Conduction System

The conduction system of the heart is composed of the SA or Sino atrial node, AV node and Bundle of His. Understanding of the structure of the conduction system is important for the interpretation of the electrocardiogram.

The conductions system is composed of the SA node, internodal tracts, AV node and bundle of his. The electrical impulse also conducts through the myocardium in the atrium and ventricles.

Atrial Conduction System

The SA node or Sino Atrial Node is located in the right atrium near the junction with the SVC (Superior Vena Cava).

There are 3 internodal tracts that run from the SA node to the AV node, named Anterior, Middle and Posterior Internodal tract respectively and one conduction tract that innervates the left atrium called Bachmann's Bundle.

The AV node (Atrioventricular) is located between the atria and ventricles. The conduction system continues down the ventricles through the bundle of his.