J-wave syndromes (JWS)-comprising Brugada syndrome (BrS) and early repolarization syndrome (ERS)-are important causes of malignant ventricular arrhythmias and sudden cardiac death in patients whose hearts appear structurally normal. Since the 2016 consensus, advances in genetics, pathophysiology, and therapy have redefined both understanding and management. BrS, once viewed as a purely electrical disorder, is now recognized along a microstructural-electrical continuum, with sodium-channel dysfunction and subtle epicardial fibrosis of the right ventricular outflow tract as key contributors. Likewise, ERS-historically considered benign-carries significant risk when inferolateral J-waves coexist with arrhythmic events. Genetically, SCN5A remains the sole gene with definitive disease association, while polygenic susceptibility materially modulates risk, underscoring complex inheritance. Risk stratification remains challenging: patients with prior cardiac arrest or arrhythmic syncope are highest risk, whereas asymptomatic individuals warrant multiparametric assessment integrating clinical features, ECG markers, electrophysiologic studies, and genetics. For decades, treatment centered on implantable cardioverter-defibrillators and quinidine, both limited by availability, tolerance, and device complications. More recently, epicardial substrate ablation has emerged as a transformative therapy, with large registries and randomized trials demonstrating durable suppression of ventricular fibrillation and acceptable safety. This APHRS-organized international consensus updates and extends the 2016 Expert Consensus and the 2022 ESC Guidelines, providing contemporary diagnostic frameworks, pragmatic risk-stratification tools, and treatment algorithms for BrS and ERS. It emphasizes JWS as a microstructural-electrical disease spectrum and elevates substrate ablation as a major therapeutic advance, while outlining priorities for genetics, risk-stratification and treatment algorithms.

BACKGROUND:In long QT syndrome, longer QT intervals indicate increased arrhythmic risk, and a rate-corrected QT interval (QTc) of ≥500 ms denotes high risk. Establishing similar associations in short QT syndrome (SQTS) remains elusive. OBJECTIVE:This study aimed to demonstrate that shorter QT intervals denote a higher risk of malignant arrhythmias in SQTS and to define the "high-risk" QTc value in SQTS. METHODS:Pooled analysis of patients treated in our institutions or those reported in the literature revealed 162 patients with SQTS and known symptomatic status; 57 of them (35.2%) had arrhythmic symptoms (sudden death, cardiac arrest, or malignant syncope). RESULTS:There was a significant inverse association between the QTc and arrhythmic symptoms (with a median QTc of 315.0 ms [interquartile range 300.5-338.0] among symptomatic patients vs 330.0 ms [interquartile range 312.5-355.0] among asymptomatic patients; P = .0023). Receiver operator characteristics analysis showed that shorter QTc values were associated with a higher risk (area under the curve 0.64 ± 0.04; P = .0024). When patients were grouped by QTc range, most of those with a QTc of ≤320 ms had malignant arrhythmic symptoms, whereas the reverse was true for those with a QTc of ≥320 ms. Male patients were overrepresented in the SQTS cohort and more so in the subgroup with malignant symptoms. CONCLUSION:This pooled analysis of patients with SQTS demonstrates that, among patients with congenital SQTS, a shorter QTc is associated with a higher risk of malignant ventricular arrhythmias. A QTc shorter than 320 ms correlates with a higher arrhythmic risk. Men seem to be at higher risk.

Intracardiac echocardiography (ICE) has evolved into an integral imaging modality in contemporary electrophysiology, providing real-time visualization that enhances both the safety and efficacy of complex procedures. Although most operators rely exclusively on imaging windows obtained from the right atrium and right ventricle, this may limit comprehensive assessment of left cardiac structures. This review examines the emerging role of ICE imaging directly from the left atrium (LA) and left ventricle via transseptal access, with a focus on technical and practical considerations, highlighting catheter positioning, imaging views, and relevant anatomic relationships. In addition, we discuss the applications of LA/left ventricular ICE to guide left-sided electrophysiology procedures, including ablation of atrial and ventricular arrhythmias and LA appendage occlusion.

