Which artery typically supplies the inferior portion of the heart?

• A. Posterior Descending Artery
• B. Right Coronary Artery
• C. Left Circumflex Artery
• D. Left Anterior Descending Artery

Answer: (A)

Blood flow to the heart’s inferior (diaphragmatic) surface is provided mainly by the posterior descending artery, which runs in the posterior interventricular groove to supply the inferior wall and the posterior part of the interventricular septum. In the majority of people, this artery arises from the right coronary artery, reflecting right-dominant circulation, which is why the posterior descending artery is the typical supplier of the inferior portion. In left-dominant hearts, a branch from the left circumflex artery can give rise to a PDA, but that’s less common. The left anterior descending supplies the anterior wall and front part of the septum, and the left circumflex and right coronary arteries mainly feed other regions. So the posterior descending artery is the vessel that typically supplies the inferior portion.