title: Consistency of complex fractionated atrial electrograms during atrial fibrillation.
abstract: BACKGROUND
  Temporal variation in complex fractionated atrial electrograms (CFAEs) exists during atrial fibrillation (AF).
  
  
  OBJECTIVE
  This study sought to quantify the variation in CFAEs using a fractionation interval (FI) algorithm and to define the shortest optimal recording duration required to consistently characterize the magnitude of the fractionation.
  
  
  METHODS
  Twenty-seven patients undergoing AF mapping in the left atrium were studied. The FI and frequency analysis were performed at each mapped site for recording durations of 1 to 8 seconds. The magnitude of the fractionation was quantified by the FI algorithm, which calculated the mean interval between multiple, discrete deflections during AF. The results from each duration were statistically compared with the maximal-duration recording, as a standard. The FI values were compared with the dominant frequency values obtained from the associated frequency spectra.
  
  
  RESULTS
  The FIs obtained from recording durations between 5 and 8 seconds had a smaller variation in the FI (P < .05) and, for those sites with a FI < 50 ms, the fractionation was typically continuous. The fast-Fourier Transform spectra obtained from the CFAE sites with recording durations of >5 seconds harbored higher dominant frequency values than those with shorter recording durations (8.1 +/- 2.5 Hz vs. 6.8 +/- 0.98 Hz, P < .05). The CFAE sites with continuous fractionation were located within the pulmonary veins and their ostia in 77% of patients with paroxysmal AF, and in only 29% of patients with nonparoxysmal AF (P < .05).
  
  
  CONCLUSIONS
  The assessment of fractionated electrograms requires a recording duration of > or =5 seconds at each site to obtain a consistent fractionation. Sites with the shortest FIs consistently identified sites with the fastest electrogram activity throughout the entire left atrium and pulmonary veins.
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.forename: Ching-Tai
authors.initials: CT
authors.lastname: Tai
authors.forename: Tsair
authors.initials: T
authors.lastname: Kao
authors.forename: Shih-Lin
authors.initials: SL
authors.lastname: Chang
authors.forename: Wanwarang
authors.initials: W
authors.lastname: Wongcharoen
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Lo
authors.forename: Ta-Chuan
authors.initials: TC
authors.lastname: Tuan
authors.forename: Ameya R
authors.initials: AR
authors.lastname: Udyavar
authors.forename: Yi-Jen
authors.initials: YJ
authors.lastname: Chen
authors.forename: Satoshi
authors.initials: S
authors.lastname: Higa
authors.forename: Kuo-Chang
authors.initials: KC
authors.lastname: Ueng
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D000465:Algorithms; D000704:Analysis of Variance; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D016009:Chi-Square Distribution; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D013997:Time Factors