Search

The interatrial septum (IAS) is thought to be involved in the mechanism of persistent atrial fibrillation (PeAF). Simultaneous contact mapping of both sides of the IAS has not been performed previously.The purpose of this study was to describe wave front (WF) activation patterns and extent of left and right atrial septal electrical dissociation in patients with PeAF.Simultaneous mapping of both atrial septal surfaces using 2 high-density grid catheters was performed. Filtered electrograms of continuous atrial fibrillation, sinus rhythm (SR), and atrial pacing recordings were exported to MATLAB for off-line phase/activation analysis, and activation patterns on paired surfaces were analyzed. WF activation patterns between the 2 grids were evaluated to determine whether activation WFs were associated or dissociated.Eight patients with PeAF undergoing catheter ablation were included. Complete dissociation of WF activation patterns between the 2 sides of the septum existed throughout the mapping period with no 2 consecutive WF activation patterns matching. Single linear WFs were the most prevalent activation pattern on both septal grids. No focal breakthroughs were seen. Transient rotational activity was seen in 10% of phase activations. During SR and atrial pacing, both grids appeared to be activated independent of each other with no evidence of contralateral conduction across the 2 grids.Simultaneous biatrial septal mapping of human PeAF, SR, and atrial pacing shows complete WF dissociation between the left and right IAS with no evidence of trans-septal conduction, indicating that the 2 sides function as electrically discrete structures. No stable septal drivers were observed. These findings may have implications for mapping and ablation of PeAF.

Background Catheter ablation is an effective strategy in atrial fibrillation (AF). However, its timing in the course of management remains unclear. The aim of this study was to determine if an early vs. delayed AF ablation strategy is associated with differences in arrhythmia outcomes during 12-month follow-up. Methods and results One hundred patients with symptomatic AF referred to a tertiary centre for management were randomized in a 1:1 ratio to either an early ablation strategy (within 1 month of recruitment) or a delayed ablation strategy (optimized medical therapy followed by catheter ablation at 12 months post recruitment). The primary endpoint was atrial arrhythmia free survival at 12 months post-ablation. Secondary outcomes included: (i) AF burden, (ii) AF burden by AF phenotype, and (iii) antiarrhythmic drug (AAD) use at 12 months. Overall, 89 patients completed the study protocol (Early vs. Delayed: 48 vs. 41). Mean age was 59 ± 12.9 years (29% women). Pulmonary vein isolation was achieved in 100% of patients. At 12 months, 56.3% of patients in the early ablation group were free from recurrent arrhythmia, compared with 58.6% in the delayed ablation group (HR 1.12, 95% CI 0.59–2.13, P = 0.7). All secondary outcomes showed no significant difference including median AF burden (Early vs. Delayed: 0% [IQR 3.2] vs. 0% [5], P = 0.66), median AF burden amongst paroxysmal AF patients (0% [IQR 1.1] vs. 0% [4.5], P = 0.78), or persistent AF patients (0% [IQR 22.8] vs. 0% [5.6], P = 0.45) or AAD use (33% vs. 37%, P = 0.8). Conclusion Compared with an early ablation strategy, delaying AF ablation by 12 months for AAD management did not result in reduced ablation efficacy.

AimsRadiofrequency (RF) ablation for pulmonary vein isolation (PVI) in atrial fibrillation (AF) is associated with the risk of oesophageal thermal injury (ETI). Higher power short duration (HPSD) ablation results in preferential local resistive heating over distal conductive heating. Although HPSD has become increasingly common, no randomized study has compared ETI risk with conventional lower power longer duration (LPLD) ablation. This study aims to compare HPSD vs. LPLD ablation on ETI risk.Methods and resultsEighty-eight patients were randomized 1:1 to HPSD or LPLD posterior wall (PW) ablation. Posterior wall ablation was 40 W (HPSD group) or 25 W (LPLD group), with target AI (ablation index) 400/LSI (lesion size index) 4. Anterior wall ablation was 40–50 W, with a target AI 500–550/LSI 5–5.5. Endoscopy was performed on Day 1. The primary endpoint was ETI incidence. The mean age was 61 ± 9 years (31% females). The incidence of ETI (superficial ulcers n = 4) was 4.5%, with equal occurrence in HPSD and LPLD (P = 1.0). There was no difference in the median value of maximal oesophageal temperature (HPSD 38.6°C vs. LPLD 38.7°C, P = 0.43), or the median number of lesions per patient with temperature rise above 39°C (HPSD 1.5 vs. LPLD 2, P = 0.93). Radiofrequency ablation time (23.8 vs. 29.7 min, P < 0.01), PVI duration (46.5 vs. 59 min, P = 0.01), and procedure duration (133 vs. 150 min, P = 0.05) were reduced in HPSD. After a median follow-up of 12 months, AF recurrence was lower in HPSD (15.9% vs. LPLD 34.1%; hazard ratio 0.42, log-rank P = 0.04).ConclusionHigher power short duration ablation was associated with similarly low rates of ETI and shorter total/PVI RF ablation times when compared with LPLD ablation. Higher power short duration ablation is a safe and efficacious approach to PVI.

