title: Prevalence of fractionated electrograms in the coronary sinus: comparison between patients with persistent or paroxysmal atrial fibrillation and a control population.
abstract: BACKGROUND
  Complex fractionated atrial electrograms (CFAEs) are often identified as targets for radiofrequency ablation in the coronary sinus (CS) of patients with atrial fibrillation (AF).
  
  
  OBJECTIVE
  The purpose of this study was to determine whether similar features are present in a normal control population.
  
  
  METHODS
  Twenty-four patients with AF (12 paroxysmal, 12 persistent) were compared with 12 controls (undergoing radiofrequency ablation for supraventricular tachycardia) in whom at least 1 minute of AF was induced by rapid atrial pacing. Electrogram comparisons during sinus rhythm and AF were made offline. A random 10-second window of AF was used for analysis of fractionation and dominant frequency.
  
  
  RESULTS
  The three groups were age matched. CFAEs during AF were less prevalent in the control versus the AF groups (control = 30% +/- 28%, paroxysmal AF = 63% +/- 34%, persistent AF = 62% +/- 29%, P = .01). This difference was significant for the proximal to mid-CS only. Conduction velocity within the CS was slower in AF versus control patients (paroxysmal AF = 51 +/- 6 cm/s, persistent AF = 52 +/- 6 cm/s, control = 73 +/- 11 cm/s, P <.001). Minimum AF cycle length was shorter in the AF groups versus the control group (paroxysmal AF = 132 +/- 34 ms, persistent AF = 127 +/- 34 ms, control = 168 +/- 30 ms, P = .01). No differences in dominant frequency or prevalence of sinus rhythm CFAE was seen among the three groups.
  
  
  CONCLUSIONS
  AF patients have a higher prevalence of CFAE and short cycle length activation within the proximal CS than control patients with nonclinical AF. CFAE are associated with slowed CS conduction in AF patients. No difference in the dominant frequency during AF was seen. CS CFAEs are common in a control population with induced AF and are unlikely to signify clinically important AF drivers in this setting.
authors.affiliation: Department of Cardiology, Royal Melbourne Hospital and Department of Medicine, University of Melbourne, Melbourne, Australia.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Teh
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Kalman
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kistler
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Lee
authors.forename: Fiona
authors.initials: F
authors.lastname: Sutherland
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Morton
authors.forename: Jitendra K
authors.initials: JK
authors.lastname: Vohra
authors.forename: Paul B
authors.initials: PB
authors.lastname: Sparks
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D054326:Coronary Sinus / Q000503:physiopathology* / Q000601:surgery; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008875:Middle Aged; D013614:Tachycardia, Paroxysmal / Q000503:physiopathology* / Q000601:surgery