A total of 66 patients with acute myocardial infarction (MI) were examined: 39 of them received treatment with intracoronary administration of streptokinase within the first 3-20 h from the beginning of anginal pains, the other 27 patients (controls) were treated using routine methods. Occlusion of the coronary artery (CA) was found in 31 of 39 patients of the intervention group, stenosis over 75% was found in 8 patients. CA recanalization was achieved in 21 of 31 patients with CA occlusion. CA stenosis of various degree remained at the site of former occlusion in all the patients after recanalization. Repeated coronarography in 28 days showed reocclusion of the coronary artery at the site of stenosis in 20% of the cases. Blood flow restoration in the CA was often accompanied by the appearance of ventricular arrhythmias. Data on precordial ECG mapping (35 leads) showed the development of lesser size MI in the patients with the restored blood flow in the CA as compared to the group on routine therapy.