What is the conduction velocity of the AV node?

What is the conduction velocity of the AV node?

• A. 0.4 m/s
• B. 1 m/s
• C. 2 m/s
• D. 0.2 m/s

Answer: (A)

Conduction velocity through the AV node is intentionally slow to create a delay between atrial and ventricular activation. This AV delay gives the atria time to contract and top off the ventricles with blood before they pump. In teaching resources, the AV node is described as conducting at about 0.4 m/s, which is slower than atrial muscle (roughly 1 m/s) and much slower than the His-Purkinje system (several m/s). That slower velocity is what produces the PR interval seen on the ECG. So 0.4 m/s is the value used to represent this nodal delay, reflecting the AV node’s role as the gatekeeper between atrial and ventricular conduction.

Conduction velocity through the AV node is intentionally slow to create a delay between atrial and ventricular activation. This AV delay gives the atria time to contract and top off the ventricles with blood before they pump. In teaching resources, the AV node is described as conducting at about 0.4 m/s, which is slower than atrial muscle (roughly 1 m/s) and much slower than the His-Purkinje system (several m/s). That slower velocity is what produces the PR interval seen on the ECG. So 0.4 m/s is the value used to represent this nodal delay, reflecting the AV node’s role as the gatekeeper between atrial and ventricular conduction.