How does a first degree AV block appear on an EKG?

How does a first degree AV block appear on an EKG?

• A. Prolonged PR interval of greater than 0.2 seconds
• B. Normal PR interval
• C. Absent P waves
• D. Prolonged QT interval

Answer: (A)

A first-degree AV block is characterized by a prolonged PR interval, specifically one that exceeds 0.2 seconds. This finding indicates a delay in conduction through the atrioventricular (AV) node, thereby extending the time it takes for electrical impulses to travel from the atria to the ventricles.

In the context of an EKG, you will observe consistently prolonged PR intervals across multiple beats, which differentiates it from other types of AV blocks. This condition typically does not impact the rhythm or the individual components of the EKG significantly; hence the QRS complex generally remains normal, and there are no missing P waves or abnormal QT intervals. Understanding this characteristic is crucial for identifying and interpreting AV blocks accurately in clinical practice.