title: Relationship between the electrocardiographic atrial fibrillation cycle length and left atrial remodeling: a detailed electroanatomic mapping study.
abstract: OBJECTIVE
  The purpose of this study was to characterize the association between the extent of left atrial electroanatomic remodeling in atrial fibrillation and the atrial fibrillation cycle length derived from lead V₁ of the surface ECG (V1AFCL).
  
  
  METHODS
  Twenty-three patients in atrial fibrillation (AF) who presented for AF ablation underwent detailed electroanatomic mapping of the left atrium. The digital 12-lead ECG was exported for offline analysis, with signal filtering and QRST subtraction used to reveal the fibrillatory baseline in lead V₁. Mean V1AFCL was determined by direct annotation of the fibrillatory baseline, and the corresponding dominant V1AFCL was determined by Fourier transformation to derive the dominant frequency from the frequency power spectrum. The simultaneous AFCL from proximal and distal coronary sinus recordings was determined using the same methods. The strength of the association between various left atrial remodeling variables and V1AFCL was determined.
  
  
  RESULTS
  The 2 methods of deriving V1AFCL and intracardiac AFCL were found to produce highly equivalent results. V1AFCL showed significant correlation with intracardiac AFCL derived from both proximal and distal coronary sinus recordings. A longer V1AFCL was associated with slower left atrial conduction velocity and greater signal complexity but not with other remodeling variables, including left atrial size, atrial refractoriness, and mean endocardial voltage.
  
  
  CONCLUSIONS
  A longer atrial fibrillatory cycle length in surface ECG lead V1 is significantly associated with parameters of more advanced left atrial electroanatomic remodeling, specifically slower atrial conduction and more extensive electrogram fractionation.
authors.affiliation: Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia.
authors.forename: Tomos E
authors.initials: TE
authors.lastname: Walters
authors.affiliation: Department of Cardiology, Austin Hospital, Melbourne, Australia.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Teh
authors.affiliation: Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
authors.forename: Steven
authors.initials: S
authors.lastname: Spence
authors.affiliation: Department of Cardiology, Alfred Hospital and Baker IDI, Melbourne, Australia.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kistler
authors.affiliation: Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia.
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Morton
authors.affiliation: Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia. Electronic address: jon.kalman@mh.org.au.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Kalman
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology*; D064752:Atrial Remodeling / Q000502:physiology*; D018780:Body Surface Potential Mapping / Q000379:methods; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
keywords: Atrial fibrillation; Cycle length; Left atrium; Remodeling