Question

_________ AV node block occurs when the rate of impulse conduction through the AV node exceeds 0.20 second.

A. First-degree
B. Second-degree
C. Third-degree
D. Fourth-degree

Answer 1

The correct answer is A. First-degree AV node block, which is characterized by a delay in conduction between the SA and AV nodes, resulting in an abnormally long PR interval on an ECG.

Step-by-step explanation:

Atrioventricular (AV) node block is a condition affecting the electrical conduction system of the heart, where the transmission of impulses through the AV node is impaired. In the case of an AV node block occurring when the rate of impulse conduction through the AV node exceeds 0.20 second, the correct answer is A. First-degree.

A first-degree AV block is indicated by a delayed conduction between the SA and AV nodes, which manifests on an ECG as an abnormally long PR interval.