PV isolation
After first-pass encircling PV antrum ablation, electrical conduction between the left atrium and PV remained in 12 of 30 (40%) ipsilateral PVs. Mapping using the mini-basket catheter identified 48 ablation points through which the propagation wave entered the PV (ablation points with a gap). At the remaining 742 ablation points, the propagation wave was blocked along the PV isolation line (ablation points without a gap). Additional ablation targeting ablation points with a gap successfully eliminated conduction between the left atrium and PV. In the end, PV isolation was achieved without complications in any patients.
RFA was unexpectedly suspended at 84 of 790 (11%) ablation points due to a rise in esophageal temperature (42 points), bradycardia (4 points), or catheter dislodgement (38 points). RFA duration was significantly shorter at points with unexpected suspension than those without (14 ± 5 vs. 28 ± 8 sec, p<0.0001). However, the presence of gaps was comparable between the two groups (5% vs. 6%, p=0.51).