Melinda's Cardiologist was briefly mentioned in the episode Safe.
Melinda had a severe allergy to peanuts, when Melinda Bardach was left alone for the first time, she ate one chocolate chip cookie, there was peanut butter in the dough. She had an allergic reaction, she didn't have her epi-pen on her, she drove herself to the hospital, passed out, steering wheel crushed her heart. Her cardiologist got her a transplant, whenever she asked how long she had left, the cardiologist told her that there could be breakthroughs that could give her another twenty years. However she googled it at found out otherwise. Foreman repeated exactly the same thing to her when she asked him.