What Causes Episodes Of Nausea And Heartburn?

Hello. my mother has frequent bouts with nausea, vomiting and heart burn. I know that persistent heartburn can be a sign of something major...like a heart attack, which she had 2 the same day a few months ago with no signs of chest pain or pains shooting up her arm into her shoulder, jaw, chest or neck. She is a stroke patient, as well, has diabetes, on hemodialysis, End-Stage Renal Failure, Coronary Artery Disease, Peripheral Vascular disease, dual BKA and has lost an extensive amount of weight. She has had an ERCP done and a stent was put in her bile duct due to narrowing. Nausea, vomiting, and heartburn is constant. Of course, when she starts this cycle, she won t eat. I don t know what else to do to remedy the situation. Can you give me some insight?