Incidence and pattern of conduction gaps after pulmonary vein isolation with the endoscopic ablation system

Durable pulmonary vein isolation (PVI) is the goal of atrial fibrillation (AF) ablation. The endoscopic ablation system (EAS) is associated with a high rate of persistent PVI. The aim of this study was to analyze the incidence and pattern of conduction gaps in patients with arrhythmia recurrence after an EAS-guided PVI.

Repeat ablations after an EAS-guided PVI were analyzed. After PV angiograms, PV reconnection was assessed. Radiofrequency ablation was delivered at the earliest pulmonary vein (PV) activation site (gap) with the goal of PV re-isolation. First, the incidence of reconnected PVs per patient was assessed. Second, the gap pattern according to the individual PV quadrant was analyzed.

Fifty-nine out of 373 (16%) patients underwent a second procedure after index EAS. PV reconnection was observed in 71/230 (31%) PVs without statistically significant differences between individual PVs. A higher incidence of gaps was found for right PVs (49 vs. 27; p 0.0006). The carina between the superior and inferior PV presented a low incidence of gaps (18 vs. 56, p < 0.0001). Gaps were also predominant at the AS segment of the RSPV (11 gaps). No predictors of reconnection were found, except the higher total amount of application in the reconnected right inferior PV (26.03 ± 1.30 vs. 32.04 ± 2.89; p 0.0396).

EAS-guided PVI results in a 72% durable PVI rate in patients with AF recurrences without difference between individual PVs. More of the gap was found in the right PVs especially in the anterosuperior segment of the RSPV.