When to Suspect Sleep Apnea and What to Do About It.

Obstructive sleep apnea (OSA), which is characterized by recurrent upper airway obstruction during sleep with resultant hypoxia-reoxygenation and sleep fragmentation, is prevalent among patients with cardiovascular disease. Refractory hypertension, nocturnal angina or arrhythmias, and stroke in particular should prompt consideration of OSA. The symptoms of OSA include snoring and excessive daytime sleepiness; risk factors include obesity and reduced upper airway dimensions. Up to 50% of patients with congestive heart failure (CHF) may manifest OSA, central sleep apnea-Cheyne-Stokes respiration (CSA-CSR), or both. Patients with CSA-CSR may present with fatigue, disrupted sleep, and paroxysmal nocturnal dyspnea. Objective sleep recording is required to document the nature and severity of sleep apnea. The gold standard is in-laboratory overnight polysomnography (PSG), including monitoring of electroencephalography and other signals to determine sleep-wake state, and recording of body position, airflow, respiratory effort, and pulse oximetry. Portable cardiorespiratory recorders are now approved for diagnosis in patients without comorbidities. Full PSG is recommended for diagnosis in all other cases, although OSA and CSA-CSR can be identified from portable recorders in some patients with CHF and other conditions. The objectives of treatment are to improve symptoms, quality of life, and cardiovascular outcomes. The mainstay of treatment for moderate-to-severe OSA is positive airway pressure (PAP). Automated PAP devices may be used in uncomplicated OSA, whereas continuous fixed PAP is the treatment of choice for other patients with OSA, and may also treat a proportion of patients with CSA-CSR. A form of bi-level PAP known as adaptive servoventilation is effective in treating a majority of patients with CSA-CSR.