My 81 year old mother who is in excellent health except for a aortic valve that s not closing properly and a 90% blockage in a small artery on the back of her heart (which she will be having surgery to correct in the next few weeks) is having a weak spell, normal pulse 62, bp 173, 82. not on any meds except yesterday and today took her first doses of bystolic - she has occassional racing heart rate. She feels quivery all over, like her pulse is beating all over her body. What should we do?