Welcome @alex1962. Am I understanding correctly that you have heart disease as a result of radiation treatments for cancer? If yes, you may be interested in this related discussion:
- Cancer Treatment Induced Heart Disease https://connect.mayoclinic.org/discussion/radiation-induced-heart-disease/

It sounds like you are looking for information about how to request an appointment at Mayo Clinic. Here's the contact information to call or submit a request online. You can self-refer or have your doctor refer you. http://mayocl.in/1mtmR63

Mayo Clinic offers a program to address heart problems associated with cancer treatment called cardio-oncology. The Cardio-Oncology Clinic (https://www.mayoclinic.org/departments-centers/cardio-oncology-clinic/overview/ovc-20442193) evaluates people prior to cancer treatment and patients who have experienced side effects due their treatment.