title: Complex fractionated electrograms and AF nests in vagally mediated atrial fibrillation.
abstract: BACKGROUND
  Catheter ablation targeting of complex fractionated atrial electrograms (CFAEs) is one of the techniques used for atrial fibrillation (AF) ablation. The ablation of sites showing a high-frequency spectral component (HFC) during sinus rhythm, known as AF nests, has been introduced as an adjunct to conventional ablation. Known locations of some AF nests are similar to CFAE sites. However, it has not been systematically evaluated whether these two targets represent the same foci. The purpose of this study was to compare the anatomical locations of these sites using an animal model of vagally mediated AF.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Seoul National University Hospital Cardiovascular Center, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea. seil@snu.ac.kr
authors.forename: Seil
authors.initials: S
authors.lastname: Oh
authors.forename: Hyoun-Joong
authors.initials: HJ
authors.lastname: Kong
authors.forename: Eue-Keun
authors.initials: EK
authors.lastname: Choi
authors.forename: Hee Chan
authors.initials: HC
authors.lastname: Kim
authors.forename: Yun-Shik
authors.initials: YS
authors.lastname: Choi
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation / Q000379:methods; D054326:Coronary Sinus / Q000033:anatomy & histology / Q000503:physiopathology / Q000601:surgery; D004285:Dogs; D022062:Electrophysiologic Techniques, Cardiac; D006325:Heart Atria / Q000033:anatomy & histology / Q000503:physiopathology / Q000601:surgery; D008297:Male; D011667:Pulmonary Veins / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D014630:Vagus Nerve / Q000503:physiopathology* / Q000601:surgery