseases during the initial 2 years of follow-up. The extent to which this population comprises mild ARVC/D, CS, or other diseases is not clear.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-04-2016
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
DOI: 10.1161/CIRCEP.114.002522
Abstract: Ventricular tachycardia (VT) refractory to antiarrhythmic drugs and standard percutaneous catheter ablation techniques portends a poor prognosis. We characterized the reasons for ablation failure and describe alternative interventional procedures in this high-risk group. Sixty-seven patients with VT refractory to 4±2 antiarrhythmic drugs and 2±1 previous endocardial/epicardial catheter ablation attempts underwent transcoronary ethanol ablation, surgical epicardial window (Epi-window), or surgical cryoablation (OR-Cryo age, 62±11 years VT storm in 52%). Failure of endo/epicardial ablation attempts was because of VT of intramural origin (35 patients), nonendocardial origin with prohibitive epicardial access because of pericardial adhesions (16), and anatomic barriers to ablation (8). In 8 patients, VT was of nonendocardial origin with a coexisting condition also requiring cardiac surgery. Transcoronary ethanol ablation alone was attempted in 37 patients, OR-Cryo alone in 21 patients, and a combination of transcoronary ethanol ablation and OR-Cryo (5 patients), or transcoronary ethanol ablation and Epi-window (4 patients), in the remainder. Overall, alternative interventional procedures abolished ≥1 inducible VT and terminated storm in 69% and 74% of patients, respectively, although 25% of patients had at least 1 complication. By 6 months post procedures, there was a significant reduction in defibrillator shocks (from a median of 8 per month to 1 P .001) and antiarrhythmic drug requirement although 55% of patients had at least 1 VT recurrence, and mortality was 17%. A collaborative strategy of alternative interventional procedures offers the possibility of achieving arrhythmia control in high-risk patients with VT that is otherwise uncontrollable with antiarrhythmic drugs and standard percutaneous catheter ablation techniques.
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.HRTHM.2014.09.002
Abstract: Entrainment can be useful for mapping atrial tachycardias (ATs) after atrial fibrillation (AF) ablation but may result in AT alteration or termination. We aimed to determine the incidence and risk factors for AT alteration or termination. In 30 consecutive patients, 62 ATs (mean cycle length [CL] 268 ± 53 ms) in which overdrive pacing for entrainment mapping was performed were retrospectively analyzed. AT was classified as altered if the CL or activation pattern remained altered 10 seconds after pacing. The variability in the PP intervals was determined over 10 beats from 2 measures: (1) the difference between the shortest and the longest CL expressed as a percentage of the CL and (2) the mean difference between sequential PP intervals expressed as a percentage of the AT CL (CLDmean). Of 386 total pacing attempts (tachycardia CL [TCL] - pacing CL [PCL] difference 15 ± 6 ms), 5 (1.3%) altered or terminated AT and 381 did not change AT (98.7%). When the TCL - PCL difference was ≤20 ms, only 2 of 353 (0.5%) attempts altered or terminated AT. When the TCL - PCL difference was >20 ms, 3 of 33 (9%) attempts altered or terminated AT. The difference between the shortest and the longest CL expressed as a percentage of the CL was significantly greater in ATs that were altered or terminated by pacing than in those unchanged (11.0% ± 9.6% vs 4.5% ± 4.5% P = .007), but the mean difference between sequential PP intervals expressed as a percentage of the AT CL was not significantly different (3.8% ± 2.6% vs 1.9% ± 2.1% P = .06). Overdrive pacing for entrainment mapping rarely alters or terminates after atrial fibrillation AT, provided that AT is stable before pacing and that the PCL is ≤20 ms shorter than the AT CL.