Background:Early conversion of recent-onset atrial fibrillation (AF) is of clinical value. Vernakalant is an atrial-selective, rapid-acting antiarrhythmic drug. We report a large cohort of consecutive patients receiving vernakalant for the conversion of AF and review the clinical trials reporting on its safety and efficacy. Objective:This study aimed to determine the effectiveness and safety of cardioversion of recent-onset AF with intravenous vernakalant in the emergency department. Methods:Retrospective observational study of adults presenting with recent-onset AF (≤48 hours) treated with intravenous vernakalant. Patients received either a simplified fixed-dose protocol (300 mg ± second dose of 200 mg) or a weight-adjusted protocol (3 mg/kg ± 2 mg/kg). The primary efficacy end point was conversion to sinus rhythm. Safety end points included all adverse events (AEs). Results:Among 328 consecutive patients treated with vernakalant (median age 61 years; 56% male), vernakalant restored sinus rhythm within minutes of administration in 268 patients (82%). First-dose conversion occurred in 68% (70% of the fixed-dose group vs 56% of the weight-adjusted-dose group; P = .015). Within a 48-hour time window, a shorter time from symptoms to treatment had a relatively low predictive ability (area under the receiver operating characteristic curve 0.61) for predicting cardioversion. AEs occurred in 34 patients (10%) but were almost invariably mild; serious AEs occurred in only 1 patient (0.3%) but involved a fatality attributable to unrecognized severe cardiomyopathy. Conclusion:In an emergency department, intravenous vernakalant was highly effective for terminating recent-onset AF, rapidly converting 82% of AF episodes within minutes of drug administration.

Pulsed field ablation has emerged as a novel non-thermal treatment modality with a distinct safety profile for the interventional treatment of atrial fibrillation. By inducing irreversible electroporation, pulsed field ablation achieves myocardial ablation while preserving surrounding structures such as nerves, vasculature, and the oesophagus. This European Heart Rhythm Association of the European Society of Cardiology scientific statement, endorsed by major international societies, reviews the biophysics, technology, clinical evidence, workflow, safety, and training aspects of pulsed field ablation. Randomized trials demonstrate comparable efficacy to radiofrequency and cryoballoon ablation, with advantages in safety and efficiency. The statement provides practical advice for clinical implementation and operator training and identifies key gaps in evidence and priorities for future research and innovation.

BACKGROUND:Congenital short-QT syndrome (SQTS) is a genetic disorder characterized by short QT interval on electrocardiography (ECG) and a high risk for malignant ventricular tachyarrhythmias. OBJECTIVES:The aim of this study was to describe a new variant in the SQTS-associated gene SLC4A3 at the molecular and clinical levels. METHODS:Using whole-exome sequencing, a novel missense variant in SLC4A3 was identified, encoding for the cardiac anion exchanger 3. The mutant was characterized using computational structural modeling and functional transport studies in human embryonic kidney 293 cells. Patients were assessed using resting ECG, 12-lead Holter recordings, and a novel diagnostic test termed here the Ippon test. RESULTS:A novel heterozygous SLC4A3 variant (p.R1016G) was detected in a family with 6 cases of sudden cardiac death and a case of documented polymorphic ventricular tachycardia in 5 generations. Functional analyses in human embryonic kidney 293 cells revealed gain of function rather than the loss of function expected on the basis of previously reported SQTS-associated SLC4A3 variants. Although affected family members exhibited shorter corrected QT intervals on resting ECG compared with nonaffected members (360 ± 20 ms vs 380 ± 30 ms; P = 0.0068) and 12-lead Holter monitoring (350 ± 20 ms vs 380 ± 30 ms; P = 0.0013), significant overlap existed. The sudden heart rate deceleration provoked by the Ippon test revealed that the QT interval in carriers failed to prolong in response to the sudden bradycardia, resulting in inappropriately short corrected QT intervals, leading to a better distinction of affected from nonaffected patients (340 ± 30 ms vs 370 ± 10 ms, respectively; P = 0.0003). CONCLUSIONS:SLC4A3 p.R1016G is a novel SQTS-associated variant associated with a gain-of-function effect. The Ippon test is a new provocation maneuver that identifies SQTS variant carriers with high diagnostic accuracy.

