Hemorrhagic myocardial infarct. An analysis of the distribution of the hemorrhage and of the permeability of the artery related to the infarct

PURPOSE: To study the extent of hemorrhagic myocardial infarction (HMI) and patency of the infarct related artery. METHODS: Forty seven cases of HMI diagnosed by necropsy (patient age range 30-81 years, mean 59) were studied retrospectively. Hemorrhagic extent was evaluated by microscopic analysis of myocardial sections of the infarcted areas and coronary patency was studied by angiography and by serial coronary sections at necropsy. RESULTS: In 12 cases hemorrhage extended outside the infarcted area and in the remaining cases it was restricted to the necrotic zone. Coronary patency was spontaneous in 8 of 24 cases, secondary to thrombolytic therapy or angioplasty in 8 and post coronary artery bypass in 15. Recent occlusive thrombus was diagnosed in 26 of 44 cases. Grouping all cases according to angiographic or macro and microscopic evidences of coronary patency, it was found that 35 of 47 studies cases (74.4%) had the infarct related coronary artery free of occlusion. In most cases of HMI myocardial hemorrhage restricted to the infarcted necrotic zone but in almost 25% it could reach areas beyond the infarcted necrotic zone probably resulting in deleterious consequences. CONCLUSION: Reperfusion is frequent and it plays a role in the hemorrhagic event but it was not seen in 25% of these studied cases. These findings suggest that other mechanisms could participate of the pathogenesis of HMI.