Frustrations with rate response, communication related to device selection

Apologies for length of this post:

I am interested in knowing if my experience is shared by others.  I am a recent (12/10/2018) of a pacemaker. I am 69 years old and very active.  I probably do 3-4 times the recommended 150 minutes/week on a regular basis. I have been a swim coach for 40+ years so swimming is a primary exercise but I also bike, paddle, XC ski, hike and I run some.  I have had a very low resting HR for quite a while (low-mid 40s). In recent years it seemed like I could not get my HR up, typically 110-120 at the max. In October 2017 I had a tick disease called Anaplasmosis which among other things knocked my red cell count way down and it has not fully recovered.  As a result, when I felt very poorly last year I attributed it to the anemia. Eventually, I got the opinion that my level of anemia, while below normal, was not enough to account for my exercise difficulties. A Holter monitor and other evaluations led to a diagnosis of Sick Sinus Syndrome. An EKG taken on 11/8 showed the absence of the small bump that should have been the SA node firing.  When I saw this, I reluctantly was forced to agree with diagnosis.

On that day, I discussed my lifestyle and level of activity with the EP/Surgeon.  I wanted to know about the rate response function and how that worked. He indicated that the pacemaker would sense my respiration and emotion (maybe he just said motion) and that it would then appropriately increase my HR.  I really liked this doc and had a lot of confidence in him. I was told scheduling would take about three weeks and that they would call when they had an opening.

After two weeks, I called to see if they could give me some sense of a timeframe since I had travel plans for January 7 and needed to know if I had to cancel them.  They said they were waiting on insurance. I called the insurance company and they indicated they had notified the cardiology place with approval. I called back the next week and was told they had three opening the following week, so I signed up for Monday the 10th.  I’m not sure if they were going to call me as they had indicated.

When I went in the prep room, there was a whiteboard with my surgeon’s name on the top and a list of things they needed to do, IVs etc.  They checked them off as they completed them. About an hour before I was due to go in, they erased my surgeon’s name and wrote another one.  They didn’t know why but was assured that the new guy was very good. I was not happy with this but went ahead with it and as far as I can tell, the actual surgery was fine.  The next day, the original doc came to my room apologizing, saying he didn’t even know I’d been scheduled and that he had been out of the country the previous week.

For probably the first time in my medical life, I followed the recovery instructions to the letter.  No swimming for six weeks, no driving for four weeks-all of that. I started walking right away and after about two weeks, I felt like I was actually getting faster.  I had my first follow up appointment and all systems looked fine. I asked the device tech guy if I could begin to push the effort a bit and he said that was fine. About three weeks post-op I was walking up to two minutes faster per mile than previously, 15-16 minutes instead of 17-18 minutes.  I did one six mile walk where I had only one mile over 16, I thought that was pretty good. I traveled to Florida on 1/7/19 and kept up the walking there, even adding a little jogging. I felt like I was getting the first training response I had felt in a long time. I was very encouraged but was anxious to see how things went in the pool when I could start that.

I started swimming on 1/21 and was very cautious at first but made steady progress for about 2 ½ weeks.  Then things stagnated, or so I felt, plus I was sensing that some other aspects of the PM performance felt a little off.  I called the office and they had me send a “transmission”. They called indicating that it seemed to be working properly but made an appointment to come and see the device tech folks.  This is where things get interesting.

I met with a different tech person than I had seen previously.  She asked me to describe what I was feeling.  I told her that I did not feel like the rate response was kicking in as soon as it was, that my HR in the pool was still only about 110 and that other times ,like walking up a steep hill, it was only in the mid 90s.  I also had some very faint episodes of re-syncope, which had totally disappeared. She then said something like “I’m surprised they gave you that device.” She indicated that my Medtronics device had only a motion sensitive accelerometer and is not responsive to some forms of exercise.  I had read some things about certain devices not working well with swimming and/or cycling. I saw some references to a particular German device that worked well for swimming. I also saw accounts such as the older gentleman from Australia who had set some masters national records since his surgery-so I it seemed that a PM could be effective for swimming if it’s the right one.  

The device tech mentioned above then continued along this line:  “I should not ‘bash’ my company since I work for them, but I can tell you why they gave you the device they did." It seems that the local hospital and associated health care network has a business arrangement with two companies, Medtronic and one other, neither of which makes a device for which the rate response works on anything but motion, not respiration.  She said that the doctor’s hands were tied regarding which device to give me based on the “business model” and that the health care system placed that business model ahead of patient care.

