What is referred to by Wenchbach AV block?

Wenckebach AV block, also known as Mobitz type I, represents a specific form of 2nd degree AV block characterized by a progressive prolongation of the PR interval until a beat is dropped (a QRS complex is not conducted). This phenomenon occurs due to a gradual increase in the refractory period of the AV node, leading to the failure of conduction at irregular intervals.

In Wenckebach, the pattern is distinctive: patients typically present with a regular rhythm but experience missed beats at regular intervals. The distinctive pattern of the gradually lengthening PR interval followed by a dropped beat helps differentiate it from other types of AV blocks.

This type of block can occur in a variety of situations, including during sleep, as a result of increased vagal tone, or in the setting of myocardial ischemia, especially in the context of inferior myocardial infarctions. Recognizing this specific type of block is essential for understanding cardiac conduction issues and for determining appropriate clinical management.

In contrast, the other types mentioned, such as 3rd degree AV block, would result in a complete disassociation between the atrial and ventricular activity, leading to a more severe condition. Normal sinus rhythm indicates a healthy heart rhythm without block, while flutter rhythm signifies a