Unrecognized anomalous origin of the left coronary artery from the pulmonary artery as a cause of ventricular fibrillation after patent ductus arteriosus ligation in an infant.

We present a case of an infant who developed ventricular fibrillation after patent ductus arteriosus (PDA) ligation. The infant had unrecognized anomalous origin of the left coronary artery from the pulmonary artery before PDA ligation. Acute reduction in systemic pulmonary artery pressures after PDA ligation resulted in an abrupt reduction in left main coronary artery blood flow. After prompt resuscitation, cardiac catheterization confirmed the diagnosis of anomalous origin of the left coronary artery from the pulmonary artery. The infant subsequently underwent coronary artery translocation and recovered uneventfully.