Reduced occurrence of atrial fibrillation in acute myocardial infarction treated with streptokinase.

In a historical follow-up study of 152 hospital patients with acute myocardial infarction, the frequency of life-threatening arrhythmias (ventricular fibrillation, sustained ventricular tachycardia, 3rd degree AV-block, 2nd degree AV-block (Mobitz type II), and asystole) and atrial fibrillation in 76 patients treated with streptokinase was compared with their frequency in 76 patients who did not receive a thrombolytic therapy. Among those treated with streptokinase two patients (3%) developed atrial fibrillation, compared with 12 (16%) in the control group (P = 0.009). Life-threatening arrhythmias occurred with equal frequency in the two groups. Further studies should confirm and clarify the mechanism of the reduced frequency of atrial fibrillation in the streptokinase-treated patients.