Posterior interventricular artery
Ramus interventricularis posterior
Also known as: posterior descending artery, PDA
The posterior interventricular artery runs in the posterior interventricular groove from the crux toward the apex. It supplies the inferior left ventricular wall and the posterior third of the septum, and the artery that gives rise to it defines coronary dominance.
Overview
The artery descends in the posterior interventricular sulcus next to the middle cardiac vein. Its septal branches supply the posterior third of the interventricular septum, including part of the AV conduction tissue. Its ventricular branches supply the adjacent inferior walls of both ventricles and usually the posteromedial papillary muscle. Near the apex it anastomoses with the terminal LAD.
It arises from the RCA in about 70–80% of hearts (right dominance), from the circumflex in about 5–10% (left dominance), and from both in about 10–20% (codominance).
Anatomy
- Course
It starts at the crux, usually as the continuation of the RCA, and runs in the posterior interventricular sulcus toward the apex.
Function
- Supplies the inferior (diaphragmatic) walls of both ventricles.
- Supplies the posterior third of the interventricular septum.
- Usually provides the only supply to the posteromedial papillary muscle.
Clinical significance
Inferior MI and papillary muscle rupture
Occlusion of the posterior interventricular artery, or of the artery it comes from, causes an inferior MI. Because the posteromedial papillary muscle usually depends on this single artery, it is the papillary muscle most likely to rupture.
Compiled from standard anatomy and physiology references — see the Cardiovascular System sources. For education only; not medical advice.