Pathology of atherosclerotic heart disease in sudden death. II. The significance of myocardial infarction.

The role of myocardial infarction was investigated in 121 cases of sudden death with atherosclerotic heart disease. In addition to supporting other reports which have demonstrated the importance of chronic occlusion of the coronary vessels in relation to the high rate of infarctions found in such cases, the authors presented evidence which showed differences in occurrence in the sites of remote and recent infarctions, a lack of concordance between the sites of recent infarctions, and acute thrombosis in coronary vessels proximal to these lesions. No relationship between patient age or prior symptoms could be associated with the occurrence of infarction. Evidence was also presented which discounted the possible role of transmural infarction in the formation of acute thrombosis. These pathological observations support the concept that sudden cardiac deaths are results of functional instability of the myocardium produced by advanced coronary atherosclerosis.