3 - RCA distal

The distal right coronary artery (dRCA; RCA distal; Segment 3; R3) refers to the segment of the right coronary artery (RCA) following the mid right coronary artery that courses beyond the acute marginal branches, typically after the vessel passes the crux of the heart, and extends toward its terminal branches.

In most individuals, this includes the portion of the RCA that gives rise to the posterior descending artery (PDA) and, when present, the posterior right diagonal artery (PRDA), as well as any terminal branches supplying the inferior and posterior aspects of the right ventricle and interventricular septum. The distal RCA is the site of origin for branches that supply the inferior wall of the heart and the posterior third of the interventricular septum, particularly in right-dominant coronary circulation.