Well, it's too late for her to see a Dr. She passed away in her sleep. The Dr. was giving her somthing to lower her blood pressure to bring down the rate which was not working..
I told here three days before she died to call the Dr. back because I din't think what he was doing was working...
I would definitely see your doctor about this. It is probably important do a history and physical, blood work, and then possibly a holter, echo and /or stress test. There are some reversible causes like thyroid and other possible endocrine problems and there are other causes that are not reversible. It is important to determine what the heart rhythm is in case it is not a normal rhythm. An initial visit with your doctor should help narrow down the possible causes.
I hope this helps.