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.HRTHM.2015.02.016
Abstract: Ventricular arrhythmias (VAs) from the left ventricular outflow tract (LVOT) region can be inaccessible for ablation because of epicardial fat or overlying coronary arteries. We describe surgical cryoablation of this type of VA. From March 2009 to 2014, 190 consecutive patients with VAs originating from the LVOT underwent ablation at our institution. Four patients (2%) underwent surgical cryoablation for highly symptomatic VAs after failing catheter ablation. In all patients, endocardial or percutaneous epicardial mapping was consistent with origin in the LVOT. In 2 patients, the points of earliest activation during VAs were marked with a bipolar pacing lead in the overlying cardiac vein for guidance during surgery. Surgical cryoablation was successful in 3 of the 4 patients. The fourth patient subsequently had successful endocardial catheter ablation. During a mean follow-up of 22 ± 16 months (range 4-42 months), all patients showed abolition of or marked reduction in symptomatic VA. However, 1 patient subsequently required percutaneous intervention to the left anterior descending coronary artery another developed progressive left ventricular systolic dysfunction caused by nonischemic cardiomyopathy and a third patient underwent permanent pacemaker implantation because of complete atrioventricular block after concomitant aortic valve replacement. Surgical cryoablation is an option for highly symptomatic drug-resistant VAs emanating from the LVOT region. Despite extensive preoperative mapping, the procedure is not effective for all patients, and coronary injury is a risk.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.JACEP.2018.01.016
Abstract: This study sought to examine the relationship between the number of oral antiarrhythmic drug (AAD) failures before referral for ventricular tachycardia (VT) ablation and subsequent clinical outcomes. Failure of AADs prompts referral for VT ablation. Consecutive patients (n = 669) with sustained VT who were referred for a first-time ablation were ided into 2 groups according to the number of oral Class 1 or 3 AAD failures before referral: single-drug failure (≤1 AAD n = 256) or multidrug failure (>1 AADs n = 413). Outcomes were stratified according to underlying disease type (no structural heart disease [SHD] [n = 87] ischemic cardiomyopathy [ICM] [n = 368] and ischemic cardiomyopathy [NICM] [n = 214]) and reported at a mean follow-up of 35 ± 46 months. Patients with multidrug failure, compared with patients with single-drug failure, had more advanced SHD and required more extensive ablation to control arrhythmia. Multidrug failure, compared with single-drug failure, was associated with lower ventricular arrhythmia-free survival in ICM (46 ± 4% vs. 58 ± 6% p = 0.03) and NICM (26 ± 5% vs. 49 ± 6% p = 0.008), but not in the absence of SHD (71 ± 8% vs. 85 ± 7% p = 0.10). Overall survival was lower in multidrug failure versus single-drug failure groups in patients with ICM (71 ± 3% vs. 84 ± 4% p = 0.03) and NICM (70 ± 5% vs. 88 ± 4% p < 0.001). Multidrug failure was independently associated with a higher risk of ventricular arrhythmia recurrence (hazard ratio: 1.6 p = 0.01) and mortality in NICM (hazard ratio: 2.6 p = 0.008), but not in ICM. Patients with SHD and failure of multiple oral AADs before VT ablation referral have more advanced heart disease and worse clinical outcomes following ablation, especially in NICM.
