AV block

In second degree AV block type Mobitz 2, is the atrial-ventricular rate of conduction fixed = always the same?

Since the AV node is influenced by the vegetative nervous system, and the sympathetic nerve is positively dromotropic, only a small degree of physical activation is necessary to increase the rate of conduction. On occasion, the number of transmitted excitations changes several times within the space of a few heart beats.