Am I just bone idle?

How is Chronotropic Incompetence diagnosed or do they turn Rate Response  on in the absence of a confirmed diagnosis to try to improve exercise capacity?

I had another device check yesterday and was told that I had flat histograms for the third time, with my heart rate stuck at 70 bpm (which is also my base rate).  I found that hard to believe because I walk a lot and really push going uphill.  Surely I get my heart rate above 70 bpm?  I also do some vigorous exercising at home.  Could this be a pacemaker reporting error or is my heart rate not increasing as it should?  

I have now had my Rate Response turned ON, OFF, ON, OFF and now back ON.

I know I have sinus node disease, but does this always mean Chronotropic Incompetence?  Although I can struggle sometimes with exercise, especially during an arrhythmia, when I am arrhythmia free, I don’t seem to have any major problems with exercise, so why is my rate stuck at 70 bpm?  Is my low dose beta blocker holding my heart rate down I wonder?  Surely not at Bisoprolol 2.5 mg dose daily?  Can anyone throw any light on this? 

The technicians will be speaking to my EP because I have started noticing more in the way of chest discomfort mainly during an arrhythmia.  Hopefully I will get more answers when he contacts me and perhaps some proper stress testing, but your thoughts as always would be appreciated.  Thank you


Your interrogation

by Good Dog - 2024-02-03 14:01:31

Hi Gemita!

I guess that I am wondering the same thing that you are. It just does not seem logical that you would have a flat-line 70 bpm. So I'm wondering when you do an interrogation, do they give you the results either electronically or on paper? The reason that I ask is that in all the data is a tracing and also a table (histogram) that details the number of events you are paced within a specific range for the period from the previous interrogation. For example (my base rate is 50 bpm):

Rate Range          Events       Percent of total

50-59                5,472,204          68.1%

60-69                1,001,514           12.5%

70-79                  938,100             11.7%

ETC., etc., etc, (I tried to paste the actual table here, but the site would not allow it)

I guess you already know this, but my point is; if they would provide you with this data then you would know for sure exactly what has occurred. Can you ask for it? Really, while I suppose it is possible, what they are telling you just does not make sense. I would see if you could get some data from them so that you can know exactly what is happening instead of wondering.



base rate

by new to pace.... - 2024-02-03 15:17:57

Sorry to hear Gemita you are having to deal with this issue.  I am wondering if your base rate was lowered to 60.  Would it than move up to 70+? 

new to pace 

I will seek advice

by Gemita - 2024-02-03 15:18:53

Dave thank you for your response and for your efforts trying to post your results. 

I have online access to MyChart but the results are not through.  They might be by Monday, otherwise I can email the pacemaker clinic for advice and a proper explanation.

I told the technicians (not my usual ones) that I was confused by the number of RR changes over the last few years.  They seemed surprised too.

I am waiting for appointments to come through and dates when I can submit downloads to the clinic for them to see whether RR is working effectively.  I can go back any time if it is not.  It is definitely working because by tapping on my device my BP monitor is giving me a higher heart rate, closer to 100 bpm.  My heart rate otherwise is fairly static at 70-75  bpm.  

I haven’t noticed any real improvement with exercise since RR was switched on again yesterday.  I had to climb many steps exiting the bus station and walked about a mile.  Only thing I noticed was a bit of mid central chest discomfort


by Lavender - 2024-02-03 15:23:06

It's always perplexing to find out things need tweaking and you're not sure how this happened. 

Would a third lead help to synchronize things?

I wonder if they will schedule a stress test?

I was just going to ask you if you noticed any benefits of RR being on?

new to pace

by Gemita - 2024-02-03 15:23:37

My base rate is unchanged and has been 70 bpm since implant.  They mentioned yesterday I still had 3 years battery life remaining which is very welcome news at least


by Penguin - 2024-02-03 15:48:00

As Dave has a Medtronic device his advice may be the best to rely on as he has the same data format as you.    

I assume you've had an exercise test? 