Publisher: Elsevier
Date: 2018
Publisher: Elsevier BV
Date: 10-2014
Publisher: Elsevier BV
Date: 07-2020
Publisher: Oxford University Press (OUP)
Date: 22-06-2012
Abstract: The prognostic significance of ventricular tachycardia (VT) induced by three extrastimuli (ES) is similar to that of VT induced by one or two ES in patients with coronary disease and abnormal left ventricular (LV) function. The significance of VT inducible with four ES is unclear. To examine the prognostic significance of VT inducible with the fourth ES in patients with post-myocardial infarct (MI) LV dysfunction. Consecutive patients (n= 432) with post-MI LV ejection fraction ≤40% underwent electrophysiological (EP) studies for risk stratification. Inducible VT ≥ 200 ms cycle length (CL) with one to four ES was considered inducible. The primary endpoint of arrhythmia (sudden death or spontaneous VT/ventricular fibrillation) was compared among patients with VT inducible with less than or equal to two, three, and four ES. The incidence of inducible VT was 37.9% (n= 164). In patients with inducible VT, inducibility was with less than or equal to two, three, and four ES in 24% (n= 39), 46% (n= 75), and 30% (n= 50). Compared to VT induced with less than or equal to three ES, VT induced with the fourth ES was of shorter CL (218 vs. 256 ms, P = 0.01) and more likely to be haemodynamically unstable requiring cardioversion (77 vs. 55%, P = 0.05). After 3 years the primary endpoint occurred in 28 ± 8, 28 ± 6, and 18 ± 6% in patients with VT induced with less than or equal to two, three, and four ES, respectively (P= 0.31) and in 5 ± 2% of EP-negative patients (P< 0.01). In patients with post-MI LV dysfunction, VT can be induced in a significant proportion of patients with the fourth ES. These patients are at comparable risk of arrhythmia to patients with inducible VT with less than or equal to three ES.
Publisher: Oxford University Press (OUP)
Date: 24-06-2013
Abstract: Percutaneous coronary intervention (PCI) and catheter ablation are well-accepted therapeutic interventions for treatment of coronary artery disease and atrial fibrillation (AF), respectively. We sought to examine temporal trends in the provision of these services over the past decade in Australia. A retrospective review of the numbers of PCIs and AF ablations from 2000/01 to 2009/10 was performed on data from three sources: the Australian Institute of Health, Welfare and Aging (AIHW), Medicare Australia database (MA), and local records at a high volume tertiary referral centre (RMH) for AF ablation. Linear regression models were fitted comparing trends in population-adjusted procedural numbers over the 10-year period. There was a 5% per year population-adjusted increment in PCIs over 10 years from both the AIHW and MA sources, respectively (P < 0.001). This was similar to the growth rate of all cardiovascular procedures (AIHW: 5.1 vs. 3.8%/year, P = 0.27). Atrial fibrillation ablations showed a 30.9, 23.2, and 39.8% per year population-adjusted increment over 10 years from the AIHW, MA, and RMH sources respectively (P < 0.001 for all). Growth of AF ablations was significantly higher than PCIs (P < 0.001 for AIHW and MA sources) and all cardiovascular procedures (AIHW: 30.9 vs. 3.8%/year, P < 0.001). The provision of catheter-based AF ablation services in Australia has increased exponentially over the past decade. Its annual growth rate exceeded that of PCIs and all cardiovascular procedures. Given the increasing epidemic of AF, these data have critical implications for public health policy assessing the adequacy of infrastructure, training, and funding for AF ablation services.
Publisher: Oxford University Press (OUP)
Date: 05-2018
Publisher: JMIR Publications Inc.