BACKGROUND:Managing pocket infections in cardiac implantable electronic devices (CIEDs) during early pregnancy presents significant clinical challenges, as current guidelines mandate complete system extraction. However, extraction carries high maternal-fetal risks, including surgical complications, radiation exposure, and teratogenic effects of systemic antibiotics. CASE SUMMARY:A 29-year-old woman, 5-week pregnant, was referred for a CIED pocket infection with an extruding implantable cardioverter-defibrillator implanted 9 years earlier for idiopathic ventricular fibrillation. Given the risks of extraction and the patient's desire to preserve her pregnancy, a conservative salvage approach integrating controlled in situ-targeted ultrahigh-concentration antibiotic administration with minimally invasive surgery was performed. The procedure involved limited surgical intervention, targeted antibiotic administration, and meticulous shielding to minimize fetal radiation exposure. Antibiotic levels were monitored daily, maintaining a mean vancomycin area under the concentration-time curve over 24 hours to minimum inhibitory concentration ratio of 31.7 (95% CI: 26.9-36.5) μg·hour/mL, ensuring effective infection control while minimizing systemic toxicity. The patient remained infection-free and underwent a successful cesarean delivery of a full-term healthy baby. WHY BEYOND THE GUIDELINES?: Current recommendations advocate complete CIED system removal for pocket infections; however, they do not address early pregnancy, where extraction may entail significant procedural, maternal, and fetal risks that could, in some cases, lead to consideration of pregnancy termination. This case highlights a safe and effective alternative, supporting the need for guideline expansion to include conservative salvage strategies in high-risk patients. TAKE-HOME MESSAGES:Controlled in situ-targeted ultrahigh-concentration antibiotic administration with minimally invasive surgery offers a safe and effective alternative for managing infected CIEDs in pregnancy, avoiding extraction-related risks, and minimizing maternal and fetal harm while maintaining high local antibiotic concentrations with minimal systemic exposure. Integrating area under the concentration-time curve over 24 hours to minimum inhibitory concentration-guided monitoring ensures precise dosing, reinforcing the need to expand guidelines to include conservative salvage options for high-risk patients.

BACKGROUND:Posterior wall isolation (PWI) is often performed in addition to pulmonary vein isolation (PVI) during ablation of persistent atrial fibrillation (PersAF) to decrease recurrence. However, in studies using radiofrequency energy, the addition of PWI failed to demonstrate improved outcomes compared with PVI alone, possibly owing to challenges in achieving durable PWI. PWI with pulsed field ablation (PFA) results in high rates of durable PWI. OBJECTIVE:We hypothesized that PVI plus PWI, performed with tissue-contact visualization with intracardiac echocardiography (ICE) and confirmation with high-output pacing, would effectively treat PersAF. METHODS:We studied consecutive patients with PersAF undergoing their first ablation with PFA. PVI and PWI were conducted with the FARAPULSE system using a strict protocol that included (1) continuous tissue-contact visualization with ICE and (2) confirmation of PVI and PWI with high-output pacing. RESULTS:A total of 109 consecutive patients with PersAF (age 70 years [interquartile range 64-75]; 30 females [27.5%]; CHA2DS2-VA score 2.5 ± 1.5) were studied. PVI and PWI were achieved in all patients without complications (procedure time 84 ± 12 minutes; dwell time 48 ± 10 minutes; mean PFA applications 58 ± 3.8; fluoroscopy time 14 ± 8 minutes). The mean follow-up was 15.8 ± 5.5 months. At 12 months, freedom from recurrent atrial arrhythmias was achieved in 79 patients (72%). Eight patients opted for a second ablation. Durable PVI was confirmed in 90% of veins, and persistent PWI was confirmed in 87% of patients. CONCLUSION:A high long-term success rate of ablation is achievable in PersAF with PFA and tissue-contact confirmation using ICE.

