Atrial Lead Amplitude Update - Mystery Problem Solved

 

I've found the problem with the help from everyone - Thank you so much!!! There are likely a bunch of typos here, because I was up half the night thinking and working on this! Sorry for that!

I have sifted through all my previous interrogations for my atrial lead going back 5 years. I built a spreadsheet so that I can cover all the bases. I appreciate all the help including Piglet that I have yet to respond to. Thanks! Actually, agentX86 was correct. The problem for the voltage spike is the Auto-capture management being turned-on and set to "Adaptive" on my new generator. When I discovered that the resistance (impedance) was withing the normal range(s) and there was no unusual increase, it confirmed to me that the lead was not faulty. So I then started to compare my old settings (my old generator) with the new ones. While there were a couple additional changes, the change to "adaptive" caused the increase in battery drain. No doubt about it. That feature automatically increases the voltage at the first step 2x (double). So that resulted in 2.5V to increase to 5.0V. 

Here is the thing; I DO NOT NEED AUTO CAPTURE TURNED-ON!!! This old lead has always had a sensing problem. My previous Docs' pacer Tech's were always pulling their hair out trying to adjust the sensing (optimizing it) for the last 15 years. It always either over-sensing or under-sensed. They struggled to get it "just right". So the amplitude was always marginally above or below 2.5V, but almost never above 3.0V. At some point they just decided to leave well enough alone and keep it at 2.5V. I have always felt fine at that setting. So if capture was not always optimal, it did not present any issues for me. My point is that there is no reason for the amplitude to be above 2.5V. If so, only minimally above and not 2x above. The Adaptive setting does not allow for marginal changes. It is either 2x, 4x, etc. It may work for some folks, but not for me, 

Now the problem will be getting them to turn-off the auto-capture management. They are draining my battery either, because they don't know any better or it was an oversight. The other possibility is that the adaptive setting makes their job simple (much easier) despite the fact that it is a serious problem for me. Frankly, I think I can tell you when the switch from 2.5 to 5.0 took place. I felt the change, although the impact was very minimal and very subtle. I began having sleep problems about a week and a half ago. I also started getting sharp, but relatively minor pains in the area of my heart as well as a stiff-neck. Not sure I can attribute all of those to this, but I definitely have not felt as well as in the past. At my most recent in-office interrogation I asked, as I was leaving; "what is the amount of batter life remaining"? She said 7 years. I responded, WHAT, it was just 9 years a couple weeks ago. She said; "that old lead is draining your battery". That was it! And it was what started me on this journey to find the problem. Well; thankfully I did! I have to say that I am so relieved knowing that I do not need an extraction. I do continue to plan to take this old lead to my grave whenever that may be. Now I just need to get those changes made.

Once again; I just want to thank everyone for pitching-in and responding in an effort to help. I am extremely grateful for this website and the folks in it.

Sincerely,

Dave

13 Comments

😬😮😵‍💫

by Lavender - 2024-04-27 09:46:21

Dave,

Lay people should not have to know all this stuff. It's awesome that you, along with other awesome people here can know so much and problem solve. But it infuriates me and concerns me that most of us would never be able to decipher this stuff and depend totally on pacemaker techs etc to do what's best for us!  
 

I am already always trying to self advocate and watch over decisions made by my health care team. I cannot begin to study enough about my pacemaker to watch over 😵‍💫😫

Dave...et al...I am astounded by the group brain storming. 🤯 I am so happy you can now get this taken care of on Monday hopefully. 🙏🏻 

Lavender - Thanks

by Good Dog - 2024-04-27 11:13:20

I appreciate your sentiments. Frankly, I really do not know much of anything related to the programming of my device. I am only learning by necessity when problems develop. I agree with you about the concern of putting our trust in the Pacer Tech's. Although, I really cannot blame anyone specifically for this issue, it is the 2nd time that I feel I have been harmed in some way by them. Be it an oversite (most likely the case here) or in the case of the Tech that turned-on my rate response when I did not want it on, and then failed to even tell me it was turned-on, it is all a bit scary. I continue to believe that incident cased my stroke. Fortunately here there is no real harm done since I caught it. 

In any case, thanks again!

Sincerely,

Dave

Oh to find answers

by Gemita - 2024-04-27 12:40:45

Dear Dave, I can imagine you slept well when you arrived at a satisfactory conclusion.  The number of possibilities we were offering you were certainly not exhaustive and I am sure there will be more to come should you ever require our expert assistance in the future!  Of course we are still left with a couple of old, functional leads, so we need to remain watchful.

