P0398 - Late presentation of asymptomatic anomalous origin of the Left Coronary Artery from the Pulmonary Artery

Introduction
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly that typically manifests during infancy with heart failure secondary to myocardial ischemia. Late presentation of ALCAPA is rare but may occur if well-developed collateral circulation exists. We present the unusual occurrence of this in an older child with no signs of cardiac ischemia.

Case Description
An 11-year-old male was referred for cardiac consultation secondary to a murmur heard on sports physical evaluation. The patient was asymptomatic with no significant medical history or medication use. Physical exam was significant for a 3/6 holosystolic murmur to the left upper sternal border. EKG was normal. Transthoracic echocardiogram was done and revealed anomalous left coronary artery from the pulmonary artery with severe dilation of the left and main coronary artery structures. Cardiac dimensions and ventricular function were normal. He underwent surgical repair with reimplantation of the anomalous LCA to the aorta. His ICU course was complicated by ventricular tachycardia for which he was started on propranolol. A follow up clinic visit revealed new ST segment changes on EKG and echocardiogram at that time was concerning for flow reversal in the left main and left anterior descending coronary arteries. Cardiac catheterization was thus performed and demonstrated markedly abnormal coronary arteries with diffuse dilation/ectasia and sluggish filling of the LAD but no significant stenosis at the surgical anastomosis site. Exercise stress test and stress echocardiogram were subsequently performed with normal results. Follow up Holter was normal and propranolol was discontinued. He remains asymptomatic on aspirin therapy.

Discussion
Surgical treatment with the aim of creating a dual coronary arterial system is the treatment of choice for ALCAPA with options for repair including the Takeuchi operation, use of extracardiac arterial blood supply or direct reimplantation of the LCA.

While surgical repair is a clear choice in those with symptomatic presentations, the role of revascularization in an asymptomatic patient with functional collateral coronary vessels and subclinical myocardial ischemia remains somewhat contentious. Literature in the adult population suggests that myocardium supplied by longstanding ischemic vasculature may be permanently scarred and unable to regain function despite intervention. Furthermore, there remains risk of lethal ventricular arrythmias and high incidence of sudden death at a young age.

While the benefits of surgical revascularization were weighed against risks of surgery in this case ultimately the patient underwent reimplantation of the LCA in hopes of preventing further suboptimal coronary perfusion.

Conclusion: This case report presents the late diagnosis of anomalous left coronary artery from the pulmonary artery and the associated challenge of determining the need for surgical revascularization in the absence of symptomatology.