Aims: 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.