Ace the 2025 CCT Challenge – Boost Your Career with Cardiographic Confidence!

A consistently prolonged PR interval is a clear indicator of conduction delay in an ECG rhythm strip. The PR interval represents the time taken for an electrical impulse to travel from the atria through the atrioventricular (AV) node to the ventricles. When this interval is prolonged, it suggests that there is an obstruction or delay in the conduction through the AV node or in the His-Purkinje system.

This can occur in various types of heart block, such as first-degree AV block, where the delay is consistent and can be measured. A normal PR interval generally ranges from 120 to 200 milliseconds, so any lengthening beyond this range signifies that the heart's electrical conduction system is not functioning as efficiently as it should, hence indicating a conduction delay.

Other choices do not correctly signify a conduction delay: a prolonged QT interval suggests issues with ventricular repolarization, a shortened R-R interval points to increased heart rate, and a missing QRS complex may indicate a failure of ventricular depolarization, but does not specifically denote a delay.