Sleep-disordered breathing and chronic atrial fibrillation

Background: Little has been known about the prevalence of sleep apnea in patients with atrial fibrillation (AF). Studies have suggested that the prevalence of AF is increasing in patients with sleep-disordered breathing. We hypothesize that the prevalence of OSA is higher in chronic persistent and permanent AF patients than a sub-sample of the general population without this arrhythmic disorder. Objective: Evaluate the frequency of Obstructive Sleep Apnea in a sample of chronic AF compared to a sub-sample of the general population. Methods: Fifty-two chronic AF patients aged (60.5 +/- 9.5, 33 males) and 32 control (aged 57.3 +/- 9.6, 15 males). All subjects were evaluated by a staff cardiologist for the presence of medical conditions and were referred for polysomnography. The differences between groups were analyzed by ANOVA for continuous variables, and by the Chi-square test for dichotomous variables. Statistical significance was established by alpha = 0.05. Results: There were no differences in age, gender, BMI, sedentarism, presence of hypertension, type 2 diabetes mellitus, abdominal circumference, systolic and diastolic blood pressure, and sleepiness scoring between groups. Despite similar BMI, AF patients had a higher neck circumference compared to control group (39.9 cm versus 37.7 cm, p = 0.01) and the AF group showed higher percentage time of stage 1 NREM sleep (6.4% versus 3.9%. p = 0.03). Considering a cut-off value for AHI >= 10 per hour of sleep, the AF group had a higher frequency of OSA compared to the control group (81.6%, versus 60%, p = 0.03). All the oxygen saturation parameters were significantly worse ill the AF group, which had lower SaO(2) nadir (81.9% versus 85.3%, p = 0.0 1) and mean SaO(2) (93.4% versus 94.3%, p = 0.02), and a longer period of time below 90% (26.4 min versus 6.7 min, p = 0.05). Conclusion: Sleep-disordered breathing is more frequent in chronic persistent and permanent AF patients than in age-matched community dwelling subjects. (c) 2007 Elsevier B.V. All rights reserved.