Question

In an ECG pattern, the PQ interval indicates how long it takes for the cardiac impulse to travel from the

A. SA node to the atrial muscle fibers.
B. SA node to the Purkinje fibers.
C. AV node to the atrial muscle fibers
D. SA node through the AV node.

Answer 1

The PQ interval, also known as the PR interval, in an ECG pattern signifies the duration it takes for the electrical impulse to travel from the SA node through the AV node, represented by option D. in your multiple-choice question.

Step-by-step explanation:

In an ECG pattern, the PQ interval, more commonly referred to as the PR interval, indicates the time it takes for the cardiac impulse to travel from the SA node through the AV node. The correct option is D. SA node through the AV node. During a cardiac cycle, following the depolarization of the atria represented by the P wave, there is a passage of the impulse through internodal pathways to the atrioventricular node.

The PR interval includes both the P wave and the subsequent PR segment, with the latter representing the delay in the AV node that allows the atria to complete their contraction before the ventricles begin to contract. This is reflected in the ECG pattern and is an important indicator of the conduction system's functionality. If there is an abnormal prolongation of the PR interval, it can indicate a first-degree AV block.