She made a few tweaks to my device which she hoped would help.  So far, I do not notice an appreciable difference. I continue to be able to walk at an increased pace over flat ground and struggle with hills.  It was explained to me that the problem with hills is that you tend to slow down your speed and your stride rate. With the slower stride rate, the accelerometer senses less movement and lowers the HR just when you need it the most.  She said that she gets the same complaint from runners a lot.

I am very frustrated at many levels with this experience.  I very much trusted the doctor who told me that the device would sense my respiration rate and respond accordingly.  I can also accept the possibility that he may be very competent at diagnosing my issues and as a surgeon but may not really understand how the devices work.  There has been miscommunication and misinformation from every angle. At this point I am not sure how I will proceed and who to register my concerns with. I am very interested to know if anyone on the forum has had a similar experience or if there are any suggestions.




Rate Response & Medtronic PM

by catthree - 2019-02-24 15:59:42

I can't offer anything that will help your situation, merely let you know that I, and others, have had similar rate response issues with Medtronics units, for the same reason, i.e. the RR is triggered purely by accelerometer. I'm 71, with an extensive background in bicycle racing and distance running, which extended at the Master's level into my 60s until atrial flutter, and then V-tach got in the way.

Despite successful ablations, which seem to have eliminated the rhythm problems, I am still on 25mg of beta blocker, plus a low dose of ranazoline, both to minimize or eliminate the electrical issues. 50 years of competitive running and cycling gave me a resting pulse around 48 bpm (which dropped lower during sleep) , so my PM function is set to keep  my HR from dropping below 50.

My doctors discouraged cycling, sayijng they simply did not know what triggered my arrhythmias. So I took up walkling as you did, 5-6 miles almost daily, and on what I considered satisfying days, kept the average in the high 14 minute range, but more often in the 15s. I had exactly your experience: quick on the flats, able to jog a little on downhills and sometimes on flats, but always uncomfortable going up hill. For exactly your reason: the accelerometer thinks you are easing back going up hill, not the reverse.

About a month ago I developed plantar fasciitis in one foot. so I decided to put one of my dust-collecting racing bikes on an indoor trainer. I've been doing that for about a month now, and again the Medtronics unit is a poor match. The accelerometer doesn't recognize cycling, especially with a relatively non-moving upper body, as exercise. So HR does not respond to effort properly, and it is impossible to pedal at the higher cadence typical of experienced cyclists, since cadence stresses the cardiovascular system (needs the HR rate response). Total power output or any other cycling metric is depressingly low, and during a 50-minute workout which has me dripping sweat, my average HR stays around 90 bpm.

It just seems to be a problem with the Medtronics design, it is not meant for "exercise outliers" such as you or me, And yes, my hospital system is also matched up with Medtronics.





oh wow.

by Tracey_E - 2019-02-24 19:12:54

It sounds like the original doctor was planning to give you a Boston Scientific. They are the only one that use both breathing (minute ventiltion) and motion (accelerometer) in their rate response. Medtronic and St Judes only use motion. Biontronik uses CLS (closed loop stimulation)

A hospital will have an agreement with one or more companies and primarily use them. Primarily, as in when it doesn't make a difference, so there are exceptions. 99% of patients will do fine wtih any of them and in fact are better off with one that their doctor uses the most because they know it inside out. Rate response is the main difference between them, otherwise they are very similar. Many patients don't even use rate response and the ones that do use it get by just fine with accelerometers- unless they swim or cycle.

The doctor can use whoever they want and the fact that he even discussed it with you implies he had every intention of giving you Boston so the mistake was made either in scheduling you when he wasn't there or the doc who filled in not reading enough of the chart to know your doc had other plans for you. 

Have you talked to the original doctor and expressed your disappointment and frustration? Replacing it probably wouldn't fly with the insurance company, assuming if you'd even want to do that. There are other things they can do to make the rate response more aggressive. Cycling is more or less hopeless because it's all legs but sometimes there is enough arm movement in swimming that they can set it aggressive enough to help. There are quite a few settings in rate response so there is likely more they can do than what they already havae. They like to make changes in small increments so don't be shy about going back., tho I would push to see the doctor not the tech. 

A note, mine is set very aggressive so my rate shoots right up when I work out. I love it at the gym, but the downside is I get short of breath walking across the room sometimes. Annoying, but I'll take it if that's the price I have to pay to get in a good workout. 


Medtronic Rate Response

by AgentX86 - 2019-02-24 21:03:23

Medtronic's rate response is pretty weak.  I walk quite a lot (100-130mi/wk), about half on a treadmill and half on fairly flat ground, so I'm in reasonable shape. Still, stairs get to me, as does walkimg uphill.  There are places where I have to tell those with me why I'm having a little trouble keeping up or getting winded, why.  They all know I walk a lot but are surprised when I'm having trouble and they don't even notice the hill.  It seems that Medtronic doesn't even have a 3-axis accelerometer equal to a FitBit.  You aren't alone in your assessment of Medtronic's technology.

