Absence of the Left Circumflex Artery in Congenital Heart Disease With Vasospastic Myocardial Infarction

Congenital absence of the left circumflex artery (LCx) is extremely rare, and we have limited understanding of its mechanisms, diagnosis challenges, and clinical implications.

A 36-year-old woman with a history of atrioventricular septal defect repair presented with recurrent chest pain. High-sensitivity cardiac troponin T was 0.441 ng/mL (reference range: <0.014 ng/mL), and the electrocardiography showed ST-segment depression in V₁-V₄. Coronary angiography revealed congenital absence of the LCx, with perfusion from the right coronary artery (RCA). Severe stenosis in the posterolateral branch originating from the RCA resolved after nitroglycerin administration, confirming coronary spasm as the underlying cause of the myocardial infarction.

This case highlights the clinical importance of congenital LCx absence, its link to congenital heart defects and coronary spasm, and the crucial role of detailed imaging in diagnosis and management.