Penguin and Lavender

by Gemita - 2024-02-03 16:08:55

I haven’t had a stress test in years (last during Ehlers Danlos autonomic testing in 2012, two years before Atrial Fibrillation was picked up).  During autonomic exercise testing they confirmed a problem getting my heart rate up, so exercise testing would be helpful I am sure to get this sorted.  Do they turn RR off for the duration of testing and/or stop beta blockers?

I don’t think I need resynchronisation therapy.  I am 100% atrial paced with almost no RV pacing, at present 0.7%.  No benefits from RR whatsoever which is weird.  That is why they keep turning it off.  One technician even said I don’t need it.  If they don’t offer a stress test, I will ask for one.

Penguin's last sentence is important !

by IAN MC - 2024-02-03 16:13:43

My Chronotropic Incompetence was first identified when I was invited to do a treadmill test using the "Bruce Protocol'

I was wired up for ECG  and blood pressure readings while walking/running on a treadmill .The test is done in 3 stages with varying speeds and treadmill gradients ,

If you haven't had one I would push your cardiology dept to do the test.........I'm sure this would help answer many of your questions ........ unless , of course, you're just too bone -idle.



I forgot to address one of your questions

by IAN MC - 2024-02-03 16:24:20

It IS  very possible to suffer from Sick Sinus Syndome and NOT have C.I.      Its occurrence in SSS patients has been reported as being anywhere beween 25 and 60 % depending on which paper you read.

Ian x

PS  Sorry your reply to Penguin re Exercise Stress Testing  crossed in the post with my comment.

Poor man's treadmill

by Repero - 2024-02-03 16:43:14

Hello again Gemita.

My RR was turned off (and remains off) at my first 4-week review. I had already noticed that my heart rate had been doing strange, inappropriate things during that early period, but they got to the bottom of it during an extended session at that first review - luckily I was the last patient of the day and they made extra time for me.

Lacking a proper treadmill, they just had me walk down a floor, along the corridor below to the next staircase, and back up again. They immediately quizzed the PM to see the histogram of heart rates. They could also see what fraction of pacing was instigated by my own sinus node, or internally generated by the PM. I did it quite a few times. The only orderly response came when they turned RR off. My body proved to be entirely capable of regulating my heart rate: apart from the AV block which the PM needed to bypass. Since my chronotropic competence was never in question, I do not know whay they ever turned RR on in the first place.

I sincerely hope they can find out what is going on in your case.


by Gemita - 2024-02-03 16:49:43

Thank you Ian.  Yes I can see an exercise test is well overdue.  They keep looking at my histograms, see little activity and assume I am a couch potato which has never been the case, but I never really followed this up.  

I assumed they wouldn’t want to offer a coach potato an expensive exercise test to see whether there was a problem but after seeing time and time again Rate Response is off with “flat histograms” on correspondence and now being told I am stuck at 70 bpm, I am finally questioning this


stress test

by new to pace.... - 2024-02-03 16:55:21

Since i have bad knees did not do the treadmill test.  Had whatever that chemical test is called.  Twice now once before the pacemaker and then again after implanted.

new to pace


by Gemita - 2024-02-03 17:05:37

That is very useful information Repero.  Thank you so much.  At least this time I am not having increased rhythm disturbances from turning on RR, but it is strange I don’t feel any different with RR turned on.  I don’t even notice when my heart rate increases.  It just feels flat - totally flat.  I only know it has increased by feeling my pulse

New to Pace

by Gemita - 2024-02-03 17:30:15

Thank you New to Pace I hadn’t thought about an alternative test without me actually doing the work.  I see that Dobutamine rather than an exercise stress test has been used during echocardiography to look for chronotropic incompetence.  Not sure which one is the gold standard test or how easy it would be to assess the real values using a chemical test without increasing Dobutamine but it is certainly worth asking about this alternative test as well in the event that I fail to perform adequately during an exercise test

chemical stress test

by new to pace.... - 2024-02-03 18:45:29

My heart was pushed I think harder than if i had walked the treadmill.  Do think they will only do one not both tests.  I know i am not fond of chemicals/perservatives.  I did ok with it.  My arteries were also tested and along with the pictures of the heart .  As i had to move my arms for them to get the pictures.

new to pace

Exercise Test Q's

by Penguin - 2024-02-03 18:55:09

'Do they turn RR off for the duration of testing and/or stop beta blockers?'

