A three-month old infant was referred because of prolonged difficulties in feeding, and increased sweatiness of recent onset. On physical examination, there were signs of congestive cardiac failure, including a gallop rhythm, but no significant murmur. Echocardiography revealed a dilated heart with a poorly contractile left ventricle, while the electrocardiogram revealed a strain pattern in the left praecordial leads (Fig. 1).

Figure 1.

The coronary arteries were examined in detail at echocardiography (Fig. 2). The right coronary artery was prominent, and arose from the right coronary sinus. The origin of the left coronary artery (LCA), however, was not seen in its usual position. Instead, it took its origin from the pulmonary trunk (PT). Its bifurcation into the anterior descending (LAD) and circumflex (Circ) arteries is also shown in Figure 2. Figure 3 shows the reversal of flow from the anomalous origin into the pulmonary trunk as seen with colour flow mapping during systole.

Figure 2.

Figure 3.

In the majority of infants with dilated cardiomyopathy, the aetiology is idiopathic, and the prognosis is usually poor. Anomalous origin of the left coronary artery from the pulmonary trunk is a rare, but surgically correctable, cause of the morphological features, as demonstrated in our patient. It is important, therefore, to exclude this possibility when evaluating cases of presumed dilated cardiomyopathy with early onset. Anomalous origin the left coronary artery from the pulmonary trunk explains well the clinical presentation of a healthy newborn who started developing symptoms in the second month of life, since the pressures in the pulmonary circuit drop markedly after birth. The effects of this change were demonstrated on both the electrocardiogram and the echocardiogram.