DAYTIME SLEEPINESS IN PATIENTS WITH CONGESTIVE-HEART-FAILURE AND CHEYNE-STOKES RESPIRATION

Study objective: To determine whether patients with congestive heart failure who develop Cheyne-Stokes respiration (CSR) during sleep experience excessive daytime sleepiness. This was addressed by comparing sleep quality and daytime sleepiness in three groups: patients with CHF and CSR during sleep (CSR group), patients with CHF without CSR (CHF group), and healthy control subjects (control group). Design: Single-blind, cross-sectional study. Setting: Patients referred by cardiologists and control subjects recruited from the general community. Patients: Twenty-three men: 7 in the CSR group, 7 in the CHF group, and 9 in the control group. Measurements: Each subject had an overnight sleep study and an assessment of sleepiness the following day. Results: The three groups were a similar age: CSR, 68+/-15 years; CHF, 62+/-4 years; and control, 65+/-4 years; and left ventricular ejection fraction was the same in patients with CSR (20+/-1.5%) and CHF (23+/-5%). Sleep latency was significantly shorter in patients with CSR (4+/-1.1 min) than patients with CHF (11.3+/-4.8 min) and healthy controls (12.4+/-1.9 min) and was within the diagnostic range of severe sleepiness. Patients with CSR had significantly more stage 1 and 2 non-rapid eye movement (NREM) sleep (CSR, 83+/-7; CHF, 64+/-9; control, 63+/-9% total sleep time), less REM sleep (CSR, 10+/-3; CHF, 22+/-8; control, 22+/-7% total sleep time), and a higher frequency of arousals from sleep (CSR, 30+/-16; CHF, 18+/-15; control, 10+/-2/h of sleep); 66% of arousals were associated with CSR. Regression analysis revealed that sleep latency was inversely related to the amount of stage 1 and 2 NREM sleep(r=-0.67), arousal frequency (r=-0.46), and the apnea-hypopnea index (r=-0.63) and was positively correlated with the amount of slow-wave sleep (r=0.45) and REM sleep (r=0.56) and the mean oxygen saturation during sleep (r=0.50). Conclusions: Patients with CHF who develop CSR experience excessive daytime sleepiness due to sleep disruption. This should be considered the clinical evaluation of these patients' daytime complaints.