Single coronary artery (SCA) is a rare anomaly, usually diagnosed incidentally during coronary artery angiogram. Individuals with this anomaly mostly remain asymptomatic while some present with symptoms such as chest pain, dyspnoea and even sudden death. The origin and the proximal course of anomalous coronary artery are the main prognostic factors. Several classification systems have been proposed based on the site of origin and anatomical distribution of anomalous artery. Coronary computed tomography angiography has become the reference method for such an assessment noninvasively. Herein, we report a series of two cases of SCA diagnosed on CT angiography. In one case it was single left coronary artery associated with other congenital cardiac anomalies, whereas in other it was single right coronary artery and was an isolated anomaly.
Our first case was of a 19-year-old female who presented with chest pain and dyspnoea. Transthoracic Echocardiography (TTE) features were suggestive of Tetralogy of Fallot (TOF) with infective endocarditis. Cardiac CT angiography revealed the presence of a large SCA arising from left aortic sinus with absence of normal origin of right coronary artery (RCA). This artery was dividing into and supplying different coronary arterial territories with pre-pulmonic course of RCA. The patient underwent Aortic valve replacement with pulmonary Commissurotomy and improved in post-operative period. Our second case was of a 50-year-old man with complaints of breathlessness and normal ECG and Echocardiography examination findings. Coronary CT angiography revealed the presence of SCA arising from right aortic sinus and supplying the territories of both RCA and Left coronary artery (LCA). The patient was managed conservatively with emphasis on aggressive control of risk factors.
SCA is a rare anomaly and may lead to catastrophic life threatening complications. The accurate delineation of the origin and course of the anomalous vessel is of paramount importance while planning surgical intervention. Management usually involves a multi-disciplinary approach with cardiologists and cardiac surgeons aiming for deciding an individual plan based on presentation and anatomy of each case.