Pvcs while laying on stomach

I have confirmed (by cardiologist and electro physiologist) pvcs. I have also had runs of them (nsvt). However, both doctors have ruled them benign. Well lately when I go to bed....I may have not had a single PVC all day, but can lay down on my stomach and I get a run of pvcs that takes my breath and jerks me awake. I am forced to turn to my side to sleep or I will continue to get these runs of pvcs. Just wondering if anyone else with confirmed pvcs gets them worse while laying in stomach and if anyone knows why this happens?