Obstructive Sleep Apnea and Cardiovascular Disease.

Obstructive sleep apnea (OSA) presents as repetitive interruptions of ventilation >10 seconds during sleep as a result of upper airway obstruction resulting in increased respiratory effort. Intermittent hypoxia causes physiologic changes resulting in increased catecholamine production, increased total peripheral resistance, tachycardia, and increased venous return, leading to increased cardiac output, hypertension, tachyarrhythmias, left ventricular hypertrophy, and heart failure. OSA causes an abnormal dip on 24-hour ambulatory blood pressure monitoring. Definitive diagnosis is made by polysomnography. Continuous positive airway pressure (CPAP) remains the first-line treatment. Effective treatment using CPAP reduces blood pressure and is indispensable for proper management of atrial fibrillation.