Myocardial pathology in sudden ischemic death: peculiarities of morphologic diagnosis

Objective. The aim of the investigation was to determine morphological criteria of acute myocardial injures in sudden ischemic death. Material and methods. Morphological investigation of the whole myocardium and coronary arteries in 170 victims of sudden out-of-hospital death due to ischemic heart disease was performed in the framework of the international WHO program “Myocardial Infarction Register in Population” and joint (at that time) USSR– USA project on sudden death. Results. It was established, that out-of-hospital sudden death due to ischemic heart disease in all cases is related to irreversible myocardial injury: 92.9% – to acute myocardial infarction, and 7.1% – to micronecrosis. The following phases of morphological development of infarction were determined: early myocardial infarction – in 48.8, definite – in 21.8, and progressing – in 22.3%. Since the signs of early infarction were also found in 34 cases of progressing myocardial infarction, it was reasonable to suppose that in 117 (71.1%) patients the occurrence of sudden out-of-hospital death due to ischemic heart disease was somehow connected with the very early and early phases of acute myocardial infarction. Conclusions. Accurate identification of early myocardial infarction is available only by microscopic investigation of histotopograms of the whole myocardium considering the complex of signs of cardiomyocyte alteration as well as early inflammatory reaction. Acute pathology (erosion or rupture of atherosclerotic plaque and thrombosis) of “culprit” coronary artery indirectly indicates regional myocardial irreversible injury