Approx 3 months ago I began to exercise again after a very long period of problems with my pacing settings that made exercise very difficult and pretty daunting.  

Initially I over did it and this resulted in about 48 hrs with exhaustion and a worn feeling in my chest that concerned me.  On medical advice I calmed down and just walked instead. Walking is now going well after several months and although I’m still not great going uphills, my stamina is very much improved on the flat. However, I still can’t push myself and I get the worn feeling in my chest if I do.  (By ‘push myself’ I mean cycle, run or dance with any speed for 10 mins of so) , or if I do say, two types of exercise in one day). The exhaustion is overwhelming and lasts 24 hrs. 

RR is on and set around the mid range, but surely, I should be able to do more by now without these symptoms.  Do I need to push more, more often or should I listen to my body? Any advice?


I don't have the same conditions as you other than the HB...

by USMC-Pacer - 2024-03-12 16:58:19

My sinus is normal.. 

I had similar exercise symptonms as you. The NP and Tech put me on a treadmill with the monitor attached and noted my avdelay settings were way off. During exercise, my avdelay would narrow or broaden (I forget which) and it would throw my ventricles out of sinc and cause symptoms.. ie: sick feeling in stomach, SOB, weakness and just a feeling of not getting enough blood and energy. After those adjustments, I was off like a rocket. Worked for me, might be worth a shot for you. 

Have you been ill with a virus?

by Gemita - 2024-03-12 16:59:05

Penguin, can I just get a better definition of “I get the worn feeling in my chest”.  Can you better define worn and where exactly do you get this discomfort and does it radiate anywhere else?  Does the discomfort get worse as you push and ease as you slow down?

It sounds to me as though you might have some other problem present like a virus when you say the exhaustion is overwhelming and lasts 24 hrs after working out for 10 mins.

I don’t think pushing more would help.  You should not exert yourself to the point of becoming exhausted for 24 hrs afterwards otherwise I feel you will do more harm than good.  You need to exercise slowly, consistently.  Continue listening to your body, not pushing yourself past your “comfort” zone.

As you know I am trialling RR.  I am getting chest discomfort as my heart rate increases and I cannot “comfortably” push through it


by Tracey_E - 2024-03-12 17:08:18

If you have an accelerometer type rate response, it's not likely to know the difference between walking up a hill and walking where it's flat. Same for cycling. Running and dancing should get your rate up. 

I would not push to the point of exhaustion. That's your body talking to you. 

Are sleep, nutrition, hydration and electrolytes all good? Any of those will affect energy levels.

If walking has noticably improved your stamina, and the other things exhaust you, I think I'd stick with what's working for longer. Perhaps find a personal trainer with cardiac experience to guide you?

I have a running coach and she's constantly slowing me down. I've just started running again after a year off due to an injury and we are progressing at a snails pace (in my opinion lol). That's why I have her, she knows better than me. I'm slow, I'm bored, but I'm also pain free so I'm trying to trust the system and not go faster. But I really, really want to. 

You can always ask for a stress test. That's the best way to judge fitness and see if there's anything else going on that's holding you back. 

Responses - USMC, Tracey, Gemita

by Penguin - 2024-03-12 18:15:08

Thank you all for the useful suggestions. Lots of food for thought in each of them. I am listening to my body and will continue to do so. 

USMC Pacer - I do have long AV delays in place. I have considered this as a cause. There's been some mention of Wenkebach block but I'm unclear as to whether this is settings related or not.  I'm fine at a steady pace. I can push my rate up but I know it afterwards.  It's the recovery. 

TraceyE - I have the same PM as you - so yes an accelerometer.  I don't think it's my rate failing to increase. I can go faster in a short bursts (as in HIT training) but my heart feels worn out when the work out finishes and I don't recover from the 'HITs'. My heart doesn't seem to tolerate these faster rates. I am listening to it - it happened yesterday and today when I pushed my heart rate up. It doesn't feel 'right'.

Originally I thought it was de-conditioning, but I've been building up slowly and I walked for hours on a recent city break (mainly on the flat) and only my feet hurt and a bit of muscle stiffness in the morning, but no cardiac 'worn' feeling in my chest.  I walked at a steady pace - not fast / not ambling - and I felt great and completely able to do this.  

