Confused after implant

Settings

by piglet22 - 2024-09-27 05:44:02

Hello 

Have you been reviewed by your team yet? Three weeks might still be too soon.

It could be that your settings need a closer look.

Are you monitored remotely or by face to face?

You device should be recording events like AF.

Unless you are specifically programmed, why are you going  as low as 40 BPM when it sounds as though your base rate is set to 60 BPM?

I had a base rate of 60 which was raised to 70 this year.

When I'm relaxed, I expect and get a fairly constant output of 70 give or take one or two points. I wouldn't want to be seeing 40.

Out of interest, how do you check your heart rate?

During Mode Switch a higher lower rate limit is I am afraid fairly normal

by Gemita - 2024-09-27 05:54:01

Welshblood, firstly welcome.  

With most manufacturer pacemaker devices, the Lower Rate Limit (Base Rate) is often seen to be higher when a setting called “Mode Switch” is activated during an atrial tachy arrhythmia like Atrial Fibrillation (AF).  The Mode Switch function protects patients by switching the device pacing mode to a nontracking mode upon detection of an atrial tachyarrhythmia.  When the atrial tachy arrhythmia stops, our pacemaker returns to our normal pacing mode and all its original settings, including your base rate (60 bpm).  By operating in a nontracking mode, the device prevents rapid ventricular pacing that may result from a high atrial rate when you are in AF which would be dangerous.  I am afraid this is all rather technical.  

So the setting is called Mode Switch which usually contains an active Rate Response Mode and a higher Lower Rate Limit for the duration we are experiencing an atrial tachy arrhythmia.  Most pacemakers or ICDs will have Mode Switch programmed ON and yes it is recommended to keep it ON if we are arrhythmia sufferers.  I don't know how high your heart rate reaches during AF, but clearly your episodes have been high enough to trigger a Mode Switch.

I am unclear whether your pacemaker manufacturer setting for the Lower Rate Limit during Mode Switch activation can be reduced from 80 bpm?  Clearly during automatic Mode Switch for the duration of the atrial tachy arrhythmia, there will be certain features that may or may not be easily adjusted for our own safety, depending on our heart condition. 

I believe the Mode Switch operates at a higher lower rate because as it switches to a non atrial tracking mode, we lose what is called the Atrial kick, which is a loss of atrial contraction.  This can cause a decrease in cardiac output.  The increase to 80 bpm is to compensate for this loss of atrial contribution, although clearly when you are trying to sleep this will not be helpful.   Atrial kick occurs as the atria contract prior to ventricular contraction and contributes up to 15-35% to the volume of blood in the ventricle.  As we get older we really miss the atrial kick due to AF and to Mode Switch!  I certainly do, so I appreciate having a higher heart rate setting to compensate, but for some it will feel uncomfortable.

I hope your doctors can relieve your symptoms by making a few adjustments, perhaps to your night time settings at least and to help you to get your AF under better control?

Thanks so much

by Welshblood - 2024-09-27 06:46:27

To answer Piglet. My usual 30-40bpm was prior to implantation of the PM. I was having AF (mostly nightly but often during the day too with a beat to beat measurement of 33 to 170, I assume that's the same. I have a Merlin box by the bed (size of an iPad) so the technicians have reviewed that remotely to confirm it's kicking in at the 80bpm buttwhen in AF. I measure with Fitbit versa, a Kardia mobile 6 lead and by hand although that's not that easy in AF. I tend tk use the 6lead the most but don't bother now I know the Merlin downloads all this stuff.
None of this have been explained to me so it's super helpful having this level of info and mostly I suppose I have to get use to it. I have never had a resting heart rate in the 60's never mind the 80's so it's all a bit new to me. If it is clinically correct and functioning then it's for me to adapt and get on with it I guess. Hopefully I can stop sleeping with my window open as I am so hot at night soon.. and the little drum in the ears will go away 😂 thanks for the info and I will try and read up some more but Genita has given me loads to absorb. Think Forest Gump, I can run for a long time but you wouldn't ask me to write you a thesis on it! 

It is still early days

by Gemita - 2024-09-27 07:00:14

Oh dear, I know!  You asked a technical question and I have “attempted” to answer it. 

You don’t have to accept or to tolerate your symptoms without some help from your doctors. Go back to them and ask whether during Mode Switch your sleep rate can be lower than 80 bpm for your device?

Your “overheating at night” is probably partly caused by your AF too.  I know mine is, so getting this under control will help too. 

You are still healing from your pacemaker implant and I am sure when things settle down, all your rhythm disturbances will ease and you will feel more comfortable.  Don’t panic, don’t overthink any of this or change things too quickly.  Time is often a great healer 

Thanks

by piglet22 - 2024-09-27 07:13:05

The extra information is useful

I guessed afterwards that your rate of 40-BPM was pre-pacemaker. Was this due to the heart block or being very fit, or both?

In the near 20 years I've had a device fitted, CHB bradycardia, I've always trotted along at the IPG base rate of 60 or 70 BPM as set with nothing programmed to change that during sleep or relaxation. Obviously that rises with exercise, but never goes below, give or take one or two beats.

