What is considered a normal PR interval duration on an ECG?

The normal PR interval duration on an ECG is categorized as ranging from 0.12 to 0.20 seconds. This interval measures the time taken for electrical impulses to travel from the atria to the ventricles, specifically from the onset of atrial depolarization to the onset of ventricular depolarization. A PR interval within this range indicates that the conduction through the AV node is functioning appropriately, which is key for maintaining a coordinated heartbeat.

Intervals shorter than 0.12 seconds may suggest a pre-excitation syndrome or other conduction anomalies, while intervals longer than 0.20 seconds can indicate a first-degree AV block or other forms of delayed conduction. Therefore, understanding the normal PR interval range is crucial in diagnosing various cardiac conditions based on the ECG reading.