If they're testing to see if you are chronotropically incompetent they will most likely turn RR off to see if your heart rate goes up unaided. 

After that, and depending on what they find, they may then switch it back on and tweak it to get the right settings for you. 

Suggestion: If they decide that you need RR, perhaps ask them to set the rate at which your h/rate returns to normal to 'medium or slow'. I found that a fast return to normal meant that my h/rate changed too quickly from fast to slow and that this was a trigger for arrhythmia. 

Re: beta blockers. I'm not the person to ask as I don't take them. People I've spoken to tell me that their BBs limit their h/rate but 70 bpm is quite low.  If you've taken them for quite a long time, I assume it will be unwise to stop them suddenly for a test and could be dangerous. 

CI seems to be very confusing.  You could take your own advice and go by how you feel. If you exercise without RR and you don't struggle (e.g. I had legs that felt like dead wood during exercise when CI was diagnosed) then I'd leave well alone. RR interferes with lots of other settings. 

 Is there any chance that the reporting of stats on your device could be wrong and that some algorithm or other has been accidentally switched off during the multiple changes made to RR over the years ?  


by Gemita - 2024-02-04 02:12:50

Thank you for telling me to take my own advice “if I feel well, all is probably well”.  This is clearly the case most of the time although I have started getting some chest discomfort when I exert myself which is new for me.

By the way, I found an old Pacemaker Club link on Atrial Histograms.  Contributions from our valued members at that time (Donr and Inga) are particularly helpful.  Have a read Penguin and other members.  It does give lots of excellent info about how the data is generated.  

Although my figures are static and around 70 bpm, it doesn’t perhaps mean that I cannot exceed this magic figure on occasions. However having said this, I am well due for a formal exercise stress challenge after all these years.  I am clearly not paralysed or bed ridden, so I should be getting more in the way of variation reported on my Histograms.  

In the meantime, I am going to challenge myself to see how RR and my heart behaves.  I will send an email to my clinic and ask some questions and report back to this thread in due course.  This has been a learning process for me and something I really need to understand, so thank you all for your help.

Old Thread

by Penguin - 2024-02-04 04:21:28

Those explanations on that old thread make sense if your techs are looking at histograms only.

I come back to the chart of HR ranges that Dave writes about in his reply to you. What he refers to isn't a graph / histogram - it's a table.  You will have to wait for your interrogation results to see if one of these charts is contained within it perhaps? If so, I hope that it will give you some helpful & relevant info. 

PS: Taking your own advice was a compliment - it makes sense!   


Same device

by piglet22 - 2024-02-04 05:03:27

Hi Gemita

I'll be interested to see how you get on as we have the same device fitted.

Quite an array of things going on.

I have some of the symptoms you mentioned, i.e apparent lack of response to exercise.

It might be age, but in 18 months my ability to cope with things like hill climbing has gone down the pan.

I think this must be related to the high dose of Bisoprolol (5 mg twice daily) that I'm now stuck on (PVC interference).

If that's not the case, then I don't know what's going on.

I am due to see the pacing consultant in just over three weeks and this will be on the agenda.

I haven't a clue what my settings are.

The settings have.never been offered but I assume rate response is on.

I might start taking out the oximeter when I do walk, but radial pulse feeling suggests that my heart is hardly racing.

Never a dull moment.


by Gemita - 2024-02-04 07:47:22

Piglet, I have just sent an email to my pacing clinic.  Hopefully they will respond tomorrow.  They are usually very prompt.  I did ask specifically for the information as set out in Good Dog’s response because it will give me the exact percentage time I am supposedly stuck in the 70 bpm range as opposed to higher heart rate ranges. I am not sure whether I will get this detail sent to MyChart, although I am sure they will give a reasonable account of why my histogram is so flat/blunt all the time despite my efforts.