Pulsed field ablation (PFA) is emerging as an efficient, effective and safe energy source to achieve pulmonary vein isolation (PVI) for the treatment of atrial fibrillation (AF). 1 Reddy V.Y. Gerstenfeld E.P. Natale A. et al. Pulsed Field or Conventional Thermal Ablation for Paroxysmal Atrial Fibrillation. N Engl J Med. Nov 2 2023; 389: 1660-1671 Google Scholar ,2 Verma A. Haines D.E. Boersma L.V. et al. Pulsed Field Ablation for the Treatment of Atrial Fibrillation: PULSED AF Pivotal Trial. Circulation. May 9 2023; 147: 1422-1432 Google Scholar One of the most appealing aspects of PFA compared to conventional thermal ablation sources is the differential tissue sensitivity with reported tissue-specific ablation thresholds. 3 Sugrue A. Maor E. Del-Carpio Munoz F. Killu A.M. Asirvatham S.J. Cardiac ablation with pulsed electric fields: principles and biophysics. Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology. Sep 1 2022; 24: 1213-1222 Google Scholar ,4 Li W. Fan Q. Ji Z. Qiu X. Li Z. The effects of irreversible electroporation (IRE) on nerves. PLoS One Apr. 2011; 14e18831 Google Scholar Pre-clinical studies with different PFA platforms have suggested that selective myocardial ablation can be achieved, with sparing of adjacent non-myocardial tissue such as nerves, vascular structures and esophageal tissue. 5 Koruth J. Kuroki K. Iwasawa J. Enomoto Y. Viswanathan R. Brose R. Buck E.D. Speltz M. Dukkipati S.R. Reddy V.Y. Preclinical Evaluation of Pulsed Field Ablation: Electrophysiological and Histological Assessment of Thoracic Vein Isolation. Circulation Arrhythmia and electrophysiology. Dec 2019; 12e007781 Google Scholar ,6 Koruth J.S. Kuroki K. Kawamura I. Brose R. Viswanathan R. Buck E.D. Donskoy E. Neuzil P. Dukkipati S.R. Reddy V.Y. Pulsed Field Ablation Versus Radiofrequency Ablation: Esophageal Injury in a Novel Porcine Model. Circulation Arrhythmia and electrophysiology Mar. 2020; 13e008303 Google Scholar Results from clinical studies have largely confirmed these findings, with no published reports to date of esophageal injury and PV stenosis, although it has become evident that reversible coronary vasospasm can occur when PFA is applied in proximity of coronary arteries, and at least temporary impairment with PFA in proximity to the phrenic nerve is possible. 7 Higuchi S. Buck E.D. Schneider C.W. Gerstenfeld E.P. What is a safe distance for delivering pulsed field ablation near coronary arteries?. Heart rhythm Jul. 2023; 20: 1066-1067 Google Scholar , 8 Howard B. Haines D.E. Verma A. Kirchhof N. Barka N. Onal B. Stewart M.T. Sigg D.C. Characterization of Phrenic Nerve Response to Pulsed Field Ablation. Circulation Arrhythmia and electrophysiology Jun. 2022; 15e010127 Google Scholar , 9 Pansera F. Bordignon S. Bologna F. Tohoku S. Chen S. Urbanek L. Schmidt B. Chun K.J. Catheter ablation induced phrenic nerve palsy by pulsed field ablation-completely impossible? A case series. Eur Heart J Case Rep Sep. 2022; 6: ytac361 Google Scholar One interesting phenomenon that has been documented with PFA within the PV antra adjacent to cardiac ganglionated plexi (GP) is the induction of vagal responses with significant sinus pauses and/or atrioventricular block. 10 Ekanem E. Reddy V.Y. Schmidt B. et al. Multi-national survey on the methods, efficacy, and safety on the post-approval clinical use of pulsed field ablation (MANIFEST-PF). Europace : European pacing, arrhythmias, and cardiac electrophysiology. journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology. Sep 1 2022; 24: 1256-1266 Google Scholar ,11 Schmidt B. Bordignon S. Neven K. et al. EUropean real-world outcomes with Pulsed field ablatiOn in patients with symptomatic atRIAl fibrillation: lessons from the multi-centre EU-PORIA registry. Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias. and cardiac cellular electrophysiology of the European Society of Cardiology. Jul 4 2023; : 25 Google Scholar Clinically, vagal responses have been mitigated by atrial and/or ventricular pacing or administration of atropine. However, these strategies, although easily applicable to most patients undergoing AF ablation, have some limitations. For instance, pacing requires a separate intracardiac catheter which, in case of vagally-induced atrioventricular block, needs to be advanced within the right ventricle (or a ventricular branch of the coronary sinus) with potential for perforation in fully anticoagulated patients. Routine administration of atropine is also not an ideal option as it may be associated with potential side effects related to the systemic anticholinergic activity which may be particularly problematic in patients with associated comorbidities (e.g., glaucoma, prostate enlargement). Pulsed Field Ablation of the Right Superior Pulmonary Vein Prevents Vagal Responses Via Anterior Right Ganglionated Plexus ModulationHeart RhythmPreviewPulsed field ablation (PFA) is selective for the myocardium. However, vagal responses and reversible effects on ganglionated plexi (GP) are observed during pulmonary vein isolation (PVI). Anterior-right GP ablation has been proven to effectively prevent vagal responses during radiofrequency-based PVI. Full-Text PDF Open Access

