Aim:This study aimed to systematically review and synthesise existing real-world evidence on the clinical characteristics and outcomes of patients with post-ablation AF recurrence in east Asia. Methods:Following the PRISMA guidelines, main Chinese- and English-language databases were searched for observational studies published from 2019 to 2024. Inclusion criteria targeted East Asian patients aged ≥18 years with post-ablation AF recurrence. Two independent reviewers conducted study selection, data extraction and quality assessment using the Newcastle-Ottawa Scale. Meta-analyses were performed using a random effects model to synthesise the extracted data. Results:A total of 68 studies involving 28,750 patients were included. Paroxysmal AF accounted for about half of the population (53.4%; 95% CI [47.8-58.9]). Common comorbidities included hypertension (52.6%; 95% CI [50.2-55.0]), coronary artery disease (17.2%; 95% CI [12.9-22.5]) and diabetes (16.8%; 95% CI [14.9-18.8]). The AF recurrence rates after repeat ablation (21.4%; 95% CI [16.6-27.1]) and antiarrhythmic drug therapy (19.6%; 95% CI [18.0-21.2]) were similar. Recurrence was higher in patients with late recurrence (32.6%; 95% CI [26.9-38.8]) than those with early recurrence (21.5%; 95% CI [17.9-25.6]). The pooled 3-year incidence of major events included heart failure hospitalisation (3.2%; 95% CI [2.8-3.6]), ischaemic stroke (1.2%; 95% CI [0.9-1.7]) and cardiovascular-related death (0.3%; 95% CI [0.1-0.5]). Conclusion:Post-ablation AF recurrence in East Asia imposes a considerable disease burden with high recurrence rates even after repeated ablation or antiarrhythmic drug therapy. The presence of prevalent comorbidities and measurable risks of morbidity and mortality further contribute to the long-term clinical and economic burdens of AF.
Background: It is unclear whether on-going fibrillation in isolated pulmonary veins (OFIP) may coexist with AF in patients undergoing ablation for non-paroxysmal AF (PAF). This study explored the prevalence of OFIP in non-PAF ablation with the aim of developing an algorithm to distinguish between OFIP and isolation failure, thereby minimising excessive ablation. Methods: Non-PAF patients undergoing first-time ablation were divided into a retrospective induction cohort (IC; n=300) and a prospective validation cohort (VC; n=263). In the case of on-going pulmonary vein (PV) fibrillation after ablation, the completeness of PV isolation was assessed based on the change in PV potential and after additional ablation. Results: Among 563 patients, 20 (3.55%) had OFIP (9 in the IC; 11 in the VC). No significant predictors of OFIP were identified in terms of baseline characteristics or procedural factors. Based on three right-sided, five left-sided and one bilateral case of OFIP in the IC, the disappearance of PV potential (either spontaneous or mechanical bumping-induced) or a combination of bipolar voltage reduction >80%, local activation time later than PV recordings and no response to carina ablation were adopted as major criteria in the algorithm to discriminate between OFIP and isolation failure. Among the 20 patients in the VC with on-going PV fibrillation, the algorithm identified true OFIP in 11, false OFIP in three and true incomplete PV isolation in six. The sensitivity, specificity and positive and negative predictive values of the algorithm were 100%, 66.7%, 78.6% and 100%, respectively. Conclusion: The rate of OFIP was not negligible in non-PAF patients undergoing ablation procedures to achieve efficient and safe PV isolation. A novel four-step algorithm was developed to discriminate OFIP from isolation failure, with good predictive value.
AF and heart failure (HF) commonly coexist, and this significantly increases patient morbidity and mortality. Maintaining sinus rhythm is a key treatment goal, as it helps prevent HF progression, improves quality of life and reduces cardiovascular mortality. Catheter ablation (CA) has emerged as an effective and preferred alternative to antiarrhythmic medications for rhythm control in patients with AF and HF. Multiple studies have demonstrated the superiority of CA over medical therapy for maintaining sinus rhythm and improving left ventricular function in the HF population, particularly those with reduced left ventricular ejection fraction. Additionally, CA is associated with a low complication rate due to advancing technology and is cost-effective. With growing evidence and endorsement from recent guidelines, clinical practice has shifted towards early CA in patients with AF and HF. Prioritising early intervention represents a proactive approach to improving long-term outcomes.
