JACC. Clinical electrophysiology最新文献

Background: Loss-of-function mutations in the SCN5A gene, which encodes for the predominant cardiac Na_V isoform, Na_V1.5, result in either deficiency in the channel expression or function. Impaired Na_V1.5 expression and function underlie reduced peak Na⁺ current (I_Na) and result in ventricular conduction velocity slowing, predisposing the heart to conduction block and ventricular arrhythmias clinically associated with Brugada syndrome (BrS). Recently, a missense mutation in Na_V1.5 selectivity filter (DEKA motif), K1419E (DEEA), has been identified in patients with BrS. Despite early characterization of mutations in selectivity filter of other Na_V isoforms, little is known about the impact of DEEA on Na_V1.5 function as well as on cardiac electrophysiology.

Objectives: In this study, we generated a mouse heterozygous for Na_V1.5 DEEA to characterize the mutation and investigate the outcome of this functionally deficient Na_V1.5 variant on cardiac electrophysiology and arrhythmias.

Methods: Patch clamp electrophysiology studies were conducted in Chinese hamster ovary cells expressing the DEEA variant, along with immunolabeling, voltage optical mapping, and in vivo electrocardiography studies in a DEEA murine model of BrS.

Results: A heterologous expression system and isolated cardiomyocytes revealed lower current density and unchanged Na_V1.5 expression in DEEA vs wild type (DEKA). On the organ level, optical mapping revealed conduction velocity slowing in DEEA hearts, which was accentuated by flecainide, resulting in in vivo ventricular arrhythmias.

Conclusions: Overall, to our knowledge, we provide the first mechanistic insight into the proarrhythmic consequences of a functionally deficient BrS mutation in Na_V1.5.

Background: A novel balloon-in-basket catheter integrated into a mapping system may advance pulsed field ablation (PFA) of atrial fibrillation (AF) with demonstrated deeper lesions, less hemolysis, and promising initial clinical experience.

Objectives: The goal of this study was to assess the 1-year clinical outcomes of the balloon-in-basket PFA system.

Methods: The multicenter VOLT-AF IDE Clinical Study enrolled patients with symptomatic, paroxysmal (PAF), and persistent AF (PeAF) . Pulmonary vein isolation (PVI) was performed with the investigational system. The primary effectiveness endpoint was acute PVI and 12-month freedom from atrial arrhythmia, antiarrhythmic escalation/initiation, cardioversion, or repeat ablation. The primary safety endpoint was device- and/or procedure-related serious adverse events within 7 days of any ablation. Follow-up consisted of 12-lead electrocardiograms at discharge, 3 months, and 12 months; biweekly and symptomatic transtelephonic monitoring; and 24-hour Holter monitoring at 12 months.

Results: Of the 392 patients enrolled, 335 were main cohort patients (57 roll-ins), and 320 were treated (165 PAF and 155 PeAF). Their mean age was 65 ± 11 years, and the mean CHA₂DS₂-VASc score was 2.3 ± 1.6. Left atrial catheter dwell time was 44.1 ± 18.1 minutes (including a 20-minute wait). A mean of 4.6 ± 0.9 applications were delivered per vein. Primary effectiveness was 81.1% (95% CI: 74.3%-86.3%) in PAF and 63.3% (95% CI: 55.1%-70.4%) in PeAF. Freedom from documented arrhythmia recurrence was 84.2% in the PAF group and 67.8% in the PeAF group. Primary safety events occurred in 1.9% of patients, with none in the PAF group. During redo ablation in 19 patients, 78.5% of pulmonary veins remained durably isolated.

Conclusions: This multicenter trial reports high PVI-based effectiveness of the novel balloon-in-basket PFA device with excellent safety.(VOLT-AF IDE Clinical Study; NCT06223789).

Background: Despite a common rhythm control strategy, use and safety of atrial fibrillation (AF) ablation pursued urgently among inpatients has not been adequately characterized.

Objectives: This study sought to describe the use and safety of urgent AF ablation, defined as an ablation pursued among inpatients hospitalized for a nonprocedural indication.

Methods: Using the National Cardiovascular Data Registry AFib Ablation Registry, patients who underwent AF ablation from January 1, 2016, to June 30, 2023, were stratified by urgent or elective ablation. Factors, trends, and in-hospital complication rates associated with urgent AF ablation were analyzed.

Results: Among 140,051 patients who underwent index AF ablation, 2,714 (1.9%) were conducted as urgent and 137,337 (98.1%) as elective procedures. Those undergoing urgent ablation had higher rates of comorbidities including: diabetes (30.6% vs 20.4%; P < 0.0001), coronary artery disease (30.8% vs 22.7%; P < 0.0001), and heart failure (47.1% vs 20.8%; P < 0.0001). Urgent AF ablation was more often used among Black patients (OR: 1.68; 95% CI: 1.41-2.0) and those presenting to the procedure in AF (OR: 1.73; 95% CI: 1.36-2.20). A higher hospital volume of AF ablations (OR [per 100 cases]: 1.22; 95% CI: 1.20-1.25) was associated with a higher odds of urgent ablation. Urgent AF ablation increased over the study period (0.5% to 2.0%; P < 0.0001) and the adjusted procedure-related complication rate was significantly higher compared with elective ablation (4.9% vs 2.4%; P < 0.0001).

Conclusions: The rate of urgent inpatient AF ablation has increased over time. Compared with elective ablation, patients who underwent urgent AF ablation had more comorbid conditions, particularly heart failure, with a higher rate of risk-adjusted, procedure-related complications.

