Tachycardia that's not fast. One in a million--that's me

Is there such a thing as Pacemaker Mediated Tachycardia without the tachycardia?

Background: back in the early days after I got my little friend, I developed pounding, pain, and if I tried to push through it instead of sitting down, I would collapse.

After two years of steadily getting worse, I was finally diagnosed with PVC induced PMT. (But only after I demonstrated the collapsing part while in the EP's clinic.) Since there was no heart block, the sinplest solution was to turn off the ventricle lead.

I did well for about 3 years, but then developed LBBB and heart block Type 1. The Type I heart block led to fainting, which neccessitated turning the ventricle lead back on. The EP did some very fancy programming to reduce the chance of PMT.

Again, I did well for 18 months to 2 years, but then started to have PVCs that I really felt, followed by my heart feeling "shaky" for a few minutes. The problem was tolerable until early September of this year, when I was walking the dog on a very hot afternoon, and I felt what felt just like the PMT I used to have--including feeling extremely weak and close to collapse. 

I have already ranted about the subsequent visit to the clinic. I was told most emphatically that I wasn't having PMT and my PVC burden was low. Subliminal message: why are you bothering me lady when you probably don't know a PVC from a swallow-tail butterfly. Grudgingly, the PA acknowleged that even though my "burden" was low, I was symptomatic, and prescribed diltiazem.

The diltiazem seemed to help. I went from 3-4 collapsing episodes a day, to a couple a week.

When I was seen for my regularly scheduled device check, this NP listened to me carefully.  She noted that during the Holter monitor test, when I had reported symptoms, I was being paced in the ventricle.

She was able to pace the ventricle and reproduce the symptoms--at 90bpm. Which technically isn't tackycardia, but without question, it's pacemaker mediated.

In the last week, the symptoms have gotten much worse suddenly. Instead of lasting for seconds they last for minutes, and once, for almost an hour.

So, oh wise ones, clearly something needs to be done. But what? I wish I had a better understanding of PMT, so that I could discuss it more intelligently. I also realise I have never seen the actual printout of the Holter monitor. Would it be reasonable to ask for it?

What questions should I be asking?

BTW, the NP said the current programming is so extraordinary as to be incomprehensible to the ininitiated. "Never let anyone tinker with your settings," I was warned. A tech unfamiliar with my history would assume that my settings had to be wrong!

[wry smile while shaking head] That's me.





Just a thought . . .

by Gemita - 2019-11-13 21:01:43

Could it be one of your meds causing  pro arrhythmic effect and maybe altering pacing thresholds ?  I am out of my depth here but I have read something about certain anti arrhythmic meds affecting pacemaker capture thresholds.

I recently stopped Flecainide and my symptoms, not altogether dissimilar to yours, are much improved. It seems my pacemaker is now working more effectively without the adverse effects of Flecainide. I would suggest that our meds have an affect on our pacing requirements so you could ask your doctors about this possibility?

I really hope you get answers. That feeling of weakness and close to collapse is so draining, I know it well. Even with my pacemaker I still seem to get intermittent sudden heart rate dips and surges which is very destabilising but stopping Flecainide has been immensely beneficial for me. 

You are a puzzle which needs to be solved and I look forward to hearing from others how this can be achieved !! I would say there is such a thing as pacemaker mediated tachycardia without the usual 100 bpm+ heart rate because if you are frequently collapsing, then a heart rate of 90bpm will most definitely be fast for you. Yes do ask to see your monitor downloads. You know your body best and you might pick up something helpful to confirm the problem especially if you have kept diary notes of episodes of syncope/pre-syncope to correlate with your monitor results 



