Rate response poor, nearly always at 60

Hi

My 83 year old mum has just had a pacemaker fitted. A Medtronic, though I do not know the model (a recent one though). The reason was her heart rate was very low - it would drop to 45 at times - when doing moderate activity her heart rate would also drop, not rise, sometimes.

Initially the PM was just set to 60, and that is all it ever did. So we took her back to get it adjusted, because the rate response was not working. They said stuff about grey response and supposedly adjusted it.

The thing is - they never made her do any activity in the hospital, to see if they had fixed it - she just sat there plugged in while they did stuff, then left.

Now, the rate response still seems to not work. Before the PM was fitted, when she did some activity her rate would sometimes rise (it seemed to be more OK in the afternoon, worse late evening).

We walked up her garden (on side of a hill) and basically her heart rate hardly rose - it got up to about 75. At one point it dropped back to 60, while going up the garden, then rose again. At the top of the garden it rose to 80 for a bit, but quickly dropped back down.

During the day her heart rate, while moving around the house, is stuck at 60 most of the time.

Sometimes when she moves around, she says she feels her heart pounding - not often - but it seems to be when it should be accelerating but isn't.

My main concern is it seems very slow. I would have expected that during the day it would tend to be more like 70, not locked to 60. Then when going up the garden shouldn't it rise to 80 or 90 at least, and not drop back within a minute, but take several minutes, and then stay at 70 or more, rather than drop back to 60?

Other info - my mum is a tough lady - very much a stoic, so its hard to get her to describe when its a problem - but she always under-complains about problems. She has also had a fairly healthy lifestyle, does not smoke. She is overweight, but still will do 3 hours gardening in a day (until the heart problem anyway).

My sister, who took her for the check, said she thought they said they were setting it to a base of 70, but that has not happened.

Does it all sound OK, or does it sound as if they have not set it up right (yet)?

It seems that the heart signal is so weak much of the time that the rate response is not picking up the signal to boost - it just detects nothing, so enforces 60. When the signal occasionally gets strong enough from the natural heartbeat, her heart goes faster, but that only happens sometimes.

If the natural signal is rarely strong enough to trigger the pacemaker to rate respond, should the base be set to higher than 60?

If the rate response rarely works, and its at its most aggressive setting, should the pacemaker be changed for one using a different method of detecting activity? Or could it be the wires are in the wrong place?

Thanks,
Jeremy

5 Comments

New Pacemaker

by SMITTY - 2011-05-18 01:05:05


Hey Jez,

The causes of shortness of breath are many. Of course if the heart is not beating fast enough is one and the causes of your Mum's problem could be that in addition to other things. I am not suggesting this could be your Mum's problem, but use it just to show what I mean. A few months after I got my first PM I was having extreme SOB with almost any physical activity. Adjustments were made on the PM until hell wouldn't have it, all to no avail. So the Dr did a heart cath and found a partially blocked heart artery. A stent solved my SOB problem.

Unfortunately she will need a different mind set when it comes to that PM. There are more Dr implanting them than know how to set one up. To make things worse, it sometimes takes more than try to get the proper settings and just because that nurse/technician is doing things during a checkup we have never before seen does not necessarily mean they known what they are doing. If the PM hasn't helped much yet then she will have to remember the squeaky wheel gets the grease until she gets the help she deserves.

There may be other means of jump starting a rate response but all I know is the accelerometer depends on body movement to increase the heart rate. At least mine does. By the way I got my dual lead Medtronic Versa in Oct. 2009. What you describe as the way you think a PM works is correct. But that works with both the regular settings and the rate response.

I don't think the location of the lead has to be as precise as you said. It detects the electrical impulse, or lack thereof, from the heart's natural pacemaker to send a signal to the manmade PM so it will know whether it should or should not send an impulse. That impulse from the hearts natural PM is strong enough to be detected from almost any area inside the heart chamber.

You hit the nail on the head with "It all seems very much left to the patient to do the running, in getting their pacemaker set up correctly. I am very surprised to be honest - I would have expected a much more proactive approach, and a more scientific one, especially for an elderly patient who doesn't understand the technology." Let's face it, a PM is an electronic marvel and gets more complicated with each update. I think that is compounded by the fact there are many Dr doing PM implants that have never mastered the use of their TV remote.

My 80 setting did bother me for a few minutes each night for two or three days and I still hear it occasionally but it doesn't bother me.

I can agree that given the patient more control sounds like a good way to solve problems but that would also be a sure way to kill a lot of PM recipients. I can see the first thing some would do is get the upper and lower heart chambers so far out of sync that death would follow.

What the patient has to do is put that Dr on speed dial and let them know you have a problem. We have to remember that to the Dr we are out of sight and out of mind unless he hears from us.

There are sensitivity setting on the rate response and that may have to be looked into for your Mum.

Good luck,

Smitty


Pacemaker settings

by Selwyn - 2011-05-18 07:05:55

You can ask for a paper copy of the settings at a pacemaker check up and see at a glance, the rate response settings, the return settings, top and bottom rates etc.
I keep mine on file, then if anything is messed at the new check up I can look back and see how I have been messed.
Hope this helps

call them back

by Tracey_E - 2011-05-18 09:05:57

If her rate isn't dropping below 60, she's pacing so the wires are in the right place. This sounds like a programming issue and it's very common. There are a lot of settings that can be fine tuned on rate response and it's common to take a few tries to get it right. It can be a fine line between going up as needed with activity and not skyrocketing every time we sneeze so it takes a while to find a balance. They often make the changes in small increments, that way if they're not on the right track they know exactly what to change next time. It can be frustrating but it makes sense if you think about it. I wouldn't wait until the next appointment, call and tell them she doesn't feel right yet. They can sometimes put us on a treadmill and watch what the heart does on exertion, that helps but a lot of time with rate response the only thing we can really do is go home and test it out.

