Pulmonary vein isolation combined with superior vena cava isolation for atrial fibrillation ablation: a prospective randomized study

Circumferential pulmonary vein isolation (CPVI) is an established strategy for atrial fibrillation (AF) ablation. Superior vena cava (SVC), by harbouring the majority of non-pulmonary vein (PV) foci, is the most common non-PV origin for AF. However, it is unknown whether CPVI combined with SVC isolation (SVCI) could improve clinical results and whether SVCI is technically safe and feasible.

A total of 106 cases (58 males, average age 66.0 ± 8.8 years) with paroxysmal AF were included for ablation. They were allocated randomly to two groups: CPVI group ( n = 54) and CPVI + SVCI group ( n = 52). All cases underwent the procedure successfully. Pulmonary vein isolation was achieved in all cases. The procedural time and fluoroscopic time were comparable between the two groups. The mean ablation time for SVC was 7.8 ± 2.7 min. Superior vena cava isolation was obtained in 50/52 cases. In the remaining two cases, SVCI was not achieved because of obviating diaphragmatic nerve injury. During a mean follow-up of 4 ± 2 months, 12 (22.2%) cases in the CPVI group and 10 (19.2%) cases in the CPVI + SVCI group had atrial tachyarrhythmias (ATa) recurrence ( P = 0.70). Nine of 12 cases in the CPVI group and 8/10 cases in the CPVI + SVCI group underwent reablation ( P = 0.86), and PV reconnection occurred in 7/9 cases in the CPVI group and in 8/8 cases in the CPVI + SVCI group. All PV reconnection was reisolated by gaps ablation. There was no SVC reconnection in the CPVI + SVCI group. In two cases without PV reconnection from the CPVI group, SVC-originated short run of atrial tachycardia was identified and eliminated by the SVCI. At the end of 12 months of follow-up, 50 cases (92.6%) in the CPVI group and 49 (94.2%) in the CPVI + SVC group were free of ATa recurrence ( P = 0.73).

In our series of paroxysmal AF patients, empirically adding SVCI to CPVI did not significantly reduce the AF recurrence after ablation. Superior vena cava isolation may be useful, however, in selected patients in whom the SVC is identified as a trigger for AF. However, because of the preliminary property of the study and its relatively small sample size, the impact of SVCI on clinical results should be evaluated in a large series of patients.