CRT-D and Breathlessness

I cycle raced from 10 to my early 60s with some wins and many races that I have learned made life worth living.  In 2005 I had a dual chamber Medtronic inserted and continued to cycle with others.  This pacemaker was replaced in 2012 with a dual chamber Boston Scientific.  This developed 'noises' in the summer of 2015 and my EF had droped below 35 which qualified me for a CRT .  By 'lucky dip' I got a Boston Scientific CRT-D. This was when my exercise tolerance started to tumble both in the gym and on the bike.  After three years with a cardiologist who seemed to have no concern about pulses which would not stray beyond the range of 70 - 74 bmp and EFs as low as <25.  I changed my cardiologist about 12 months ago.  I have seen many in his team and had a 'syncope' in front of one of then which led to my Canasartan being reduced from 8 to 4 mg.  Since I had another 'syncope' a fortnight ago and spent a night in hospital I have been taken off Candasartan.  My present cardiologist tells my that my heart function as improved 'dramatically' it is just unfortunate that the symptoms haven't.  What appears to me as a contradiction is reduced to a conflict between scans and my inability to move without becoming breathless and in discomfort.

Does anyone have any comparable experiences?



CRT and Breathlessness

by satnavstan - 2019-05-14 15:59:47

HI, as a lifelong bike rider I had a pacemaker fitted at age 75. Had nothing but problems ever since with breathlessness and arrythmias. I am currently seeing another Cardiologist regarding these problems and he has just infomed me he doesn't  know anything about pacemakers and is going to refer me to a colleague who does - Thats the state of the british NHS. I regret ever signing the consent forms, my quality of life is rubbish now and as for riding my bike ever again  I feel very pessimistic. I hope you eventually get sorted ... you have my sympathy

Just an observation

by IAN MC - 2019-05-14 18:15:58

You were both keen cyclists. You are both now struggling with breathlesssness because  your exercise tolerance has fallen. As far as  I can tell you are both in your late seventies.

Inadequate exercise tolerance is known as Chronotropic Incompetence "  and one of the commonest causes of C.I. is GETTING OLDER. . A major reason for this is probably that every blood vessel carrying oxygenated blood is losing its elasticity so they become less efficient. 

Then, on top of getting older, you each have your own individual heart conditions.

I'm not suggesting for a moment that where you are now is    " as  good as it gets " because both of you would probably benefit from further PM adjustments ideally done while you run on a treadmill or pedal on a stationary bike BUT you must have realistic expectations of your likely performance in your late seventies (  as an ex-marathon runner and lifelong cyclist I say this with considerable regret ! )

Pacemakers can obviously compensate for chronotropic Incompetence with their Rate Response functions but these are only as good as their inbuilt sensors which attempt to detect when you're exercising. Cycling is a particular challenge for the St Jude model which Stan has because the sensor only detects upper body movement. Theoretically the Boston Scientific model which ADALONGWORTH has is better for cyclists as it has dual sensors, one detects upper body movement,  the other detects increased breathing  .I see that you switched from a Medtronic to Boston Scientific. I am curious, did you in fact find it was better for cycling ?

Finally , being also in the UK , I must defend the NHS.   I don't know how you can blame the NHS , Stan for you meeting a cardiologist who had the honesty to tell you that he knows nothing about pacemakers and then wants to refer you to someone who does understand them. That sounds like good medical practice to me.

I hope you both find answers to your problems . Let us know if you do.



Chronotropic Incompetence

by AgentX86 - 2019-05-14 19:45:30

Is the inablilty of the heart to increase its rate based on the oxygen demand of the body.  It's only one reason for exercise intolerance.  It is specifically what is addressed by pacemaker rate response, with varying degrees o success.  It is one of the issues that I believe all of us, here, have.  I know there are certain places that I have trouble walking, where a steeper grade would be no problem, for example.  My assumption is that the grade and length are enough that I'm working harder than normal but gentle enough that my PM doesn't notice.