Background: Percutaneous epicardial access has been increasingly adopted in clinical practice, particularly for ventricular tachycardia ablation. "Dry" epicardial puncture (Dry-EPI) carries a considerable risk of access-related complications, even with modified techniques. Pericardial carbon dioxide insufflation (EpiCO₂) has emerged as a promising alternative, potentially enhancing safety by increasing anatomical clearance between pericardial layers.

Objectives: This study compared the safety and efficacy of EpiCO₂ vs traditional Dry-EPI techniques through systematic review, meta-analysis, and meta-regression.

Methods: PubMed/MEDLINE, Embase, Scopus, Web of Science, and Cochrane databases were searched using medical subject heading terms "epicardial access," "carbon dioxide insufflation," "complications," and similar key words. Random-effects meta-analyses of proportions and means, subgroup analyses, and meta-regressions were conducted.

Results: One hundred nineteen studies (8,784 procedures) were included; most (95.0%) were of moderate or high quality. Ventricular tachycardia ablation was the main access indication (n = 7,178). EpiCO₂ was used in 493 procedures (5.6%) and Dry-EPI in 8,291 (94.4%). Among 5,786 Dry-EPI cases with specified needle type, 5,184 (89.6%) used a large-bore needle and 602 (10.4%) a micropuncture needle. EpiCO₂ was associated with significantly fewer complications requiring surgery compared with Dry-EPI (0.24% [95% CI: 0.00-0.93] vs 1.55% [95% CI: 1.27-1.86], P < 0.010), large-bore needle (0.24% [95% CI: 0.00%-0.93%] vs 1.58% [95% CI: 1.23-1.97], P < 0.010), and micropuncture (0.24 [95% CI: 0.00-0.93] vs 1.66% [95% CI: 0.60-3.17], P = 0.020). Inadvertent ventricular puncture was also lower with EpiCO₂ compared with Dry-EPI (0.28% [95% CI: 0.00-1.00] vs 3.17% [95% CI: 2.36-4.10], P < 0.010).

Conclusions: Compared with Dry-EPI, EpiCO₂ was associated with significantly lower risk of inadvertent ventricular puncture and complications requiring surgery, supporting broader clinical adoption.

Background: The diagnosis of carotid sinus syndrome requires the reproduction of spontaneous symptoms during carotid sinus massage (CSM) alongside clinical features indicative of a reflex mechanism. In contrast, the significance of asymptomatic asystolic carotid sinus hypersensitivity (CSH) remains uncertain, as it is frequently observed in older adults without syncope.

Objectives: This study aimed to evaluate the correlation between asymptomatic asystolic CSH and spontaneous events documented via implantable loop recorder (ILR).

Methods: In this study, 92 reflex syncope patients with an asymptomatic pause >3 seconds during CSM (average 4.9 ± 1.7 seconds) received an ILR and were followed for a median of 23.1 months. The control group consisted of reflex syncope patients with negative CSM drawn from a historical ILR population and matched with the propensity score method to the CSH group based on clinical variables.

Results: During the observation period, 38 (41.3%) CSH patients had recurrence of syncope, which was associated with asystole of 8.0 seconds (95% CI: 5.3-13.5 seconds) in 29 (76.3%) cases. Although the actuarial rate of total syncope recurrence in CSH group was similar to that in the control group (HR: 1.22; P = 0.40), CSH patients showed a higher rate of asystolic syncope (HR: 2.13; P = 0.011) and asystolic pauses (HR: 2.06; P = 0.009).

Conclusions: Patients with asymptomatic asystolic CSH were more likely to experience spontaneous asystolic syncope than those without CSH. Among CSH patients who experienced a recurrence of syncope documented by an ILR, the positive predictive value of an asystolic pause detected during CSM was 76.3%.

Background: Left atrial appendage occlusion (LAAO) has emerged as an effective stroke- prevention strategy for selected patients with nonvalvular atrial fibrillation (NVAF). However, LAAO outcomes data in patients with hypertrophic cardiomyopathy (HCM), rheumatic heart disease (RHD), or cardiac amyloidosis (CA), are limited.

Objectives: This study aimed to compare the safety and efficacy of LAAO in patients with NVAF, with and without comorbid HCM, RHD, or CA.

Methods: Using OptumLabs Data Warehouse, a retrospective cohort of adult patients undergoing LAAO (2015-2023) was analyzed. Outcomes included mortality, stroke/transient ischemic attack (TIA), and bleeding, with multivariable Cox models and subgroup analyses.

Results: A total of 14,755 patients (mean age 76.5 ± 7.0, 43.7% female, median follow-up 1.4 [0.8-2.4] years) were included. Compared with patients with AF, patients AF + RHD had high risk of nongastrointestinal/intracranial bleeding events (HR: 1.24; 95% CI: 1.04-1.49; P = 0.02), whereas AF + CA showed higher risk of composite endpoint (mortality, stroke/TIA, bleeding) (HR: 1.63; 95% CI: 1.17-2.27; P = 0.004), stroke/TIA (HR: 2.00; 95% CI; 1.13-3.54; P = 0.02), and gastrointestinal bleeding (HR: 2.50; 95% CI: 1.14-5.47; P = 0.02). There were no significant differences in clinical outcomes between patients with AF alone and those with AF + HCM.

Conclusions: Patients with AF and either RHD or CA experienced higher bleeding rates following LAAO compared with those without these conditions, despite similar stroke/TIA rates in AF + RHD, suggesting a higher inherent bleeding risk and possibly further supporting a role of LAAO. Importantly, there was no difference in outcomes between patients with AF and HCM vs those without. Because of the small sample size, the results in HCM and CA cohorts are mainly hypothesis generating.