[Periodic breathing and disorders of cardiac activity during sleep in patients with ischemic heart disease].

A total of 75 coronary patients were examined during nocturnal sleep. Thirty-eight of them had periodic apnoe or hypopnoe breathing which occurred more commonly during light sleep in patients with myocardial contractile dysfunction, compromised cerebral circulation and overweight. Periodic respiration was accompanied by heart rhythm oscillations, variations in the muscle and peripheral vascular tone, by EEG activation and, in some cases, by the activation of T-wave on the EEG. No direct association was found between apnoe episodes and cardiac activity impairments (rhythm and conductivity disturbances, ST segment changes on the ECG). However, dangerous rhythm irregularities were noted more commonly in patients with periodic breathing manifestations during sleep. Thus disorders in heart activity and periodic respiration during sleep may be associated with depressed vegetative regulation.