I am taking care of a 90 year old woman with congestive heart problems. She has had atrial fibrillation and is now on a pacemaker. She was ok for over a year and then developed the atrial fib again. It took 5 days on all the meds used for that for that until her heart rate came down although it was irregular. It is now regular but since that last hospitalization she has been very weak. She can only tolerate taking 2-4 steps maximum before becoming extremely nauseated and weak. Is this normal?