Heart rate when cycling

I had my PM implant 17th June 2022, to overcome bradycardia and sick sinus issues.  Resting HR now 60, up from about 45.

I had been noticing increasing fatigue generally, and as a cyclist increasing struggle to keep up with my mates, especially uphill.

Since the implant I generally feel better.  But I have not gained any noticeable benefit when cycling.  After the implant and when riding, my HR would rise to 130 and then 'flat line'.  The technician explained that the PM was preset to only pace my heart up to 130.  On my request she adjusted it to pace up to 150.

Now what I find is that when climbing my HR still tends to only rise to about 130, when I want it higher, at least in the 150 range.  Perversely when I am descending with very little exertion, my HR will often climb to 150.  
The technician thinks that the cause may be that when I am climbing the motion sensor may only be detecting relatively low body movement (even though the exertion level is high), and when descending it may be detecting high body movement from the fast pedalling or vibration (even though the exertion level is low).

Is this anyone else's experience, and is anyone aware of any 'work around' or adjustment that may be available?


This is why SSS+CI patients are so keen on 'tuning' the PM

by crustyg - 2022-08-18 07:35:03

OK, so now you have a more realistic maxHR (well done for getting that).

Now you're facing the common challenge for road cycling for those who are dependent on the PM for an increased HR when cycling uphill.  There's little to no upper body movement, so nothing for the accelerometer in your PM to detect, so it doesn't feed anything into the Rate Response algorithm.

There are a couple of folk here who have managed to get a half-sensible RR response out of a Medtronic PM when road cycling, but it's not easy.

The other approach is to have selected a PM that has an additional way to sense the need for a higher HR: BostonSci using Minute Ventilation (literally breathing rate multiplied by depth of each breath) and Biotronik measure the force of contraction of each heartbeat.

Being blunt, you don't have the best PM for a road cyclist with SSS+CI - not much help, I fully understand.  Search for the other posts - some contributors here report decent results for road cycling with Medtronic.

Best wishes.

Heart rate

by Skeet - 2022-08-18 07:54:35

I could have written your post myself. Have had my pacemaker for fifteen years. Not much has changed.


Crusty is spot on

by Julros - 2022-08-18 09:58:45

I have a Boston Scientific, but regretably, not with minute ventilation. My heart goes faster when walking my dog than cycling up hill. I"ve tried thumping my chest (EP suggested) but not much help. 


Does standing help?

by dogtired - 2022-08-18 13:57:04

If you put the bike into a low gear and stand maybe the high cadence while standing will induce enough upper body motion to cause the PM to pace higher?  I'm guessing if you coast downhill the PM will pace lower.  Let me know if this makes any difference.

From a lap swimmer

by KF - 2022-08-23 16:49:12

I'm an avid lap swimmer. I have a Medtronic azure XT since April of 2020. I also have sick sinus and bradycardia. I, at 71, can swim almost nonstop for about 1/2 hour. I rest for just about a minute at each end of the pool. My HR goes to around 100. Just recently I had a nuclear stress test, Bruce protocol , and my HR got up to 132 on the tread mill. According to my latest scan, my lower is set at 60, upper set at 140, and upper sensor is at 130 bpm. My ADL is set at 95 bpm. Just a thought, I also cycle, climbing up a hill is intense, I think that racing down a hill expecially in traffic can also be quite exiting (for the heart). 

Check the Medtronic mode settings with your tech

by MTBer - 2022-08-25 13:23:23

New poster here and still have my Steri-Strips on.   Here's my experience.   I have SSS as well.   I have a Medronic W1DR01 that I'm still healing from and have not outdoor ridden yet.  But, indoor on the trainer, I have no issues with getting my heartrate up to my previous levels.  Did a short one this morning with a 142 ave and 170+ max.  


My PPM is set for MVP mode.   My minimum heart rate is set for 45 BPM.   In Medtronic MVP mode, it operates in AAI(R) mode unless it senses loss of AV conduction, then it switches to DDD(R) mode.  Then monitors for establishment of AV conduction and switches back to AAI(R).  In my case the 'R' Rate Response is not activated.   May just question your techs more on the specific mode your PPM is set for.   It seems to me that for SSS, you only need to make sure your heart doesn't stop (like mine was) or go way to low.  Don't see any need for Rate Response settings which involve the unit accelerometer.  (From what I understand!)

Heart rate and cycling

by Pushy1 - 2022-08-30 05:10:01

Thanks all for your comments. Most interesting and reassuring. I will respond as best as I can but I can see that I need to get more information from the technician. 
My PM is a Medtronic W3DR01. The cardiologist sang its praises about how clever it would be to respond to increasing and decreasing exertion. You have enlightened me about there being more suitable types for cycling, but it's a bit late now for a changeover!

I have tried standing when riding uphill, pulling on the tops of the bars, increasing cadence, even swinging my shoulders, all with little or no effect. (Since I wrote my initial post I have tested myself again. Climbed a steep hill for 12 minutes and couldn't get my HR above about 130, rested for a couple of minutes while it came down under 100, then descended without pedalling.  By the time I got to the bottom my HR was on 150.)

I was interested that MTBer got their HR up to a good rate on a trainer.  Whether this is because of a different model of PM, different settings, or different underlying medical condition I cannot say.

Thanks again all for your feedback. 

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