title: Complex fractionated electrograms in the right atrial free wall and the superior/posterior wall of the left atrium are affected by activity of the autonomic nervous system.
abstract: BACKGROUND
  Complex fractionated atrial electrograms (CFAEs) are supposed to be related to structural and electrical remodeling. Animal studies suggest a role of the autonomic nervous system (ANS). However, this has never been studied in humans.
  
  
  OBJECTIVE
  The goal of this study was to investigate the influence of ANS on CFAEs in patients with idiopathic atrial fibrillation (AF).
  
  
  METHODS
  Thirty-six patients (28 men, 55 ± 9 years) were included before undergoing catheter ablation. In the 24 hours preceding the procedure, 20 patients were in AF (group 1) and 16 were in sinus rhythm (SR, group 2). With 2 decapolar catheters, 1 in the right atrium (RA) and 1 in the left atrium (LA), 20 unipolar electrograms were simultaneously recorded during a 100-second AF-period (in group 2 after induction of AF). After atropine and metoprolol administration, a second 100-second AF-period was recorded 30 minutes later. Five patients of group 2 served as controls and did not receive atropine and metoprolol prior to the second recording. CFAEs were assessed and the prevalence of CFAEs was expressed as percentage of the recording time.
  
  
  RESULTS
  The prevalence of CFAEs was greater in group 1 than in group 2 in both RA and LA (P = 0.026, P < 0.001, respectively). Atropine and metoprolol significantly reduced CFAEs in group 1 (P < 0.001) and prevented the time-dependent increase of CFAEs in group 2.
  
  
  CONCLUSIONS
  The prevalence of CFAEs is greater in long-lasting AF episodes. Atropine and metoprolol administration reduces CFAEs in both atria. Thus, CFAEs are at least partly influenced by the ANS.
authors.affiliation: Department of Cardiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Sevasti-Maria
authors.initials: SM
authors.lastname: Chaldoupi
authors.forename: Andre C
authors.initials: AC
authors.lastname: Linnenbank
authors.forename: Fred H
authors.initials: FH
authors.lastname: Wittkampf
authors.forename: Leif H
authors.initials: LH
authors.lastname: Boldt
authors.forename: Harry
authors.initials: H
authors.lastname: VAN Wessel
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: VAN Driel
authors.forename: Pieter A
authors.initials: PA
authors.lastname: Doevendans
authors.forename: Richard N
authors.initials: RN
authors.lastname: Hauer
authors.forename: Jacques M
authors.initials: JM
authors.lastname: DE Bakker
authors.forename: Peter
authors.initials: P
authors.lastname: Loh
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology*; D001285:Atropine / Q000008:administration & dosage; D001341:Autonomic Nervous System / Q000187:drug effects / Q000503:physiopathology*; D016009:Chi-Square Distribution; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000294:innervation*; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage; D008875:Middle Aged; D010276:Parasympatholytics / Q000008:administration & dosage; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013565:Sympatholytics / Q000008:administration & dosage; D013997:Time Factors
chemical_list: D010276:Parasympatholytics; D013565:Sympatholytics; D001285:Atropine; D008790:Metoprolol