Heart rhythm最新文献

Background: A novel focal lattice-tip catheter allowing the delivery of either pulsed field (PF) or radiofrequency (RF) energy has recently received regulatory approval. The technology features a proprietary 3-dimensional electroanatomic mapping system.

Objective: We describe the first real-world and multicenter experience.

Methods: Consecutive AF patients undergoing first-time or redo atrial tachyarrhythmia ablation with the Affera system were prospectively enrolled at 3 different centers. PF was the only energy source allowed when ablating the posterior left atrium; anterior applications were performed with either RF (PF/RF strategy) or PF (PF/PF strategy) on the basis of the operator's preference. The primary efficacy end point included acute electrical isolation of pulmonary veins and posterior wall or bidirectional block in case of linear lesions.

Results: The study included 130 patients (mean age, 67 ± 10 years; 63.8% [n = 83] male; 61.5% [n = 80] nonparoxysmal AF; 55.4% first-time AF ablation). First-time pulmonary vein isolation was performed in 72 patients: RF/PF in 13 (18.1%) patients and PF/PF in the remaining 59 (81.9%); first-pass isolation for pulmonary vein and posterior wall was achieved in 100% of cases. A total of 289 ablation lines were performed (roof line, 91 patients; inferior line, 83 patients; anterior mitral line, 32 patients; posterior mitral line, 45 patients; cavotricuspid isthmus line, 38 patients). First-pass isolation and primary efficacy end point were 96.2% (roof line, 100%; inferior line, 100%; anterior mitral line, 96.9%; posterior mitral line, 84.4%; cavotricuspid isthmus, 92.1%) and 100%, respectively. We had 2 (1.5%) major complications: 1 ST-segment elevation at the inferolateral leads requiring intracoronary administration of nitrate and 1 complete atrioventricular block.

Conclusion: Catheter ablation with a novel 9-mm lattice-tip catheter confirmed high efficacy and safety in a real-world scenario.

Background: Atrial fibrillation (AF) prediction improves by combining clinical scores with a polygenic risk score (PRS) for AF (AF-PRS), but there are limited studies of PRS for ventricular arrhythmia (VA) prediction.

Objective: We assessed the value of including multiple PRS for cardiovascular risk factors (CV-PRS) for incident AF and VA prediction.

Methods: We used 158,733 individuals of European ancestry from UK Biobank to build 3 models for AF: CHARGE-AF (AF1), AF1 + AF-PRS (AF2), AF2 + CV-PRS (AF3). Models for VA included sex and age (VA1), VA1 + coronary artery disease (CAD) PRS (CAD-PRS, VA2), and VA2 + CV-PRS (VA3), conducting separate analyses in subjects with and without ischemic heart disease (IHD). Performance was evaluated in individuals of European (N = 158,733), African (N = 7200), South Asian (N = 9241) and East Asian (N = 2076) ancestry from UK Biobank.

Results: AF2 had a higher C-index than AF1 (0.762 vs 0.746, P < .001), marginally improving to 0.765 for AF3 (P < .001, including PRS for heart failure, electrocardiogram and cardiac magnetic resonance measures). In South Asians, AF2 C-index was higher than AF1 (P < .001). For VA, the C-index for VA2 was greater than VA1 (0.692 vs 0.681, P < .001) in Europeans, which was also observed in South Asians (P < .001). VA3 improved prediction of VA in individuals with IHD.

Conclusion: CV-PRS improved AF prediction compared to CHARGE-AF and AF-PRS. A CAD-PRS improved VA prediction, while CV-PRS contributed in IHD. AF- and CAD-PRS were transferable to individuals of South Asian ancestry. Our results inform of the use of CV-PRS for personalized screening.

Background: Congenital long QT syndrome (LQTS) is characterized by delayed ventricular repolarization, predisposing to potentially lethal ventricular arrhythmias. The variability in disease severity among patients remains largely unexplored, underscoring the limitations of current risk stratification methods.

Objective: We aimed to evaluate the potential utility of electrocardiographic markers from the exercise stress test (EST) in identifying patients with high-risk LQTS.

