The American journal of cardiology
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The clinical features of patients treated with streptokinase for chest pain and anterior ST-segment elevation who subsequently develop non-Q-wave infarction are unknown. Of the 75 consecutive patients who initially presented with chest pain and ST-segment elevation in the anterior leads (V1-V6, I, aVL) and were treated with intravenous streptokinase (time from symptoms to treatment averaged less than 3 hours), 32 (43%) developed a non-Q-wave and 43 (57%) a Q-wave myocardial infarction. Twenty seven of 32 patients (84%) from the non-Q-wave group and 39 of 43 (91%) from the Q-wave group were studied by angiography at 5.16 +/- 2.88 days after the onset of myocardial infarction. ⋯ In summary, when patients presenting with chest pain and ST-segment elevation are treated with streptokinase, a significant portion of these symptoms will evolve into a non-Q-wave infarction. Patients with a non-Q-wave infarction will have a better preserved left ventricular function than patients who develop a Q-wave infarction. This suggests the need for equal distribution of such patients in randomized trials of thrombolytic therapy for acute myocardial infarction to avoid misinterpreting data between groups.