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

Obstructive sleep apnea (OSA) is a common condition that contributes to atrial fibrillation occurrence, but the evidence on the 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, especially PAF events during the nighttime, and determine the frequency and potential underdiagnoses of OSA in patients with PAF.

We recruited consecutive patients who had undergone a recent 24-hour Holter monitoring and showed at least 1 episode of PAF. All patients were invited to undergo a clinical evaluation. To assess OSA status, we conducted validated portable sleep monitoring. OSA was defined by an apnea-hypopnea index of ≥ 15 events/h.

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 (odds ratio = 1.78, 95% confidence interval = 1.12-2.83; P = .014). Interestingly, the distribution of PAF episodes over 24 hours showed that patients with OSA had more atrial fibrillation episodes between 10 pm and 4 am than patients without OSA (OSA: median = 10 [interquartile range = 7.5-11] vs No OSA: median = 2 [interquartile range = 3-5.5]; P = .037), suggesting an abnormal day-night pattern of the PAF occurrence.

OSA is common, underdiagnosed, and in patients with OSA, associated with a higher nighttime occurrence of PAF episodes compared with patients without OSA.

Rocha CMG, de Medeiros HD, Brigido ARD, et al. Obstructive sleep apnea and the day-night pattern of paroxysmal atrial fibrillation burden. J Clin Sleep Med. 2025;21(12):2073-2079.