[Influence of a streptokinase-induced fibrinolysis on the extent of the acute experimental myocardial infarction (author's transl)].

In 17 unaesthetized dogs several side branches of the left descending coronary artery were ligated. The ST-segment elevation in the epicardial ECG ascended to 22 mV after 5 min and to 19 mV after 20 min. Aortic pressure, left ventricular enddiastolic pressure, heart rate and hemostasiological parameters (thrombin-time, thrombin-coagulase-time, reptilase-time, plasma-fibrinogen, staphylococcal clumping test) did not change significantly. 20 min after the beginning of coronary occlusion, the vessels were reopened. When ST-segment elevation had disappeared, a controlled fibrinolytic therapy (Streptokinase 1.5 Mega I.E. in 30 min, later on 0.75 Mega I.E./h) was induced. When an effective fibrinolysis could be demonstrated by the hemostasiological parameters, the same vessels were occluded again. Now the hemodynamic parameters too did not change significantly, but the ST-segment elevation was significantly diminished for more than 50% compared with simple ligation. A control group, which only got the solvent of the streptokinase, showed the same ST-segment elevation. This effect, induced by streptokinase is ascribed to fibrinogen degradation products and a diminution in the amount of fibrinogen which cause an improvement of microcirculation.