Beyond the Pulmonary Veins: The Influence of Pulsed Field Ablation on the Superior Vena Cava

Pulsed field ablation (PFA) selectively ablates myocardial tissue while minimizing damage to surrounding structures. However, its effects on the superior vena cava (SVC) during right superior pulmonary vein (RSPV) isolation remain unclear.

This study aimed to assess the impact of PFA on the SVC and determine whether anatomical proximity contributes to conduction delay or isolation.

This prospective, single-center observational study analyzed 15 patients with paroxysmal atrial fibrillation (AF) who underwent PFA at our institution between December 2024 and February 2025. A 12-F multipolar PFA catheter (FARAWAVE) was used. The shortest RSPV-SVC distance was measured using preprocedural contrast-enhanced CT and intraprocedural electroanatomic mapping.

Among the 15 patients, 10 (67%) exhibited PFA-induced conduction abnormalities in the SVC, including conduction delay or partial isolation. Partial SVC isolation was observed in seven patients (47%), with three (20%) developing SVC-originating AF that required additional SVC ablation. The shortest RSPV-SVC distance on CT was significantly shorter in the impact group (6.25 ± 1.7 mm) than in the nonimpact group (9.7 ± 2.0 mm; p = 0.04). Electroanatomic mapping showed no significant difference in the application-SVC distance between groups (p = 0.12). ROC analysis identified 7.15 mm as the cutoff for predicting SVC involvement (AUC = 0.86; 95% CI, 0.63-1.00).

PFA for RSPV isolation can cause SVC conduction abnormalities, with anatomical proximity as a key determinant. Preprocedural CT assessment may predict unintentional SVC involvement, which may alter arrhythmogenicity. Further studies are needed to assess long-term clinical implications.