Hi All!

It's been a while since my last post but I've been narrowing down my issues and I wanted to get anyone's thoughts on AV DELAY. When the PM was first placed it was set at 50/120 and nothing else. I felt fine. Then from there I've had the CLS turned on, then turned off, Rate Response turned on, then turned off. I had the AV DELAY HYSTERESIS turned on with I believe a 300ms delay but according to my EP it was causing occasional Retrograde Conduction. Now I have the AV DELAY HYSTERESIS with a 200ms delay. With all that said I truly feel the AV DELAY is my issue. Allow me to explain. 

Last PM check (10 days ago) I was using Atrial Pacing less than 1% and V-Pacing over 11%. My original diagnosis was for nightly pausing, Bradycardia and intermittent heart block. ALL of this happened ONLY when I slept. Now since my Atrial pacing is less than 1% that takes care of the Brady and pausing. The 11% for V-Pacing seems excessive and I know based off my continued intermittent symptoms this has to be the issue. 

I still INTERMITTENTLY have trouble with chest discomfort. It feels like my chest is clogged. At times it feels like I'm drowning/suffocating somehow. It's horrible! The real problem is that it only happens out of the blue and at odd times. Sometimes I am moving around. Sometimes I am turning on my side in bed and sometimes I am just sitting still. There is no rhyme or reason, it just happens. I am starting to wonder if they turn off this AV Delay will it help or if they play with the timing will that help?! The other way I can explain what I feel is if my heart beat is 1,2,1,2 normally, when I feel the issue it's like a 1,2,1,1,2,2,1,2,1,2 it's like the rhythm is off. I feel like the AV DELAY is coming in at the wrong time or is not needed and is causing me these issues. I hope this makes sense. 

Also please keep in mind I had NO IDEA anything was happening to my heart prior to the PM. I never felt anything prior to the PM. I was able to exercise and I felt great. Now anytime I exercise or do something trivial I feel this awful chest discomfort it's so hard to explain. It makes me not want to exercise or do anything very active. I am beyond frustrated and I just want the docs to get this right already! 

Does anyone have thoughts on this? I don't find many AV Delay posts on here so any input is greatly appreciated. Thank you all in advance for reading my post. God bless! 


Brady and block

by AgentX86 - 2021-03-28 22:53:37

A pacing percentage of 1% does not rule out Brady and pausing.  There are about 86,000 heartbeats a day.  If you put 1% of 1% in a row, that's a pause of 8-seconds.  Since they're only happening at night, multiply by 3.  24-second pauses are really bad for your health.  There is a very good chance your heart won't restart at all.  For every extra second of pause, the chances that it won't restart increase significantly.  Yeah, you need a pacemaker for Bradycardia and pauses.

I beat of 1-2-1-2 sounds like a Mobitz-II block.  There is nothing keeping it from being any other multiples.  Mobitz-II almost always degenerates further, eventually into third-degree.

For these fine points, it's better to leave it to the professionals.  Armchair EPs aren't going to cut it.  If you don't like how you're feeling, with these symptoms, see your EP.  If you're getting no joy from him, get a second opinion (then change EPs if he can resolve the problem).

Intermittent symptoms

by Selwyn - 2021-03-29 06:02:30


Sorry to hear of your difficulties and distress. Given the nature of your symptoms I would have thought more ECG monitoring (event recorder/Holter)  is required to capture on an ECG the events you describe feelings of drowning and suffocation, especially as you have noted heart beat irregularity at the time. 

Also, given your symptoms of awful chest discomfort with exercise, an exercise ECG could be indicated to try to capture the events associated with your symptoms. 

Both of the above investigations are routine in cardiology. Best not to get bogged down in the technical details of pacing when there may be an elephant in the room !

In your position, I would certainly be wanting to have a chat with my cardiologist rather than the pacemaker people.

So good to hear from you !

by Gemita - 2021-03-29 06:55:00


How lovely to hear from you.  Are congratulations in order ?  I think you mentioned on the forum you might be marrying in March?

Have you by chance seen quikjraw’s post (scroll just over half way down this current page) on treadmill test - experiences.  In many ways you two seem to be having similar problems trying to pinpoint exactly what might be going on with your settings and how they can be optimised to make you feel better.  Have you had a full treadmill test?  

We need to trigger those symptoms when you are actually being tested and play around with those settings to try to overcome your symptoms.  If despite this and long term monitoring they cannot pinpoint a problem with your settings, pacemaker or see an arrhythmia, then we need to look elsewhere for a cause.  Even though I understand you feel you felt fine prior to your pacemaker, I do not think we can say with certainty that the settings/pacemaker has caused your current difficulties.

