Jaı̈s, Pierre

Abstract Aims Conduction system pacing (CSP) has emerged as a physiologic alternative to cardiac resynchronization therapy (CRT) with biventricular pacing (BiVP) in heart failure with reduced ejection fraction (HFrEF), yet its comparative effects remain uncertain. This meta-analysis sought to compare outcomes of CSP vs. BiVP in patients with HFrEF undergoing CRT. Methods and results MEDLINE, Embase, Scopus, and the Cochrane Database were searched through 4 May 2026. Randomized controlled trials (RCTs) were synthesized using random-effects meta-analysis. Thirteen RCTs including 1320 participants were analysed (657 CSP, 663 BiVP). Conduction system pacing was associated with a lower risk of the composite of hospitalization for heart failure (HHF) or all-cause mortality compared with BiVP (46 vs. 83 events; odds ratio [OR] 0.51, 95% confidence interval [CI] 0.28–0.93). No significant differences were observed for HHF alone (OR 0.68, 95% CI 0.36–1.27) or all-cause mortality (OR 0.75, 95% CI 0.36–1.58). Conduction system pacing was associated with greater improvement in the 6-min walk distance (mean difference [MD] 21.53 m, 95% CI 4.33–38.73) and New York Heart Association functional class (standardized mean difference [SMD] −0.27, 95% CI −0.47 to −0.07), but not quality of life. Conduction system pacing also reduced QRS duration compared with BiVP (MD −10.94 ms, 95% CI −17.55 to −4.34), with no significant differences in left ventricular ejection fraction, left ventricular end-systolic volume, overall pacing threshold, total procedure time, fluoroscopy time, any complication, or reintervention. Conclusion In patients with HFrEF undergoing CRT, CSP is associated with lower composite risk of HHF or all-cause mortality compared with BiVP. Conduction system pacing is also associated with improved functional capacity, without significant differences in safety or procedural outcomes.

Abstract Aims Mitral valve prolapse (MVP) is a common valvular disorder associated with ventricular arrhythmias (VAs) in a subgroup of patients, known as arrhythmic MVP (AMVP). Arrhythmic MVP patients with malignant VAs typically receive an implantable cardioverter-defibrillator (ICD) for secondary prevention. However, data regarding the incidence of appropriate ICD therapy and the type of arrhythmia recurrence in this population remain scarce. This study aimed to evaluate the incidence of appropriate ICD therapies and type of arrhythmia recurrence in AMVP patients with an ICD implanted for secondary prevention. Methods and results A systematic literature search was conducted in PubMed/MEDLINE and EMBASE databases until January 2025. Studies reporting the incidence of appropriate ICD therapy in AMVP patients were included. A total of 9 studies met the inclusion criteria, resulting in 166 AMVP patients with ICDs for secondary prevention. The mean age was 41.8 years, with 55.8% of patients being female. Over a weighted mean follow-up of 4.9 ± 3.1 years, 34.9% [95% confidence interval (CI): 28.1–42.5] of the patients experienced recurrence of VA. The pooled incidence of appropriate ICD therapies during follow-up was 8.1 per 100 person-years (95% CI: 5.6–10.5, I2: 11.7%). Regarding the type of arrhythmic recurrence, the majority of arrhythmias (53.8%, 95% CI: 44.3–63.0%) were in the form of ventricular fibrillation or polymorphic ventricular tachycardia (VT), while the remaining arrhythmias were reported as monomorphic VT. Among 67 ventricular arrhythmic episodes reported in 7 studies with available data, 65 required shock therapy, corresponding to a shock proportion of 97.0% (95% CI: 89.6–99.6%). Conclusion Arrhythmic MVP patients with ICDs for secondary prevention exhibit a high risk of recurrent arrhythmias, with recurrences in the form of polymorphic VA occurring in more than half of the cases. PROSPERO registration number: CRD42024588610

Abstract Aims Intracardiac echocardiography (ICE) is increasingly incorporated into atrial fibrillation (AF) ablation workflows, enabling real-time anatomic guidance and procedural precision. Nevertheless, ICE utilization shows substantial geographic variability, and its clinical benefit remains incompletely understood. This meta-analysis evaluated the efficacy, safety, and procedural performance of ICE-guided vs. non-ICE-guided AF ablation. Methods and results MEDLINE, the Cochrane Library, and Scopus were systematically searched through 3 August 2025. Three reviewers independently performed study selection, data extraction, and risk-of-bias assessment. Random-effects models were used to pool data from 44 AF ablation studies comprising 482 043 patients. ICE guidance was associated with lower odds of any complication (OR 0.69; 95% CI 0.53–0.89), including significant reductions in cardiac tamponade (OR 0.58; 95% CI 0.53–0.62) and mortality (OR 0.21; 95% CI 0.16–0.27). ICE-guided ablation was also associated with shorter total procedure and fluoroscopy times, reduced radiation exposure, and lower contrast agent utilization. Atrial tachyarrhythmia (AT) recurrence did not differ between groups (OR 0.92; 95% CI 0.79–1.06). However, ICE use was associated with higher odds of first-pass pulmonary vein isolation (OR 1.62; 95% CI 1.09–2.41) and successful isolation of all pulmonary veins at the end of the procedure (OR 2.12; 95% CI 1.37–3.27), and lower odds of repeat ablation (OR 0.65; 95% CI 0.59–0.72). Conclusion ICE-guided AF ablation is associated with superior procedural safety and efficiency and a similar risk of AT recurrence compared to non-ICE-guided approaches.

