What does a PR interval of 0.24 seconds indicate in a telemetry assessment?

What does a PR interval of 0.24 seconds indicate in a telemetry assessment?

• A. Normal sinus rhythm
• B. First degree AV block
• C. Second degree AV block
• D. Complete heart block

Answer: (B)

A PR interval of 0.24 seconds indicates a first-degree AV block. The PR interval represents the time taken for electrical impulses to travel from the atria to the ventricles. A normal PR interval ranges from 0.12 to 0.20 seconds. When the PR interval measures more than 0.20 seconds, it signifies a delay in conduction through the AV node, which characterizes first-degree AV block. In this case, the duration of 0.24 seconds indicates that the conduction delay is present but not severe enough to meet the criteria for a second-degree AV block, where the conduction disturbances are more pronounced, often leading to dropped beats. A complete heart block would result in a dissociation between atrial and ventricular activity, leading to a much different clinical picture. Therefore, the prolonged PR interval in this telemetry assessment is indicative of a first-degree AV block.

A PR interval of 0.24 seconds indicates a first-degree AV block. The PR interval represents the time taken for electrical impulses to travel from the atria to the ventricles. A normal PR interval ranges from 0.12 to 0.20 seconds. When the PR interval measures more than 0.20 seconds, it signifies a delay in conduction through the AV node, which characterizes first-degree AV block.

In this case, the duration of 0.24 seconds indicates that the conduction delay is present but not severe enough to meet the criteria for a second-degree AV block, where the conduction disturbances are more pronounced, often leading to dropped beats. A complete heart block would result in a dissociation between atrial and ventricular activity, leading to a much different clinical picture. Therefore, the prolonged PR interval in this telemetry assessment is indicative of a first-degree AV block.