Introduction
Durable pulmonary vein isolation is the determinant of the outcome in
patients with atrial fibrillation (AF) after catheter
ablation[1-3]. Pulmonary vein reconnection (PVR)
has been considered as a major reason for AF recurrence after index
ablation[4-5]. Therefore, an observation period in
the index procedure was usually given for identification of acute PVR
and minimizing the possibility of repeat ablation. However, the detailed
conduction property at reconnection sites has not been sufficiently
investigated.
Presence of epicardial musculature connecting distal PVs and the atrium
is common as the wall of the atrium can be uneven in thickness with
bilayer architecture found in a large area[6,7].
Epicardial connection has been recently described as a cause of failed
first-pass isolation[8-11]. It can also be
observed in the reconnected PVs during the waiting period, which
requires treatment but lacks description and exploration including its
related ablation parameters.
In this study, we aimed to understand the role of acute epicardial PVR
(AEPVR) and its influencing factors by investigating its prevalence,
locations, electrogram (EGM) characteristics and related lesion set
parameters, which were compared to endocardial gap as well as the
epicardial PVR found in repeat procedures.