Abstract 14320: Regionalization of Non-Pulmonary Vein Triggers for Atrial Fibrillation Using Non-Invasive Electrocardiographic Imaging

Abstract

Introduction Ablation of non-pulmonary vein triggers (NPVTs) after pulmonary vein isolation (PVI) reduces atrial fibrillation (AF) recurrence, but localizing NPVTs can be challenging. We evaluated the potential for noninvasive electrocardiographic imaging (ECGi) to regionalize NPVTs and expedite more focused catheter-based mapping. ECGi combines measured body surface potentials with heart-torso geometry acquired from computed tomography (CT), to generate an activation map from a single recorded beat. Methods In 12 patients with AF undergoing first time AF ablation, the ECGi vest was fitted for preprocedural CT scan and then worn during procedure. Following completion of PVI, we paced from 15 atrial sites where NPVTs commonly arise (Figure 1), and evaluated the epicardial activation map generated by ECGi during steady state pacing at cycle length of 700-800 ms allowing an unobscured P wave. Merging of invasive anatomic map with CT-based ECGi map allowed comparison of ECGi activation map with true pacing location (Figure 2). Results From 180 pacing sites in our patient cohort (67% male, 58% persistent AF, 67% left atrial dilation), median distance between earliest activation site on ECGi map and pacing location was 16 mm (interquartile range, 11-22 mm), with 95% of sites within 30 mm (Figure 2). Septal pacing sites were measured to the epicardial aspect of the interatrial septum. Conclusions ECGi is able to consistently approximate the origin of paced beats from common NPVT sites and suggests the potential for rapid regionalization of NPVTs. The identified region can then be the focus of more detailed catheter-based mapping techniques to facilitate successful ablation of NPVTs.