Obstructive sleep apnea and the day-night pattern of paroxysmal atrial fibrillation burden.

Abstract

Study objectives: Obstructive sleep apnea (OSA) is a common condition that contributes to atrial fibrillation occurrence, but the evidence on day-night pattern of paroxysmal atrial fibrillation (PAF) is still scanty. The aim of this study was to evaluate whether OSA is associated with a higher occurrence of PAF and especially PAF events during the nighttime and determine the frequency and potential underdiagnoses of OSA in patients with PAF.

Methods: We recruited consecutive patients who had undergone a recent 24-hour Holter monitoring and showed at least one episode of PAF. All patients were invited to perform a clinical evaluation. To assess OSA status, we conducted validated portable sleep monitoring. OSA was defined by an apnea-hypopnea index ≥15 events per hour.

Results: We studied 102 patients (mean age: 64±9 years, 56% male). Sixty patients (57%) had OSA (none with a previous diagnosis). A total of 339 episodes of PAF (a third of them occurring at night) were available for analysis. We observed a significant association between OSA and nighttime PAF episodes: patients with OSA had a higher chance of nighttime episodes than those without OSA (OR: 1.78, 95% CI: 1.12-2.83; p=0.014). Interestingly, the distribution of PAF episodes over 24 hours showed that patients with OSA had more AF episodes between 10PM and 4AM than patients without OSA (OSA: 10 [7.5-11] vs. No OSA: 2 [3-5.5]; p=0.037), suggesting an abnormal day-night pattern of the PAF occurrence.

Conclusions: OSA is common, underdiagnosed, and associated with a higher nighttime occurrence of PAF episodes than patients without OSA.