Anomalous origin of the left coronary artery from pulmonary artery mimicking antero-lateral ST-elevation myocardial infarction: a case report.

Background: Anomalous origin of the left coronary artery (LCA) from the pulmonary artery (PA) (ALCAPA) is a rare congenital abnormality. We present a case of an ALCAPA in a 25-year-old man.

Case summary: A 25-year-old male with no past medical history was admitted to our intensive cardiac care unit after sudden cardiac arrest due to ventricular fibrillation and suspected acute coronary syndrome. After being treated with shock by automated external defibrillator, an electrocardiogram (ECG) demonstrated sinus tachycardia with antero-lateral ST-segment elevation. Initial transthoracic echocardiography showed severe and diffuse left ventricular dysfunction and dilatation. Coronary angiography revealed anomalous origin of the LCA from the PA and extensive collateral circulation from a giant RCA. An ECG-gated cardiac computed tomography confirmed the diagnosis of anomalous left main originating from the left PA. Cardiac magnetic resonance demonstrated an enlarged left ventricle with globally reduced function and extensive sub-endocardial scarring of the anterior, antero-lateral, and lateral walls. Following a multidisciplinary heart team discussion, the patient successfully underwent repair of aberrant LCA with direct LCA re-implantation to the aorta and subcutaneous implantable cardioverter defibrillator implantation. Optimal medical therapy for heart failure with reduced ejection fraction was initiated, and the patient was discharged home for a close clinical and echocardiographic follow-up.

Discussion: In conclusion, ALCAPA in the adulthood is a very rare congenital anomaly that clinicians should be aware of. The preferred treatment, when diagnosed in time, is direct re-implantation of the LCA to the aorta.