Organ
Atrioventricular node
A controlled delay between atrial and ventricular activation
High-yield
The AV node delays conduction and limits how many rapid atrial impulses reach the ventricles.
Overview
At the upper part of Koch's triangle, atrial muscle connects through transitional tissue with the compact AV node. Slow conduction here spaces ventricular activation after atrial activation. The node continues into the His bundle, which crosses the fibrous insulation of the atrioventricular junction.
Reference facts
- Location
- Near the apex of Koch's triangle on the right atrial septal aspect
- Parts
- Compact nodal tissue, transitional atrial connections and inferior extensions
- Blood supply
- An AV nodal artery, usually from the right coronary artery; circumflex origins also occur
- Innervation
- Sympathetic cardiac input generally facilitates conduction; vagal input slows it
- Relations
- Close to the septal tricuspid attachment and the region of the coronary sinus opening
- Function
- Delays atrioventricular transmission; the AV junction can provide a subsidiary rhythm
Clinical correlation
AV nodal re-entry uses pathways with different conduction properties. Conduction disease or injury near this region can cause AV block; the clinical significance depends on the disturbance and its level.
Frequently asked questions
Where is the atrioventricular node located?
The atrioventricular node lies near the apex of Koch's triangle on the right atrial septal aspect.
What does the atrioventricular node do?
Delays atrioventricular transmission; the AV junction can provide a subsidiary rhythm.
What are the parts of the atrioventricular node?
The parts of the atrioventricular node are the compact nodal tissue, transitional atrial connections and inferior extensions.
What is the blood supply of the atrioventricular node?
An AV nodal artery, usually from the right coronary artery; circumflex origins also occur.