Nocturnal myocardial ischemic events and sleep-disordered breathing in patients with coronary artery disease

To investigate the occurrence of nocturnal myocardial ischemia and its relationship with sleep-disordered breathing (apneas and oxygen desaturations) in patients with angina pectoris undergoing coronary an-giography. Methods Eighty-two men and 14 women referred for consideration of coronary intervention were randomly selected. Observation by an overnight sleep monitor and Holier recording were performed to study sleep-disordered breathing (oxyhemoglobin desaturations ^4% and apnea-hypopneas) , heart rates, and ST-seg-ment depressions ( ^ Imm, ^ 1 min) . Results Nocturnal ST-segment depressions occurred in 37% of the patients. ST-segment depression within 2 min after an apnea-hypopnea or desaturation occurred in 17% of the patients . This temporal association was seen in 21 % of the patients with nocturnal ST-segment depressions, more frequently in men (P <0.05) and more frequently in those with severe disordered breathing (P <0.05) . Most of these ST-segment depressions were preceded by a series of breathing events: repeated apnea-hypopneas or de-saturations or both in 73% of the patients. Conclusions Episodes of nocturnal myocardial ischemia are com-mon in patients with angina pectoris. A temporal relationship between sleep-disordered breathing and myocardial ischemia was present in some of our patients, and occurs more frequently in men and in those with severely dis-ordered breathing.