Mum's Pacemaker

by SMITTY - 2011-05-18 11:05:38

Hello Jez,

Let me start by saying I'm not unfamiliar with a situation like your Mum's. I have a Medtronic PM and I just had my 82nd BD a few days ago. My unassisted heart rate is in the mid to upper 40s. The low set point on my is 80, but that is by my request as I needed that to solve an arrhythmia problems. Before the 80 it was 70. My rate response is turned on but I have no idea what the upper limit is as I have never asked. I just know it will increase my heart rate when I have any significant physical activity.

Now, don't misunderstand me when I say this, but I just need to know if your Mum is concerned about her situation, or is it mostly her children? Reading your message, I see concern from the children more so than concern from your Mum. The reason I say that, my kids can worry the daylight out of me thinking something should be different when I am perfectly happy with things as they are.

With that said, I'll make a suggestion or two for your Mum, if she wants to do it. One is if she thinks her heart rate should be higher ask the Dr if there is any reason she can't have say a 70 (or whatever she wants) for a low set point. There is nothing magic about the set points so long as they will give a heart rate that will supply the needs of the person without stressing the heart. I've had a PM 11 years (on my 2nd one now) and I've had several different low set points, from a low of 40 to a high of 80, at my request. Like I said, if your Mum, is interested in a higher heart rate, ask the Dr if it would be alright for hers to be increased.

As for not the Dr checking out the rate response when it was turned on, I have never heard of anyone having that done. So far as I know they "dial" in the numbers they want for it the same as the do for the other set points on the pacemaker. The rate response is mainly activated by an accelerometer which detects body motion. I understand some will also increase the heart rate with an increase in body temp. or stress. The changes brought on by the accelerometer and temp. I can understand. but the stress I can get a handle on that one.

I can tell you my way of checking my rate response. My pacemaker is under my left collar bone and if I want to see if it will increase my heart rate I just tap (firm but not hard enough to be uncomfortable) on my chest about 3 or 4 inches from my PM. My favorite spot is at the top of the ribs and just to the left of the sternum. Before starting the tapping I check my heart rate and then tap for about 20 to 30 seconds and check my heart rate again. The tapping is enough jarring for the accelerometer to detect and it will increase my heart rate. Within one to two minutes after I quit tapping my heart rate will return to what it was before I activated the rate response. Give some of this a try and maybe it will give your Mum some numbers to discuss with her Dr.

I just noticed your last paragraph. No, you should lot even consider requesting a change in pacemakers. The one she has will meet all of your Mum's needs. All it needs is to have the correct setting for her life style. Sometimes getting those "correct" settings is easier said than done and make take more than one visit to her Dr. If your Mum can't get the results she wants maybe she will need to consider changing Dr.

I wish your Mum the best,

Smitty

Various

by jez6363 - 2011-05-18 12:05:08

Thank you both for your replies.

The concern started with my mum, after it was fitted - she found that a short walk (around a shopping mall) was making her really out of breath and tired. No longer desparate and close to collapse - but still not good.

She then referred to how she could sometimes feel her heart pounding - she timed her pulse and it was at 60, when it should have been much higher.

Walking up the garden she was very out of breath and had to pause several times - that frustrates her very much as she loves her hours in the garden.

As with many people of that generation though, the idea that the medical profession may make a mistake, or not get it right, is alien. So she is already falling into the 'thats the way it should be' mindset. Its not that she is happy with it - just she feels she cannot change it.

The people who set it up have obviously not communicated to her the fact that it is an iterative process, she just thinks that is over and done with. I am sure that is not how it is supposed to be though, and your comments confirm that.

I am also not sure that her pacemaker works like yours does Smitty. The accelerometer approach to increasing the rate - is it still used for rate response. The explanation I was given was that they use the implanted wire to also detect when the heart is generating its own signal, and then boost it if it is weak - at least that is how it was explained to me.

To make that system work, it needs to be able to sense the weak signal, which relies on the wire being implanted in exactly the right place. Its not whether its in the right place to pace - its whether its in the right place to detect the signal - and I think that is a more difficult thing to get right when implanting the wire.

That said - from info I read on the web, there are either acceleration based rate response units, or breathing rate based ones - no mention of one like I described.

It all seems very much left to the patient to do the running, in getting their pacemaker set up correctly. I am very surprised to be honest - I would have expected a much more proactive approach, and a more scientific one, especially for an elderley patient who doesn't understand the technology.

Smitty - you said you have trie various base rates - and ae now on 80 - 80 seem very high for sleeping - did it affect that, or was it OK?

To be honest, they would be better giving the patient more control of this stuff, so they can try things (within a safe window of course) so people can see what works best for them. Some sort of home programming switch that could switch it between say 4 pre-set modes, or something.

Given where she is at though - I think the thing to ask the technicians to do is:

- Raise the base from 60 to 70
- Make the rate response at least 1 notch more aggressive

It just seems that what people do is this iteration process, but only if they are like yourselves, and know enough about it, and are pushy enough to ask for it. That can't be right, can it? I wonder how many badly set up pacemakers there are out there - on the basis of what I have read and seen, I am guessing half of them are a long way from optimal setup...

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Today I explained everything to my doctor, he set my lower rate back to 80 and I felt an immediate improvement.