I am not a doctor as this isn't the expert forum and I had to look this up but from what I understand perfusing pvcs mean there is still a pulse with them. So I would hazard to guess that the non perfusing means the heart isn't beating as efficiently though to be honest I am not sure how much of a difference there is in the danger to the patient as most pvcs are benign. I guess it would depend on the number the person is having. If you have a lot of non perfusing pvcs that may mean the heart rate is super slow and it could cause some symptoms that are troubling to the patient. If a person's pvcs are not causing a lot of troubling symptoms like shortness or breath or passing out then the pvcs are likely not a danger to them regardless if they are perfusing or not. But to be sure I would ask a doctor. Everyone's situation can be very unique to them. Hope that helps.