Sleep-Disordered Breathing and Heart Disease

Clinically important sleep-disordered breathing (SDB) affects ≈2% to 4% of the general adult population, and its incidence is highest in the older segment of the population.1 Atherosclerotic heart disease is also largely a disease of older people, and often declares itself by an ischemic event or the onset of heart failure (HF). SDB causes multiple physiological perturbations, promoting stress and intermittent hypoxia and negatively affecting cardiac function.2 Predictably, untreated SDB may promote atherosclerosis and aggravate cardiac failure.3Article see p 1280Emerging evidence indicates that reverse causation may also be true. A recent study of patients with HF and proven SDB indicates that, during sleep, fluid from the lower extremities shifts to the neck region of the body, causing mechanical constraints in the upper airway and worsening their SDB.4 Moreover, patients with significant cardiovascular disease can develop ventilatory instability as a result of pulmonary congestion and circulatory delays.5 Although it is well known that ventilatory instability is an important risk factor for central sleep apnea and Cheyne-Stokes respiration,6 recent data indicate that it is also a risk factor for severe obstructive sleep apnea.5,–,7 With these plausible mechanisms in place, it would be prudent …