by donr - 2019-11-15 01:29:59

Rhythm:  let me see if I can help a bit.   Read this PDF file:https://www.bostonscientific.com › quality › english › ACL_PMT_20120625  I found it through Google using "pacemaker mediated tachycardia.  It is a reasonably decent discussion of PMT & its causes.  The first three lines lists all the things that can cause a PMT event, & it sounds like you have several of them.  Do you know what  "Retrograde" means?  That is the key to undersstanding the basics of the PM operation.  It means "Backwards."    There is a time when the heart kinda shuts down after the ventricles fire - it's called a "Refractory Period."    During this period, nothing can happen.  It is called the PVARP (Post Ventricle-Atria Refractory Period)  The EP can vary this period with a setting - it can be lengthened or shortened, I think.   If there is a conduction path BACKWARDS (Retrograde) from the V node to the S node & a PVC occurs Outside the PVARP period, the Atria thinks it is a P wave & starts the beat sequence, making the Ventricles beat way too soon.  That can start a Tachy episode if there are too many incidents of PVCs or other phenomena that can cause an early Ventrical comtraction.  I have no idea what kind of unique programming your EP did, but it sounds like he lengthened your PVARP.  I had that done once.  You taalk about a "Light" PVC load - what is your load?   That can make a big difference.  In some respects, Tachy is relative.  Its definition for recording can be established by a setting in your PM.  My Cardio set the definition at 120 BPM for 5 successive beats so he could see what was happening at lower rates.  Usually they set the definition at about 175 BPM for 5 successive beats.  If your heart exceeds that it makes a report.    I am on Metoprolol to help "Calm" my heart - cut down on the number of PVC's.  From the sounds of your story, I have a similar problem to yours, but not as severe.

You answered one question for yourself - YES yyou can have Tachy a low rates, like 90 BPM.  They showed it to you.  AnD I suppose it could make you feel funny, since the heart isn't working like it should.

By all means, ask for a copy of the Holter report - then ask them to explain it to you. 



by Gotrhythm - 2019-11-15 14:33:43

I overheard the doctor to say that he had widened the PVARP as much as possible. Also, I discovered through reading the interrogation printout, he reset the mode to DDIR.

I will read the PDF you recommend. Thanks.

You mentioned my "load." I was only told that my "burden was light." Which sounds vaguely Biblical. They didn't give any numbers. Another question I need to ask.

Thanks for the encouragement to see the Monitor report for myself.

Thanks for everything.


by Gotrhythm - 2019-11-15 14:54:04

Interesting about the proarrythmic nature of antiarrythmics. I got a lot worse suddenly after I started a slow release form of diltiazem.

I stopped it and went back to the regular form of 30mg every 4-6 hours. The episodes have substantially decreased, in number and more importantly, in duration. When they last a long time, 50 minutes was the longest I've measured, I'm wiped out for hours.

I haven't done an A-B-A trial yet, to see whether the difference truly correlates with what form of diltiazem I'm taking, or if the apparent difference was just a chance occurance.

Thanks for the input.

I am so grateful for this group.

A little tutorial on PVARP and related PMT stuff

by AgentX86 - 2019-11-15 15:17:49



by ROBO Pop - 2019-11-16 16:52:59

I call it PMC, pacemaker mediated crap because it can cause a lot of crap not justV-tach.

At any rate (get the pun?) Two options.

1. Increase your pacing rate by 10bpm ( it may require several iterations. I went from 60 to 70 to 80.


2. Shut off rate response this is the recommended solution.

Worked for me

Robo and Agent

by Gotrhythm - 2019-11-16 18:00:33

Robo, I was thinking about you just yesterday! Thanks for ringing in with an opinion as well as  humorous take.

But I loooooove RR! Without it, I don't think I would want a pacemaker at all. But I don't think it's causing the problem. The PMT is as liklely to happen when I'm sitting still--even lying down, as when I'm moving. But it does seem sometimes that standing after I've been sitting a while kicks it off.

AgentX86. Thanks for the Url. I'll look it up.

your choice

by ROBO Pop - 2019-11-16 19:50:18

Well my dear your choice. Rest assured though the recommended solution to PMT is to shut off rate response. I struggled a few days after mine was shut off but adjusted and haven't had an episode in nearly a year. No I can't dance or run marathons but hey ...

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