Atrioventricular Node (AV Node) — ECG/EKG Terminology

Definition: Specialized tissue between the atria and ventricles that delays electrical impulses slightly, allowing the atria to finish contracting before the ventricles begin.

Key Facts

• Located between the atria and ventricles
• Deliberately slows the electrical impulse
• This delay allows ventricles to fill before they contract
• Acts as a backup pacemaker at 40-60 bpm if SA node fails

ECG Connection: The AV node's delay creates the brief pause you see between the P wave and QRS complex on the ECG (the PR interval).

Why It Matters: PR interval changes point to AV node delay or block—important findings for clinical decision-making.