Aims: We evaluated the effect of pulmonary vein (PV) anatomical characteristics on PV isolation (PVI) and long-term efficacy of ablation with phased radiofrequency (RF) energy and pulmonary vein ablation catheter (PVAC) multi-electrode catheter.
Methods and results: Before the procedure, PV anatomy was visualized by magnetic resonance imaging (MRI). Consecutive patients with paroxysmal atrial fibrillation were treated with the PVAC with successful acute isolation. Follow-up was performed at 3, 6, and 12 months with electrocardiogram and 7-day Holter recording at 6 and/or 12 months. Symptomatic patients received additional event recording. In 110 patients a pre-procedure cardiac MRI was performed. Ninety-seven (88%) had a separate left superior PV and separate left inferior PV, all patients had a separate right superior PV and separate right inferior PV. Fourteen (13%) had a left PV with common trunk and 27 (25%) had a separate right middle PV (RMPV). After a follow-up of 1 year, 57 of 110 (52%) patients were free of AF without anti-arrhythmic drug. No specific anatomical variable that was related to long-term failure could be found. There was a trend for patients with larger veins (>24 mm) or separate RMPV to have a lower efficacy. The number of applications per vein or procedure did not influence long-term outcome.
Conclusions: In patients who have undergone PVI with phased RF energy and PVAC multi-electrode ablation, long-term efficacy is not significantly affected by PV anatomy or number of applications, although a trend for reduced efficacy is seen for PV with diameter >24 mm, and presence of RMPV.