Mystery diagnosis

I'm ba-a-ack. Once again with something that feels like an arrythmia, but nobody can find it.

Since March of this year, I have two week-long monitors, in both cases, the official result was no abnormal rhythms detected. However, my EP theorized that I was still having RNRVAS. He widened the PVARP even more (making it so that I'm practically never paced in the ventricle.) Almost immediately I could feel a 60-75% improvement.

However, I still have the other symptoms showing up. I have good days and bad days, even good weeks and bad weeks. The good times are good. I would say I'm in remarkably good condition for my age. Able to live completely independantly. The bad times--well, I have to wonder if I'm a candidate for assisted living.

The bad episodes are like this: I feel a mild flutter-feeling in chest. SOB, but P/O above 94% and often as high as 99%. Slight pain in right chest just to the right of the breast bone. I feel a little woozy, a little disoriented in vertical axis. I notice I'm having a hard time standing up straight or walking in a straight line. I haven't fallen because I can move quickly to recover. My legs feel tired, weak and heavy. Even a one-block walk with my dog seems like too much.

Although I can go upstairs with ease usually, when I have an episode on the stairs, about 2/3 the way to the top, I'm suddely so weak and SOB, I'm afraid I can't make it up the last 3-4 steps. My bed is only a few feet from the landing. I collapse there for a few minutes until episods passes.

The big reason though that the episodes are a problem is that on the days I have a lot of them, I feel terrible, tired. But worse, my mental powers desert me. During an episode short term memory is wiped out. I have great difficulty sequencing even enough to recite things like my address or phone number. I can't type because even though I know the letters in a word, I can't sequence them.

I feel like this a cardiac problem, but the EP I have worked with and who has always been excellant, only tells me to consult my PCP.

Here's what I wonder. I know I have PSVT. Is there a subclinical form? Something not quite enough to qualify as tachycardia, but still enough to feel and interrupt blood flow to the brain?

And if so, is there anything to do about it?




by Penguin - 2023-11-14 15:56:03

Sorry to hear this GotRhythm.  I've sent you a PM. 


It certainly sounds cardiac

by crustyg - 2023-11-14 16:16:40

I think you're right about brain blood flow: apparently they teach the fast-jet pilots that if they *do* blackout from a high-G manoeuvre, even for a second or so, when they recover, their cortical function is mostly absent.  All of the higher learning is temporarily absent, they can see around but can't understand anything. Simple motor skills are available, but there's no understanding, no situational awareness - basically they are sitting ducks for 5-10s.

I think you describe the same loss of higher function very well.

So, assuming it's caused by sudden reduction of cardiac output - and being frank, it doesn't need to be a *big* reduction - the Q is why?

Your EP-doc feels that the cardiac causes have been excluded with 2*week of external monitoring.  So you either push for an implanted Reveal or consider a non-cardiac cause.  It does *sound* as though the episodes are activity-related, but I suppose this could be something like petit-mal epilepsy.  You know me - always cheerful, upbeat, glass half-full!  As if!

What does your PCP say?


by Penguin - 2023-11-14 16:29:42

Crusty - Could an adaptive PVARP setting help do you think based on what you say above? 

Adjusts for rest and exercise? I think that the Assurity has this function.

'Most modern dual-chamber pacemakers are capable of detecting PMT and initiating PMT intervention by automatically prolonging the PVARP for the beat after a ventricular-sensed event that is not preceded by atrial pacing, ie, a PVC (PVARP extension). This problem also can be minimized by the use of adaptive PVARP in rate-responsive (DDDR) pacemakers; the PVARP is long when the patient is at rest and shortens when the sensor indicates activity, allowing the pacemaker to track higher atrial rates with minimal risk of PMT.'

It's a guess? 


I think it's now a challenge to get the EP-team to reconsider

by crustyg - 2023-11-14 17:17:22

I don't say you're wrong Penguin: this isn't something that I have any real expertise around.