As far as the NHS goes...  I'm a left pondian so have no valid opinion of your NHS but I also think the doctor in question did exactly the right thing by pointing to someone who specializes in pacemakers.  I don't believe anyone with a pacemaker should (only) be seeing a cardiologist, in any case.  An electrophysiologist is trained specifically to deal with electrical issues and pacemakers fall more directly under this subspecies of cardiologist.  It really does take a specialist to know how to set up a PM properly and deal with electrical issues. A cardiologist may also be needed to deal with structural issues that go along with the electrical.

Each to his/her own. Types of cardiologists and training.

by Selwyn - 2019-05-15 12:25:14

General Clinical Cardiologist 



Interventional cardiologist

Adult Congenital Cardiologist 

Nuclear cardiologist

Heart Failure and Transplant Cardiologist 

Computed Tomography/Magnetic Resonance Imaging Cardiologist 

Preventive Cardiologist 

Paediatric Cardiologist

...and this list is not complete!

Times change , medicine has become more technical. 

If you wish to see how the NHS trains it's cardiologists, see

My daughter is training in respiratory medicine and is rotating around that speciality's sub specialites....etc.

Kind regards.


by AgentX86 - 2019-05-16 08:20:21

It's not just a matter of training but also PRACTICE. All doctors have had surgical training and you're welcome to go to a dermatologist for a heart transplant but I'd rather go to someone who specializes a little more. Perhaps your beloved NHS doesn't even have specialists. Great plan but it would save money.

PMs and cycling

by crustyg - 2019-05-18 06:34:01

I echo Ian MC's comments.  Having a cardiologist humble enough to admit lack of specialist expertise in the area of PMs and cycling is a good thing - as long as you both do something about it.  I'm a keen cyclist - but nowhere near your capabilities - and due for a dual chamber PM this coming week, and have already got my cardiologist's agreement that I shall have a static bike programming session where we can determine the best response rate of the Boston Sci unit, based on one or other of the breath rate sensor inputs and attempt to optimise it from the start (well nearly the start once the leads have embedded).  We've already had the discussion about the max rate to be set - other folk on this club have pointed out that it's uncommon for cardiologists to be comfortable telling the PM programming tech to set a max HR greater than 130bpm, but there's no particular reason why this shouldn't be done where appropriate - the PMs can handle it these days.  Probably a little high for you.  And if your LV EF is really 25% then you're not going to achieve the sort of cardiac output that you might like, no matter how you drive your HR.

In the great book, The Haywire Heart, there's a chapter that focusses on the mental adaptation to loss of peak performance for the athlete / patient.  I'm re-reading it.....


Exercise intolerance and PM?

by AddieJ - 2019-05-23 11:29:52

I think this relates....I do ride and have a nice Specialized gravel grinder to cross train on.....but I’m not as good a cyclist as I am a runner (this is in context to and relative to my age.)  I have run and raced all my life through many age groups and until lately (last two years) just enjoyed getting older but being grateful to do well in a couple marathons a year.  I’m old.  71. I have a dual lead PM. I would do 6-10 miles about 4 times a week but more when getting ready to run long distance.....but yesterday I couldn’t make a mile.....down from over the last year when I would hit a wall at 4 miles.  I am aware I’m getting older.  Of course!  I don’t need to be told that.  But when I am used to running distance and not looking to break any records and knowing my speed decreases over time and being ok with that.....but I’m clicking along at my older/slower pace and according to my Garmin or i watch (whichever I’m wearing), my heart rate suddenly drops from 98-100 bpm to 60-70 and my run is over.  I can’t get my breath, my legs are lead.  I walk back home...bewildered.  My cardiologist says I shouldn’t even be out there.  And that whatever is happening “his” pacemaker is not to blame.  I’ve seen a pulmonologist.  They have me walk in a hall for three minute. Walk.  For three minutes.  I can do that, of course, so they say “what’s the problem?”  Here’s the deal though....I can cycle for an hour and a half, hard, with sprints. So that’s what I do. No problem.  But I love running.  What is the deal and does anyone else have the ‘sudden heart rate drop when exercising’ thingy? I reiterate....I’m not trying to break any records....i just want to be out there doing what I have done my whole life...but slower.  

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