Because of PVCs, my PM is now set to a minimum of 80bpm during the day (50 at night) but walking on the flat, it only rises to about 90 or maybe 95.  I get it to about 110 on the treadmill and I think that's limiting me.  I've sort of plateaued in what I can do. 

I've attempted to get my PM tweaked up but the techs are very reluctant to get very agressive but they will work with me.  They did show me that going too far isn't good either, so my plan is to just keep asking for a little more each time.  That way, I should be able to get used to the new settings more slowly, so they won't feel like a step back. 

Medtronics for Athletes

by KonaLawrence - 2019-02-25 02:25:21

Aloha Jwren,

I sympathize with your problems with the Medtronics PM .  I had similar problems.  I now have it working better, but things will never be as good as before.  Ho hum...

Anyway, you might take a look at some of my lengthy previous posts, like
If you wish to search for my posts there are a number about this issue.   I highly recommend you read the Medtronics Manual, expecially the Rate Response section.  I had much better results with the Medtronics Techs when I could ask specific questions about settings.  You can get it here...
Pages 28-41 cover Rate Response and definitely look at the tables on pages 199 & 200.  The bottom line is that the Rate Response Optimatizion routine doesn't expect you to exercise more than 100 minutes per week.  If you do, it increases the "Upper Rate Setpoint" which makes it harder and harder for you to get your rate up!  Ultimately I had them turn off the Rate Response Optimazation and fix the Setpoints.  That has problems too, but I can get a higher rate during exertion.

Good Luck, Lawrence

Medtronic and all the others

by IAN MC - 2019-02-25 04:48:25

Mine is a similar tale. I was a marathon runner and very keen cyclist till Sick Sinus Syndrome changed my life.

My cardiologist subsequently apologised for fitting me with a Medtronic PM and stated that he should have taken my lifestyle more into account.

The Medtronic accelerometer has enormous limitations but after many sessions on a treadmill I now have it set as good as it gets.

It sounds pessimistic but Kona said it all with his statement " things will never be as good as before ". I strongly believe that this applies no matter what make of PM you have ( if you like to exercise hard.)

The natural physiological mechanism whereby heartrate increases when you exercise is VERY complex and PM manufacturer attempts to simulate it with their RR sensors are still very primitive in my opinion. It would seem that dual  sensors are better than single accelerometers but some people with dual sensors have encountered massive problems getting optimum adjustments.

Doctors cannot even agree on a definition of chronotropic incompetence !

I really sympathise with you JWREN but life can still be good with a Medtronic pacemaker.  I gave up marathons and  serious cycling but now enjoy other activities .. it is a case of having different targets to before.

Best of luck




different pacemaker

by Skeet - 2019-02-25 14:31:48

Let me say first, I feel all of the frustration that you all feel. I have a Boston Scientific pacemaker with MV. It may help some, but it is not answer to all pacing problems. I am 71 years old and on my second pacemaker. I raced bikes for 30 years off and on, and am still riding. No one can tell me when I am climbing and breathing very hard why my pulse does not go up and stay up. I believe there are controls in the pacemaker that shut pulse down. What they are, I can't find anyone that knows. I have talked to BS tech through customer service and all they can say is tap on pacemaker. That really didn't work for me.

I believe there is no pacemaker or settings on a pacemaker that can match our natural heart. 

Everyone that has exercised for an extended period of time, I would encourage you to read a book, "The Haywire Heart" by Case, Mandrola, and Zinn. I always thought exercise was good for me. Guess not.



Rate response

by JWren - 2019-02-25 15:21:17

Thank you to all who have responded to my initial post.  Clearly I am not the only one with the problems I've encountered.  Hopefully things will improve as further adjustments are made.  As of now, I am better at walking on flat ground and that's about the only change I can see since my surgery.

Two months before my surgery of 12/10/18, I did a north to south rim to rim hike in the Grand Canyon in 10 hrs/50 mins.  The last three miles were really hard (and slow).  I am determined to finished the rim-to-rim-to-rim trek and have booked a trip for September.  We'll see how it goes in the prep while going uphill.  


You know you're wired when...

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Member Quotes

I had a pacemaker when I was 11. I never once thought I wasn't a 'normal kid' nor was I ever treated differently because of it. I could do everything all my friends were doing; I just happened to have a battery attached to my heart to help it work.