Congenital absence of the left circumflex coronary artery and an unusually dominant course of the right coronary artery.

Congenital absence of the left circumflex artery (LCX) is a very rare congenital anomaly of the coronary circulation, and only a few cases have been reported in the literature. We report on a 55-year-old female with atypical chest pain. Routine coronary angiography showed a normal left anterior descending coronary artery (LAD), no LCX and a dominant right coronary artery (RCA), which continued beyond the crux, running the full course of the LCX and terminating in the left atrial branch. Neither aortography nor pulmonary angiography showed a separate ostium for the LCX. There were no atherosclerotic lesions in the coronary arteries, or ischaemia on stress myocardial perfusion imaging. Multidetector row computed tomography (MDCT) was performed to confirm the diagnosis.