Abstract 11178: Right Atrial Rotors and Focal Impulses in Human Atrial Fibrillation May Explain Success Rates of Conventional Ablation
Introduction: Atrial fibrillation (AF) may recurs post ablation even after extensive left atrial procedures. Accordingly, we hypothesized that localized electrical rotors and focal beats, that have recently been shown to cause human AF, may also lie in right atrium (RA) where targeted ablation (Focal Impulse and Rotor Modulation, FIRM) should eliminate AF.
Methods: In 54 consecutive AF patients (62±9 years; 39 persistent), we recorded AF with 64 pole basket catheters in both atria (Constellation. Novel physiological imaging, using the Hilbert transform, was used to identify rotors/focal beats during AF. In n=26 patients of the series, sources were identified in real-time then prospectively ablated (FIRM), followed by conventional ablation.
Results: Rotors and focal beats were revealed during AF in 52/54 patients (96%). Patients showed 2.0±0.8 sources, that controlled AF propagation (p<0.05). 38% of sources lay in RA (n=33 patients), and n=3 patients had only RA sources; 62% lay in LA (n=49 patients), and n=14 patients had only LA sources. The rotor/focal beat ratio was higher in RA vs LA (40:4 vs 32:27; p<0.01). In the prospective cohort, FIRM at all sources terminated AF in 16/26 patients (n=4 in RA) and slowed AF in 8/26. Fig A shows a repetitive focal beat (color-coded radial emanation) in RA in paroxysmal AF, and fig B shows an RA rotor (color coded clockwise spiral wave) in persistent AF, both with fibrillatory conduction to LA. FIRM of both RA sources terminated AF to sinus rhythm in 4, 5.5 minutes, respectively, prior to conventional ablation. Both patients are AF-free on implanted monitors at 8 and 12 months, respectively.
Conclusions: Physiological mapping reveals rotors and/or focal impulses that sustain human AF in RA in a third of patients. Direct FIRM ablation at right atrial sources was able to terminate AF and enable long-term AF elimination. These results demonstrate the importance of patient-tailored mechanistic ablation.
- © 2011 by American Heart Association, Inc.