My 6 year old leads are both showing Autocapture as Adaptive.  Difficult to know what is best for each one of us without experimenting I suppose.  I hope you can convince your team at least to try to leave it off for a period and then to re-assess the results?

It is worrying that many of us feel we have to educate ourselves to get the best results, when the outcome could be so different if we don’t choose the right path.  And none of us can be expected to grasp these technical details overnight, and without understanding what is set up in our pacemakers, we are already at a disadvantage when it comes to discussing any settings changes or other treatments with our doctors.

Are you busy preparing your narrative to discuss with your technician? Focus on points you can agree on.  Aim to listen also and find a result that works for both of you.  Good luck Dave.  

Gemita - THANKS!

by Good Dog - 2024-04-27 13:06:36

Yes, you hit the nail on the head. I am working on a narrative and intend to respectfully request the changes I see as necessary. Frankly, after reviewing my previous interrogation reports it is very clear to me that neither the condition of my heart, nor the condition of the lead has changed much in recent years. Of course, I could be wrong. I am not pretending to know much of anything. Much of this seems like common sense. That adaptive-capture-management setting seems to be nothing more than a catch-all that eliminates the need for the Pacer Tech to manually adjust the capture settings. I suppose that there could be patients for which their condition finds it beneficial, but I do not know. I have certainly gotten by for 37 years in manual mode wirthout a problem. Further, I think that maintaining the capture sensing adjustment manually can provide the benefit of maximizing the battery life. That is important to me. If you think about the fact that when 2.5V is not quite high enough and 3V is optimal, the Adaptive (auto) setting will increase 2.5V to 5V instead of the 3V that is necessary. That is signifiant overkill and battery drain. As far as I am concerned; if I can stretch battery life by a couple of years, I see that as a huge benefit. Even if only a half-year. I really try to forget that I have this device in my chest. However, the approaching generator change is always a constant reminder of it. At least I do not have to worry about what happens when I hit ERI anymore. Or so I think?

Sincerely,

Dave

Im lucky

by atiras - 2024-04-27 15:36:48

I had a couple of techs who picked this up on my first check after the new pacemaker went in. By turning off auto capture and extending the delay before i was paced slightly they upped my battery life from2 years to 10. This was with new leads.

Impressive Detective Work

by SeenBetterDays - 2024-04-27 15:51:22

Hi Good Dog

So pleased you got to the bottom of the voltage change. If you can get them to adjust the adaptive capture management setting then this should surely help to extend your battery life which is incredibly important for minimising the frequency of surgeries. I agree with Lavender that this should not really be the job of the patient to research and investigate but more and more I feel we need to increase our knowledge base so that we can help ourselves and others in a similar position. I wonder if this setting is automatically set to on and whether it is something we all need, particularly if it has an impact on battery longevity. I also wonder why the voltage can't be programmed to increase in a more incremental way rather than doubling as it did in your case. 

Anyway, I think it's fantastic that you've come to a solution and you have something to take back to your medical team. Surely they have to listen to your suggestions, the evidence seems pretty compelling. Sorry you've had an anxious time and hope you get this resolved soon. Keep us posted Good Dog.

Adaptive capture

by AgentX86 - 2024-04-27 16:02:35

You indicated that the adaptive capture settings went from 2.5V, directly to 5V. That didn't sound right. Also, it seems there is some confusion about capture and sensing.  They're the opposite. "Capture voltage" is when the voltage is high enough for the heart to beat. The "Capture margin" is the multiplier on that, just in case something changes.

"Sensitivity" is the voltage that the pacemaker will recognize as a heartbeat from the heart's natural pacemaker. If they had trouble getting the "sensitivity" right, it may (probably) not affect the capture voltage at all.

Anyway, m curiosity piqued, I looked up the technical manual on the ADDR03 (from your profile). 

https://www.medtronic.com/content/dam/medtronic-com/01_crhf/brady/pdfs/200601057cENp6_adapta_dr_pacing_system_spec%20Sheet.pdf

I see an adaptive capture voltage of 0.5V to 3.5V, in 0.25V increments, with a margin of 1.5x to 5x, in 0.5x increments. So, if the adapted capture voltage was 2.5V, and the margin was 2x (sorta normal and the default), the output of the generator is already 5V.

The manual settings are 0.5V to 3.5V in 0.25V increments, and 3.5 to 7V in 0.5V increments, so there is a wide range available but It's not adaptive, then. It's fixed until the next in-office session.

I'm not understanding something here. If he adaptive setting was set to manual and voltage set to 2.5V (that includes the threshold, as specified by your EP), the total voltage is, of course, 2.5V. 

