Value in Distinguishing Anomalous Left Coronary Artery from Congestive Cardiomyopathy

In infants and children, anomalous origin of the left coronary artery (ALCA) from the pulmonary artery may be difficult to distinguish from congestive cardiomyopathy (CCM) of other causes. We performed thallium-201 myocardial perfusion imaging in seven children with ALCA and in nine with CCM to study the usefulness of this technique in distinguishing between these lesions. Localized abnormalities of thallium uptake were present in each of the seven patients with ALCA, including two asymptomatic 4-year-old children. Thallium distribution was normal in five patients with CCM, diffusely irregular in three, and was absent in the lateral and posterobasal portions of the left ventricle in one patient. We conclude that thallium-201 imaging is a sensitive noninvasive method of detecting ALCA. However, perfusion abnormalities are not limited to patients with coronary artery abnormalities, and may be present in patients with myocardial ischemia or infarction of other causes.