A few weeks ago I posted looking for anyone else out there like me and no one responded with a similar situation. I am getting very discouraged and worried. I am back at Mass General once or twice a week because of problems with my PM. They just can't seem to get the settings right. My problem is my heartrate dropping dramatically when I exercise but this week, as I was exercising my heart went the other direction. I have a very high heart rate to begin with when I exercise but the other day it went from 171 to 223! Everyother time it has dropped. Does anyone else have problems with their heart doing both? I'm getting a little worried!