Outcome of Cardiac Monitor During Sleep Study for Screening of Subclinical Atrial Fibrillation

Background There is growing evidence of a strong association between obstructive sleep apnea (OSA) and cardiovascular co-morbidities including atrial fibrillation (AF). We wanted to assess the usefulness of the overnight cardiac monitoring to screen for AF during the sleep study in patients newly diagnosed with OSA, in order to establish the usefulness of overnight active screening for subclinical AF during the sleep study in these patients. Methods A retrospective study in patients with new diagnosis of OSA carried out between January 2014 and December 2019 in the sleep clinic at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. All patients newly diagnosed with OSA (apnea-hypopnea index >5) were selected to undergo a clinical questionnaire regarding symptoms, co-morbidities and risk factors. Subjects with history of cardiac arrhythmias or having anti-arrhythmic treatment were excluded. Eligible patients underwent an overnight rhythm monitoring to screen for AF or any rhythm disturbance. Results We included 250 respective patients with OSA, 54% were males and 82% aged more than 35 years. The majority of patients were married (83%), of Saudi nationality (81%), and 90% were overweight or obese, apnea hypopnea index (AHI) was mild (5-14) in 30%, moderate (15-29) in 38% and severe (30 or more) in 32% of the patients. No cardiac arrhythmia was detected in all the study population, while only two patients complained of palpitations and was due to sinus tachycardia. Assessment of other risk factors showed 26% cases of diabetes mellitus, 39% of hypertension, 1% of renal failure, 9% of ischemic heart disease, 17% of thyroid dysfunction, 6% of stroke and 4% of dyslipidemia. Conclusion The findings of this study show null incidence of cardiac arrhythmia during the apnea-hypopnea episodes in a cohort of patients with confirmed OSA. However, in view of the frequently reported association, the screening for subclinical atrial fibrillation needs long-term rhythm surveillance and should be targeted to symptomatic patients.