Hydration - tick, Nutrition - I'm dieting but the same calorie count sustained me for hours on the city break - although I probably ate a little more to be fair, sleep - tick,  electrolytes - don't know.  I've not been sweating excessively when exercising. 

Gemita - by 'worn' I mean 'worn out' like a muscle that's been worked beyond it's capacity.  It's a strange feeling. People I speak to on here who've had low EF%s  can generally relate to the description. It's hard to describe unless you've had it, but distinctive. I recognise it all too well, but am told that my EF% is normal.

No no infections / viruses.  I am trying to lose weight - hence trying to step things up. The weight loss has stalled, but it seems I can't push my heart beyond these limits.  There's no radiating chest pain - just a heart that feels 'worn out' with higher heart rates. 




by piglet22 - 2024-03-13 06:57:05

Hello Penguin

Do you have any heart rate figures for resting and immediately after exercise?

I can't raise mine significantly above 70 BPM, maybe to between 80 and 90, despite lugging heavy shopping up steep hills on a 4 mile walk every day.

It's not breathlessness that gets me but aching legs.

I've even tried PM tapping.

All a far cry from 18 months ago when I was cycling and walking.

stress testing I believe is the way forward

by Gemita - 2024-03-13 10:37:12

Penguin I have re-read your response several times now.  Since you have been battling with symptoms for quite some time and have been questioning your pacemaker as a potential cause, I would tend to look no further for answers.  I feel that the answer lies with your pacemaker in the absence of another known health condition.  I can see this has become a chronic problem now and is holding you back.

I too agree that stress testing would help to pick up any new rhythm disturbance or potential condition which might be causing your symptoms and give your technicians/EP some answers for your difficulties, or point to any settings which might need reviewing.  AV interval being one of them perhaps.  I believe challenging your body under close observation is the safest and best way forward.  A stress test either chemically or exercise induced will surely give answers and further direction.  Whatever the cause, if you clearly struggle or can trigger symptoms during a stress test they will have confirmation of the problem and more importantly, of the need to do something about it.

Piglet & Gemita

by Penguin - 2024-03-13 12:37:27

Piglet - H/rates post exercise / during exercise.  I'll see about getting a h/rate monitor. I did have one years ago, but can't find it.  The symptoms come on at rest post exercise not during exercise.  That thing you put on your finger that we were all told to buy during Covid (SATs monitor?) said 92/93 this morning but improved with deep breathing.  

I sympathise re: aching legs. Mine were exactly like that pre-pacemaker with low h/rates. It was a struggle to exercise.  Sounds like you're not getting enough oxygenated blood! 

Gemita - I don't understand (the settings induced?) Wenkebach thing but wonder if an explanation might help me. I can't post about my precise issue here as it's too public, but could do with an explanation if you're up to it as it could be relevant. 

I woke up exhausted this morning and went to bed with a level of exhaustion that was overwhelming.  My chest is kind of tight but not painful or radiating or anything serious.  Just feel knackered! 

Not sure if this will help

by Gemita - 2024-03-13 15:47:15

Penguin, my understanding is that Wenckebach happens and causes symptoms when we exceed our Maximum Tracking Rate.  Once the sinus rate falls below this limit, our heart rhythm should return to normal and we should be symptom free again.

Wenckebach happens as our heart rate increases and the time between beats get shorter. The upper rate limit monitors this time interval and when it becomes short enough to cause the heart to exceed the upper rate limit, it skips a beat.  As our heart rate keeps increasing, the effect is for your heart to only contract on every other beat.  If you were wearing a monitor it would show your heart rate going up to your maximum tracking rate, say 130 bpm and then dropping by half to 65 bpm and we would certainly be troubled by this.

Missing beats occur less frequently when the sinus rate is only slightly higher than the maximum tracking rate but more frequently when the sinus rate well exceeds the maximum tracking rate. Once the sinus rate falls below the maximum tracking rate, the 1:1 AV tracking is restored.  Many members raise their upper rate limit, so that Wenckebach can be avoided.

I don’t know whether my FAQ on Upper Rate Behaviour will make more sense now and I quote from it:

"A commonly encountered device-related arrhythmia is Upper Rate Behaviour, known as Wenckebach or 2:1 Block.  Upper-rate behaviour is a feature of dual-chamber pacemakers with atrial tracking mode. Upper rate behaviour occurs when the atrial rate increases and approaches the Maximum Tracking Rate (MTR). In dual-chambered pacemakers, it is necessary to limit the atrial rate at which the device can pace the ventricle.  This limit is called the MTR, and it is a programmable value.  

