Indium-111-antimyosin uptake in acute and remote myocardial infarction: comparison with pathohistologic findings.

Indium-111-Fab antimyosin antibody accumulation was studied in an 81-yr-old patient who was treated twice for unstable angina on ECG, signs of apicoseptal infarction, anterolateral and inferior ischemia without clinical evidence of an acute coronary event. During the last hospitalization, 9 and 3 mo after the previous ones, additional ischemia in the inferoposterior wall was demonstrated. Antimyosin was administered to detect acute infarction but pump failure developed and the patient died. Autopsy confirmed all stages of infarction on the anterior and lateral walls, predominant fibrosis in the apicoseptal region and predominant acute necrosis in the inferior wall. Macroscopic and scintigraphic examinations of transverse slices gave concordant results. A mixture of infarctions and normal tissue was confirmed by histologic findings. Antimyosin antibody accumulation was seen in areas of acute necrosis or bordering areas of reduced uptake in myocardium with remote damage, probably caused by prolonged episodes of unstable angina without evident acute coronary event.