In patients without atrial fibrillation and flutter (AF), obstructive sleep apnea (OSA) is associated with cyclic and often marked changes in heart rate (HR). We aimed to assess whether presence of OSA impacts optimal HR control in patients in AF. We retrospectively correlated diurnal HR patterns (recorded by 24-hour Holter monitoring) in patients with AF who independently also underwent diagnostic polysomnography. Exclusion criteria were paced rhythm or inadequate recordings from polysomnography and Holter monitoring. The relationship between the presence and severity of OSA and the mean, minimum, maximum HR, as well as pauses (>2 seconds) and their diurnal variation were studied. Of the 494 studied patients (age 69 ± 10 years; 26% women) mild-moderate OSA (apnea hypoxia index ≥5 and <20) was present in 171 (34%) and severe OSA (apnea hypoxia index ≥20) in 254 (51%). Mean 24-hour HR in patients with severe OSA and mild-moderate OSA was similar to those without OSA (78 vs 80 vs 79 beats per minute; p = 0.39), and there was no significant difference observed in minimum and maximum HR of these groups. However, the frequency of short pauses was greater in OSA patients (p = 0.009), with a prominent nocturnal distribution. In conclusion, OSA was not associated with increased HR in patients with AF suggesting that adequate HR control was similarly achievable in patients with and without OSA. The increased frequency of nocturnal pauses in OSA patients may function as a clinical hallmark, and the timing of pauses (during sleep vs wakefulness) should be noted before making therapeutic decisions regarding HR control.

Keck School of Medicine University of Southern California Los Angeles California

Mayo Clinic Rochester Minnesota

St Anne's Hospital ICRC Brno Czech Republic

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