Sleep apnea: from the nose to the heart

Obstructive sleep apnea (OSA) is a disorder consisting of repetitive obstruction of the upper airway during sleep accompanied by ineffective respiratory effort.

We developed this clinical review using an extensive MEDLINE review of the literature and data from our laboratories. This review examines (1) the prevalence of OSA; (2) the pathophysiology involved including the causes of obstruction, the physiologic stimuli, and resulting autonomic changes; (3) the cardiovascular manifestations; and (4) the therapeutic approaches to patients with OSA with emphasis on arrhythmia management.

OSA is highly prevalent and largely underdiagnosed. As part of a much broader spectrum of respiratory disturbances during sleep, OSA can result in a multitude of systemic manifestations. Structural changes occur in the airway to obstruct airflow during OSA, and the resulting apnea activates hypoxic and hypercapnic reflexes, which in turn lead to profound elevation in sympathetic nerve activity and cyclical changes in parasympathetic nerve activity. These autonomic effects are thought to contribute to the associated cardiovascular diseases (eg, hypertension) and frequently observed brady- and tachyarrhythmias. The ultimate goal in the treatment of OSA is to restore airway patency and sleep continuity and to improve daytime functioning and quality of life. Treatment usually results in improvement of clinical symptoms.