A case report of reversible dilated cardiomyopathy due to left main coronary artery ostial stenosis: optimal imaging is key.

Background: Congenital coronary artery anomalies are a rare but reversible cause of dilated cardiomyopathy in infants and children. Optimal imaging strategies to efficiently identify and confirm the diagnosis in the setting of extracorporeal membrane oxygenation (ECMO) are crucial to timely surgery. Case summary: A 2-month-old boy presented with dilated cardiomyopathy and severe left ventricular dysfunction requiring ECMO support. During an unsuccessful ECMO wean, turbulent flow was noted at the origin of the left coronary artery on echocardiography with subsequent computed tomography (CT) angiogram and cardiac angiogram via catheter confirming the very rare diagnosis of left main coronary artery ostial stenosis. He underwent emergency left coronary artery augmentation with excellent outcome. Discussion: A high index of suspicion for coronary artery anomalies is required for infants presenting with suspected dilated cardiomyopathy. While CT is a potential diagnostic tool for investigating coronary abnormalities in children, image optimization on ECMO is challenging, with further imaging often required. The superior spatial and temporal resolution of cardiac angiography via catheterization allows definitive diagnosis of coronary artery abnormalities in this situation and facilitates timely surgical intervention.