What is the range of the AV node rate?

The atrioventricular (AV) node serves as an important electrical relay station in the heart, facilitating the passage of impulses from the atria to the ventricles. The intrinsic firing rate of the AV node typically ranges from 40 to 60 beats per minute (BPM). This rate is crucial because, under normal conditions, the AV node acts as a backup pacemaker when the primary pacemaker, the sinoatrial (SA) node, is either not firing or is firing at a rate that is not sufficient for the heart's needs.

When the SA node's impulses are blocked or not present, the AV node can take over pacing the heart at its inherent rate. This ensures that the heart continues to beat, although at a slower pace than normal, which is a vital mechanism in maintaining circulation during episodes of bradycardia or in various forms of heart block.

Understanding the rate of the AV node is essential for identifying and managing various cardiac arrhythmias.