Which node is supplied by the Right Coronary Artery in 55% of individuals?

The correct answer is the Sinoatrial (SA) node. The SA node is known as the natural pacemaker of the heart, responsible for initiating the electrical impulses that trigger heartbeats. In approximately 55% of individuals, the right coronary artery provides blood supply to the SA node. This is particularly significant in the context of cardiac function and rhythm regulation, as a well-perfused SA node is essential for maintaining normal heart rate and rhythm.

The reason this particular coronary artery has a higher incidence of supplying the SA node is related to the dominance of the coronary circulation, which varies among individuals. In most right-dominant coronary systems, the right coronary artery supplies the right atrium and parts of the conduction system, including the SA node.

Understanding the anatomy and blood supply of the heart's conduction system is crucial for recognizing how ischemia or other cardiac events can impact heart function. In the scenarios where the SA node is compromised due to lack of adequate blood supply, this can lead to various arrhythmias, further emphasizing the importance of the right coronary artery in cardiovascular health.