What is the heart rate range for a 3rd degree AV block?

In a third-degree AV block, also known as complete heart block, the atria and ventricles beat independently of each other due to a failure of the conduction pathway between the atria and ventricles. This results in a dissociation between the electrical signals in these two chambers of the heart.

The heart rate observed in third-degree AV block typically ranges from 20 to 40 beats per minute in most cases because the ventricles are usually reliant on an intrinsic pacemaker that is lower in rate. Sometimes, the rate can be slightly higher if there is a junctional escape rhythm present, but it rarely exceeds 60 beats per minute. Therefore, stating the heart rate range as 60 - 100 bpm would be incorrect given this context, as that range is characteristic of normal or accelerated rhythms.

The correct heart rate range in a third-degree AV block reflects the characteristic bradyarrhythmia of the condition, where the ventricular rate is significantly slowed due to the reliance on an inherent pacemaker within the ventricles, which is not capable of maintaining a higher heart rate. Hence, the focus is on recognizing that rates in third-degree AV block tend to be slower, specifically within the traditionally recognized spectrum of 20 to 40 bpm or slightly higher