Pacing rate change/rate response


i noticed from my last visit that my atrial pacing percentage has changed:

1-9-23 atrial pacing: 35%

3-27-24 atrial pacing: 59.8%

my ventricle paces 100% of the time and I'm pretty sure always has since I had a pacemaker.

i have complete heart block. 

the EP was explaining to me that my heart works fine but what doesn't work is the connection area (forget the term) where the atrial speaks to the ventricle to relay the beats etc. So that's what my pacemaker does. 

however after looking over my chart more she called me and said there is room to make changes in my settings and turn on rate response. I go back Wednesday next week and a Medtronic rep will be there.

1. Has anyone's rate percentage changed on them? What does this mean? Is my heart getting worse?

2. Do you all have rate response on your pacers? If so please explain to me more about it. 




Simple explanation

by Lavender - 2024-04-02 21:57:33

from online:

Electrical signals cause muscles to contract. Your heart has a special electrical system called the cardiac conduction system. This system controls the rate and rhythm of the heartbeat. Cardiac conduction disease is progressive over time.

With each heartbeat, an electrical signal travels from the top of the heart to the bottom. As the signal travels, it causes the heart to contract and pump blood. The heartbeat process includes the following steps:

The signal begins in a group of cells, called pacemaker cells, located in the sinoatrial (SA) node in the right atrium.

The electrical signal then moves down to a group of pacemaker cells called the atrioventricular (AV) node, located between the atria and the ventricles. 

The AV node fires another signal that travels along the walls of your ventricles, causing them to contract and pump blood out of your heart.

The ventricles relax, and the heartbeat process starts all over again in the SA node.

I have a pacemaker because my AV node no longer works. The pacemaker picks up the signal and sends it to the ventricles. I am 100% dependent on my CRT-P. 

I do not have rate control turned on. I don't need it. Rate-responsive pacing adapts the pacing rate to changes in the patient's physical activity. An activity sensor is used to measure the patient's movement and to determine the appropriate pacing rate.


by Amyelynn - 2024-04-02 23:16:12

Hi Lavender

thanks for that explanation yes my AV node also does not work... that's the correct term "AV Node" that I could not remember.

Pacing rate change/rate response

by Gemita - 2024-04-03 07:25:50

Amyelynn, our pacing percentages can change which can be normal since our heart condition never stays the same, nor perhaps our medication, state of general health, or lifestyle which may change our requirement for pacing too.   So too can any of our settings, like the Base Rate.  My Base Rate is set at 70 bpm and I am 100% paced in my right atrium.  Reduce that Base Rate to 40-50 bpm and the % time I am paced in the right atrium might also decrease.

We always say “how we feel is more important than those percentages”, so how do you feel?  You say you have complete block, so I know from this that the upper chamber signals are not getting through your atrioventricular node to your ventricles, the main pumping chambers of your heart.  For this reason you are pacing 100% of the time in your ventricles.  This is perfectly normal for you.  Whether or not you have chronotropic incompetence, a condition where your heart rate doesn’t rise appropriately with exercise, would require stress exercise testing to help confirm.

I have just had my Rate Response setting turned off because it was not helping and seemed to be causing a higher resting heart rate which my doctor wanted to treat with more beta blockade which would only make my flat rate histograms even flatter. 

So yes my pacing percentages can go up and down which can be normal for the reasons I have explained.  Rate Response can be tricky to adjust to suit your unique needs, but well worth trying first to see if it helps.  I am glad the manufacturer rep will be present next week.  They know so much more about their own product.  Rate Response has to learn “you”, the patient, and this will take time.  Good luck next week

Rate response

by Good Dog - 2024-04-03 07:43:44

Lavender provided a great explanation. I just want to add that your pacing percentages really don't mean much other than advising the extent to which you are PM dependent. Really, what matters more than anything else; is how you feel. How do you feel throughout the day when you are active. Do you have any symptoms such as shortness of breath? Are you able to do all the things that you want/need to do? If you have troubling symptoms and/or do not have sufficient strength endurance, then you may need rate response turned on. You have been through a lot and that may be the case.

My point is this: the decision to turn-on rate response should be made based upon how you feel, not on your settings and/or interrogation results. It should only be turned on if you feel that you need it. Your decision. If you feel you need it, then by all means; turn it on. If you are doing well without it, then I would leave it off. Why work your heart unnecessarily and use more battery if you do not need it. It is your decision with concurrence by your Doc. If you decide to use RR, then keep in mind that it will likely require some adjustments down the road.  

I am confident you will make the best decision for yourself.

I wish you the best!


Late edit: I wrote this before I saw Gemita's post. So sorry for any redundancy.

Good Dog

by Gemita - 2024-04-03 08:32:41

Dave, your work will never be redundant.  It always provides "clarity"


by Amyelynn - 2024-04-03 11:27:47

Thanks Geminta & Dave

i guess my atrial rate could have changed when they increased my base HR from 50 to 60.

one of my concerns I expressed with the EP was my cardio and how I don't think it is where it should be after this last generator change. I get more tired than usual on more intense hikes and workouts. 

I think at first she thought my atrial set the pace for my ventricle but then after learning that my atrial is paced 60% she realized I could get rate response turned on?

im a bit hesitant now after learning from you both and also the EP mentioned that it could take a few times/changes to make things right for me. Eek sounds inconvenient and also I don't want to feel worse. However the thought that I could feel better with some changes makes me interested in trying the RR. 

thanks again for both of your help!


I would try it with confidence

by Gemita - 2024-04-03 12:24:02

Amy, you will have the benefit of having the Medtronic rep there next week, so take advantage and explain everything to him/her.  I would at least try Rate Response.  What have you got to lose?  

If they let you use an exercise bike or treadmill next week, they can get a better idea of what rate response settings you might need.  You are clearly more active than I will ever be and so may benefit more from Rate Response.  It will be worth the trial and error in getting the settings adjusted to suit you.  I hope you will be a new person soon

You know you're wired when...

Your heart beats like a teenager in love.

Member Quotes

A properly implanted and adjusted pacemaker will not even be noticeable after you get over the surgery.