All coronaries from the right coronary cusp

This 36-years old man with atypical chest pain came for a cardiac CT. He had no coronary artery disease, but extremely unusual anatomy.

The RCA was normal (Figs. 1, 2). The LAD arose from the right coronary cusp and directly coursed into the interventricular groove (Fig. 1, 4). It was a small type 1 vessel. The circumflex (CX) arose just posterior to the RCA origin and took a retro-aortic course (Figs. 3-5). It gave off a diagonal like branch and then the obtuse marginals.