Large sub-mitral aneurysm compressing the left circumflex coronary artery presenting with atypical chest pain - Rare presentation.

Sub-mitral aneurysm (SMA) is a rare cardiac malformation commonly reported in young adults of African ancestry. SMA is considered a congenital disease caused by developmental defect due to weakness at the atrioventricular junction near the posterior mitral annulus. In the past two decades, a considerable number of cases regarding this rare disease have been reported in Asians, highlighting the importance of considering SMA in differential diagnosis of young patients presenting with mitral regurgitation and chest pain. Herein, we report the case of a young male with atypical chest pain with compression of left circumflex coronary artery by a large SMA. < Sub-mitral aneurysm is a rare cardiac malformation, caused by developmental defect due to weakness at the atrioventricular junction near the posterior mitral annulus. Patients may be entirely asymptomatic, or they can present with mitral regurgitation with or without left ventricular dysfunction, heart failure, systemic thromboembolism, ventricular wall rupture causing tamponade, myocardial ischemia due to compression of coronary arteries, ventricular arrhythmias, or sometimes sudden cardiac death. Strong suspicion and early diagnosis followed by surgery can prevent sudden cardiac death.>.