Complex Fractionated Electrograms and AF Nests in Vagally Mediated Atrial Fibrillation

Abstract

Methods: Five anesthetized open-chest dogs were evaluated. Atrial electrograms were obtained epicardially. AF was induced by burst atrial pacing with 20 Hz during vagal stimulation. A total of 15 sites (eight sites in right atrium and seven sites in left atrium) were evaluated in each animal. The CFAE was determined during AF according to the electrogram patterns. After sinus conversion, real-time spectrum analysis was used for AF nest assessment at the same location. Results: The CFAE was observed at the high and mid sulcus terminalis areas, pulmonary vein antrum, and mid portion of the coronary sinus. Among them, only 60% of the CFAE sites showed HFC during sinus rhythm. In addition, some of the non-CFAE sites (22%) showed HFC during sinus rhythm. Conclusion: The CFAE sites were not the same as the AF nests in this animal model of vagally mediated AF. Therefore, these two types of ablation methods appear to target different substrates of AF. (PACE 2010; 33:1497-1503).