There are exceptional circumstances which I won't muddy the waters with, where the apparent rate can drop well below the set base rate, even though the device is working correctly.

If you want a real reading exercise, download the clinicians full manual for your device to geta feel for the myriad of settings available. As you are UK and given the pressures on the NHS, it might take a while for anyone to spend time optimising settings.

Good luck

My Experience With Assurity PM and Base Rate Settings

by DoingMyBest - 2024-09-27 10:55:51

I received the same St Jude pacemaker for most of the same reasons one year ago at age 68 and physically active at the gym. Where we differ is with the AF, which I generally do not have. In the US, my pacemaker clinic typically does a pacemaker interrogation every three months (I've had some extra when getting adjustments made). On each report I usually see a small handful of AMS (automatic mode switch) events, each resolving in a few seconds - so not really indicative of an AF problem for me.

You can expect it to take a couple months for your heart to heal and arrythmias to settle. Also, with the PM in place to keep you going, the cardiologist can increase your medications needed to suppress your AF. I am hopeful the AF will improve for you.

My PM came with out-of-the-box default settings other than MTR (max tracking rate), which I got them to set to 150 BPM initially. Base Rate was 60 BPM. After a few months, I got them to enable Rest Rate at 50 BPM which allows a slower rate while sleeping. After nine months, I was able to get them to lower the Base Rate to 50 BPM and the Rest Rate to 45 BPM. This seems to suit me well. This change has allowed my AP% (atrial pacing percentage) to drop from 24% to 4%. Virtually all my atrial pacing occurs during rest at the lowest (base or rest) rate.

As to battery life, I was initially concerned as well about the effect of excessive pacing. I don't have actual numbers, but what I've learned is that the pacemaker battery usage is dominated by its internal electronics and the pacing is actually a lesser portion of the usage. So, perhaps something like 70% to the electronics, 30% to the pacing. With this in mind you can see that changes in pacing amount have less effect on battery life than you might think.

Give it some time and keep asking questions. It takes awhile for the heart to settle and to understand enough to aleviate your anxiety, then everything will improve.

Sleep mode

by Amyelynn - 2024-09-27 11:11:53

Maybe ask your doctor about turning on the sleep mode option if your pacemaker has this.

they are able to set you at a lower rate like 50 at night between specific hours so say  10pm-6am it will be 50bpm. Maybe they can also lower the afib tracking mode to at least 70 at night? Not sure if that's also an option

good luck!

Amy 

St Jude Assurity

by sgmfish - 2024-09-27 17:55:51

I have a St Jude Assurity PM. I've educated myself on the PM settings (of which there are many). I am no expert, but I do know that there are at least 3 settings that would affect what you are talking about: Base rate, AMS base rate, Atrial tachycardia detection rate. The 1st sets the normal resting rate; the 2nd is the rate used when your PM is in AMS mode, and the 3rd is the artial rate at which your PM switches into AMS mode. AMS mode is to protect against the PM attempting to send pulses to the ventricles to follow an excessively high rate in the atria (often 200+ beats); so if you are in AMS mode your ventricles are 100% paced at the AMS base rate because following the sensed rate from the atria would be way too high. All 3 of these parameteres can be changed by the techs. BTW, "out of the box" these parameters are often set at: Base rate = 60, AMS base rate = 80.

Thanks once more

by Welshblood - 2024-10-04 14:54:21

Thanks again all. It’s hasn’t settled but I continue to get on with it. I walk daily and had one session on the spin cycle. I am in AMS it seems more and more. I assume I am "out of the box" settings as it is 60 base rate and 80 ams base rate, no idea what the atrial tachycardia detection rate is out of the box but I am triggering that a lot. I have some strange triggers for going into AF and one of the strangest ones is singing. I sing in a band and went back to rehearsal and had one of the biggest AF episodes since AF. Makes me feel quite ill, sweat ridiculously, slight breathlessness and bizarrely I desperately need to urinate! My tech appointment is not for another 3 weeks to see if they can tweak anything but I really hope so. I am on no blood thinners or other medication for anything. They better sort it out soon as I hope to be swinging the golf clubs again and getting back to the gym.

its amazing how much I learn from this forum compared to anything the med professionals have provided. Thank you..

Biggest AF Episode

by Penguin - 2024-10-04 15:12:25

HI, 

Sorry to hear this. Sounds very difficult.  Just for clarification purposes, what do you mean by 'one of the biggest AF episodes' ?  Do you mean that it was more intense than usual or longer than usual or somethign else?  IMHO, (and I'm no expert) each of these things may be important, in terms of how your pacemaker is programmed to respond during the episodes. E.g. sometimes settings can cause the arrhythmia to continue rather than being able to terminate it. This may be due to the rate at which it occurs and whether or not the pacemaker is able to terminate lower rate AF. 

In terms of intensity, you may need to ask about why you are feeling the arrhythmia more intensely than before you had a pacemaker. Settings may be adjustable to lessen this type of discomfort. It's worth asking about it although I'm unable to advise.

Btw. St Jude isn't the name used by your PM manufacturer anymore. Ownership changed to Abbott some time ago.  I see that your PM was implanted in 2024. Abbott would have been the name on the box at that time. A lot of the US people on here still use the name St Jude.