Obstructive sleep apnea and atrial fibrillation

Keith Todd, William F McIntyre, Adrian Baranchuk

Department of Cardiology, Kingston General Hospital, Queen’s University, Kingston, Ontario, Canada

Abstract: Atrial fibrillation (AF) is the most common sustained arrhythmia. The clinical impact of AF results primarily from its association with stroke, heart failure, and increased overall mortality. Recently there has been increasing evidence of an important association between obstructive sleep apnea (OSA) and AF. OSA is a common breathing disorder affecting an estimated 5% of the population and is highly prevalent in patients with established cardiovascular disease. The prevalence of OSA among patients with AF is remarkable with estimates ranging from 32%–49%. The pathophysiological connection between AF and OSA remains speculative, but appears to be the result of apnea-induced hypoxia, intrathoracic pressure shifts, inflammation, heightened sympathetic activity, and autonomic instability leading to hypertension, diastolic dysfunction, left atrial enlargement, and electrical remodeling. Initial results appear promising that intervention with continuous positive airway pressure may be effective in reducing the burden of AF in this population, however, further investigations are needed. Here, we review the literature on the current epidemiologic data, pathophysiology, and therapeutics linking these two common conditions.

Keywords: cardiac arrhythmia, autonomic imbalance, intrathoracic pressure changes, diastolic dysfunction, hypertension, sleep-disordered breathing