EFFECTS OF CORONARY THROMBOLYSIS ON LEFT VENTRICULAR EJECTION FRACTION IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION

Left ventriculograms were performed on 65 patients with acute myocardial infarction, once upon admission and again 3 months later. In 29 cases urokinase was injected intravenously and/or intracoronarily. The other 17 were treated without urokinase. In 8 out of 29 patients whose infarct-related coronary arteries remained completely occluded following urokinase therapy, the global ejection fraction was reduced from 54 ± 3% during the acute stage to 46 ± 5% during the chronic stage (p < 0.001). However, for the 21 patients whose coronary arteries were successfully recanalized, the 2 values were the same (52 ± 2%). The highest global ejection fractions were seen in 19 spontaneously recanalized patients (acute: 54 ± 2%, chronic: 55 ± 2%). For the 8 unsuccessful patients, the regional ejection fraction for the infarcted portion was reduced from 20 ± 5% during the acute stage to 18 ± 6% during the chronic stage. But for the successful patients there was an improvement from 22 ± 2% during the acute stage to 27 2% during the chronic stage. Again, the regional ejection fraction was the highest for the spontaneously recanalized group, being 31 2% and 36 3% during the acute and chronic stages, respectively. These results indicate that if the coronary artery remains occluded during the acute stage the reduced left ventricular function continues to deteriorate even more during the chronic stage. Successful coronary thrombolysis, however, might salvage the infarcted myocardium as well as preserve the function of the left ventricle.