I will assume one reason she has a pacemaker is her un-paced heart beats too slowly, and the
PM gives it more beats at some level. I don't wear a PM, so I'm tryin
g to help from memory on what I have read in the
past. If my memory is correct it would seem very possible that it takes some time for the
PM to pick up the
HR. And if the
happens only sometimes, it could be because she has a lower HR just before risin
g on those occasions.