The upper-rate behaviour depends upon the MTR and total atrial refractory period (TARP). The TARP is equal to the atrioventricular (AV) delay + PVARP (Post Ventricular Atrial Refractory Period). When the atrial rate exceeds the MTR, it results in pacemaker Wenckebach. If the atrial rate keeps increasing and exceeds the TARP, it will result in pacemaker 2:1 AV block.  

If properly programmed, the device tracks in a 1:1 fashion until reaching the programmed upper rate. As the atrial rate increases, ventricular pacing cannot violate the upper rate limit, resulting in progressively longer AV intervals. This is referred to as pacemaker Wenckebach. However, if the TARP is excessively long, abrupt 2:1 block may develop with a sudden slowing of the ventricular rate, which may cause symptoms. This occurs because when the atrial rate hits the TARP, every other event falls in the PVARP and is not tracked. Effectively, the ventricular pacing rate is one-half of the MTR. Undesirable upper rate behaviour is avoided by meticulous attention to intervals, by programming to allow a Wenckebach interval between the maximum tracking rate and the 2:1 block rate, and by allowing rate-adaptive shortening of the AV and PVARP intervals". 

You say you woke up exhausted this morning and went to bed with a level of exhaustion that was overwhelming.  Your chest is kind of tight but not painful or radiating.  Something is clearly not right.  Sounds also like chronic fatigue syndrome where there is often no evidence of a past viral infection, but I would rule out one organ at a time and the heart and second heart (the device) is a good place to start

I found an excellent basic principles of pacing PDF when doing the FAQ

by Gemita - 2024-03-13 16:47:23

Wenckebach upper rate response 

When the atrial rate exceeds the upper tracking rate, the pacemaker prolongs the AV delay progressively so that the ventricular pacing stimuli are not delivered at a rate faster than the upper rate limit. Therefore, as the AV delay gets progressively longer, the P wave gets closer to the preceding paced ventricular beat, until eventually the P wave is within the PVARP of the preceding beat and that P wave is not tracked.  This is the way that a properly programmed dual chamber pacemaker will behave when the atrial rate increases to, and is then above, the programmed upper tracking rate.

In patients with intact AV conduction, or only partial block, competition from intrinsic conduction may partially mask upper rate behaviour.  

Hope it is all beginning to make sense

Beginning to make sense

by Penguin - 2024-03-13 17:35:14

Thanks Gemita, 

My AV conduction is intact and slightly prolonged. It's complicated by the v.long AVDs which we have discussed a lot. 

My h/rate will definitely be going above the upper rate limit (130 bpm). The workout I've been doing has 10 mins warm up / slower music then 10 mins of faster music which I can't always keep up with, followed by strength exercises / stretching / cool down for 10 mins.

For the last two days I have pushed myself to try to keep up with the higher pace of the middle section which has approx 10 x 1 min high intensity exercises to fast music. 

I didn't recover well after the first day, but figured no pain no gain! - but was then totally wiped out yesterday after the workout.   I had exactly the same feeling when I overdid it 3 months ago when I was de-conditioned and my h/rate spiked when I did some high intensity exercise for 10-15 mins or so. Presumably the same cause. 

You quote that in a well programmed device ' When the atrial rate exceeds the upper tracking rate, the pacemaker prolongs the AV delay progressively so that the ventricular pacing stimuli are not delivered at a rate faster than the upper rate limit.'

My AVD timings accommodate AVDs up to 350 ms and this can repeat up to x 3.  I did feel V.pacing yesterday during the faster part of the workout, so presumably the PM breached the AVD limit of 350 ms to trigger VP.  Lord only knows what the 3 x repetition of AVDs must do when it kicks in!  

Still not sure I completely understand what's happening but I certainly feel awful and haven't done much today other than light gardening (e.g. telling hubby where to dig!)  Chest still feels tightish. 

Thank you Gemita. I will investigate further.

