Malignant non-dominant RCA arising from left coronary sinus

This pre-menopausal lady with vague chest pain came for a cardiac CT. Her scan was normal, except for the RCA arising from the left coronary sinus and coursing between the RVOT and aorta (Fig. 1). There is also mild narrowing of the proximal RCA, where it gets compressed between the two vessels (Fig. 2).

The RCA however was non-dominant ending in the mid-portion. Moreover the patient had no objective cardiac symptoms and a subsequent stress test was normal.