Is Pulmonary Vein Isolation Necessary for Curing Atrial Fibrillation?

Background— Pulmonary veins (PVs) play a pivotal role in initiating and perpetuating atrial fibrillation (AF). We investigated if PV electrical isolation from the left atrium is required for curing AF. Methods and Result— Fifty-one patients with paroxysmal or persistent AF underwent circumferential radiofrequency ablation of PV ostia performed with an anatomic approach. The end point of the ablation procedure was the recording of low peak-to-peak bipolar potentials (<0.1 mV) inside the lesions. Left atrium pacing was used to assess the conduction between the PVs and the left atrium. During a mean follow-up period of 16.6±3.9 months, 41 patients (80.4%) were free of atrial arrhythmias. When patients with and without AF recurrence were analyzed, no significant difference was observed in the mean number of PVs in which the ablation end point was reached (3.4±1.2 versus 3.7±0.87) and PVs isolated (1.5±1.4 versus 1.6±1). We noted that, although in 29 of 41 patients (71%) without AF recurrence, the ablation end point was reached in all PVs mapped, it was only possible to demonstrate the isolation of all PVs mapped in 2 patients. On the other hand, in 7 of 10 patients (70%) with AF recurrence, the ablation end point was reached in all PVs mapped, whereas one patient had all PVs isolated. Conclusions— Our findings show that with the use of a pure anatomic approach, it is possible to prevent AF in >80% of patients undergoing catheter ablation. Moreover, the isolation of PVs is not crucial for curing AF.