Final answer:
Interpolation PVCs occur during the normal R-R interval without interrupting the normal cycle.
Step-by-step explanation:
When PVCs occur during the normal R-R interval without interrupting the normal cycle, they are known as interpolation PVCs. These PVCs usually occur due to a delayed recovery of the ventricles from the previous contraction. They can manifest as an extra beat in the middle of the normal rhythm, but the subsequent beats continue in the normal sequence.