Atrial fibrillation (AF) is the most persistent arrhythmia today, with its prevalence increasing exponentially with the rising age of the population. Particularly at elevated heart rates, a functional abnormality known as cardiac alternans can occur prior to the onset of lethal arrhythmias. Cardiac alternans are a beat-to-beat oscillation of electrical activity and the force of cardiac muscle contraction. Extensive evidence has demonstrated that microvolt T-wave alternans can predict ventricular fibrillation vulnerability and the risk of sudden cardiac death. The majority of our knowledge of the mechanisms of alternans stems from studies of ventricular electrophysiology, although recent studies offer promising evidence of the potential of atrial alternans in predicting the risk of AF. Exciting preclinical and clinical studies have demonstrated a link between atrial alternans and the onset of atrial tachyarrhythmias. Here, we provide a comprehensive review of the clinical utility of atrial alternans in identifying the risk and guiding treatment of AF.

Abstract Aims Catheter ablation is an effective treatment for post-infarction ventricular tachycardia (VT). However, some patients may experience a worsened arrhythmia phenotype after ablation. We aimed to determine the prevalence and prognostic impact of arrhythmia exacerbation (AE) after post-infarction VT ablation. Methods and results A total of 1187 consecutive patients (93% men, median age 68 years, median ejection fraction 30%) who underwent post-infarction VT ablation at six centres were included. Arrhythmia exacerbation was defined as post-ablation VT storm or incessant VT in patients without prior similar events. During follow-up (median 717 days), 426 (36%) patients experienced VT recurrence. Events qualifying as AE occurred in 67 patients (6%). Median times to VT recurrence with and without AE were 238 [interquartile range (IQR) 35–640] days and 135 (IQR 22–521) days, respectively (P = 0.25). Almost half of the patients (46%) who experienced AE experienced it within 6 months of the index procedure. Patients with AE had had longer ablation times during the ablation procedures compared to the rest of the patients (median 42 vs. 34 min, P = 0.02). Among patients with VT recurrence, the risk of death or heart transplantation was significantly higher in patients with than without AE (hazard ratio 1.99, 95% CI 1.28–3.10; P = 0.002) after adjusting for age, gender, ejection fraction, cardiac resynchronization therapy, post-ablation non-inducibility, and post-ablation amiodarone use. Conclusion Arrhythmia exacerbation after ablation of infarct-related VT is infrequent but is independently associated with an adverse long-term outcome among patients who experience a VT recurrence. The mechanisms and mitigation strategies of AE after catheter ablation require further investigation.

Catheter ablation has brought major advances in the management of patients with atrial fibrillation (AF). As evidenced by multiple randomized trials, AF catheter ablation can reduce the risk of recurrent AF and improve quality of life. In some studies, AF ablation significantly reduced cardiovascular hospitalizations. Despite the existing data on AF catheter ablation, numerous knowledge gaps remain concerning this intervention. This report is based on a recent virtual workshop convened by the National Heart, Lung, and Blood Institute to identify key research opportunities in AF ablation. We outline knowledge gaps related to emerging technologies, the relationship between cardiac structure and function and the success of AF ablation in patient subgroups in whom clinical benefit from ablation varies, and potential platforms to advance clinical research in this area. This report also considers the potential value and challenges of a sham ablation randomized trial. Prioritized research opportunities are identified and highlighted to empower relevant stakeholders to collaborate in designing and conducting effective, cost-efficient, and transformative research to optimize the use and outcomes of AF ablation.

Background: Sudden cardiac death because of ventricular fibrillation (VF) is commonly unexplained in younger victims. Detailed electrophysiological mapping in such patients has not been reported. Methods: We evaluated 24 patients (29±13 years) who survived idiopathic VF. First, we used multielectrode body surface recordings to identify the drivers maintaining VF. Then, we analyzed electrograms in the driver regions using endocardial and epicardial catheter mapping during sinus rhythm. Established electrogram criteria were used to identify the presence of structural alterations. Results: VF occurred spontaneously in 3 patients and was induced in 16, whereas VF was noninducible in 5. VF mapping demonstrated reentrant and focal activities (87% versus 13%, respectively) in all. The activities were dominant in one ventricle in 9 patients, whereas they had biventricular distribution in others. During sinus rhythm areas of abnormal electrograms were identified in 15/24 patients (62.5%) revealing localized structural alterations: in the right ventricle in 11, the left ventricle in 1, and both in 3. They covered a limited surface (13±6 cm 2 ) representing 5±3% of the total surface and were recorded predominantly on the epicardium. Seventy-six percent of these areas were colocated with VF drivers ( P <0.001). In the 9 patients without structural alteration, we observed a high incidence of Purkinje triggers (7/9 versus 4/15, P =0.033). Catheter ablation resulted in arrhythmia-free outcome in 15/18 patients at 17±11 months follow-up. Conclusions: This study shows that localized structural alterations underlie a significant subset of previously unexplained sudden cardiac death. In the other subset, Purkinje electrical pathology seems as a dominant mechanism.