Myocardial Infarction in a Young Adult: A Rare Case of Left Coronary Artery Arising from the Pulmonary Artery

Anomalous origin of the Left Coronary Artery from the Pulmonary Artery (ALCAPA), also known as Bland-White-Garland syndrome, is a rare congenital coronary anomaly with an estimated incidence of 1 in 300,000 live births. While commonly diagnosed in infancy, adult presentations are exceedingly rare and pose significant diagnostic challenges. Delayed diagnosis may result in progressive myocardial ischemia, heart failure, arrhythmias, or sudden cardiac death. Surgical correction is the definitive treatment, with the goal of restoring a dual coronary artery system and preventing irreversible myocardial damage. We present the case of a 30-year-old male with a prior history of non-ST-elevation myocardial infarction who was referred for evaluation of exertional angina and symptoms of heart failure. Transthoracic echocardiography revealed a dilated left ventricle with an ejection fraction (LVEF) of 35%. Coronary angiography and cardiac MDCT identified an anomalous origin of the left circumflex artery (LCx) from the right pulmonary artery (RPA) and a coronary-pulmonary artery fistula involving the LAD. The patient underwent successful surgical correction with reimplantation of the LCx into the ascending aorta. Postoperative recovery was uneventful. At 3-month follow-up the patient was symptom-free, though echocardiography revealed persistent LV dilation and reduced LVEF, necessitating continued pharmacologic therapy and monitoring. This case highlights the importance of maintaining a high index of suspicion for ALCAPA in adult patients with unexplained cardiomyopathy or ischemic symptoms. Early diagnosis and surgical intervention remain crucial for improving long-term outcomes and preventing life-threatening complications.