AbstractThis report describes successful results from intracoronary streptokinase administered beginning 6 hr after onset of symptoms to a 32‐year‐old male with subtotal vessel occlusion by thrombus. Coronary angiography 26 days later demonstrated normal vessels. We conclude that 1) duration of symptoms beyond 3–4 hr should not preclude the use of thrombolytic therapy in evolving myocardial infarction, 2) this patient exemplifies the higher incidence of subsequently demonstrated normal coronary arteries in patients under age 35 with acute myocardial infarction; arterial spasm and platelet aggregation are the most likely causes of coronary occlusion in these pat