Question

Damage to the AV node could cause

A. the absence of the T wave on an ECG.
B. multiple Q waves on an ECG.
C. multiple T waves on an ECG.
D. multiple P waves on an ECG.

Answer 1

Damage to the AV node can cause a third-degree or complete block, resulting in no correlation between atrial and ventricular activity on an ECG. This can lead to a slower heart rate as the AV node takes over as a pacemaker.

Step-by-step explanation:

The damage to the AV node can result in a third-degree or complete block, where there is no correlation between atrial activity (P wave) and ventricular activity (QRS complex) on an ECG. In this type of block, some impulses initiated by the SA node do not reach the AV node, while others do. As a result, the P waves are not followed by the QRS complex.

This condition can significantly affect heart rate (pulse). In a third-degree block, the heart rate may become slower because the impulses from the SA node are not reaching the ventricles consistently, and the AV node takes over as a pacemaker with a slower intrinsic rate of 40-60 contractions per minute.