Cycling - heart rate

why slow

by Tracey_E - 2013-11-18 07:11:19

What makes your heart rate slow? Not everyone depends on rate response to get their rate up, so it may not make a difference. If you do use rr, it can be tricky. We have a few cyclists here, hopefully they will chime in. Some pm's use respiration sensors as well as motion but I don't know if SJM is one of them.

Cycling - an old hand

by philip.thecyclist - 2013-11-19 05:11:24

Hello TraceyE,

I echo a lot of what Inga has said. My first accelerometer-only PM (a Medtronic) did not respond well pysiologically - it would increase my HR when going downhill because of the increased vibration felt through the 'bars, but would lag on uphill stretches. My medical team did adjust the sensitivity so a compromise could be reached. My understanding is that the algorithms used in modern accelerometer-based PMs are more sophisticated and partly address this problem, so you may find that your experience turns out to be satisfactory - my Medtronic was implanted 17 years ago, and a lot of technology has passed under the bridge since then. My two most recent PMs (Guidant/Boston Scientific) have had dual accelerometer/minute ventilation sensors, and have been a distinct improvement over the old Medtronic. I can tell when the MV sensor kicks in. Despite the limitations of the old Medtronic, I still kept cycling although my ability was limited compared to my one-time well-functioning heart, so my guess is that with a more up-to-date PM, even if accelerometer-only, you will still be able to keep cyling, even if at a lower intensity.

Good luck,
Philip.

Rate response

by golden_snitch - 2013-11-19 06:11:09

Hi!

I can understand your worries, and must say that my experience with cycling and motion sensor only is not a good one - neither in my old Medtronic pacer, nor in my current Sorin. I recently talked to someone from Medtronic who admitted that cycling really is an unsolved issue with their current pacemakers which only feature an accelerometer. St. Jude has a motion based sensor only, too.

If your cardio knew about your cycling, he either did not give you a pacer with two rate response sensors because he thinks that your heart rate is only too slow at rest, but reacts well when exercising; or simply because he does not know pacemakers with two sensors; or does not implant them for other reasons (some cardios have contracts with certain manufacturers). I hope my first explanation is true, because the other two would be unacceptable.

If what you fear becomes true, and you can hardly cycle any longer, there's still the option of replacing the St. Jude pacemaker with a Boston Scientific or Sorin pacer that has accelerometer plus minute ventilation (other manufacturers don't feature this). This sensor combination will provide you with a better rate response. However, please keep in mind that no sensor will work as perfectly as a fully functioning sinus node. If you depend on the rate response, you'll always need to compromise. But you'll definitely do a lot better than without a pacer, and with a dual-sensor rate response you can do quite a lot, incl. cycling.

Best wishes

Inga

St Jude PM

by regor - 2014-09-06 01:09:28

I had a St Jude Medical PM implanted in 2013. I had been an avid cyclist, but seem to be suffering many similar problems with this PM. I wear a heart rate monitor and find that when I am climbing my heart rate simply does not increase. I have been told that they have set aggressive settings on the PM. But I also have found that if I lean over several times on the bike that my heart rate will increase for a short period of time. But I have to continue this process to keep my heart rate higher. I also have experienced rolling on the level or down hill and when I hit some bumps, my hear rate will jump up. It is unlikely that I can change to a Boston Scientific until the battery dies on the current one. Anybody have any good ideas for better settings on the St Jude Medical PM for cycling?

My Experience with cycling & pacer won't increase heart rate appropriately

by sesquipod - 2016-08-01 10:44:05

I had a medtronic Advisa pacer installed two months ago - June 2016, and have had the same experience as others on this topic -- my heart rate doesn't increase with increased exertion.  Here are some tricks I've learned to get the rate up during cycling:

1) I use a hybrid - during my ride i would swerve off paved road to adjacent terrain - grass or dirt area.  after 20 seconds or so the bouncing around/vibrations from rougher terrain is enough for the accellerometer to sense 'exercise' and increase your heart rate.  This can be dangerous, and cause more wear and tear on the bike.  Thus far I haven't broken the bike or myself with this practice - but it's not an ideal solution

2) This one is inelegant, but effective.  I've found that if I pump my left shoulder vigorously up and down, it stimulates the accelerometer, and this can also raise your heart rate by faking 'exercise'.  I've done this in the mirror to confirm I look like an idiot.  While biking i did this and it worked well, but it's somewhat difficult to do in a coordinated  fashion.

Also, In my first pacer clinic - a week ago, I tried the following, which was partially effective, but ended up being a disaster.  I asked them to change my Activity Threshold to 'Low' from 'Medium/Low'.  The end result was really good for exercise on my elliptical machine - and somewhat better for bike (but still not good at all).  The BIG problem with this setting for me was that sleeping has become much more difficult.  I'm averaging about 3-4 hours sleep at night, and am finding it impossible to take a nap ... due to (my guess) higher resting heart rate.  Somehow my resting heart rate is between 80-90 instead of 60ish.  Anyway, my exercise quality increased, but my overall quality of life much less with the sleep issues.  Not sure if everyone will have the same reaction - but this is what happened to me.  Good news is my homeroom cardiologist is able to see me later today w/medtronic tech person in attendance to reset me to Medium/Low.  

Future experiments on getting my pacer to work better for cycling include:

1) attaching some kind of (gentle) vibration device to an elastic strap that goes around my chest - where the vibrating component is over the device in such a way that it stimulates the accelerometer in a safe manner for the device, and the heart rate goes up.  It's predictable the cardiologist community won't like this one

2) Maybe figure a way to get a vibrating bike seat that simulates riding on rough terrain - like when I ride on a dirt road.  This easily gets the heart rate higher.  Ideally you could switch this on an off so it isn't always vibrating.

And in conclusion - I will continue to try to better understand my rate response parameters better to find optimal settings to make my biking and general living experiences more productive and enjoyable.