atrioventricular nodal artery

The atrioventricular (AV) nodal artery is a small but critical coronary artery that supplies blood to the atrioventricular node, the specialized cardiac tissue responsible for conducting electrical impulses from the atria to the ventricles.

In the majority of people (approximately 80–90%), the AV nodal artery branches from the right coronary artery at the crux of the heart, which is the posterior intersection of the interventricular and atrioventricular grooves. In the remaining individuals with left-dominant circulation, it arises from the left circumflex artery.

Occlusion of the AV nodal artery can cause ischemia of the AV node, leading to atrioventricular conduction disturbances such as first-degree, second-degree, or complete (third-degree) heart block. This is commonly seen in inferior myocardial infarctions caused by right coronary artery occlusion.

Knowing the coronary dominance pattern determines which artery supplies the AV node. In right-dominant individuals, inferior MI (right coronary artery territory) is more likely to cause AV block than anterior MI. Identifying this relationship guides prognosis and management of conduction disturbances after myocardial infarction.

Yes, these terms are used interchangeably. It is a small branch that specifically targets the AV node, distinct from the larger septal perforating branches that supply the bundle of His and bundle branches, though all these structures form the cardiac conduction system.