Exceeding upper limit

Hey New member, I've had my pacemaker for 2 weeks now and have been given the go ahead to work out a little (exercise bike, elliptical), legs no arm stuff.

I have second degree heart bock and my pacemaker is set with an upper limit of 140. I noticed today my heart rate crept above 140 by the monitor on the bike. When i felt my pulse it was hard to count, seemed slow and real erratic. Once it slowed down a little it stabilized and kicked in fast with about 120 or so rate.

So what happens when you exceed you upper limit? Is it dangerous? Does the limit need to be increased? Without the pacemaker I could not get my heart rate much over 80.

Sorry, another question. Pain is essentially gone, but there are times when the scare area pains, all most a burn. Is this normal, will it eventually go away.

Anybody out there continue playing hockey after getting one of these things? Any recommendations?

Any advice would be greatly appreciated
Thanks
Jim

9 Comments

limits

by Tracey_E - 2009-09-03 08:09:49

The pm will only pace you to 140. Your heart can go higher than that on its own and the pm won't stop it.

Something else that may be happening- the monitor on the bike may not be too accurate now. Sometimes they pick up pm spikes and count them as extra beats. The best thing to do is stop and count.

They can raise your upper limit. The numbers they send us home with are for average pm patients, not those who are young and active. It's common to need a few tweaks.

What you're feeling is normal healing.

You'll find members here who play any sport you can name! Just wear your protective gear for hockey.

typo

by Tracey_E - 2009-09-04 02:09:11

last sentence of the first paragraph, if your atria is doing 180 or 190 or whatever, your hr will only be 140 and you'll miss some beats.

pacing

by Tracey_E - 2009-09-04 02:09:53

No, in that case your hr would likely stay at your upper limit. Frank can explain this better than me but here goes! The pm doesn't really work in beats per minute. To keep the math simple, let's say it's programmed at 60 bpm, that's one beat per second. If your sinus node goes more than a second and doesn't beat on its own, the pm causes an atrial beat. That's for atrial pacing. For ventricular pacing, they program how long the pm allows the ventricle time to beat on its own after the atria beats. Say a tenth of a second as an example. So, if the atria beats and a tenth of a second later the ventricle hasn't beaten, the pm will kick in and make the ventricle keep up with the atria. If you have a 2:1 block the pm will theoretically only do this about half the time. But it will only kick in up to 140 (or whatever your upper limit is). So, if the atria is doing 140, your hr will only be 140 and you'll be missing some beats.

Something that may possibly be happening and can be fixed with programming... sometimes the atria will go a lot faster than the pm, say 200. In that case, the pm might think you are in afib and as a safety measure it will put you into an artificial 2:1 block and only pace you to 100. I had that happen. I'd be working out and my hr would suddenly drop, then it would bounce back up to my upper limit again. Doesn't feel too good and it will end a work out quickly! I've never had a problem with fibrillation so they turned off that safety mechanism and adjusted my settings, now I don't get the fast drops.

Limit

by Jmiller - 2009-09-04 03:09:45

Thanks to all for the comments. I guess I need to check in with the doctor for him to figure out what I was feeling.
I was exercising but was not in any physical distress but trying to take my pulse was difficult. I would not have noticed anything if I hadn't stopped to take my pulse. Maybe as you say it just topped me out at 140 and I was just feeling some dropped beats.

Thanks
Jim

counting

by Tracey_E - 2009-09-04 07:09:22

I know it's tempting to take your pulse all the time when you have a new pm, but try to resist the urge. If you're working out and feel good, trust that the pm is doing it's job and keep going with your workout. A lot fewer headaches that way ;o)

Upper Limit

by ElectricFrank - 2009-09-04 12:09:05

When you hit the upper limit there are two possibilities.

1. If you don't have AV block or don't pace 100% of the time then your HR keeps on climbing as Tracey mentioned.

2. If you have 100% AV block the pacer enforces the limit by skipping beats. This results in an erratic beat that isn't very comfortable. While it isn't supposed to be harmful, what it does do is limit cardiac output at a time when the body needs it. The best approach is to limit exercise to a HR of about 135 and expect it to overshoot that by a few bpm when you back off. Then at your next checkup asked to have it raised to 150. That should let you go to 145 safely.

frank

Upper Limit

by Jmiller - 2009-09-04 12:09:42

I have what they are calling 2:1 heart block. Under excercise conditions my vertricals are only responing every other beat (or firing of the sinus node). So what happens once I reach 140, doe the pace maker drop out and then I go to my own natural heart rate, whcich I would predict is between 70-80.

Once my sinus node is firing less that 140 does the pacemaker kick in.

That's what feels like happens.

Even though I don't fully understand the full workings of this device, I have to say it is an amazing thing.

Jim

2:1 block

by ElectricFrank - 2009-09-05 01:09:12

There are a number of reasons for 2:1 block. They generally involve slow conduction or repolarization of the AV pathway. The pacemake by sensing an atrial beat and then wiring around the block paces the ventricles.

Tracey said it well so I won't run it by again. Since you didn't have complete block before the pacemaker, the timing of pacemaker and your natural pacer together with the pacer doing its thing to limit upper rate makes for a complex cardiac beat.

My guess it that the doc should be able to adjust the upper limit away from the critical point.

frank

similar experience

by hotreds - 2009-09-12 11:09:14

The cardio doc wanted me to take a stress test. When I reached 130 on the treadmill, the pacer kicked me back down to 80! Natch, I had to stop then and there! Happily, they found no other problems- I have full heart block. The doc adjusted the device to 140 tops- I think I'll want that upped a bit more next visit. Truly amazing!

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