Abstract
BACKGROUND: The superior vena cava (SVC) is a common non-pulmonary vein trigger site in atrial fibrillation (AF), and its ablation improves treatment success rates. However, conventional SVC ablation carries risks of sinoatrial node injury (SNI) and phrenic nerve injury (PNI) due to its anatomical proximity to the sinoatrial node. This study evaluated the safety and efficacy of high-power short-duration (HPSD) ablation of the SVC using the right superior pulmonary vein roof (RSPV roof) as an anatomical landmark to minimize complications. METHODS: This retrospective study analyzed 110 patients with paroxysmal AF who underwent circumferential pulmonary vein isolation (CPVI) combined with SVC isolation (SVCI). The RSPV roof and SVC junction were used as anatomical landmarks. HPSD ablation (50 W/7 s) was performed without phrenic nerve(PN)mapping. The electrical sinoatrial node (eSAN) was defined as the highest point of the earliest activation site during sinus rhythm mapping.Patients were divided into an eSAN-mapped group (n = 50) and a non-eSAN-mapped group (n = 60). Safety and efficacy outcomes were compared between groups. RESULTS: The median age was 60.0 years (IQR: 52.0-69.0), with 65 males (59.1%). SVCI was successfully completed in all patients. The median height from the SVC-RA junction to the RSPV roof was 15.1 mm (IQR: 13.5-17.1 mm), with no significant difference between groups. Only one case of PNI occurred in each group, both resolving within 1-2 months. Other complications included pericardial effusion (10.9%) and hematoma (2.7%). No SNI, cardiac tamponade, organ embolism, arteriovenous fistula, or mortality was observed. CONCLUSION: Using the RSPV roof and SVC junction as anatomical landmarks for SVC isolation may offer a safe and effective approach. Additionally, HPSD ablation (50 W/7 s) of the SVC was achieved without the use of routine PN mapping in this cohort, resulting in successful isolation and a low incidence of transient PNI. This suggests it may represent a potential alternative strategy; however, the occurrence of PNI underscores that techniques such as PN mapping remain crucial for risk mitigation.