title: The effect of electrogram duration on quantification of complex fractionated atrial electrograms and dominant frequency.
abstract: BACKGROUND
  Sites of complex fractionated atrial electrograms (CFAEs) and highest dominant frequency (DF) have been proposed as critical regions maintaining atrial fibrillation (AF). This study aimed to determine the minimum electrogram recording duration that accurately characterizes CFAE or DF sites for ablation without unduly lengthening the procedure.
  
  
  RESULTS
  Fourteen patients with AF undergoing catheter ablation had high-density (498 +/- 174 points) biatrial mapping performed during AF before ablation. At each point, 8-second electrograms were recorded. CFAE characterization using the NavX software provided a representation of electrogram complexity (CFE-mean). CFE-mean for each point from 7-, 6-, 5-, 4-, 3-, 2-, and 1-second subsamples were compared with the index 8-second CFE-mean. Offline spectral analysis defined DF as the frequency with greatest power, and DF of subsamples were compared with index DF. Index 8-second electrogram CFE-mean was 114 +/- 20 ms for right atria and 102 +/- 17 ms for left atria (P = 0.01); DF was 5.7 +/- 0.8 Hz for right atria and 6.0 +/- 0.8 Hz for left atria (P = 0.02). Means from shorter electrograms were nonsignificantly decreased for CFE-mean and overestimated for DF (P < 0.001). Mean absolute differences between subsampled and index values ranged from 3.3 to 20.1 ms for CFE-mean and 0.11 to 1.18 Hz for DF. Subsampled electrograms deviating >10% from index values ranged from 2.5 to 56% for CFE-mean and 3.5 to 41% for DF. Intraclass correlation coefficients ranged from 0.992 to 0.788 for CFE-mean and 0.897 to 0.233 for DF. Unacceptable differences from index values were found with CFE-mean and DF from electrograms <5 seconds.
  
  
  CONCLUSIONS
  Electrograms of >or=5-second duration are required to accurately characterize CFAE and DF sites for ablation.
authors.affiliation: Cardiovascular Research Centre, Department of Cardiology, Royal Adelaide Hospital, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Martin K
authors.initials: MK
authors.lastname: Stiles
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Brooks
authors.forename: Bobby
authors.initials: B
authors.lastname: John
authors.forename: Lauren
authors.initials: L
authors.lastname: Wilson
authors.forename: Pawel
authors.initials: P
authors.lastname: Kuklik
authors.forename: Hany
authors.initials: H
authors.lastname: Dimitri
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Lau
authors.forename: Ross L
authors.initials: RL
authors.lastname: Roberts-Thomson
authors.forename: Lorraine
authors.initials: L
authors.lastname: Mackenzie
authors.forename: Scott
authors.initials: S
authors.lastname: Willoughby
authors.forename: Glenn D
authors.initials: GD
authors.lastname: Young
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
mesh_terms: D000368:Aged; D000465:Algorithms; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000601:surgery; D018780:Body Surface Potential Mapping / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors