I am worried about my sister her symptoms were erratic fast heartbeat vomiting And extreme tiredness some mild pain left upper arm she is 80 years old 9st and quite frail she had a stroke about 6 years ago. The second time afew days later the heartbeat was very slow and like a heavy thump with nausea does she need to see her doctor only she is very stubborn she also suffers with high blood pressure. I think she has had a mild heart attack.