Hemodynamic parameters of left ventricular function were assessed in 179 patients with acute myocardial infarction, who were treated with intracoronary thrombolysis during first six hours after the onset of chest pain. Some of them were subjected to coronary angioplasty. Patency of the infarct related artery was controlled between the 2nd and 3rd week after acute myocardial infarction concomitant with evaluation of EF and LVEDP. Reperfusion of the infarct related artery was obtained in 121 patients (67.6%) and also significant increase of EF was observed in those patients. EF rose in patients with a patent coronary artery after 2-3 weeks (not significant) in contrast to patients with obstructed coronary artery in whom there was a fall in EF. The rise of EF was more pronounced in patients with reperfusion reached in 3 hours after the onset of infarct pain and without coronary angioplasty. It was shown that LVEDP is not usefull in estimation of left ventricular function.