Radiofrequency Catheter Ablation of Atrial Fibrillation in Patients with Anomalous Pulmonary Venous Return: A Multicenter Case Series

Background Atrial fibrillation (AF) has been observed in adults with anomalous pulmonary venous return (APVR), but data on catheter ablation outcomes in this population remain limited to case reports and small series. Methods We retrospectively reviewed 14 adult patients with confirmed APVR who underwent catheter ablation for AF at three tertiary academic centers in the United States between July 2003 and May 2025. Baseline, procedural, electroanatomic mapping, and outcome data were collected. Freedom from atrial arrhythmia recurrence was estimated by Kaplan-Meier analysis. Results Mean age was 56 ± 13 years and 79% were male. Heart failure was present in 64%, and hypertension and coronary artery disease in 43% each. Most had partial APVR (86%), and 57% had prior surgical correction. Radiofrequency ablation was used in all patients, combined with pulsed-field ablation in one. Acute success was achieved in all patients, although areas with residual pulmonary vein or SVC electrical activity were left untreated in 3 (21%). Non-pulmonary-vein electrical activity was more common in patients with prior surgical correction than in those without (43% vs 17%). Median follow-up was 3.4 years (IQR, 2.0-9.6). Freedom from arrhythmia recurrence was 78.6% at 1 year and 53.9% at 5 years. Two patients (14%) required reablation; complications occurred in 3 (21%) without long-term sequelae. Conclusions Catheter ablation was acutely successful in all patients in this largest reported APVR cohort, despite substantial comorbidity burden and anatomic complexity. The arrhythmogenic substrate often extended beyond the anomalous vein, particularly in surgically corrected patients, supporting individualized, substrate-guided ablation in this population. CLINICAL PERSPECTIVE What Is Known Atrial fibrillation has been reported in adults with anomalous pulmonary venous return (APVR), but data on catheter ablation outcomes in this population are limited to case reports and small series. What the Study Adds In the largest reported cohort of patients with APVR undergoing catheter ablation for atrial fibrillation, pulmonary vein isolation achieved acute success in all patients despite substantial comorbidity burden and anatomic complexity. Non-pulmonary-vein sites of electrical activity were more common among patients with prior surgical correction, and postsurgical scar and epicardial venoatrial connections were also arrhythmogenic, indicating that the arrhythmogenic substrate in APVR often extends beyond the anomalous vein itself. These findings support individualized, substrate-guided mapping in patients with APVR, particularly those with a surgical history, and suggest a role for pulsed-field ablation near critical structures such as the phrenic nerve.