I will of course let you know by updating this thread.  

Please let us know too how your appointment goes with the consultant.  Yes Bisoprolol will depress us in more ways than we can ever imagine.  Some of us can be very sensitive to a beta blocker, especially at higher doses when it can lose some of its cardioselective protection, so it can cause more in the way of side effects as it targets other organs as well.  Bisoprolol is more cardioselective at lower doses I was told.

It looks as though we both need a proper exercise test to get a few things sorted.  I don’t suppose either of us would do that well at present.  

Have you got a Pacemaker ID sheet or card?  If you look up your Pacing Mode which should be listed, you should find an -R at the end of the Code if you have Rate Response turned on.  If no -R is showing, then Rate Response is probably turned off, but you would need to check to make sure Piglet.  I am not sure which mode you would be pacing in (DDD for example would become DDD-R if Rate Response were turned on).

You urgently need to know what some of your basic settings are. Have you got your pacemaker clinic’s email address.  If you have, you could ask them.  Only when you get your settings can you ever hope to understand what it set up and what might need to change.

Seems Odd

by SeenBetterDays - 2024-02-04 17:22:04

Hi Gemita, the flat histograms don't seem consistent with your activity level do they? Are you able to do a manual pulse check following exertion to ensure that the data is accurate? I would have thought you would have been far more symptomatic if your heart rate was sticking around 70. I don't know if I am unusual but my pulse often exceeds 100 bpm when I do normal household chores like washing up. Maybe it's the excitement! I hope you are able to get some clarity on this as it seems you are very much the opposite of a couch potato but your pm is suggesting otherwise. Puzzling. Please let us know how you get on. I have had an exercise stress test in the past and it completely wiped me out so maybe ask them not to push you too hard at this stage? Sending you love and best wishes.

Rate Response

by Lurker - 2024-02-04 18:37:54

Gemita, I really feel badly for you.  You are the glue that holds this place together.  Get well soon. 


Turning on the rate response is only half of the procedure. You can adjust the sensitivity from very low to very high sensitivity. For me it took a couple of times back to get it right. I complained I could only do about 40 minutes of yard work then I I had to rest.  The last time took me a good 3 months to get used to the change. They won't go any higher. 

Doc DX



Just one more obvious point

by Repero - 2024-02-05 11:20:32

Gemita, from your original post in this thread I get the impression that you have not been measuring your own heart rate during the walks and uphill climbs that you do?

If not, and it would provide you with valuable ammunition at your reviews, it is easily done with a chest band monitor linked to your mobile phone. I have a Polar H10 and associated free Android app.

I am sure you must know all this, and probably even do it! If so, I beg your pardon. If not, and you would like further info., please PM me.

SeenBetterDays, Lurker, Repero

by Gemita - 2024-02-05 19:33:52

Repero, thank you for your comments.  I often go by my symptoms alone and am fairly accurate in knowing what rhythm I am in.  I get breathless during an arrhythmia like AF, I feel the quivering chest symptoms and generally feel ill.  I always feel my neck pulse and know when episodes are coming in fast.  I can also get light headed.  I don’t use a monitor when out, although I have Kardia Mobile at home and a good solid BP monitor.  I have thought about getting a chest strap monitor but I keep meticulous diary notes and surprise my doctors when I tell them the times and dates when I feel my disturbances.  I am usually accurate so being “symptomatic” has its compensations.  Hope you are doing well Repero

Lurker, thank you for your support and have a wonderful trip!  I know it will take some time to get my RR settings adjusted but it will be well worth the effort

SeenBetterDays, no the flat histograms certainly do not reflect my active lifestyle.  I never have a moment to myself and am always running around.  I wear myself out!   Actually I feel my pulse often enough and it seems irregular and slow a lot of the time.  Maybe that is why I have been getting more in the way of chest pain.  It cannot be helping.  I love it when my heart beats firmly without pausing.  What a difference it makes

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