[Value of myocardial scintigraphy of coronary anomaly in the differential diagnosis of pediatric cardiomegaly].

The differentiation between anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) and other causes of cardiomegaly and thereby the decision to operate, as opposed to undertaking conservative therapy is often extremely difficult in clinical practice. Electrocardiographically, signs of myocardial infarction can be missed in ALCAPA, other forms of dilative cardiomyopathy (DCMP) often showing similar clinical features. Up to now aortography alone can make a clear-cut distinction between these two entities. In order to determine the diagnostic value of thallium-201 myocardial scintigraphy in ALCAPA, we investigated 18 children, 7 of them with angiographically or autoptically established ALCAPA and 11 patients with DCMP. The coronary artery anomaly was diagnosed on the basis of the typical myocardial perfusion defects in only 3 of the relevant 7 patients. In 9 of the 11 patients with DCMP ALCAPA was excluded by the homogeneous perfusion pattern or small focal reduction in thallium-201 activity in the left ventricular muscle mass. In view of the overall disappointing results of this method in achieving a specific diagnosis in ALCAPA, all patients with DCMP with or without suspected fibroelastosis should undergo invasive diagnosis with aortography.