Characteristics of Non-Pulmonary Vein Foci in Patients with Atrial Fibrillation

Abstract

Purpose: Non-pulmonary vein (PV) foci are sometimes difficult to identify and eliminate. This study aimed to characterize non-PV foci using the EnSite array or NavX system. Methods and Results: 138 patients with atrial fibrillation (AF) were included. All patients underwent PV isolation and additional ablation of non-PV foci if present. We revealed 17 non-PV foci in 15 patients. Nine foci induced AF and 8 foci showed more than 3 beats firing. Eight foci occurred spontaneously and the others were induced by low dose of isoproterenol (0.5γ, n=1) or high dose (≥10γ, n=8). The non-PV foci were distributed in the SVC (n=9, 50%), left atrium (LA) (n=5, 29%; 2 anterior wall, interatrial septum, appendage and mitral annulus), right atrium (RA) (n=3, 18%; lateral, posterolateral, anterolateral). 2nd session ablation was required in 36 patients (26%) and 31 patients had LA-PV reconnection. We revealed 16 non-PV foci in 14 patients in the 2nd session. Only one patient had non-PV foci recurrence from SVC. The others were firing at the different site from 1st session. Conclusion: The site of Non-PV foci was half in the SVC and each quarter in the LA and RA. The distribution of LA foci was various while RA foci existed near lateral side. If non-PV foci were successfully terminated, other foci may cause the recurrence of atrial fibrillation.