Forty-five patients with acute myocardial infarcts had technetium-99m stannous pyrophosphate (9"mTc-PYP) myocardial scintigrams with radionuclide uptake localized to the anterior or lateral wall of the left ventricle in a pattern resembling a doughnut (intense peripheral uptake and relatively less central uptake). Sixty-seven percent of these patients developed left ventricular failure with infarction. Twenty-six patients with acute anterior or lateral myocardial infarcts were selected for comparison because of 9OmTc.-PYP scintigrams which were more homogeneously positive. There were no significant differences in age, sex or electrocardiographic location of infarction. In-hospital left ventricular failure in Killip classes II, III or IV was more common in the group with doughnut scintigrams. Estimates of infarct size by scintigraphic planimetry and analysis of peak serum creatine kinase levels indicated larger infarcts in the group with doughnut scintigrams.
A doughnut "mTc-PYP myocardial scintigraphic pattern identifies a relatively large myocardial infarct that is probably associated with developing or worsening left ventricular failure. Further knowledge of the factors determining the development of this, rather than other scintigraphic abnormalities, and of the mechanism of filling in of the central defect of this doughnut in some patients, may help us understand certain aspects of the pathophysiology of acute myocardial infarcts.