Date: 02-2022
DOI: 10.2196/34778
Abstract: Atrial fibrillation (AF) is common in older people and increases the risk of stroke. The feasibility and effectiveness of the implementation of a patient-led AF screening program for older people are unknown. This study aims to examine the feasibility and effectiveness of an AF screening program comprising patient-led monitoring of single-lead electrocardiograms (ECGs) with clinician-coordinated central monitoring to diagnose AF among community-dwelling people aged ≥75 years in Australia. This is a nationwide randomized controlled implementation trial conducted via the internet and remotely among 200 community-dwelling adults aged ≥75 years with no known AF. Randomization will be performed in a 1:1 allocation ratio for the intervention versus control. Intervention group participants will be enrolled in the monitoring program at randomization. They will receive a handheld single-lead ECG device and training on the self-recording of ECGs on weekdays and submit their ECGs via their smartphones. The control group participants will receive usual care from their general practitioners for the initial 6 months and then commence the 6-month monitoring program. The ECGs will be reviewed centrally by trained personnel. Participants and their general practitioners will be notified of AF and other clinically significant ECG abnormalities. This study will establish the feasibility and effectiveness of implementing the intervention in this patient population. The primary clinical outcome is the AF detection rate, and the primary feasibility outcome is the patient satisfaction score. Other outcomes include appropriate use of anticoagulant therapy, participant recruitment rate, program engagement (eg, frequency of ECG transmission), agreement in ECG interpretation between the device automatic algorithm and clinicians, the proportion of participants who complete the trial and number of dropouts, and the impact of frailty on feasibility and outcomes. We will conduct a qualitative evaluation to examine the barriers to and acceptability and enablers of implementation. Ethics approval was obtained from the human research ethics committee at the University of Sydney (project number 2020/680). The results will be disseminated via conventional scientific forums, including peer-reviewed publications and presentations at national and international conferences. By incorporating an integrated health care approach involving patient empowerment, centralized clinician-coordinated ECG monitoring, and facilitation of primary care and specialist services, it is possible to diagnose and treat AF early to reduce stroke risk. This study will provide new information on how to implement AF screening using digital health technology practicably and feasibly for older and frail populations residing in the community. Australian New Zealand Clinical Trials Registry ACTRN12621000184875 www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=380877 DERR1-10.2196/34778
Publisher: Japanese Circulation Society
Date: 2014
Publisher: Elsevier BV
Date: 04-2009
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2013
Publisher: Elsevier BV
Date: 07-2013
DOI: 10.1016/J.HRTHM.2013.03.022
Abstract: Catheter-tissue contact force (CF) determines radiofrequency (RF) ablation lesion size. Impedance changes during RF delivery are used as surrogate markers for CF. The relationship between impedance and real-time CF in humans remains unknown. To determine whether impedance changes have predictive value for real-time CF during catheter ablation of atrial arrhythmias. Real-time CF, force-time integral, and impedance were measured in 2265 RF lesions for atrial fibrillation or flutter in 34 patients. Operators were blinded to CF measurements. Impedance preablation, at 5-second intervals for 30 seconds after the RF onset, maximal impedance fall and time to impedance plateau during RF were correlated with CF. Average CF was ided into low (≤20 g), intermediate (21-60 g), and high (>60 g) categories. Preablation impedance poorly correlated with preablation CF (R = .07). Maximal impedance fall modestly correlated with average CF and force-time integral (R = .32 and .37, respectively). There was a large degree of overlap in impedance fall between different CF categories. A maximal impedance fall of 10 Ω could predict average CF of >20 g, with a sensitivity and specificity of 71% and 53% and a positive and negative predictive value of 51% and 49%, respectively. Impedance fall was only able to differentiate between different CF categories ≥15 seconds after the RF onset. Higher CFs moderately correlated with delayed plateau in impedance (R = .41). Impedance measurements (both baseline and impedance fall) are, at best, moderately efficacious as surrogate markers for predicting real-time catheter-tissue CF. These findings highlight the importance of real-time CF measurements, rather than impedance changes to optimize ablation efficacy.
