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 in the online-only Data Supplement). Cardiac catheterization confirmed this unusual diagnosis (Figure 2). The right coronary artery arose from the normal aortic position (Figure 3). The Qp:Qs ratio was 1.8 and indexed pulmonary vascular resistance was 3.2 Wood units·m. No significant mitral valve stenosis was found. Gradient through the VSD was 18 mm Hg, and RPA saturation was 77% compared with a superior vena cava saturation of 63%. Interestingly, ECG obtained at the time of admission showed evidence of biventricular hypertrophy but no evidence of myocardial ischemia or infarction (Figure 4). The patient was taken to the operating room the following day, and the LCA was resected on a button of RPA tissue and reimplanted into the posterior aspect of the proximal aorta. Primary repair of the VSD was performed. She was discharged home on postoperative day 16. Predischarge echocardiogram demonstrated some improvement in left ventricular function. ALCAPA was first described anatomically in 1865 by Krause and in 1885 by Brooks. ALCAPA accounts for <0.5% of congenital heart disease and is thought to occur in ≈1 in 300 000 births. Typically, the LCA arises directly from the main pulmonary trunk adjacent to and in close proximity to the normal aortic origin as an isolated defect. However, rare