New pacemaker

Upper limit

by Elisabet - 2017-02-21 20:49:52

I just got my pm's upper limit adjusted from 130, which must be some sort of default, to 150. In my case the SA node works great and my body, not the pm, controls it, but the signal doesn't go through my non-functioning AV node so the ventricles have to take their cue from the atria via the pacemaker. Basically it bridges the gap between the atria and the ventricles so they work in sync.

However, when my body wanted my heart to go just a little faster than the upper limit, the pacemaker would still just fire the ventricles at the upper limit rate, which was low for someone my age. In fact, as the top and bottom of my heart got out of sync, my heart rate could actually drop as it started missing every sixth beat, or every fifth, and so on. At least I think I got that right.

Bumping that limit up by twenty seems to have made a difference, although I'm just guessing on my heart rate and exertian level most of the time. I was finding that even half an hour brisk walk would make my vision go sparkly. I've been so out of shape due to other major medical issues that experimenting with the pm just hasn't been happening this year. But I really admire you running marathons!

If your SA node is responding physiologically like mine is, your monitor may be picking that up even if the ventricles won't fire that fast because they're under the control of the pm. Just a guess.

Heart Rate

by gleesue - 2017-02-22 13:17:57

Super,

Do you know if your heart still has the ability to speed up on it's own. My RR has been set on low for the past several years. My rate was set at 50-140. The doc told me that if my rate went over 140 my heart was doing it on its own. May be that's what's happening to you.

I'm very active also, work out 5-6 days a week.

Jerry

Many Variables

by BillH - 2017-02-22 21:00:30

First there are two different "maximum" settings.

The first is the maximum tracking rate. That is important when in AV block and the ventrical does not "see" the atria firing. In that case the PM will sense the atria firing and the ventrical not firing and then act as a bridge to trigger the ventrical in sync with the atria.

The other feature is rate response. That is used when the sinus node, the natural trigger for the atria, does not speed up during activity. That has a number of different settings control the amount of avtivity need to start increasing rate, how fast it increases it, how fast it slows done after activity, and a maximum rate that it can raise the atria rate.

In many cases neither condition is absolute or exist 100% of the time.

It is very possible that during high activity levels that the sinus node and AV node work more or less 'normally".

The only way of knowing for sure is a stress test on a treadmill with EKG The firing of the PM can be seen on the EKG and afterwards a download can show what the PM is "thinking" and doing during that time.

PM why are your limits set so low. You should get them raised incase you need them.

upper limit

by fourkids - 2017-03-05 14:58:49

I had an upper limit issue.  After my pacemaker implant I could not excercise with the same intensity.

I have heart block and my pacemaker is supposed to just lie in waiting for when my heart rate drops below 50 bpm, when it takes over.  

When I would excercise, I was fine for short periods, but when excercising at high intesity for longer than 20-40 minutes, I would begin to drag.  I could always keep going, but slower and slower the longer I went.  Initially I was told that I was just getting out of shape, so I made a determined effort to get regular excercise.  In fact I ran a half marathon and then a full marathon.  So I was in shape, but no change in my dragging.  Took huge effort to work through all long excercise.

After a year of no help, I finally asked about the upper limit (which I didn't even know was in place for me).  Mine was set at 160.  My max heartrate when excercising was sometimes 174.

Long story but they raised my upper limit to 183 and I am happy to say....

No more issues.  Just a huge change.  Hope this helps someone else.

Rob