Methods: The study, which considered patients with LQTS type 1 and LQTS type 2, comprised a discovery cohort of 695 and a validation cohort of 635 patients.

Results: The change in corrected QT (QTc) interval between rest and recovery (between rest and 3-4 minutes into the recovery period, called recovery-rest ΔQTc) was consistently greater in symptomatic patients. Sensitivity analyses performed on EST data obtained on and off β-blockers as well as upon distinguishing between patients with a baseline QTc interval below and those above 470 ms demonstrated consistent findings. The association of recovery-rest ΔQTc with cardiac events remained significant in a subanalysis focusing on future events (ie, occurring after the EST). An optimal recovery-rest ΔQTc cutoff was determined for LQTS type 1 (35 ms) and LQTS type 2 (16 ms) separately and was shown to be significantly associated with cardiac events.

Conclusion: Our findings suggest that in patients with LQTS, dynamic QT interval measures obtained during the EST are associated with lifetime arrhythmic events and events after the EST. Such measures can be helpful in identifying a higher-risk subset of patients with LQTS in order to optimize their management. Further research may confirm these findings in larger cohorts and explore the potential benefit of combining genetic and EST data for more precise risk stratification.

Background: Hydroquinidine reduces arrhythmic events in patients with Brugada syndrome (BrS). The mechanism by which it exerts antiarrhythmic benefit and its electrophysiological effects on BrS substrate remain incompletely understood.

Objective: This study aimed to determine the effect of hydroquinidine on ventricular depolarization and repolarization in patients with BrS in vivo.

Methods: Twelve patients with BrS underwent electrocardiography (standard, high-lead, and signal averaged) and electrocardiographic imaging at baseline and "on-treatment" with hydroquinidine 300 mg twice daily. ST-segment elevation, activation time, repolarization time, and activation-recovery interval (ARI) were computed for the ventricles and right ventricular outflow tract (RVOT). Serum hydroquinidine levels were determined, and adverse drug events were captured through a medication survey.

Results: Hydroquinidine increased repolarization time (301.1 ± 24.1 ms vs 348.8 ± 28.3 ms; P<.001), repolarization gradients (1.1 ± 0.4 ms/mm vs 1.6 ± 0.4 ms/mm; P<0.001), and ARI (241.3 ± 18.1 ms vs 284.8 ± 21.5 ms; P<.001) in the RVOT, with a greater change in the RVOT than in the rest of the ventricles. In contrast, activation parameters did not change significantly on-treatment with hydroquinidine, although there was a subtle increase in ST-segment elevation over the RVOT (1.5 ± 0.7 mV vs 1.8 ± 0.8 mV; P<.001). Hydroquinidine levels did not correlate with electrophysiological changes or occurrence of adverse drug reactions. One patient developed frequent nonsustained ventricular tachycardia on-treatment with hydroquinidine.

Conclusion: Hydroquinidine primarily affects ventricular repolarization and action potential duration (indicated by ARI) in patients with BrS and demonstrates regional variation with more significant changes in the RVOT.

Background: The adaptive cardiac resynchronization therapy (CRT) (aCRT) algorithm provides an important clinical benefit. However, a significant number of patients are nonresponders.

Objectives: The goals of this study were to quantify electrical synchrony in patients programmed with aCRT and to assess the echocardiographic effects of optimization in CRT nonresponders and incomplete responders.

Methods: We studied 125 patients programmed with aCRT and measured electrical synchrony at multiple device settings using novel electrical dyssynchrony mapping (EDM) technology. Electrical synchrony was quantified as cardiac resynchronization index (CRI), a measure that analyzes areas between multiple pairs of anterior and posterior electrograms and calculates synchrony normalized to native rhythm.

