Pacemaker Replacement

I am a 35 year old female from Canada. I was born with Tricuspid Atresia. I have had numerous surgeries including the Fontan in 1987 with a revision of the Fontan in 2006, where at that time I also had a Medtronic Enrhythym Pacemaker install. 3 weeks ago I had a Pacemaker replacement due to the fact my battery on my Pacemaker was running low. The new Pacemaker installed is a Medtronic Adapta. Since the new pacemaker my Heart beat has been all over the place. My 1st Enrhythym was paced at 80 bpm, and it pretty much stayed like that for 5.5 years until the battery started to go. The problem is is that the new Pacemaker is not like that at all! My heartbeat goes from 56 to 93, back to 71 then 86, and has gone a high as 100. It is all over the place. The Enrythym never went under 80. This Adapta is not doing that. Since the new Pacemaker I am weak, dizzy, have had low oxygen levels, and chest pain. Can anyone answer me? I feel that they have put in the wrong Pacemaker.

[Jerry_NJ]

Sorry you haven't gotten any input from someone with experience.  So far I have been spared needing a pacemaker...but I know others who have them and have read about them here...so here's what I think:
1) It appears your new pacemaker needs to be "adjusted"
2) I don't understand the old stable 80 bpm pace maker, didn't your heart rate go up when you were moving about, going up stairs say?
3) Are the new pacemaker variations exhibited when you are not changing your activity level, say all are at a true rest?
4) You symptoms must be diagnosed, but it sounds like you lower limit may be too low.

Talk with your doctor(s) and/or other technical support if there is such a thing.  I do recall reading about people having their pacemaker adjusted.

[UMarv]

Have the doctors been able to tell you anything about why your heartrate is all over the place and you are having low oxygen and weakness since the pacemaker replacement?  My father is experiencing similar symptoms since his pacemaker was replaced in August.  The battery in his old one ran low and they replaced it with a Medtronic Adapta.  His heart races with any little movement (even just walking a few feet) and he has trouble breathing, whereas with the old pacemaker (even with a low battery) he was fairly active with no problems.  They haven't been able to find any cause yet and insist the problem is not the pacemaker because the 'computer' says it is functioning properly.