Florida State Paramedic Test 2025 – 400 Free Practice Questions to Pass the Exam

The normal PR interval for a QRS complex ranges from 0.12 to 0.20 seconds. This interval represents the time taken for an electrical impulse to travel from the sinoatrial (SA) node through the atria, the atrioventricular (AV) node, and into the ventricles, which is measured from the beginning of the P wave to the beginning of the QRS complex.

An interval shorter than 0.12 seconds may indicate a conduction pathway bypassing the normal route, such as in conditions like Wolff-Parkinson-White syndrome. Conversely, an interval longer than 0.20 seconds can suggest a first-degree AV block where there is a delay in conduction through the AV node. Understanding the normal range of the PR interval is essential because it reflects not only the electrical activity of the heart but also overall cardiac function.

By recognizing the standard range of the PR interval, healthcare professionals can effectively assess the electrical conduction system within the heart and identify potential abnormalities in rhythm and conduction pathways.