If an action potential is able to traverse the accessory pathway and then return retrograde through the AV node ― or vice versa ― a reentrant circuit can be created, resulting in AVRT.

In this situation, there are two separate conduction pathways within the AV node instead of just one (present in about 5% of the general population). This is sometimes termed “dual AV nodal ...

"His synchronous PVC" delivered during SVT: AVRT over a septal pathway (tachycardia cycle length 275 ms). A PVC delivered during His refractoriness advances the timing of atrial activation by 15 ...