The temperature-sensing catheter with microelectrodes and 6 thermocouples delivers radiofrequency ablation in very-high power short-duration (vHPSD, 90W/4s) or conventional-power temperature-controlled modes (CPTC, ≤50W). CARTONET, a cloud-based data management and artificial intelligence-powered insights system is being used to evaluate ablation characteristics of the 2 modalities in Afib cases performed on SECURE, a prospective observational study.

Pulsed field ablation (PFA) is an emerging technology for the treatment of atrial fibrillation (AF), for which pre-clinical and early-stage clinical data are suggestive of some degree of preferentiality to myocardial tissue ablation without damage to adjacent structures. Here in the MANIFEST-17K study we assessed the safety of PFA by studying the post-approval use of this treatment modality. Of the 116 centers performing post-approval PFA with a pentaspline catheter, data were received from 106 centers (91.4% participation) regarding 17,642 patients undergoing PFA (mean age 64, 34.7% female, 57.8% paroxysmal AF and 35.2% persistent AF). No esophageal complications, pulmonary vein stenosis or persistent phrenic palsy was reported (transient palsy was reported in 0.06% of patients; 11 of 17,642). Major complications, reported for similar to 1% of patients (173 of 17,642), were pericardial tamponade (0.36%; 63 of 17,642) and vascular events (0.30%; 53 of 17,642). Stroke was rare (0.12%; 22 of 17,642) and death was even rarer (0.03%; 5 of 17,642). Unexpected complications of PFA were coronary arterial spasm in 0.14% of patients (25 of 17,642) and hemolysis-related acute renal failure necessitating hemodialysis in 0.03% of patients (5 of 17,642). Taken together, these data indicate that PFA demonstrates a favorable safety profile by avoiding much of the collateral damage seen with conventional thermal ablation. PFA has the potential to be transformative for the management of patients with AF.