Final answer:
The PR interval represents the AV nodal conduction time in an ECG.
Step-by-step explanation:
The component of an ECG that represents the AV nodal conduction time is the PR interval. The PR interval is measured from the beginning of the P wave to the beginning of the QRS complex. It represents the time it takes for the electrical signal to travel from the atria to the ventricles through the atrioventricular (AV) node.