Relation of pathologic Q waves at presentation and time to streptokinase therapy with early changes in infarct-related artery flow and ventricular wall motion

Thrombolytic therapy is available worldwide for the treatment for acute myo cardial infarction, and streptokinase is frequently used. Although early re perfusion salvages myocardium,(1,2) reperfusion after 90 minutes is also be neficial through preventing ventricular dilatation, improving electrical st ability, and providing collateral flow when another artery occludes.(3) How ever, reocclusion of the infarct-related artery after initial recanalizatio n sometimes occurs and increases mortality.(4) In the Hirulog Early Reperfu sion/Occlusion (HERO-1) trial, there was a lower rate of Thrombolysis In My ocardial Infarction trial (TIMI) grade 3 flow at 90 minutes in patients who received streptokinase >3 hours after symptom onset,(5,6) and in patients with pathologic Q waves at presentation.(6) Whether these "late presenting" patients have more recanalization or fare worse from reocclusion of the in farct-related artery after the first 90 minutes is unknown. In this study, we analyze the relations between early changes of infarct-related artery fl ow, time to treatment, and Q waves at presentation.