AF and heart failure (HF) often coexist, amplifying morbidity and mortality. Catheter ablation is an effective rhythm control strategy, particularly in heart failure with reduced ejection fraction, where studies such as CASTLE-AF show improved survival, fewer HF hospitalisations and better quality of life. Evidence in HF with preserved ejection fraction is emerging; RAFT-AF included HF with preserved ejection fraction patients, but showed no significant primary outcome difference, though subgroup data offer insights across the HF spectrum. Procedural risks, influenced by patient frailty and device presence (e.g. left ventricular assist devices and CRT), necessitate careful selection and periprocedural optimisation. Advances in ablation technology, including pulsed field ablation, and adjunctive strategies show promise but require further validation. Early rhythm control, as supported by EAST-AFNET 4, may prevent adverse remodelling and improve outcomes if applied before extensive atrial disease develops. Future directions emphasise multidisciplinary, personalised approaches integrating imaging and biomarkers to optimise patient selection. Thoughtful application of catheter ablation can enhance outcomes in carefully selected HF patients with AF.
Five patients who underwent left bundle branch optimised (LOT)-CRT developed T wave oversensing (TWOS) between 2 months and 2 years post implant. LOT-CRT resulted in greater improvement in left ventricular size and function compared with historical case-matched controls. No patients experienced symptoms or inappropriate therapy as a result of TWOS. This report describes the occurrence, potential mechanisms and management of TWOS in patients undergoing LOT-CRT.
Catheter ablation remains a cornerstone in the treatment of ventricular tachycardia (VT) in structural heart disease. Part 1 of this review focused on the principles and technical aspects of radiofrequency (RF) ablation. Part 2 explores alternative strategies designed to overcome the limitations of conventional RF, in particular, achieving transmurality in complex or deep intramuscular substrates. We critically evaluate the mechanisms, evidence and clinical applications of bipolar RF ablation, pulsed-field ablation (PFA), ultra-low-temperature cryoablation (ULTC) and venous ethanol and needle ablation. Despite the rapid expansion of the technological armamentarium, current clinical evidence remains limited. The data supporting long-term safety and durability are predominantly based on preclinical and small observational studies. We advocate for continued investigation into these specialised techniques to provide a more tailored, patient-specific approach to VT management.
Cardiovascular disease is a major global cause of death, with sudden cardiac death accounting for up to half of cases, largely due to ventricular tachyarrhythmias. In the UK, approximately 60,000 out-of-hospital cardiac arrests occur annually, with survival rates of only 2-12%. Younger individuals are also affected, with one cardiac-related death daily in those under 35 years of age. Despite advances in care, arrhythmia recurrence remains high (40-50% within 5 years). ICDs have become pivotal in preventing sudden cardiac death, with continuous innovations in device design, implantation, and arrhythmia detection since their introduction in 1980. Transvenous single-chamber ICDs remain the standard, while dual-chamber and CRT defibrillator devices serve patients needing atrial pacing or heart failure support. Subcutaneous and extravascular ICD systems protect patients not requiring pacing while avoiding lead-related risks. Device selection must be individualised, considering clinical profile, comorbidities, lifestyle, patient preferences, and operator expertise. Ongoing advances, including leadless pacing and modular anti-tachycardia pacing systems, continue to expand personalised device strategies.
