The epinephrine is used to control bleeding, the lidocaine is what should numb your gums/teeth. If your cardiologist says you can't have epi, I certainly can't second guess that. They must have a good reason for saying it. In general, the epi used with lidocaine is in very low does and does not cause problems. If your cardiologist insists you can't have, it might be worth getting a second opinion. If you do get a second opinion, don't tell them the your doctor doesn't want you to have epi, wait to see if they come to the same conclusion independently. That is how I would handle if I saw a similar situation in clinic.
I hope this helps.