131Cs myocardial scintigraphy. Application to assessment of anterior myocardial infarction

Earlier studies have indicated that caesium-131 is a good myocardial scanning agent for the demonstration of anterior infarcts. One hundred and ten patients with documented anterior myocardial infarction were studied by 131Cs myocardial scintigraphy. An anterior area of decreased uptake of caesium was noted in all but 3 subjects whose necrotic zone was likely to be of small dimensions. In 20 cases, the scintigram showed a definite, sometimes very large, cold area whereas the electrocardiogram failed to display any diagnostic feature of myocardial necrosis. In most of the latter instances, the electrocardiographic diagnosis was obscured by the presence of intraventricular conduction disturbances. In order to visualize the intracardiac cavities, the 131Cs investigation was usually completed by a 113mIn scintigram, which allowed recognition of a parietal aneurysm in 12 of the 18 patients with extensive anterior lesions. In each case, an index of necrosis was computed from planimetric measurements of the infarcted area as compared to the total left ventricular surfact in both the anteroposterior and left anterior oblique projections. This index was shown to correlate with the incidence of major complications developing after the acute episode of coronary occlusion. The sensitivity, specificity, and accuracy of the method are briefly discussed. It is felt that myocardial scintigraphy represents a sound approach to the semiquantitative assessment of anterior myocardial infarction; the clinical usefulness of the technique seems sufficiently demonstrated to prompt further research in this field.