I have a pacemaker for SSS. Nothing wrong with my AV node. I started to pace in my ventricles (which is a hisbundle lead) showed kardia ekgs to doctor, he did adjustments including turning MVP off. Said he saw no block. So I continued having some ventricle pacing, rate is usually 80's/90's then all of a sudden in a resting state(aka sitting on my butt relaxed) I started pacing in ventricles at 126+.

Why would my pacemaker pace that fast at rest. Oh and the beats are fusion beats, so basically it's working when it shouldn't be if my own heart is doing its thing. Anyone have this? Could it be PMT , something wrong with my lead? Idk 


It does sound odd...

by crustyg - 2022-06-27 12:02:52

... and it would tend to suggest that your PM isn't sensing a vent activation so it's providing one.  Which would tend to suggest a fault with your vent (His-bundle) lead - *but* that doesn't really make sense if the vent lead is managing to capture and pace (although I don't think it's impossible).

Q: what is your pacing mode? One of the 'magic' AAI + Vent-if-needed modes?  I imagine you're not simply AAIR - EP-docs don't like that, even for SSS+CI as they fear that the same disease process that's clobbered the SA-node will eventually damage the AV-node...

I think we need a lot more information to provide more than crude guesses: your profile is pretty thin.  Make/model/pacing mode/voltages/impedances etc.

I don't think you have PMT: that's a retro-conduction issue where the A lead senses a vent activation back through the AV-node but backwards and should show A-then-V pacing.  Near-field sensing is another cause, but again you should see A-then-V.

Depending on how often you get these episodes, you *might* be able to sit with the EP-techs in AAIR mode and see if they disappear.  If all you have is SSS then you don't need the vent lead - but the fact that your EP-doc has gone to the trouble to make it a His-bundle lead suggests to me that the answer to your request to go AAIR will be 'No.'

Reading some of your older posts I see you have SSS+CI.  Me too.  I sometimes wake from a dream with fast, irregular HR.  What's happening is that PM is pacing A at resting rate (50BPM), and my AV-node is generating activations at 115-120BPM (about the max that those lovely little cells can manage), BUT as I'm set to AAIR the PM doesn't sense the vent activations so I am paced from two places.  Happily the refractory period in the AV-node saves me from having the PM trigger VF by pacing during the refractory period of the ventricles.  I think you would see these activations as 'fusion' beats.


by LemonPledge - 2022-06-28 12:02:43

So I'm in DDDR mode. My intervals Ap 210 my vp 180. My mvp is off.

My impedance is 494 ohms both leads. All my arrythmia interventions are off. A voltage 1.50 and ventricle is 3.00

I have a medtronic advisa sure scan

I have SSS and IC because of sa node ablation. 

Oh also when I pace in the ventricles,  they are all fusion beats. As what I've been told. They have told me that my settings are optimal and they can not do anymore adjustments. 

Oh lower is set at 70 and upper is 130

I still don't know all the lingo. 


Are you still getting Atrial Tachyarrhythmias triggering a rapid ventricular response rate?

by Gemita - 2022-06-28 13:34:27

Hello Lemonpledge, 

Just seen your latest comments.  Is it possible you may still be getting atrial tachy arrhythmias following your SA node and other ablations and since you do not apparently have an AV block, atrial tachy arrhythmias could still be getting through your AV Node to push up your ventricle rate intermittently, even at rest?  I see that all arrhythmia interventions are switched off.  I wonder if this is an area that needs looking at to see whether there are any arrhythmia programmes that could be activated to help ease your symptoms?

I would respectfully ask whether you could have longer term, external monitoring over say 10 days to a month to try to identify the problem.  A Holter monitor would give 24 hour coverage and you could make a note of the time and date you get any symptoms to correlate with the recording.  While I appreciate your pacemaker and home Kardia are capable of giving your doctors important information, sometimes additional 24 hour monitoring is needed to help identify complex disturbances.  I recall my EP telling me he wanted to keep my implanted Reveal Linq monitor in place in addition to my pacemaker implant, to help monitor my arrhythmias and to assess results of treatment.  The more monitoring, the better in my opinion especially when we are getting disturbances coming from different areas of the heart.

I certainly wouldn’t be so certain that your pacemaker is the primary cause of your rhythm disturbances since you have a long history of arrhythmias.  Being an arrhythmia sufferer myself, I know what mayhem they can cause and how difficult it can sometimes be to accurately identify the arrhythmia present from pacemaker data alone.  I can recall my pacemaker technicians having difficulty interpreting my paced Atrial intracardiac electrogram and being told by a Medtronic technician that a surface ECG would provide more accurate information.

I have definitely noticed that a high burden of arrhythmias can adversely affect pacing.  Get any arrhythmia under control and you might find your pacemaker will run more smoothly too.  I have SSS (tachy/brady syndrome) with arrhythmias coming from multiple spots upper/lower chambers.  My pacemaker mode is currently AAI<=>DDD.   

I see from your confusing history, that at one time your EP was considering an AV Node ablation, but not a total one and since you say that you do not have block, I presume you have not had your AV Node ablated?  

I note from your previous post that you have an appointment with another cardiologist coming up this week.  I do hope you will get some useful feedback.   

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