Publisher: Elsevier BV
Date: 11-2010
DOI: 10.1016/J.HRTHM.2010.07.019
Abstract: Sudden death risk is highest early after myocardial infarction (MI). Inducible ventricular tachycardia (VT) confers increased risk of spontaneous ventricular arrhythmias. The purpose of this study was to evaluate outcomes of electrophysiology (EP)-guided defibrillator implantation early after ST-elevation MI in patients with ejection fraction ≤40%. EP study was performed 9 days after MI (n = 360). Predischarge defibrillator was recommended if VT with cycle length ≥200 ms was induced with ≤4 extrastimuli (EP-positive [EP(pos)], n = 142). EP-negative (EP(neg)) patients were discharged without a defibrillator (n = 218). Primary endpoint was either sudden death or spontaneous ventricular arrhythmia. Defibrillator was implanted in 71% of EP(pos) patients (median 21 days post-MI) and withheld in 94% of EP(neg) patients. At 2 years, primary endpoint was 4.3% in the EP(neg) group and 22% in the EP(pos) group (adjusted hazard ratio 0.46, P = .035, EP(neg) vs EP(pos)). Lack of a defibrillator in EP(pos) patients conferred a fourfold increased risk of sudden death (P = .014). EP(neg) patients without a defibrillator were at significantly lower risk for the primary endpoint than were EP(pos) patients without a defibrillator (adjusted HR 0.34, P = .011). Short inducible VT cycle length (200-230 ms) and use of the fourth extrastimulus identified patients at significant arrhythmic risk. EP study performed early after MI identified patients at significant long-term arrhythmic risk at a critical time after MI in whom defibrillator implantation was protective. A large majority of patients (EP(neg) two thirds) were at significantly lower risk of arrhythmic events without a defibrillator in the long term.
Publisher: Wiley
Date: 14-03-2013
DOI: 10.1111/JCE.12121
Abstract: Pulmonary vein reconnection is a major limitation of pulmonary vein isolation (PVI) for symptomatic atrial fibrillation (AF). Adenosine may unmask dormant PV conduction and facilitate consolidation of PV isolation. We performed a systematic review of the literature to determine the impact of routine adenosine administration on clinical outcomes in patients undergoing PVI. References and electronic databases reporting AF ablation and adenosine following PVI were searched through to 31 July 2012. Six studies included 544 patients to assess the impact of catheter ablation to target adenosine-induced PV reconnection on AF ablation outcome and 3 studies included 612 patients to assess the impact of adenosine testing on AF ablation outcome. Relative risks were calculated and combined in a meta-analysis using random effects modeling. Routine adenosine testing for PV reconnection with additional targeted ablation resulted in a significant increase in freedom from AF post-PVI (RR 1.25 95% CI 1.12-1.40 P < 0.001). However, within the group of patients undergoing adenosine testing, those with reconnection identified a population with a trend to reduction in freedom from AF despite the use of further targeted ablation in the reconnection group (RR 0.91 with 95% CI 0.81-1.03 P = 0.15). Routine adenosine testing is associated with an improvement in freedom from AF post-PVI. Paradoxically acute adenosine-induced PV reconnection may portend a greater likelihood of AF recurrence despite additional ablation. Randomized controlled trials are required to determine the role of adenosine testing post-PVI.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2013
DOI: 10.1161/CIRCEP.113.000184
Abstract: Contact force (CF) during radiofrequency ablation (RFA) is an important determinant of endocardial lesion size with limited data on epicardial RFA and CF. We evaluated CF characteristics using irrigated RFA on the epicardium in an ovine model. In 12 sheep, a 7-F irrigated RFA catheter with CF sensor was introduced via a pericardial incision onto/in parallel with ventricular epicardium. RFA (30 W per 30 second duration) was applied at 5 g , 10 g , 20 g , 40 g , and 70 g : (1) over left and right ventricular myocardium with or without fat, (2) either directly over or adjacent to a coronary artery, or directly over the phrenic nerve. Force–time integral, lesion dimensions, and coronary artery hrenic nerve injury were recorded. Lesion size, volume, and force–time integral progressively increased with higher CF ( P .05). Steam pops occurred with high CF. Epicardial fat had an attenuating effect on RF penetration into myocardium ( P .05) however, myocardial RF lesions could be created at sites with .5 mm epicardial fat. At sites with epicardial fat, each 10 g increment in CF led to a 0.6 mm increase in lesion depth, whereas each 1 mm of fat reduced lesion depth into underlying myocardium by 0.7 mm. Extent of acute coronary injury with direct and indirect RFA and phrenic nerve palsy occurrence was proportional to CF. CF is a determinant of epicardial RF lesion size, steam pops, acute coronary artery injury, and phrenic nerve injury. Although epicardial fat limits lesion size, RFA with high CF can produce small myocardial RF lesions at sites of thick epicardial fat.
