I am sorry to hear of your "attacks" however until you have spoken with your Dr. and he has dx what is going on with you stop the what if thinking. It serves no good purpose in this case.
Why would you cancel your appointment with your dentist when you have come this far to complete your dental work? It feels to me like you have had a very long haul in completing your denture work and the finish line is in your sights so get it done.
and Heart/Cardiovascular Disease. "She Stood in the Storm & When the Wind Did Not Blow Her Away, She Adjusted Her Sails."