The incidence of idiopathic ventricular arrhythmias (VAs) is increasing, and the outflow tract region is the most common site of origin for these arrhythmias. While these arrhythmias are benign, significant symptoms and cardiomyopathy due to frequent premature ventricular contractions can occur. Ventricular tachycardia and/or premature ventricular contractions can exit from the right ventricular outflow tract, left ventricular outflow tract, or the left ventricular summit. Catheter ablation of outflow tract VAs can be challenging, and a detailed understanding of the complex anatomical relationships in this region and proficiency with advanced techniques, such as bipolar and transcoronary venous ethanol ablation, may be required for successful ablation. This article reviews the management of idiopathic outflow VAs with a focus on catheter ablation.
Device-detected AF, commonly labelled atrial high-rate episodes or subclinical AF (SCAF), creates a dilemma over anticoagulation: absolute stroke risk will be lowered, yet oral anticoagulation (OAC) carries a real risk of major bleeding. The author argues that searching for a universal episode-duration threshold is not the answer. Analyses of trial results show that baseline SCAF frequency and longest episode duration do not reliably identify a high-risk subgroup nor consistently justify escalation to anticoagulation treatment. Duration-only thresholding is therefore an unstable primary decision-making tool. A practical alternative is proposed: phenotype-led anticoagulation with a burden-led workflow. Phenotypes, especially vascular disease and absolute risk, drive whether OAC is plausibly beneficial; burden determines urgency, monitoring intensity and the need for escalation. This framework primarily addresses SCAF episodes below 24 hours, where clinical uncertainty is greatest and randomised evidence is most directly applicable. It is operationalised as a device-clinic pathway with electrogram adjudication as an entry criterion, burden classes for triage, and phenotype classes for OAC selection, using atrial substrate markers only as tiebreakers in borderline cases.
Radiofrequency catheter ablation (RFCA) is an established treatment for paediatric arrhythmias in children weighing >15 kg, yet its role in infants with arrhythmia-induced cardiomyopathy remains less defined. This case series evaluates the efficacy and safety of RFCA in four infants (aged ≤1 year) with arrhythmia-induced cardiomyopathy through a retrospective review of clinical profiles, procedural data and outcomes. All patients had right-sided accessory pathways, with three showing atrioventricular re-entrant tachycardia and one pre-excitation-related cardiomyopathy. Each infant had failed pharmacotherapy, and presented with heart failure and cardiac enlargement. RFCA was successfully performed in all cases without complications. Within 1-6 months postprocedure, both cardiac function and size normalised in every patient. These findings support RFCA as a safe and effective treatment for medically refractory, right-sided, pathway-mediated, arrhythmia-induced cardiomyopathy in infants, highlighting its potential for complete functional recovery.
The management of AF in patients with heart failure is complex and nuanced. This paper explores the potential antiarrhythmic effects of guideline-directed medical therapy for heart failure and reviews the pharmacological and ablative treatments for AF. Heart failure with reduced ejection fraction is discussed separately from heart failure with preserved ejection fraction. Treatment recommendations for each heart failure subtype are given.
Catheter ablation is the primary treatment for ventricular tachycardia (VT) in patients with structural heart disease. Unfortunately, its long-term success remains limited. Although mapping techniques have advanced considerably, optimal ablation indices remain essential but less well defined. This two-part comprehensive review bridges the gap between bench and bedside by evaluating methods, technologies, and VT-specific lesion parameters. Here, in part 1, we critically examined conventional and emerging techniques, including radiofrequency (RF), high-power short-duration ablation, temperature-controlled RF. In the accompanying paper, part 2, we focus on bipolar RF ablation, pulsed field ablation and ultra-low-temperature cryoablation, venous ethanol and needle ablation. Despite the growing set of tools available for VT operators, clinical data on the practical and safe creation of lesions remain scarce. The evidence supporting most of the techniques reviewed is limited. We emphasise the need for personalised ablation strategies based on substrate and myocardial anatomy and advocate for the development of future integrated, metric-driven technologies.