Please do look at the above post and keep up the pressure to find your answer.  I attach a link of an old pacemaker club post on AV delay which I found very helpful.  We need some clear explanations on what our settings all mean, don't we and I think this one on AV delay is very good:


Thank you ALL!

by arentas80 - 2021-03-29 11:31:55

Hi everyone!

Thank you for commenting! I do in fact have a stress/echo this Wednesday at 9am. Fingers crossed that this will reveal something. I am so ready to get past this. On the cardiology end I've had nothing but clean echo's, CT Angiograms etc, even stress echo's. With my last stress/echo I had the CLS activated so now that it's off I'm hoping it may reveal something. I truly believe my electrical is the real issue here.  

Gemita- yes my dear I am now a married man. March 20th was our day and it was everything we hoped for, minus all of our guests. We will do it again next year once everyone has been vaccinated and things calm down. I am humbled that you recalled such a detail. Appreciate you! 

Wonderful news

by Gemita - 2021-03-29 12:27:46

Alejandro, I think you have got the perfect cure beside you now if you just give it a little more time.  Many congratulations to you both.  You can post a wedding pic any time you like in the gallery!  

Good luck on Wednesday.  Try to push yourself as hard as you can to bring on your symptoms.  I know it sounds cruel to say this but perhaps it will be the only way to find out what is happening to your heart and pacemaker at that precise time.  Please let us know when you get the results of your tests


by PacedNRunning - 2021-04-04 23:58:08

HI! can I make a suggestion? When they interrrogate your device next time, have they look at your histograms and see when you are using your bottom lead or RV Pacing? Is it only at certain HR? Perhaps under 100bpm or 70 bpm? I started with intermittent high grade block with exercise only. It was tough getting is programmed for exercise but we got pretty darn good settings within 4 mos. 


At implant I only had high grade block above 130bpm. I did have to pace some unnecessarily in order to give me what I needed at higher heart rates. So I basically RV paced 100% once my HR went over 100bpm.  Once I came under 100bpm, it was all my own heart that worked.  In the beginning of exercise, It would be hard until the timing cycles could Catch up but nothing not tolerable.  As my block progressed I would feel palpitations or I called them chest thumping under 100bpm, The PM wasn't pacing me soon enough and I felt the late pacing thumps.  So what started as AV block above 130bpm, progressed to 80bpm, I had AV block then at 70bpm and I started having symptoms etc. Not fun! But prior to it progressing at lower rates, I paced anywhere from 37-50%.  I didn't like unnecessarily pacing but there wasn't much else we could do if I wanted to feel good with exercise


I will say hysteresis with exercise sucks! I've tried it. The problem is after so many cycles, the PM will check for your own intrinsic beats, in which case it has to extend the AV delay to allow your own hearts kick in. If you didn't kick in, then it would pace you for another XX number of beats looking for instrinic beats.  The issue with this with exercise. Is because your HR is faster, these cycles happen a lot quicker. So your feeling the thumps and bumps with it checking each time. So I would turn that off unless it's bothering you with exercise. If you feel fine with exercise then never mind. :). 

Have they tried a fixed AV delay? instead of a range can they do a fixed? Another suggestion is Biotroniks' AV delay can be programmed per HR range. Maybe they could figure out where your own PR interval is and try to match it but extend it some past your own instrinsic. This way it will give your own heart time to work and if not, it will pace you.  

Your pacing at 11% doesn't seem excessive for someone with intermittent block.  I was never that low and I only had it with exercise so my guess is I had block at other times, I just didn't feel it.  What is your heart rate range? I do find that is key also. I liked being at a low of 45bpm and high of 185, but my settings worked better raising my base to 50bpm.  

Settings are really individual and I found that intermittent pacing for aV block can be challenging to program.  Again, ask what HR ranges you actually RV pace so they can set a delay to pace in those HR ranges if possible.

For me, we finally found the perfect settings about 9 mos post op. Like I said I had pretty good settings after 4 mos. Then we did small tweaks along with a treadmill programming session and finally find the final missing piece at 9 mos post op. The missing piece was my sinus node dropping out with exercise. Never suspected that. Then at 12 mos post op, I started experiencing AV block at 80bpm and up, then 70bpm to finally 24/7. I'm in high grade block 24/7. So my pacing went from 37% to 100% by 18 mos post op. Weirdly enough, exercise became so much better.  I felt so much better with exercise and exertion. Not that 100% pacing is the goal but once my block happened at lower heart rates and more frequently, I became more miserable. 

Feel free to PM me with any questions. Ive experienced almost every setting out there. LOL especially with exercise. 

You know you're wired when...

Lifetime warranty no longer gives peace of mind.

Member Quotes

My pacemaker is intact and working great.