Introduction
Circumferential pulmonary vein isolation (PVI) is an effective therapy for atrial fibrillation (AF). Recently, the impact of first-pass isolation has become the focus of research. The success of first-pass isolation has been reported to result in less AF recurrence and a lower rate of PV reconnection during the second procedure.1-2 Advances in catheter technology and ablation strategies have reduced the residual gaps in isolation lines and increased the success rate of first-pass isolation.3 Specifically, 3D mapping systems reduce interlesion gaps. Moreover, advances in contact-force sensing and irrigation catheters have reduced transmural gaps.
However, a wide antral approach has been shown to be more effective than ostial PVI for AF.4 Yet, wide area first-pass isolation can be difficult and sometimes requires additional carina ablation, especially in right-sided PV.5-6 The presence of epicardial connections (ECs) imposes additional difficulty in PVI.5-10 Barrio-Lopez et al. reported an association between the presence of ECs and a lower success rate of PVI, leading to AF reccurence.7Thus, ECs may be one of the remaining therapeutic targets for successful first-pass isolation. However, these two studies did not evaluate the relative locations of the PVI line and ECs, and the effects of the positional relationship between the EC and right-sided PV anterior isolation line on the success rate of first-pass PVI remain unclear. The objective of this study was to examine the importance of designing an anterior line for right-sided PVI, considering the EC site.