Abstract 15602: Rotors and Focal Sources Frequently Localize Outside Anatomically-Based Ablation Sites
Introduction: Prior elegant animal studies have shown atrial fibrillation electrical rotors and focal sources may exist outside pulmonary veins (PVs). We therefore hypothesized that computational analyses may reveal such sources in human AF outside standard ablation sites.
Methods: In 54 consecutive AF patients prior to ablation (62±9 years, 39 persistent), we recorded AF with 64 electrode basket catheters (Constellation, BSC) in both atria. We used wave similarity analyses and the Hilbert transform to determine electrogram phase to identify rotors or focal beats during atrial fibrillation. NavX (St. Jude) and Carto (Biosense-Webster) geometries were used to localize identified rotor/focal beats sources, which were then grouped according to region.
Results: Rotors and focal beats were revealed in 52 of 54 patients (96%). On average, there were 2.0±0.8 sources per patient, from which centrifugal atrial activation was noted. AF source distribution by region is shown in the figure. Overall, rotors (76%) were more common than focal drivers (24%, p<0.001). Notably, the majority of identified AF-sustaining sites were outside (72%), rather than inside (28%) a typical standard ablation set (wide-area circumferential PV isolation and roof linear ablation). Additionally, 38% of sources lay in the RA versus LA (62%, p=0.02). Other common locations include the posterior LA (19%) and LA roof (11%).
Conclusions: Computational analyses reveals rotors and focal beats in human AF that lie remote from traditional anatomically-based ablation sites, which may in part explain AF recurrence despite pulmonary vein isolation. Physiologically-based AF source targeting may improve ablation success rates.
- © 2011 by American Heart Association, Inc.