PR Interval Unit Converter

The PR interval is a measurement on an electrocardiogram (ECG or EKG) that represents the time it takes for an electrical signal to travel from the upper chambers of the heart (atria) through the atrioventricular (AV) node to the lower chambers (ventricles).

It is measured from the beginning of the P wave to the start of the QRS complex. The normal range is 120 to 200 milliseconds (ms), which corresponds to 3 to 5 small boxes on a standard ECG tracing.

The PR interval is sometimes called the PQ interval because it ends at the start of the Q wave. It reflects the health and speed of your heart's electrical conduction system.

The PR interval reflects the electrical activity generated by the heart's conduction system, specifically the sinoatrial (SA) node, atrial myocardium, and atrioventricular (AV) node. The majority of the PR interval duration is due to the physiological conduction delay at the AV node, which allows the atria to finish contracting before the ventricles begin.