Only a doctor can tell you the cause of the PVCs. But if it makes you feel any better, many of us on here experience PVCs on a regular basis and our hearts are normal. The causes vary, but many times it's benign. Alot of it depends on whether you have other issues (shortness of breath, fainting, weakness, etc). Good luck!
I don't think anyone can give you this answer over the internet. You'll need to meet with your cardiologist and figure it out. Your cardiologist may or may not order imaging (echo), possibly a stress test, I'm sure they'll run another quick EKG. If those have more findings than it would usually mean more testing.