Transmural, haemorrhagic myocardial infarction after intracoronary streptokinase. Clinical, angiographic, and necropsy findings.

Abstract

Six of 101 patients with acute myocardial infarction whose coronary arteries were successfully recanalized died in cardiogenic shock 1-18 days after intracoronary thrombolysis. In 1 patient, cardiogenic shock was preceded by coronary artery reocclusion. On admission, serum creatine kinase was still normal in all 6 patients and there was significant ST elevation but no changes in the QRS complexes. Four of the 6 patients had an old infarct. The time between the onset of symptoms and coronary artery recanalization was .apprx. 2.9 h. The total dosage of intracoronary streptokinase averaged 200,000 U. Necropsy disclosed a patent vessel supplying the infarct in 5 patients and thrombotic reocclusion in the 1 patient with reinfarction. All 6 patients had a transmural acute myocardial infarction, which was typically anemic in the 2 patients with inferior infarction. In 1 of these 2 patients whose artery was recanalized within 1.7 h, the anemic infarct was only 4 cm2 in area, whereas in the other (the patient who died after reocclusion) it was 30 cm2. In 3 patients with an acute occlusion of the left anterior descending coronary artery whose vessels were recanalized within 3.5 h, the infarct was hemorrhagic and large averaging 32 cm2. Hemorrhage was always confined to the area of necrosis and there was no evidence of cardiac rupture. One other patient had both types of infarction, a large hemorrhagic infarct in the area of the recanalized circumflex coronary artery and an anemic infarct in the area supplied by the severely stenosed left anterior descending coronary artery. In this patient who died 18 days after recanalization, the speed of infarct healing was much delayed in the hemorrhagic but not in the anemic infarct area. Despite coronary artery recanalization within 3.5 h, a fatal transmural acute myocardial infarction with reperfusion hemorrhage into the area of necrosis may occur. Myocardial hemorrhage probably delays infarct healing.