Parker, Robert L.

The purpose of this investigation was to study the incidence and location of systemic arterial occlusion and pulmonary embolism in a consecutive series of cases of fatal acute myocardial infarction. Another consecutive series of cases in which healed myocardial infarction was demonstrated at necropsy was similarly studied. In none of the cases included in this study had anticoagulant therapy been employed. Massive pulmonary embolism was the most frequent fatal thrombo-embolic complication found among the cases of acute myocardial infarction. Cerebral infarction was the most frequent fatal thrombo-embolic complication found among the cases of healed myocardial infarction. Cerebral infarction was the most frequent fatal systemic arterial thrombo-embolic lesion in both groups. Acute splenic and renal infarcts were frequently demonstrated but with one exception appeared to play an incidental role in the clinical course of the patients. Although systemic arterial occlusion was frequently found in association with intracardiac mural thrombi, there were many other cases in which evidence of systemic arterial occlusion was found in the absence of intracardiac mural thrombi. A positive correlation existed between the presence of pulmonary and systemic arterial occlusion and the occurrence of congestive cardiac failure.

This is a study of the location and incidence of intracardiac thrombi in acute and in healed myocardial infarction. In myocardial infarction intracardiac thrombi occur predominantly in the left ventricle. Anterior myocardial infarcts are more commonly associated with mural thrombi than posterior myocardial infarcts. Large myocardial infarcts and congestive failure are factors which predispose to the formation of left ventricular mural thrombi in myocardial infarction.