Discussion.
CAAs are rare cardiac anomalies, with an incidence rate of <1% and are often misdiagnosed as sickle cell crisis in patients with a history of sickle cell disease or trait (3). With the exception of a coronary artery traversing between the aorta and pulmonary trunk potentially causing sudden death at a young age due to extrinsic coronary occlusion, CAAs usually carry minimal clinical significance. In a study conducted by Taylor et al., it was demonstrated that 25% of CAAs culminated in asymptomatic sudden death, with autopsies showing evidence of repetitive episodes of minor myocardial infarctions - diffuse necrosis and myocardial fibrosis (4). Obstruction of blood flow can be due to multiple causes - 1) obstruction of the coronary ostium due to slit-like morphology, 2) the aorta and pulmonary trunk compressing the right coronary artery and 3) aortic and pulmonary arterial distension leading to stretching and increased tension of the right coronary artery (5). CT coronary angiogram is advantageous over ECG and conventional coronary angiography as it detects not only the extent and site of stenosis, but also the ectopic origin and course of the anomalous coronary artery. An increase of CAAs have been diagnosed since the advent of CT coronary angiography (6).