I Have Felt a Similar Pain

by SeenBetterDays - 2024-03-14 09:57:52

Hi Penguin

Sorry I have been a bit slow to respond.  This sounds quite familiar to me,  I still experience chest pain when I push my heart rate up and have puzzled over why this occurs.  I'm not sure if this would be Wenckebach in your case as I have experienced this in the past and it would suddenly push my heart rate down to my minimum when I approached the maximum tracking rate.  This would make me feel dizzy and unable to continue exercise.  I would explore whether your maximum tracking rate could be increased if this is safe for you as it may be that your heart wants a faster rate during more intense exercise. 

AV delays will also most definitely have an impact.  I have Rate Adaptive AV set to On and this allows the AV delays to become progressively shorter as the heart rate increases.  If the AV delays are too long this will hinder your exercise capacity.  One setting which was altered in the past for me was Minimum PVARP (Post Ventricular Atrial Refractory Period) which they shortened.  My understanding is that this is the period following a ventricular contraction where the activity of the atria is ignored by the pacemaker.  This is where things get a bit more technical and I can get a little out of my depth (call to Gemita!).  

From what you said Penguin you still have a functional AV node so you are not in the same position as me.  My experiences may not therefore be relevant to you.  I suppose from my perspective I think it can be hard to get the settings on our pacemakers just right.  An artificially activated heart is never going to exactly mimic that of a natural heart and therein may lie a lot of our difficulties in navigating this situation.  I feel like each of us needs settings to be tailored to our individual needs and I have never had confidence that this is achieved in many instances.  Couple that with the fact that our heart conditions may also be changing over time and it seems quite a challenge to ensure that settings are exactly what we need.  I think it is a shame if we are not getting the full benefit of our devices because of settings issues as this can really impact our quality of life.  Too often, I have heard that the pacemaker is working well when the real question should be is the device programmed in the correct way for that individual to receive maximum benefit and achieve an optimum level of physical function?

As Gemita mentioned, post exertional malaise is also a symptom of chronic fatigue syndrome.  I experienced this following my second device and think this may have been linked to a prolonged period of stress.  In this scenario, pushing the body too hard is not advisable so I would caution against that.  I find that HIIT is too much for my body now so tend to opt for brisk walks and try to incorporate some hills to get myself a bit out of breath. My emphasis is on moderate exercise rather than pushing to the limit.  Maybe until you can find the answers to the symptoms you are currently experiencing it may be worth being kind to your body and listening to its warnings.  I know this can be frustrating but pushing through can be a mistake sometimes.

I really hope you get some clear answers soon Penguin and you are able to enjoy all the activities that you love.  Sending you love and best wishes.

Rebecca x

Seen Better Days

by Penguin - 2024-03-14 16:06:51

Thank you for your comprehensive and caring response Rebecca -  it really does mean a lot to me to have so many caring people on this forum.  Having read your reply thoroughly it sounds like you have some very relevant experience to impart and wisdom.

I agree about the exercise and have definitely considered being very careful and not pushing myself. I agree though that the device settings do have to be helpful too!  They have been a concern for some time. 

I felt better today and woke up refreshed. I did some light gardening (weeding) and managed fine and did the same exercise class (gently) in the afternoon without throwing myself into the faster section.  I walked rather than danced and just did the stretches to my own slower beat!  My chest feels OK this evening - no tightness / still a bit 'worn'. I'm still aware of something that feels like exhaustion but nowhere near as bad as it was before . It came on roughly an hour after the exercise and I still have it several hours later.  I will take it easy again tomorrow if i wake up with the same feeling.

I don't think it's CFS although I'm very aware of the causes and how nasty it can be. I've certainly had enough stress to cause it over an extended period, but there are other causes that I need to consider first and try to deal with. 

Thank you very much for your caring reply. 


Exercise and trying to lose weight

by Ahilltopper - 2024-03-16 11:41:29

I can't offer advice on your pacemaker, as I don't have that type. Sorry to hear that it is not working for your desired activities. But what caught my attention was that you said you are trying to lose weight and you need to step it (excercise) up. I'm a health scientist. This is a very common fallacy and complete myth, promoted by shows like Biggest Loser. Nearly all of those on the show failed to sustain the weight loss after the show, so for wellness it failed.  To lose significant body weight by stepping it up--- you'd need to be doing that at least 5-6 hours per day to burn enough calories. The truth is that in normal life a healthy diet is more important than exercise for weight loss. I wish you well on your journey.

You know you're wired when...

You have an excuse for gaining an extra ounce or two.

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