Conduction system pacing (CSP), including His bundle pacing and left bundle branch area pacing (LBBAP), has emerged as a physiological alternative to right ventricular pacing and an evolving modality for cardiac resynchronisation therapy. As clinical adoption expands, lead technology has become central to procedural success, electrical performance, and long-term safety. Historically, CSP has relied on lumenless leads (LLL), while stylet-driven leads (SDL) are increasingly used, particularly for LBBAP. Current evidence indicates that CSP procedures are feasible, reproducible, and show positive trends in outcomes for both bradycardia and heart failure patients, with both LLL and SDL achieving high implant success and comparable pacing parameters. However, differences in mechanical design may influence implantation technique, complication profiles, and long-term durability. Although observational studies and registries support the safety and effectiveness of both lead types, long-term data on lead fracture, extractability, and device-specific performance remain limited. At present, no clear superiority of one platform over the other can be established. Lead selection should therefore be individualised, guided by anatomy, operator experience and device-specific evidence, while further prospective studies are needed to optimise CSP lead design and long-term outcomes.
The incidences of AF and heart failure (HF) have been progressively increasing worldwide. These conditions exhibit a strong interdependence, with each exacerbating the other. HF is currently classified based on left ventricular ejection fraction (EF) as HF with reduced, mid-range or preserved EF (HFrEF, HFmrEF or HFpEF, respectively). Atrial cardiomyopathy, also known as atriopathy, involves structural, architectural, contractile, or electrophysiological alterations in the atria, driven by diverse mechanisms stemming from risk factors and comorbidities, including diabetes, hypertension, ischaemic and valvular heart diseases, hypertrophic and dilated cardiomyopathies, as well as various forms of HF. Emerging evidence also implicates infiltrative cardiomyopathies (e.g. cardiac amyloidosis), certain cancers, and chemotherapeutic agents in promoting both AF and HF. This review summarises key basic and translational science findings, along with their potential clinical applications, that connect shared pathophysiological substrates between HF and atrial cardiomyopathy.
AF can mediate left ventricular systolic dysfunction (LVSD) through a tachycardia-mediated cardiomyopathic process that may reverse with rate control alone. However, additional mechanisms contribute to AF-induced cardiomyopathy (AIC) that require rhythm control therapies. AIC can currently only be diagnosed retrospectively, as these component mechanisms are difficult to distinguish from each other and from other causes of LVSD prospectively. This narrative review considers the different potential mechanisms through which AF can impair ventricular function: rapid ventricular rate; irregularity of the ventricular rhythm; and impaired atrial contraction. How these features may exploit underlying structural vulnerability are considered and additional imaging-based parameters such as late gadolinium enhancement on cardiac MRI and contractile reserve during stress echocardiography are discussed. The limitations of existing parameters are discussed and a novel, non-parametric marker of ventricular rate with consideration of the inherent irregularity of AF - the Restitution Threshold Index (RTI) - is reviewed. Integrating RTI with these imaging-based measures may enhance clinical decision-making by more accurately identifying patients who would benefit from timely rhythm control. Further prospective validation is essential to develop accessible tools and an open-access RTI calculator has been made available (https://restitutionthreshold.com) to facilitate reproducibility and wider application.
Radiofrequency ablation is the mainstay of interventional electrophysiology. The biophysics of radiofrequency ablation involve converting electrical energy into heat to irreversibly damage an area of myocardium. To create an ablation lesion, a temperature of >50°C must be generated in the tissue for 60 seconds. This is influenced by factors affecting either the current delivered, electrode impedance, ablation duration or the thermoconductive properties of the tissue. These factors can be altered to affect ablation lesion size to optimise arrhythmia treatment.
Pulsed field ablation is an emerging strategy for cardiac arrhythmia ablation that offers tissue selectivity and a favourable safety profile, demonstrating high acute pulmonary vein isolation rates and low complication rates. Ongoing innovations in catheter design, pulse parameters and energy combinations aim to enhance lesion depth and durability, positioning pulsed field ablation as a promising cornerstone in the future of cardiac ablation.
