Very Low Heart Rate During Exercise After Generator Replacement

I had my Boston Scientific generator replacement after 6 years. The old one got me through multiple triathlons including two full Ironmen. After 2-3 adjustments on the new one I still can't get my HR high enough during exercise, which leaves me wiped out after a session. Today I biked for 3 hours at a pretty fast 21mph. My AHR was 80 which isn't even in the Areobic range. With all out 27-28mph 2 minute sprints, it never got over 95bpm (still not in the Aerobic zone which starts at 111bpm). Anyone ever experienced this? Is the new unit possabily a lemon? Any advice would be appreciated.


5 Comments

Get a stress test

by Kcambridge - 2017-02-13 22:04:25

I had a medtronic pacemaker installed last summer, and so while I can't speak to your specific situation, I was similarly struggling to keep my heart rate where it needed to be while jogging. After about 10 minutes of running, mine would drop to 70 and I wouldn't be able to get it back up and would have to sit down on the curb to catch my breath and keep from falling over.

I had a number of follow-up appointments with my doctor/EP, in which I would try to explain my symptoms, and the EP would try to make adjustments to correct for what I was describing, but it never really worked. 

Ultimately, based on the advice I got from others on the Pacemaker Club forum, I asked for and got a stress test. My doctor really didn't appreciate my symptoms or understand what adjustments needed to be made until I was physically on a treadmill in front of him showing the symptoms I had described. After the settings adjustments at that session in August, I really haven't had any more problems keeping my heart rate up while exercising.

In short, if you can, I would get a stress test. I wish I had asked for one sooner - would have saved a lot of time, anxiety, and back and forths to the doctor's office.

Best of luck!

Get a stress test

by hjfarr - 2017-02-14 00:22:46

Thanks Kcambridge, Your experience tells me I'm on the right track. I had another adjustment this morning, and came home to your post. After the tech had checked the readings, the doc came in and said he wanted me to take a stress test with him watching and telling the tech what to do.. I'm secheduled for the 2nd week in March. I'm pretty sure he'll be able to get the run part straightened out since the device measures foot strike. The key to it will be getting the effort response measurement working right for the swim and bike since there is no impact involved.

That's great!

by Kcambridge - 2017-02-14 17:16:02

Glad to hear it!

Also, thank you for your very helpful reply to my swimming questions. Having one doctor tell you swimming is perfectly fine and then to have another tell you the opposite is a bit maddening - especially when so many folks in this forum seem to be swimming for miles with no issue.

I think, in retrospect, I should have pushed back more when, pre-implantation, my lead doctor first said "breast stroke will be fine, but no freestyle." In my panicked, pre-surgical state, I took it for granted that I had no options. Live and learn.

It is helpful to know that you have longer leads to allow for range of motion. I will ask for that in 10 years when I'm due to have the leads replaced. In the mean time, I am not above breast-stroking the 0.7 mile leg of a sprint-tri!

Take care.

Heart Rate & Leads

by hjfarr - 2017-02-14 17:52:35

You might ask your doc if you are cleared to lift moderate weights, including dumbbell presses. If so you can probably do the freestyle(crawl).  You could start out with a bit of a shorter stroke, in other words, do your hand enteries just past your ear, and don't fully extend your arm before you start your downward catch and pull. You may be putting more stress on the leads doing the breast stroke than you would with the crawl. The pec area is brought int play more with the BS than with the crawl. Your EP may not be very well versed in swimming mechanics.

I did a 3 mile run yesterday evening after my AM adjustment and averaged 141bpm, a litle high for an average at my age, so they may have the foot strike setting too sensitive after the adjustment. Today I rode my trainer for 1 1/2 hours at an AHR of 115 with a max at 130 during some sprint and out of the saddle work, so that adjustment, the effort response, is getting much better

 

Exercise mechanics

by Kcambridge - 2017-02-15 10:20:16

I will look into that. What you're saying makes sense. In fact, while all of my doctors repeatedly said breast stroke would be fine, I had one nurse pointedly ask me a couple of months ago, "But you're not doing 'real' breast stroke, are you?" She was concerned about what I think you're describing with pec area involvement.

My main doc's an avid marathoner, which helps, but I think he's unfortunately pretty uncertain/inexpert when it comes to the mechanics of other exercises, not only swimming but also canoeing, kayaking, climbing, etc. I will ask him about light weights and the modified crawl stroke you're describing when I next see him. Thank you again for helping me think through the mechanical reasons for why these restrictions exist - exactly the kind of advice I was hoping for!

It sounds like you've much improved since yesterday's adjustments. The stress test will help with the final tweaks. It just takes time to get all of these settings adjusted to your unique system and needs. You''ll get there. Hope the stress test in March goes well!

You know you're wired when...

Your old device becomes a paper weight for your desk.

Member Quotes

The pacer systems are really very reliable. The main problem is the incompetent programming of them. If yours is working well for you, get on with life and enjoy it. You probably are more at risk of problems with a valve job than the pacer.