Objectives The authors performed a systematic review and meta-analysis to determine the efficacy of renal denervation (RDN) in patients with refractory ventricular arrhythmias (VA) or elec...

Double mitral and aortic mechanical valves present an access challenge when planning a ventricular tachycardia (VT) ablation. In this case report, we describe a patient who was considered for stereotactic ablative radiotherapy but was unable to proceed due to unfavorable anatomy making them at high risk of fistula formation. The patient went on to have an endocardial VT ablation via mini-thoracotomy and transapical access without complication. This case highlights the need for careful consideration when planning treatment for patients with double mechanical valves.

This study evaluated if modifying electrocardiographic (ECG) precordial leads to a higher intercostal position improved the accuracy of outflow tract ventricular arrhythmia (OTVA) localization.Precordial ECG prediction algorithms that use a standard lead configuration localize OTVA with variable accuracy.Patients who underwent OTVA ablation were prospectively enrolled to have a standard and modified (high) precordial ECG. R- and S-wave amplitudes and intervals were measured to develop an algorithm that differentiated the right ventricular outflow tract (RVOT) and the left ventricular outflow tract (LVOT) with high accuracy-the modified lead R-wave deflection interval (RWDI). This interval was defined from the earliest QRS onset (using all modified leads) to the lead with longest R-wave deflection. The RWDI was compared with all other ECG algorithms.A total of 50 patients (38 women; mean age 51 ± 17 years) had successful catheter ablation for OTVA (RVOT 60%, LVOT 40%). The modified lead RWDI was significantly shorter in the RVOT group (18.5 ms, interquartile range 25th to 75th percentile [IQRThe modified lead RWDI is a simple, easily interpretable algorithm that can potentially differentiate a right- or left-sided origin of OTVA with high accuracy.

ImportancePulmonary vein isolation (PVI) alone is less effective in patients with persistent atrial fibrillation (AF) compared with paroxysmal AF. The left atrial posterior wall may contribute to maintenance of persistent AF, and posterior wall isolation (PWI) is a common PVI adjunct. However, PWI has not been subjected to randomized comparison.ObjectiveTo compare PVI with PWI vs PVI alone in patients with persistent AF undergoing first-time catheter ablation.Design, Setting, and ParticipantsInvestigator initiated, multicenter, randomized clinical trial involving 11 centers in 3 countries (Australia, Canada, UK). Symptomatic patients with persistent AF were randomized 1:1 to either PVI with PWI or PVI alone. Patients were enrolled July 2018-March 2021, with 1-year follow-up completed March 2022.InterventionsThe PVI with PWI group (n = 170) underwent wide antral pulmonary vein isolation followed by posterior wall isolation involving linear ablation at the roof and floor to achieve electrical isolation. The PVI-alone group (n = 168) underwent wide antral pulmonary vein isolation alone.Main Outcomes and MeasuresPrimary end point was freedom from any documented atrial arrhythmia of more than 30 seconds without antiarrhythmic medication at 12 months, after a single ablation procedure. The 23 secondary outcomes included freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures, freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures, AF burden between study groups at 12 months, procedural outcomes, and complications.ResultsAmong 338 patients randomized (median age, 65.6 [IQR, 13.1] years; 76.9% men), 330 (97.6%) completed the study. After 12 months, 89 patients (52.4%) assigned to PVI with PWI were free from recurrent atrial arrhythmia without antiarrhythmic medication after a single procedure, compared with 90 (53.6%) assigned to PVI alone (between-group difference, –1.2%; hazard ratio [HR], 0.99 [95% CI, 0.73-1.36]; P = .98). Of the secondary end points, 9 showed no significant difference, including freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures (58.2% for PVI with PWI vs 60.1% for PVI alone; HR, 1.10 [95% CI, 0.79-1.55]; P = .57), freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures (68.2% vs 72%; HR, 1.20 [95% CI, 0.80-1.78]; P = .36) or AF burden (0% [IQR, 0%-2.3%] vs 0% [IQR, 0%-2.8%], P = .47). Mean procedural times (142 [SD, 69] vs 121 [SD, 57] minutes, P P Conclusions and RelevanceIn patients undergoing first-time catheter ablation for persistent AF, the addition of PWI to PVI alone did not significantly improve freedom from atrial arrhythmia at 12 months compared with PVI alone. These findings do not support the empirical inclusion of PWI for ablation of persistent AF.Trial Registrationanzctr.org.au Identifier: ACTRN12616001436460

