Right posterior descending

The right posterior descending coronary artery (Right PDA; RD; Segment 04; R4) arises from the right coronary artery (RCA) and courses in the posterior interventricular sulcus toward the apex of the heart. It supplies the posterior third of the interventricular septum and adjacent portions of the right and left ventricles. In approximately 80% of individuals, the right coronary artery gives rise to the posterior descending artery, a pattern referred to as "right dominance". The right PDA gives off perpendicular branches known as posterior septal perforators, which supply the posterior one third of the ventricular septal wall.

The dominance of the coronary circulation is determined by which artery gives rise to the posterior descending artery; in right-dominant systems, this is the RCA, while in left-dominant systems, the left circumflex artery provides the PDA.