Identification of interatrial epicardial connections between the right-sided pulmonary veins and right atrium using coherent map

A 43-year-old man underwent circumferential pulmonary vein isolation (PVI) for persistent atrial fibrillation. Although first-pass circumferential PV antrum ablation was performed, complete PVI was not obtained. A gap map showed the site of earliest activation was the right-sided PV carina, which was the same site of breakthrough on the left atrium map before ablation. Using a coherent map enabled us easily and clearly to evaluate the breakthrough sites. To identify whether the conduction from the right PV carina connected to adjacent structures, an activation map was obtained during pacing from the right PV carina. This revealed that the site of earliest activation was the posterior right atrium (RA) and implied a direct connection between the right-sided PVs and RA. The first radiofrequency (RF) application in the posterior RA resulted in only temporary isolation of the right-sided PVs with bi-directional block. Therefore, we performed a second set of RF applications to the right PV carina. PVI was obtained immediately after initiating the second set of applications and no further reconnection was observed. LEARNING OBJECTIVE: Pulmonary vein isolation (PVI) is widely accepted as an atrial fibrillation ablation procedure. Previous anatomical studies have revealed the presence of epicardial muscular bundles/fibers connecting the right-sided PVs and right atrium. In some patients, the presence of epicardial connections (ECs) precludes successful first-pass PVI. Identification and elimination of these connections is imperative to achieve complete PVI. The coherent map was useful for evaluating ECs.