What is the maximum duration of a normal PR interval?

The maximum duration of a normal PR interval is 0.20 seconds. The PR interval represents the time taken for electrical impulses to travel from the atria to the ventricles, encompassing the conduction through the AV node. A normal PR interval typically ranges from 0.12 to 0.20 seconds. When the PR interval exceeds 0.20 seconds, it may indicate a first-degree AV block, which is a slowing of conduction through the AV node.

In the context of this question, the interval being measured is significant for assessing the heart's electrical activity and identifying potential conduction abnormalities. Understanding the normal values for the PR interval is crucial for interpreting ECGs in clinical practice.