Abstract 18071: Heart Failure, Obesity and Sleep Apnea May Mediate Atrial Fibrillation by Enabling Sustaining Rotors
Background Although several comorbid conditions are known to predispose to atrial fibrillation (AF), the mechanisms by which is occurs is unknown. It has recently been shown that human AF may be sustained by localized spiral waves (rotors) or focal sources, that are effective targets for ablation. We hypothesized that heart failure, obesity and obstructive sleep apnea, in particular, may predispose to AF by enabling the formation of an increased number of rotors and focal sources.
Methods In 107 AF subjects in the CONFIRM trial (61±9 years; 76 persistent AF), patient-specific localized sources were identified by applying repolarization and conduction guided wave similarity analyses to 64 pole atrial electrograms. We related the number of AF sources to clinical variables in univariate and multivariate analyses.
Results Localized sources were identified in 98/101 (97%) of patients with intra-procedural AF, each with 2 ±1.1 sources (70% rotors, 30% focal impulses). Rotors showed head-meets-tail activation (red-to-blue in figure A) where ablation terminated or organized AF prior to pulmonary vein isolation in 86%. The number of AF sources was related to presence of obstructive sleep apnea (p<0.001), larger LA diameter (p<0.001), larger BMI (p=0.011), lower LV ejection fraction (p=0.024) and persistent AF (vs paroxysmal AF, p=0.036) (see table).
Conclusions Comorbid conditions may predispose to AF by directly enabling rotor formation. This was true for CHF, obesity, OSA and CKD. Future studies should examine whether atypical locations of such sources, such as in the right atrium, may explain the reduced success rate of conventional left atrial ablation for AF in such populations.
- © 2012 by American Heart Association, Inc.