title: Characterization of electrograms associated with termination of chronic atrial fibrillation by catheter ablation.
abstract: OBJECTIVE
  This study sought to determine the characteristics of atrial electrograms predictive of slowing or termination of atrial fibrillation (AF) during ablation of chronic AF.
  
  
  BACKGROUND
  There is growing recognition of a role for electrogram-based ablation.
  
  
  METHODS
  Forty consecutive patients (34 male, 59 +/- 10 years) undergoing ablation for chronic AF persisting for a median of 12 months (range 1 to 84 months) were included. After pulmonary vein isolation and roof line ablation, electrogram-based ablation was performed in the left atrium and coronary sinus. Targeted electrograms were acquired in a 4-s window and characterized by: 1) percentage of continuous electrical activity; 2) bipolar voltage; 3) dominant frequency; 4) fractionation index; 5) mean absolute value of derivatives of electrograms; 6) local cycle length; and 7) presence of a temporal gradient of activation. Electrogram characteristics at favorable ablation regions, defined as those associated with slowing (a >or=6-ms increase in AF cycle length) or termination of AF were compared with those at unfavorable regions.
  
  
  RESULTS
  The AF was terminated by electrogram-based ablation in 29 patients (73%) after targeting a total of 171 regions. Ablation at 37 (22%) of these regions was followed by AF slowing, and at 29 (17%) by AF termination. The percentage of continuous electrical activity and the presence of a temporal gradient of activation were independent predictors of favorable ablation regions (p = 0.016 and p = 0.038, respectively). Other electrogram characteristics at favorable ablation regions were not significantly different from those at unfavorable ablation regions.
  
  
  CONCLUSIONS
  Catheter ablation at sites displaying a greater percentage of continuous activity or a temporal activation gradient is associated with slowing or termination of chronic AF.
authors.affiliation: Service de Rythmologie, Hôpital Cardiologique du Haut-Lévêque, Université Victor Segalen Bordeaux 2, Bordeaux, France. yoshihide_takahashi@oboe.ocn.ne.jp
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Mark D
authors.initials: MD
authors.lastname: O'Neill
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.forename: Rémi
authors.initials: R
authors.lastname: Dubois
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Matsuo
authors.forename: Sébastien
authors.initials: S
authors.lastname: Knecht
authors.forename: Srijoy
authors.initials: S
authors.lastname: Mahapatra
authors.forename: Kang-Teng
authors.initials: KT
authors.lastname: Lim
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
authors.forename: Anders
authors.initials: A
authors.lastname: Jonsson
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sacher
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
authors.forename: Thomas
authors.initials: T
authors.lastname: Rostock
authors.forename: Pierre
authors.initials: P
authors.lastname: Bordachar
authors.forename: Jacques
authors.initials: J
authors.lastname: Clémenty
authors.forename: George J
authors.initials: GJ
authors.lastname: Klein
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006331:Heart Diseases / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000889:Anti-Arrhythmia Agents