An Anomalous LAD Originating Separately From Right Coronary Sinus: A Case Report

Area of Science:

• Cardiology
• Radiology
• Anatomical Pathology

Background:

• Anomalous aortic origin of a coronary artery from the opposite sinus of Valsalva (ACAOS) is a rare congenital heart defect.
• Anomalous origination of the left anterior descending branch (LAD) from the right sinus (LAD-ACAOS) is an exceptionally rare subtype of ACAOS.

Observation:

• A 71-year-old male presented with acute non-ST elevation myocardial infarction (NSTEMI).
• Invasive coronary angiography (CAG) and computed tomography angiography (CTA) revealed LAD-ACAOS with a pre-pulmonary course and myocardial bridging (MB).
• The anomalous LAD originated from the right sinus with a high ostium, coursing anteriorly around the pulmonary conus before entering the interventricular groove.

Findings:

• The case demonstrates a rare pre-pulmonary subtype of LAD-ACAOS with a high ostium in the right sinus of Valsalva.
• Myocardial bridging was identified in the mid-part of the anomalous LAD.
• This anatomical variation, despite being a non-interarteries anomaly, was associated with acute myocardial infarction, challenging the notion of benignity.

Implications:

• Accurate diagnosis of LAD-ACAOS requires high suspicion and advanced imaging modalities like CTA, as it can be missed by conventional CAG.
• The presence of myocardial bridging in conjunction with LAD-ACAOS may increase the risk of myocardial ischemia.
• This case underscores the importance of recognizing rare coronary anomalies and their potential clinical consequences, even in the absence of typical interarterial course.