Question

In an EKG, you note the presence of more P waves than QRS complexes and the absence of a relationship between P waves and QRS complexes. What type of atrioventricular block is most likely present?

1) First-degree AV block
2) Second-degree AV block
3) Third-degree AV block
4) Bundle branch block

Answer 1

The presence of more P waves than QRS complexes and the lack of correlation between the two in an EKG indicates a third-degree AV block.

Step-by-step explanation:

When an electrocardiogram (EKG) reveals more P waves than QRS complexes with no discernible relationship between them, it is indicative of a third-degree atrioventricular (AV) block, commonly known as complete heart block. In this condition, there is a complete failure of atrial electrical impulses to conduct to the ventricles.

Typically, the atria and ventricles in a healthy heart beat in a synchronized manner, with each atrial contraction followed by a ventricular contraction. However, in a third-degree AV block, the atria and ventricles beat independently of each other. The AV node or another pacemaker site distal to the AV node takes over as the pacemaker for the ventricles, but at a much slower rate than the atria, which continue to be paced by the sinoatrial (SA) node.

This lack of coordination between atrial and ventricular contractions can lead to significant disruptions in the normal functioning of the heart and may require medical intervention.