Electrophysiological end point for catheter ablation of atrial fibrillation initiated from multiple pulmonary venous foci

Background-The end point for catheter ablation of pulmonary vein (PV) foci initiating atrial fibrillation (AF) has not been determined, Methods and Results-Ninety patients underwent mapping during spontaneous or induced ectopy and/or AF initiation. Ostial PV ablation was performed by u se of angiograms to precisely define targeted sites. Success defined by eli mination of AF without drugs was correlated with the procedural end point o f the abolition of distal PV potentials. A total of 197 arrhythmogenic PV f oci (97%)-single in 31% and multiple in 69%-and 6 atrial foci were identifi ed. A discrete radiofrequency (RF) application eliminated the PV potentials in 9 PV foci, whereas 2 foci from the same PV required RF applications at separate sites in 19 cases, In others, a wider region was targeted with pro gressive elimination of ectopy. In 49 patients, multiple sessions were nece ssary owing to recurrent or new ectopy. The clinical success rates were 93% , 73%, and 55% in patients with 1, 2, and greater than or equal to 3 arrhyt hmogenic PV foci. Recovery of local PV potential and the inability to aboli sh it were significantly associated with AF recurrences (90% success rate w ith versus 55% without PV potential abolition). PV stenosis was noted acute ly in 5 of 6 cases, remained unchanged at restudy, and was associated with RF power >45 W. Conclusions-Multiple PV foci are involved in initiation of AF, and eliminat ion of PV muscle conduction is associated with clinical success.