Wide‐Area Superior Vena Cava Isolation Using a Circular Pulsed Field Ablation Catheter Guided By Spontaneous Conduction Block Lines: A Comparative Study With Radiofrequency Ablation

AIMS: The superior vena cava (SVC) is a frequent non-pulmonary vein trigger in atrial fibrillation (AF). Adjunctive SVC isolation (SVCi) may reduce AF recurrence; however, radiofrequency (RF) ablation carries risks such as phrenic nerve palsy (PNP) and sinus node dysfunction (SND). Pulsed field ablation (PFA) offers myocardial selectivity, but clinical data using a circular PFA catheter guided by spontaneous block lines remain limited. METHODS AND RESULTS: This single-centre retrospective study included 85 patients who underwent adjunctive SVCi (RF n = 45, PFA n = 40). RF ablations were performed from August 2023 to December 2024, and PFA was introduced in January 2025. Spontaneous block lines were identified using the EnSite X mapping system and incorporated into ablation planning. SVC isolation was achieved in all patients. First-pass success was higher with PFA (97.5% vs. 84.4%, p = 0.06). PFA required fewer applications (4.4 ± 2.4 vs. 14.2 ± 6.3, p < 0.01) and a shorter procedural duration (368 ± 350 vs. 847 ± 656 s, p < 0.01), with similar isolation area (14.0 ± 6.9 vs. 14.2 ± 6.3 cm², p = 0.42). Transient PNP occurred in one PFA case and none with RF. Transient SND occurred in four PFA and two RF cases; all resolved spontaneously, and no persistent complications were observed. During follow-up, atrial fibrillation recurrence rates were low and comparable between groups (7.5% vs. 8.9%, p = 0.81). Among patients undergoing repeat ablation, SVC reconnection was infrequent. CONCLUSIONS: Wide-area SVCi using a circular PFA catheter guided by spontaneous block lines is feasible and efficient. PFA reduced procedure time and ablation burden while maintaining comparable efficacy and low complication rates. This strategy provides an anatomically rational, reproducible approach for adjunctive SVCi in AF ablation workflows.