[Electrocardiographic criteria of probable localization of coronary arteriosclerosis].

Forty-nine patients with coronary atherosclerosis (according to the results of selective angiography), whose ages ranged from 29 to 59 years, were examined. Comparison with the results of ECG at rest and the findings of coronarography showed no changes in the QRS complex in 16% of patients with lesions of two and in 10% of those with obstructive changes in three main coronary artery. Displacement of the ST segment as a sign of myocardial ischemia during physical exercise tests in leads V5--V6 of the ECG coincided with obstructive lesions of the left coronary artery in 91% of cases. Patients suffering from obstructive lesions of the right coronary artery with or without atherosclerotic changes in the left coronary artery reacted by depression of the ST segment in the II, III, and aVF leads of the ECS. The authors suggest that there exists a mechanism of "intracoronary steal" of perfusion blood supply when the ischemic changes on the ECG do not coincide with the localization of coronary atherosclerosis.