AV conduction forward conduction of the cardiac impulse from atria to ventricles via the AV node or any bypass tract, represented in the electrocardiogram by the PR interval. PH conduction time is from the onset of the P wave to the first high-frequency component of the His bundle electrogram (normally 119 ± 38 msec); A-H conduction time is from the onset of the first high-frequency component of the atrial electrogram to the first high-frequency component of the His bundle electrogram (normally 92 ± 38 msec); P-A conduction time is from the onset of the P wave to the onset of the atrial electrogram (normally 27 ± 18 msec).