Abstract Body (Do not enter title and authors here): Introduction:Anomalous Left Coronary Artery Arising from the Pulmonary Artery (ALCAPA), also known as Bland-White-Garland syndrome, is a rare congenital anomaly(incidence:1 in 300,000 live births) typically presenting during infancy. Adult presentations are even rarer due to a high mortality rate of nearly 90% in the first year of life without surgical intervention. This report examines an adult patient with exercise-induced chest pain who received a delayed diagnosis of ALCAPA via multimodal imaging.
Case Summary:A 21-year-old male presented to the emergency department(ED) with severe retrosternal chest pain radiating to both shoulders and arms, which began during exercise 30 minutes prior. He had a history of similar, milder episodes during exercise, previously treated as musculoskeletal pain and gastroesophageal reflux disease in the ED. His medical, social, and family histories were unremarkable. Physical examination revealed a soft, continuous murmur along the left sternal border. During this visit, An EKG done showed sinus tachycardia at 110 bpm and deep T-wave inversions in the anterolateral leads, a dynamic ST-T changes from his baseline.Serial Cardiac biomarkers and a lipid profile were within normal ranges. Initially managed for acute coronary syndrome-unstable angina with antithrombotic therapy, beta-blockers, and nitrates, he underwent urgent coronary angiography. This revealed a dilated right coronary artery (RCA) with retrograde flow to the left coronary artery (LCA) into the main pulmonary artery (PA) via collaterals, with no evidence of atherosclerosis (Figure 1).Echocardiography (Figure 2) and coronary CT angiography (Figure 3) confirmed the diagnosis of ALCAPA. The patient underwent successful surgical repair with aortic reimplantation of the LCA and was discharged in good health.
Discussion:
In adult ALCAPA patients, good collateral circulation may develop; however, myocardial ischemia can occur due to the "coronary steal phenomenon" and poor collateral flow regulation, leading to angina, arrhythmias, and sudden cardiac death. ALCAPA should be considered a differential diagnosis in adults presenting with exercise intolerance, as most sudden cardiac death cases occur by the fourth decade. A high index of clinical suspicion and a multimodality imaging approach is essential for the early diagnosis of this rare coronary anomaly, underscoring the critical role of early surgical intervention in preventing catastrophic, life-threatening events.