Well my sister is home now and happy to be there. After all the testing the cardiologist says she didn't have a "heart attack" in the classic sense, but something known colloquially as "broken heart syndrome", or stress-induced cardiomyopathy or takotsubo cardiomyopathy, which happens to people with an otherwise perfectly healthy heart after a great shock or stress - even a *good* shock like winning the lottery can cause it! It happens primarily (90% of the cases) to post-menopausal women.
Apparently it can even be fatal in rare cases, but assuming it's not, the person who experiences it makes a full recovery, and their heart is still healthy and undamaged.
The cardiologist said my sister's heart is in such good condition that he would trade hearts with her any day.
He said that in such cases he would normally prescribe a statin since her cholesterol is slightly elevated, but since her HDL is very high, tri's very low, and her heart looks perfect he wasn't going to prescribe them. (or as my sister said to me, "good, because I would never take a statin anyway, and now I have good ammunition if any other doctor ever tries to force them on me")
He said she may feel tired and weak for a day or two as it take a little while for the heart to fall back into its normal rhythm, but said she would be perfectly okay to go back to work on Monday.
However my sister says it's work that caused the issue. She's been under stress there and on Thursday was in a meeting where she said she felt "betrayed" and that she had been "thrown under the bus". I have no more details as she can't talk about it, that just thinking about it makes her heart start to race again! But she is already writing a letter of resignation, effective immediately!
But it was while driving home from the meeting that she developed this terrible crushing pain in her chest - which is apparently how this syndrome manifests, fairly acute onset not too long after the stressful event that triggered it.
See:
http://www.webmd.com/heart/features...-cardiomyopathy
My sister now credits her 50 years of a near vegetarian diet as the reason her heart is in otherwise excellent shape.