The posterior aspect of the heart shows a barium injection of the left coronary artery with the distal branches of the circumflex overlaid in red in (b). The 2nd, 3rd and 4th obtuse marginal arteries that supply the lateral and posterior parts of the left ventricle are overlaid in red. The right coronary artery branches (all branches in white in b) is dominant since it supplies the PDA, A-V nodal and posterior left ventricular branch. These will be detailed below.

Courtesy: Ashley Davidoff, M.D.