The authors performed a systematic review and meta-analysis to determine the efficacy of renal denervation (RDN) in patients with refractory ventricular arrhythmias (VA) or electrical storm (ES).Although catheter ablation is efficacious for the treatment of structural heart disease ventricular tachycardia (VT), there are proportion of patients who have refractory VT despite multiple procedures. In this setting, novel adjunctive therapies such as renal denervation have been performed.A systematic review of published data was performed. Studies that evaluated patients undergoing RDN for VA or ES were included. Outcome measures of VA, sudden cardiac death, ES, or device therapy were required. Case reports, editorials, and conference presentations were excluded. Random effects meta-analysis was conducted to explore change or final mean values in the study outcomes.A total of 328 articles were identified by the literature search. Seven studies met the eligibility criteria and were included in the systematic review, with a total of 121 pooled patients. The weighted mean age was 63.8 ± 13.1 years, ejection fraction 30.5 ± 10.3%, 76% were men, 99% were on a beta blocker, 79% were on amiodarone, 46% had previously undergone catheter ablation, and 8.3% had previously undergone cardiac sympathetic denervation. Meta-analysis demonstrated a significant effect of RDN in reducing implantable cardiac defibrillator therapies, with a standardized mean difference (SMD) of -3.11 (p 0.001). RDN also reduced the number of VA episodes (SMD -2.13; p 0.001), antitachycardia pacing episodes (SMD -2.82; p = 0.002), and shocks (SMD -2.82; p = 0.002).RDN is an effective treatment for refractory VAs and ES, although randomized data are lacking.

Background Selecting heart failure (HF) patients for intensive management to reduce readmissions requires effective targeting. However, available prediction scores are only modestly effective. We sought to develop a prediction score for 30-day all-cause rehospitalization or death in HF with the use of nonclinical and clinical data. Methods and Results This statewide data linkage included all patients who survived their 1st HF admission (with either reduced or preserved ejection fraction) to a Tasmanian public hospital during 2009–2012. Nonclinical data (n = 1,537; 49.5% men, median age 80 y) included administrative, socioeconomic, and geomapping data. Clinical data before discharge were available from 977 patients. Prediction models were developed and internally and externally validated. Within 30 days of discharge, 390 patients (25.4%) died or were rehospitalized. The nonclinical model (length of hospital stay, age, living alone, discharge during winter, remoteness index, comorbidities, and sex) had fair discrimination (C-statistic 0.66 [95% confidence interval (CI) 0.63–0.69]). Clinical data (blood urea nitrogen, New York Heart Association functional class, albumin, heart rate, respiratory rate, diuretic use, angiotensin-converting enzyme inhibitor use, arrhythmia, and troponin) provided better discrimination (C-statistic 0.72 [95% CI 0.68–0.76]). Combining both data sources best predicted 30-day rehospitalization or death (C-statistic 0.76 [95% CI 0.72–0.80]). Conclusions Clinical data are stronger predictors than nonclinical data, but combining both best predicts 30-day rehospitalization or death among HF patients.

Heart failure (HF) readmissions are a common and serious problem of heterogeneous etiology. Left ventricular (LV) ejection fraction has not been found to be a consistent risk marker. However, LV strain has been shown to predict outcomes in other settings, so the aim of this study was to determine the association of LV strain with 30-day HF readmission, independent of and incremental to clinical and basic echocardiographic parameters.A total of 468 patients who underwent echocardiography at the time of the first admission for HF from July 2009 to June 2012 were retrospectively studied. Clinical parameters were comprehensively assessed, and standard echocardiographic parameters and two strain parameters (global longitudinal strain [GLS] and global circumferential strain) were measured using speckle-tracking. Patients were followed for all-cause 30-day hospital readmission or death after discharge, and the associations of parameters with outcome were assessed using Cox proportional hazards models.Readmission within 30 days (n = 92 patients [20%]) was associated with greater impairment of LV GLS (-8.6% [interquartile range, -10.9% to -5.9%] vs -11.1% [interquartile range, -14.6% to -7.7%], P .01). The association of GLS with readmission (hazard ratio, 1.13; 95% confidence interval, 1.07-1.19; P .01) was independent of age, male gender, systolic blood pressure, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, and comorbidity, as well as renal function, sodium, hematocrit, LV mass, left atrial size, and mitral regurgitation. Global circumferential strain was associated with outcome but not was independent after adjustment with echocardiographic parameters. In sequential models for 30-day outcome, GLS added incremental information to clinical parameters and LV ejection fraction and significantly improved reclassification (categorical net reclassification improvement, 0.34; P = .04) when LV ejection fraction was50%.GLS is associated with HF readmission, independent of and incremental to clinical and basic echocardiographic parameters.

Heart failure (HF) readmissions are a common and serious problem of heterogeneous etiology. Recently, LV strain has been shown to predict a variety of outcomes. We set up this study to examine the hypothesis that strain would improve the prediction of 30-day HF readmission over clinical and basic