Abstract 11126: Elimination of Sources for Human Atrial Fibrillation (Focal Impulse and Rotor Modulation, FIRM) Organizes and Acutely Terminates AF Prior to Pulmonary Vein Isolation: A Multicenter Experience
Introduction: This 9-center study tested the hypothesis that panoramic (wide-area) electrophysiological mapping of both atria would reveal localized rotors and focal sources that sustain human AF, where targeted ablation (Focal Impulse and Rotor Modulation, FIRM) would acutely organize and terminate human AF prior to pulmonary vein ablation.
Methods:In 86 AF patients (71 persistent AF; 60±9 years; left atrial, LA size 48±8 mm), we recorded AF from 64 pole basket catheters in both aria (Constellation, Boston Scientific MA). Unipolar maps and phase analysis were used to visualize AF sources using a novel mapping system (RhythmView, Topera Medical, MA) taking 8 minutes/map. FIRM ablation was applied to each prospectively identified source for the acute endpoint of AF termination or organization (>10% slowing).
Results:Patient-specific FIRM maps revealed 2.2±1.0 rotors or focal beats in 85 of 86 patients (99%). The acute endpoint was achieved in 74/86 patients (86%) without pulmonary vein isolation. AF terminated in 54 patients (63%) with 5.0 mins (median, IQR 2-7) FIRM ablation alone at the primary source, to sinus rhythm (n=45), typical flutter (n=4) or other tachycardia (n=5), after which AF was non-inducible in all patients. In 20 patients, FIRM ablation organized and slowed AF by 30±10 ms (17±6%) by eliminating >1 source on post-ablation maps. Fig A shows a rotor (counterclockwise red-blue) of persistent AF in the high LA with disorganized remaining LA and RA. In fig B, FIRM at the rotor only terminated AF to sinus rhythm in < 1 minute. The patient remains AF-free at 16 months.
Conclusions: Panoramic electrophysiological mapping reveals rotors and focal sources in nearly all patients with persistent or paroxysmal AF, where targeted FIRM ablation alone may rapidly terminate AF (by eliminating primary sources) or organize AF (by eliminating secondary sources). Ongoing studies on the long-term benefits of FIRM ablation for AF versus conventional ablation are warranted.
- © 2012 by American Heart Association, Inc.