A rare variant of single coronary artery and non-obstructive hypertrophic cardiomyopathy.

A single coronary artery (SCA) constitutes a rare congenital anomaly. The reported incidence of SCA ranges from 0.2 1.6% of the population undergoing coronary angiography. The congenital absence of the ostium of the right coronary artery (RCA) with the origin of the RCA as a continuation of the distal circumflex artery is an extremely rare variant of the SCA. Its real incidence is unknown. We report a case of a 38-year-old white female with non-obstructive hypertrophic cardiomyopathy associated with SCA, in which the RCA arises as an extension of the circumflex artery.