Prevalence of obstructive sleep apnea in patients with lone atrial fibrillation

Purpose The aim of this study is to detect the prevalence of obstructive sleep apnea syndrome (OSAS) in patients having lone atrial fibrillation (AF). Patients and methods Fifty patients with lone AF were referred to our sleep unit from the Department of Cardiology at the University Hospital. Lone AF was defined as AF in patients without cardiac structural abnormality and less than 60 years of age. All patients were subjected to a detailed history with stress on the number and date of documented episodes of AF and how it was terminated, OSA symptoms (excessive daytime sleepiness, witnessed apnea, loud habitual snoring, and nocturnal choking), and OSA screening questionnaires. ENT and cardiac examination by a specialist was done. Full-night attended polysomnography was performed on full night. Results The median apnea–hypopnea index in the studied group was 10.8 (range, 0.4–69.4). There were 21 (42.0%) non-OSA patients, while there were 29 (58%) OSA patients. There were eight (27.6%) mild OSA patients. Moderate OSA patients were 10 (34.5%). Severe OSA patients were 11 (37.9%). Median of the frequency of AF episodes in the last 1 year was significantly higher in the OSA group than in the normal group (P=0.01). No significant difference was present between both groups as regards the number of nocturnal arrhythmias not related to respiratory events. The frequency of paroxysmal AF episodes during the last year shows a significant positive correlation with severity of OSA, desaturation index, and total arousal index. Conclusion The results of our study support our hypothesis that OSA is a risk factor for AF. We should investigate patients with lone AF for the possibility of OSA.