Asssuming the adaptive mode is switch on, for everything to remain the same, it should select a 1.25V capture voltage with a 2x margin(if that's what your tech/EP set). If, for some reason, the capture voltage has to increase, the minimum amount would be to 1.5V.  With the margin still set to 2.0x (it's fixed until the next programming session), that's a pacing voltage of 3V.

If you had it set manually to 2.5V, then it was changed to adaptive with a 2x margin, and it stayed at 2.5V, that would be 5V but something is wrong.  It should never have selected 2.5V with a 2x margin, unless something really changed.

I also note that the self-test (when this selection is done), can be set from 11:00PM to 1:00AM, so the change should have been made at this time (don't know if this lines up with your change in symptoms).

It seems to me that they have some 'splainin' to do (maybe to me).

Agentx86

by Good Dog - 2024-04-27 17:18:09

Thanks for your efforts! I read through your post and I am now more confused than when I began. That is on me; I did not get much sleep last night. I have to leave shortly and won't have the time to go through this any more tonight. Maybe in the morning. In any case, my plan is to contact the supervisor at our pacer clinic on Monday to insure that my understanding and assumptions are correct. It is my hope to then also schedule a time for the programming change. In any case, I will post back here after my discussion with her any corrections and/or a confirmation and also hopefully can provide more clarity at that time if not sooner.

Sincerely,

Dave

A quick note in response to AgentX86

by Good Dog - 2024-04-27 18:54:51

Your comment re the self-test - Mine is scheduled for 1:00 am

The following are my atrial pacing amplitude (volts) directly from the Techs interrogation. Keep in mind that this new generator was just installed and the Capture Management turned-on to adaptive on March 14th. So it did not impact the voltage on the March 14th interrogation and there was a very abbreviated look-back period for its tests That should explain the increase from 2.5V to 4.5V and then 5.0 V.

RA Pacing Amplitude:

March 13th - 2.5 Volts

March 14th - 2.5 Volts

March 19th - 4.5 Volts

April 25th - 5.0 Volts

Pacing amplitude

by AgentX86 - 2024-04-27 21:24:57

Yeah, I'd want to know why. It was either set too low (no margin) before or something is changing.

2.5V to 5V

by AgentX86 - 2024-04-28 01:27:42

The step above 2.5V is not 5V.  I don't know why it did that. The next (adaptive) step from 2.5V is indeed 3V (1.25V x 2.0 to 1.5V x 2.0).  This assumes a margin of 2x (should be in your report).

The largest single step that I can come up with 0.5V and a capture margin of 5x (crazy). This would be 2.5V.  One step would be 0.75V x 5.0 or 3.75V. It would take a second step to get to 5.0V (1.0V x 5.0).

atiras & Seen better days

by Good Dog - 2024-04-28 09:55:02

Thank you so much for your comments! If it seems that I know what I am talking about, please do not be confused. I am learning and really do not have a great handle on atrial capture and especially this "Atrial Capture Management" feature. It is very confusing. Regardless; I am determined to get to the bottom of the increased drain on my battery since this feature was turned-on. Stay-tuned!

Thanks again,

Dave

AgentX86 - The Bottom Line

by Good Dog - 2024-04-28 10:20:27

I have been pulling my hair out trying to get a handle on all of this and hope the pacer Techs will be able help me this week. I have been going through my spreadsheet looking at the changing parameters for the previous 6 years and since capture management was turned-on. Actually, I think it was just a default setting that the Medtronic guy set to adaptive instead of adjusting capture manually when I received the devicer. Looking at the following parameters there is only one thing jumping out at me:

RA Sensing Blanking Period (ms)

Sensing Refractory Period

RA Sensing Amplitude (mv)

RA Pacing Amplitude (volts)

RA Capture Duration (ms)

RA Capture Amplitude

Significant changes to the RA Pacing Amplitude (volts), RA Capture Duration (ms), and the RA Capture Amplitude took place with the new device. Could it be in the algorithm? I just do not understand enough now to be able to determine exactly why. So here is the bottom line; regardless of how RA pacing is managed one thing is perfectly clear: I have always had the Capture Management feature available for the 9 years I had my previous device. It had never been turned-on. As I've said before, there has always been a sensing problem with this old lead and it was managed (adjusted) manually. Since the new device was put in-service the Adaptive Capture Management feature has been on and that is exactly when the voltage draw on the atrial lead essentially doubled. I do not think it is coincidence! I am sure that it is possible, but I doubt it. So I will see what the pacer techs have to say about it this week. Stay tuned!

Thank yiou for your efforts..............

Sincerely,

Dave

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