Myocardial infarction without atherosclerosis.

By far the most frequent pathologic condition preceding myocardial infarction is coronary atherosclerosis. Because the great majority of patients who are first seen with acute myocardial infarction have atherosclerotic coronary artery disease, there is usually little thought given to other causes, except in children where congenital coronary anomalies are considered. However, there are multiple other conditions, albeit far rarer than atherosclerosis, that can result in clinical acute myocardial infarction, and a classification of these other conditions, an anatomic-pathophysiologic one, was developed from illustrative material from the files of the Armed Forces Institute of Pathology. This classification is an inclusive listing of all conditions, however unusual, that can result in acute myocardial infarction.