The PR interval should not exceed what duration?

The PR interval should not exceed what duration?

• A. 0.10 seconds
• B. 0.20 seconds
• C. 0.30 seconds
• D. 0.40 seconds

Answer: (B)

The PR interval represents the time taken for electrical impulses to travel from the atria to the ventricles, encompassing the time from the beginning of atrial depolarization to the onset of ventricular depolarization. The normal duration for the PR interval is typically between 0.12 seconds (120 milliseconds) and 0.20 seconds (200 milliseconds). A PR interval exceeding 0.20 seconds may indicate a first-degree heart block, where there is a delay in the conduction through the atrioventricular (AV) node. If the PR interval is less than 0.12 seconds, it may suggest conditions such as pre-excitation syndromes (e.g., Wolff-Parkinson-White syndrome). Anything beyond 0.20 seconds denotes an abnormal conduction delay and is clinically significant. This duration is critical in the assessment of the heart’s electrical activity, helping guide healthcare professionals in diagnosing potential arrhythmias and conduction system abnormalities.

The PR interval represents the time taken for electrical impulses to travel from the atria to the ventricles, encompassing the time from the beginning of atrial depolarization to the onset of ventricular depolarization. The normal duration for the PR interval is typically between 0.12 seconds (120 milliseconds) and 0.20 seconds (200 milliseconds). A PR interval exceeding 0.20 seconds may indicate a first-degree heart block, where there is a delay in the conduction through the atrioventricular (AV) node.

If the PR interval is less than 0.12 seconds, it may suggest conditions such as pre-excitation syndromes (e.g., Wolff-Parkinson-White syndrome). Anything beyond 0.20 seconds denotes an abnormal conduction delay and is clinically significant. This duration is critical in the assessment of the heart’s electrical activity, helping guide healthcare professionals in diagnosing potential arrhythmias and conduction system abnormalities.