Results: CRI improved from baseline aCRT settings to optimal settings on the basis of EDM (56%±29% vs 92%±12%; P<.001). Patients programmed with left ventricle (LV)-only aCRT (group 1, n=68 [54%]) had a higher CRI (62%±25% vs 48%±31%; P=.014) than did patients programmed with biventricular aCRT (group 2, n=57 [46%]). In group 1 and group 2, optimal CRI during sequential biventricular (92%±13% and 93%±9%, respectively) and LV-only (92%±6% and 91%±7%, respectively) pacing was significantly (P<.001) higher than CRI at baseline aCRT setting. In a subset of 53 nonresponders optimized using EDM, there were significant improvements in CRI (37%±25%; P<.0001), LV ejection fraction (6.2%±6.6%; P<.0001), end-diastolic volume (9.5±28.2 mL; P=.015), end-systolic volume (13.4±24.9 mL; P<.001), and transverse (1.5%±4.4%; P=.014), longitudinal (1.0%±2.5%; P=.003), and circumferential (2.6%±8.5%; P=.047) strain.

Conclusion: Electrical synchrony improves 56% with CRT using aCRT programming and 92% with EDM optimization. Optimization of aCRT-programmed nonresponders results in significant improvements in LV size and systolic function, offering the possibility of converting CRT nonresponders into responders.

Background: Early recurrences of atrial tachyarrhythmias (ERATs) after pulmonary vein isolation (PVI) are common. While many correlate to late recurrences (LRs), some do not. The impact of ERATs timing is difficult to assess with noninvasive Holter monitoring because of undersampling. The recommended duration of the blanking period (BP) was recently shortened from 90 days to 8 weeks.

Objective: The purpose of this study was to evaluate the impact of ERATs timing after PVI and the effect of a shorter BP by using implantable cardiac monitors for continuous rhythm monitoring.

Methods: This is a prespecified substudy of the Comparison of the POLARx and the Arctic Front cryoballoon for pulmonary vein isolation in patients with symptomatic paroxysmal atrial fibrillation (COMPARE-CRYO) study, which enrolled patients with paroxysmal atrial fibrillation undergoing cryoballoon ablation. All patients underwent implantable cardiac monitor implantation, and the BP was 90 days.

Results: A total of 5285 ERATs episodes occurred in 117 of 201 patients (58%). Freedom from LR was 82% vs 37% in patients without vs with ERATs (P<.001). When patients were classified according to their last episode of ERATs occurring between days 0 and 30, between days 31 and 60, and between days 61 and 90, freedom from LR was 60%, 56%, and 11%, respectively (P<.001). Seven of 201 patients (3.4%) had AF recurrence in the third month after ablation, but not between days 91 and 365, which reclassifies them from ablation success to ablation failure with the shortened 8-week BP.

Conclusion: ERATs after PVI is common. The presence of ERATs in the third month after PVI was highly predictive of ablation failure, supporting the shortening of the BP to 8 weeks; however, the shorter BP reclassifies only 7 (3.4%) of patients to ablation failure instead of ablation success.

Background: Asthma is a known risk factor for atrial fibrillation (AF), the most common sustained arrhythmia. Whereas radiofrequency catheter ablation is effective in treating AF, the impact of asthma and its severity on ablation outcomes has not been previously explored.

Objective: The purpose of this study was to evaluate the impact of asthma and its severity on AF recurrence after ablation.

Methods: In this single-center retrospective case-control study, 63 case patients with AF and asthma who underwent ablation were matched with 126 controls with AF but without asthma who underwent ablation. Case patients were also compared with a nonablated cohort of patients with asthma. AF recurrence was compared between groups. Univariate and multivariate analyses were conducted to determine associations with recurrence.

Results: Compared with controls who underwent ablation, patients with asthma, particularly those with severe asthma, had a higher likelihood of AF recurrence after catheter ablation (odds ratio, 3.76 [P = .047] and 5.06 [P = .041], respectively). However, case patients were not more likely to experience adverse outcomes. Multivariate analysis revealed that persistent AF and use of a beta blocker were associated with recurrence. Patients with moderate or severe persistent asthma were more likely than patients with intermittent or mild persistent asthma to have left atrial enlargement (odds ratio, 2.53; P = .009).

Conclusion: Patients with AF and asthma, particularly those with severe asthma, were more likely than patients with AF but without asthma to have AF recurrence after ablation. Patients with AF and severe asthma were also more likely to have severe left atrial enlargement, a known predictor of recurrence after ablation.