Publisher: Wiley
Date: 12-02-2016
DOI: 10.1111/JCE.12921
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2017
DOI: 10.1161/CIRCEP.116.004998
Abstract: Recent studies have demonstrated that intramyocardial adipose tissue (IMAT) may contribute to ventricular electrophysiological remodeling in patients with chronic myocardial infarction. Using an ovine model of myocardial infarction, we aimed to determine the influence of IMAT on scar tissue identification during endocardial contact mapping and optimal voltage-based mapping criteria for defining IMAT dense regions. In 7 sheep, left ventricular endocardial and transmural mapping was performed 84 weeks (15–111 weeks) post-myocardial infarction. Spearman rank correlation coefficient was used to assess the relationship between endocardial contact electrogram litude and histological composition of myocardium. Receiver operator characteristic curves were used to derive optimal electrogram thresholds for IMAT delineation during endocardial mapping and to describe the use of endocardial mapping for delineation of IMAT dense regions within scar. Endocardial electrogram litude correlated significantly with IMAT (unipolar r =−0.48±0.12, P .001 bipolar r =−0.45±0.22, P =0.04) but not collagen (unipolar r =−0.36±0.24, P =0.13 bipolar r =−0.43±0.31, P =0.16). IMAT dense regions of myocardium reliably identified using endocardial mapping with thresholds of .7 and .6 mV, respectively, for unipolar, bipolar, and combined modalities (single modality area under the curve=0.80, P .001 combined modality area under the curve=0.84, P .001). Unipolar mapping using optimal thresholding remained significantly reliable (area under the curve=0.76, P .001) during mapping of IMAT, confined to putative scar border zones (bipolar litude, 0.5–1.5 mV). These novel findings enhance our understanding of the confounding influence of IMAT on endocardial scar mapping. Combined bipolar and unipolar voltage mapping using optimal thresholds may be useful for delineating IMAT dense regions of myocardium, in postinfarct cardiomyopathy.
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.HRTHM.2015.03.060
Abstract: Early repolarization (ER) with a horizontal ST segment (ST-h) and high- litude J waves in the inferior leads is associated with an increased risk of cardiac arrhythmic death. The effect of ethnicity and athletic status on this increased-risk ER pattern has not been established. Aboriginal Australian/Torres Strait Islander and Pacific Islander/Maori (non-Caucasian [non-C]) subjects are well represented in Australian sport however, the patterns and prevalence of ER in these populations are unknown. The purpose of this study was to assess the prevalence and effect of athletic activity on ER patterns in young non-C and Caucasian (C) subjects. Twelve-lead ECGs of 726 male athletes (23.8% non-C) and 170 male controls (45.9% non-C) aged 16-40 years were analyzed for the presence of ER, defined as J-point elevation (J wave, QRS slur, or discrete ST elevation) ≥0.1 mV in ≥2 inferior (II, III, aVF) or lateral (I, aVL,V4-V6) leads. ST morphology was coded as horizontal (ST-h) or ascending (ST-a). "Increased-risk ER" was defined as inferior ER with ST-h and J waves >2 mV. Regardless of athletic status, ER and increased-risk ER were more prevalent in non-C than in C subjects (53.8% vs 32% and 7.6% vs 1.2%, respectively, P <.0001). Whereas lower heart rate, larger QRS voltage, and shorter QRS duration were predictors of ER, non-C ethnicity was the only independent predictor of increased-risk ER (odds ratio 17.621, 95% confidence interval 4.98-62.346, P < .0001). ER patterns associated with increased arrhythmic risk are more common in young non-C than C subjects and were not influenced by athletic status. The long-term clinical significance of ER in these populations is yet to be determined.
Publisher: Springer Science and Business Media LLC
Date: 22-09-2021
No related grants have been discovered for Saurabh Kumar.