Which coronary artery is responsible for supplying the SA and AV nodes of the heart?

• A. Left coronary artery
• B. Right coronary artery
• C. Circumflex artery
• D. Anterior interventricular artery

Answer: (B)

The right coronary artery is primarily responsible for supplying the sinoatrial (SA) node and the atrioventricular (AV) node in most individuals. The SA node, which is the heart's natural pacemaker, is typically supplied by a branch of the right coronary artery in roughly 60% of the population, particularly in those where the right dominant coronary circulation is present. Additionally, the AV node receives its blood supply from the right coronary artery in the majority of cases as well.

Understanding the coronary artery system is crucial for various medical applications, including the management of ischemic heart diseases. In many patients, especially those with a right dominant coronary system, occlusions in the right coronary artery can lead to significant rhythm disturbances due to the compromised blood supply to these critical nodes.

In contrast, the left coronary artery mainly supplies the left atrium and left ventricle, while the circumflex artery predominantly feeds the lateral wall and posterior aspects of the heart. The anterior interventricular artery, also known as the left anterior descending artery (LAD), supplies the anterior part of the heart and interventricular septum, but does not play a significant role in supplying the SA and AV nodes.