title: Influence of structural heart disease on characteristics of atrial fibrillation recurrence in patients with dual-chamber pacemakers.
abstract: OBJECTIVE
  The aim of the study was to prospectively examine the influence of structural heart disease (SHD) and sinus node dysfunction (SND) on the frequency and duration of atrial fibrillation (AF) episodes in patients with implanted pacemakers.
  
  
  METHODS
  We examined episodes of AF in 207 patients (93 with SHD; 165 with SND) with known or suspected paroxysmal AF who underwent dual-chamber pacing.
  
  
  RESULTS
  Seventy-one percent of all patients experienced at least one episode of AF during follow-up, with a mean burden of 3.3 +/- 6.4 h/d (median, 0.2 hours) and a mean frequency of 11.7 +/- 26.0 episodes per day (median, 1.4). The proportion of episodes longer than 6 hours was greater in patients with SHD when compared to patients without SHD. In a logistic regression model adjusted for SND, gender, and the 2-way interactions of SND, sex, and SHD, SHD was a significant factor (P = .0188) with the odds ratio of having an episode longer than 6 hours 3.4 times higher for patients with SHD than for patients without SHD. Older patients with SHD had less frequent but longer episodes compared to younger patients. In patients without SHD, there was no comparable age difference. Burden, frequency, and average episode length were not influenced by the presence or absence of SND.
  
  
  CONCLUSIONS
  Patients with SHD have longer episodes of AF supporting the concept that SHD influences the underlying substrate to favor perpetuation.
authors.affiliation: Department of Medicine, University of Colorado Health Sciences Center, Denver, CO, USA. michael.reiter@uchsc.edu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Reiter
authors.forename: Manya
authors.initials: M
authors.lastname: Harsch
authors.forename: Te-Hsin
authors.initials: TH
authors.lastname: Lung
authors.forename: Dave
authors.initials: D
authors.lastname: Munneke
authors.forename: Michael H
authors.initials: MH
authors.lastname: Kim
authors.forename: Alaa
authors.initials: A
authors.lastname: Shalaby
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D055502:Secondary Prevention; D014481:United States / Q000453:epidemiology