Atrioventricular (AV) node

The atrioventricular (AV) node is a part of the electrical control system of the heart, propagating the electric signals in the atria to the ventricles.

The AV node is a collection of specialized cells in the posteroinferior region of the interatrial septum near the opening of the coronary sinus. The AV node conducts the normal electrical impulses generated by the SA node and passing inferiorly through the atria to the ventricles.

The AV node is quite compact (~1 x 3 x 5 mm). It is located at the center of Koch's Triangle—a triangle enclosed by the septal leaflet of the tricuspid valve, the coronary sinus, and the membraneous part of the interatrial septum.

The AV node's intrinsic firing rate (without stimulation from the SA node) is 40-60 times/minute.