Intracoronary thrombolysis with urokinase in acute myocardial infarction. Effects on reperfusion and left ventricular wall motion.

Intracoronary Urokinase administration was attempted in 20 patients (mean age 56 years) during the early phase of an acute evolving myocardial infarction. One patient died before urokinase infusion could be started. Out of the remaining nineteen patients, eighteen had total occlusion of a coronary vessel; one patient, in cardiogenic shock, failed to show occluding thrombi of the vessel related to the ECG site of infarction, and died during the procedure. Urokinase was administered at a rate of 4000 IU/min in 7 consecutive patients (Group I), 6000 IU/min in 5 patients (Group II), and 10000 IU/min in 6 patients (Group III). Recanalization of the occluded vessel was obtained in 16 patients (88%). The reperfusion time was 52 +/- 33 min. No significant variation in reperfusion time was noted in the three groups of patients treated. The time elapsed between the onset of symptoms and the successful recanalization was in our patients 4.3 +/- 1.8 hours. Ventricular arrhythmias, which required treatment, appeared after reperfusion in five patients. No serious hemorrhagic complications were noted. In fourteen patients ventriculography was performed before and immediately after thrombolysis: 15 patients had the study repeated 12 days after the procedure. Patency persisted in 13 patients and successful thrombolysis was associated with significant improvement in left ventricular ejection fraction and segmental wall motion. Our data demonstrate that different doses of Urokinase can be safely and successfully used to produce intracoronary thrombolysis in the majority of patients with acute myocardial infarction.