NOCTURNAL DESATURATION IN PATIENTS WITH STABLE HEART-FAILURE

Objective-To determine the prevalence of sleep disordered breathing wi thin a United Kingdom heart failure population. Subjects-104 patients and 21 matched normal volunteers. Methods-Overnight home pulse oximetr y with simultaneous ECG recording in the patient group; daytime sleepi ness was assessed using the Epworth sleepiness scale (ESS); 41 patient s underwent polysomnography to assess the validity of oximetry as a sc reening test for Cheyne-Stokes respiration. Results-Home oximetry was a good screening test for Cheyne-Stokes respiration (Specificity 81%, sensitivity 87%. Patients with poorer New York Heart Association (NYHA ) classes had higher sleepiness scores (P < 0.005). Twenty three patie nts had ''abnormal'' patterns of nocturnal desaturation suggestive of Cheyne-Stokes respiration. The mean (SEM) frequency of dips in Sao(2) exceeding 4% was 10.3 (0.9) per hour in the patients and 4.8 (0.6) in normal controls (P < 0.005). Ejection fraction correlated negatively w ith dip frequency (r = -0.5. p < 0.005). The patient subgroup with gre ater than or equal to 15 dips/hour had a higher mean (SEM) NYHA class (3.0 (0.2) v 2.3 (0.1), p < 0.05), and experienced more ventricular ec topy (220 (76) v 78 (21) beats/hour, p < 0.05). There was no excess of serious arrhythmia. Conclusions-Nocturnal desaturation is common in p atients with treated heart failure. Low ejection with treated heart fa ilure. Low ejection fraction was related to dip frequency. Lack of cor relation between dips and ESS suggests that arousal from sleep is more important than hypoxia in the aetiology of daytime sleepiness in hear t failure. Overnight oximetry is a useful screening test the Cheyne-St okes respiration in patients with known heart failure.