Infant With Anomalous Left Coronary Artery Arising From the Right Pulmonary Artery and Ventricular Septal Defect

A 5-month-old female baby presented to a community hospital in acute respiratory failure for which she was intubated and treated for presumed pneumonia. Chest x-ray demonstrated cardiomegaly, and a subsequent echocardiogram described mitral valve stenosis, mitral valve regurgitation, bicuspid aortic valve, perimembranous ventricular septal defect (VSD), and subaortic membrane, leading to the diagnosis of Shone complex. After several weeks of antibiotics, diuretics, mechanical ventilation, and inotropic support failed to improve her clinical course, the patient was transferred. Repeat echocardiography confirmed the previous anatomic findings, as well as moderately depressed left ventricular systolic function. Chalk sticking of the left ventricular papillary muscles was suggestive of an ischemic insult. Because of these findings, anomalous left coronary artery arising from the right pulmonary artery (ALCAPA) was suspected, but the left coronary artery (LCA) was not seen arising from the pulmonary root. A modified parasternal short-axis view revealed that that the LCA arose anomalously from the mid right pulmonary artery (RPA; Figure 1). Flow within the anomalous LCA was bidirectional, although primarily antegrade, from the RPA toward the left ventricle (Movie I …