[The potential usefulness of MIBI-99mTc SPECT at rest in identifying viable myocardium after a myocardial infarct]

We present a 65 years-old female with a silent anterior myocardial infarction. A coronary angiogram showed a left ventricle with akinesia of segments anterior, lateral and apex. Left anterior descending artery showed a unique 95% lesion. The patient was discharged with medical treatment. Two months later the patient was readmitted with atypical angina. She was submitted to tomographic study (SPECT), with 99mTc-hexakis-2-methoxy-isobutyl-isonitrile (MIBI-99mTc) at rest. The images showed a wide area of hypocaptation in the territory of the left anterior descending artery but with differences among the different segments. This image was interpreted as suggestive of necrotic and viable myocardium. A second coronary angiogram yielded the same findings as in the first study. It was performed a successful PTCA on the left anterior descending artery lesion. A new SPECT study was performed 9 days later that showed a significant improvement of perfusion in some of the myocardial segments and a significant decrease of the internal left ventricular diameter. Isotopic left ventricular ejection fraction showed an increase from 25 to 35%. The present case suggests that the study with SPECT and MIBI-99mTc at rest may be potentially useful in the identification of viable myocardium after a myocardial infarction and assesses the importance of revascularization of the culprit artery with severe residual narrowing.