This is sometimes termed “dual AV nodal physiology.” One pathway is slower and has a short refractory period, while the other is faster and has a long refractory period. Normal conduction ...

This requires two conduction pathways within the AV node (a.k.a. "dual AV nodal physiology") similar to what occurs in AVNRT. The PVC conducts back to the atrium though the slow AV nodal pathway ...