Impaired baroreflex sensitivity and nocturnal periodic breathing in patients with chronic heart failure

Nocturnal periodic breathing is a common finding in severe chronic heart failure (CHF). Patients (pts) with left ventricular dysfunction can exhibit impairment of baroreflex sensitivity (BRS) or heart rare variability (HRV). We studied 48 pts aged 57/spl plusmn/8 years with CHF in stable phase (EF=23/spl plusmn/6%). All pts underwent a sleep study to assess the occurrence of periodic breathing, and a phenylephrine test to evaluate BRS; 36 patients had also a 24 hour ambulatory electrocardiogram recording to measure HRV. Nocturnal periodic breathing was recorded in 75% of patients, BRS was markedly depressed in 60% of patients, HRV was reduced in 58% of patients. Significant correlations were found between %PB and left ventricle EF (p=0.016), BRS (p=0.0002), HRV (p=0.0001), and nocturnal oxygen desaturation (p=0.0001). Nocturnal periodic breathing is frequently associated with abnormal autonomic control of cardiac function in patients suffering from chronic heart failure.