title: Interatrial conduction time and incident atrial fibrillation: a prospective cohort study.
abstract: BACKGROUND
  Atrial electrical conduction properties have been implicated in atrial fibrillation (AF) pathogenesis.
  
  
  OBJECTIVE
  The purpose of this study was to prospectively assess the potential association of interatrial conduction time (IACT) with incident AF.
  
  
  METHODS
  The study included persons referred for invasive electrophysiologic study (EPS), aged ≥50 years, without AF history or valvular disease. IACT was defined as the interval between the high right atrium electrogram and the distal coronary sinus atrial electrogram.
  
  
  RESULTS
  Six hundred twelve subjects were included (median follow-up 43 months, interquartile range 40-47). AF incidence was 21.7 cases per 1000 person-years. IACT was a significant predictor of AF with a c-statistic of 0.770 (95% confidence interval 0.702-0.838). In time-dependent analysis, IACT was a significant stratifier of AF risk (log-rank 28.0, P <.001). The corresponding incidences of AF in each tertile of IACT were 3, 17, and 46 per 1000 person-years, respectively (all differences between tertiles were significant). IACT remained significant in multivariable Cox regression analysis, after adjustment for age, sex, hypertension, and left atrial diameter, with each millisecond of prolonged IACT corresponding to 7% (95% confidence interval 2%-12%) higher adjusted risk of incident AF.
  
  
  CONCLUSIONS
  IACT is independently associated with incident AF. The invasive nature of the measurement is a limitation for its use as a clinical risk stratifier (although it could be used in patients referred for EPS), but these results are of interest in themselves because they suggest a strong pathophysiologic connection between atrial conduction times and substrate alterations ultimately leading to AF.
authors.affiliation: Department of Cardiology, Athens General Hospital "G. Gennimatas," Athens, Greece; Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Spyridon
authors.initials: S
authors.lastname: Deftereos
authors.affiliation: Department of Cardiology, Athens General Hospital "G. Gennimatas," Athens, Greece; Hellenic Center for Disease Control and Prevention, Athens, Greece.
authors.forename: Charalampos
authors.initials: C
authors.lastname: Kossyvakis
authors.affiliation: 2nd Department of Cardiology, Evaggelismos General Hospital, Athens, Greece.
authors.forename: Michael
authors.initials: M
authors.lastname: Efremidis
authors.affiliation: Department of Cardiology, Athens General Hospital "G. Gennimatas," Athens, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Bouras
authors.affiliation: 1st Department of Cardiology, University of Athens Medical School, Athens, Greece; Hellenic Center for Disease Control and Prevention, Athens, Greece.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Panagopoulou
authors.affiliation: Department of Cardiology, Athens General Hospital "G. Gennimatas," Athens, Greece.
authors.forename: Charalampos
authors.initials: C
authors.lastname: Papadimitriou
authors.affiliation: Department of Cardiology, Athens General Hospital "G. Gennimatas," Athens, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Doudoumis
authors.affiliation: Department of Cardiology, Athens General Hospital "G. Gennimatas," Athens, Greece.
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Deftereos
authors.affiliation: 1st Department of Cardiology, University of Athens Medical School, Athens, Greece.
authors.forename: Andreas
authors.initials: A
authors.lastname: Synetos
authors.affiliation: Department of Cardiology, University of Patras Medical School, Patras, Greece.
authors.forename: Periklis
authors.initials: P
authors.lastname: Davlouros
authors.affiliation: 1st Department of Cardiology, University of Athens Medical School, Athens, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Toutouzas
authors.affiliation: Department of Cardiology, University of Patras Medical School, Patras, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Alexopoulos
authors.affiliation: 1st Department of Cardiology, University of Athens Medical School, Athens, Greece.
authors.forename: Antonis S
authors.initials: AS
authors.lastname: Manolis
authors.affiliation: Department of Cardiology, Athens General Hospital "G. Gennimatas," Athens, Greece; Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Connecticut; Hellenic Center for Disease Control and Prevention, Athens, Greece. Electronic address: ggiann@med.uoa.gr.
authors.forename: Georgios
authors.initials: G
authors.lastname: Giannopoulos
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology*; D015331:Cohort Studies; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
keywords: Electrophysiologic study; Electrophysiologic test; Incidence; Interatrial conduction time; P dispersion; P duration; P wave