What does the PR-Interval measure in cardiac conduction?

The PR interval is a critical component of the electrocardiogram (ECG) that measures the time it takes for electrical impulses to travel from the atria through the atrioventricular (AV) node and into the His bundle, which then conducts the impulses down into the ventricles.

Specifically, the PR interval begins at the onset of atrial depolarization, represented by the P wave, and ends at the beginning of ventricular depolarization, marked by the QRS complex. The duration of the PR interval provides insight into the function of the AV node, as a prolonged interval may indicate delayed conduction, which can be associated with various heart conditions, such as first-degree AV block.

Understanding the significance of the PR interval is vital for assessing cardiac conduction efficiency and identifying potential electrical conduction issues within the heart.