My mother is 89 years old and had a new pacemaker put in 9 months ago. Her old pacemaker kept her heartbeat at a constant 70 beats; the new one varies from a low of 60 up to a maximum of 120 (it has not gone above 92). Her heartbeat is averaging about 80-82 beats during the day. She is wheelchair bound, quite sedentary, has debetes and has middle stage dementia. She has begun sleeping a lot during the day even after a good night's sleep. Could the pacemaker be making her heart beat too fast and causing the fatigue?