But the challenge, as I see it, is getting the EP-team to reconsider.  It sounds as though they've set their face against a cardiac cause, so persuading them to make another adjustment might be difficult, esp. if they've gone through the Holter data with timestamps from GotRhythm recording 'episodes'.

Pardon me for talking about you, GR, not *to* you.

Hugs and🌺

by Lavender - 2023-11-14 18:25:35

You're always giving such wise good support. I have no technical answers but want to tell you that I hear you. I've been reading your writings since long before I joined the bunch here. 

My one thought is that I kept being told that I had no cardiac issues long before I got my pacemaker. I had to push and insist til my pcp finally ordered me a thirty day monitor. I did go through all the neurology tests before that. 

Go to your pcp. See if they can come up with any ideas given that your EP seems to be convinced it's not heart related. 

I send you hugs too

by Gemita - 2023-11-14 19:32:56

Gotrhythm, My heart goes out to you because I know only too well the symptoms you describe and yes it does sound as though you are having intermittent symptomatic heart rhythm disturbances.

I see they believe you are still having episodes of RNRVAS (Repetitive Non-Reentrant Ventriculoatrial Synchronous Rhythm).  You could see your PCP to rule out other causes as well like thyroid, infection, anaemia, electrolytes for example. 

The struggle to walk upstairs, fighting for air, feeling weak, tired, disorientated and close to collapse, the brain fog, chest pain - how well I know those symptoms during a symptomatic episode of an irregular arrhythmia.  My chest pain is usually related to a tachy arrhythmia episode or to a slow, irregular rhythm and goes away when the arrhythmia ends.  Any "irregular" rhythm, slow, fast, normal speed, even ectopic beats, can adversely affect my circulation.  After an episode of AF for example, it can take hours to recover from fatigue and brain fog. 

I appreciate nothing was seen, but did you have any significant symptoms during the two week Holter monitoring this year?  Short term monitoring is not effective when we are dealing with an intermittent arrhythmia.  It is often a loss of time and very frustrating.  Is there any way that you can use a Kardia Mobile monitor when your symptoms are at their most troublesome, so that you can show your doctors the evidence?   Kardia is not perfect but it is useful and a cardiologist should have no difficulty interpreting the Kardia ECG.   Otherwise, ask for a Zio patch or a Holter monitor again when you are particularly symptomatic.  If your difficult symptoms continue, I would also perhaps push for more permanent monitoring in the form of an implanted loop recorder.  It was instrumental in picking up all my arrhythmias and I kept it in place for 3+ years, even after my pacemaker implant because of its superior ability to detect, record and store arrhythmias.

Gotrhythm, sub clinical arrhythmia?   Well many of us have arrhythmias where we can be asymptomatic and this would be regarded as a silent arrhythmia as we wouldn't feel it, so I suppose we could say “sub clinical”.  For example, we often say “silent AF” since some of us don't know when we are in AF which is why AF can be so dangerous because of the potential stroke risk associated with this arrhythmia.   But any good monitor should be able to pick up either a slow, fast, regular or irregular arrhythmia, so it should never go undetected.

From what I have read, I believe your RNRVAS could well be the cause for your symptoms.  I also believe that some of your settings could be "pro arrhythmic" in an attempt to eliminate the RNRVAS and perhaps we need to work with a specialist technician to get those settings optimised.  We know RNRVAS is under-recognised as a pacemaker-mediated arrhythmia because there are no specific device algorithms to detect and store it.  My concern is that RNRVAS could induce other arrhythmias from a loss of AV synchrony and I wonder if this is beginning to happen?

I see ventricular premature beats, in the absence of a substantial increase in the pacing rate, is the most common initiating and terminating mechanism for RNRVAS.  Also, RNRVAS can cause inappropriate mode switching and this may lead to difficult symptoms too.   A long AV interval as well as a fairly fast programmed lower rate seem to favour the development of RNRVAS.  I will send you a few links tomorrow in case they are of help. 

Please don’t give up hope Gotrhythm.  You have made such good progress and have learnt and taught us all so much from your RNRVAS experience. Goodnight - you can beat this awful pacemaker-mediated arrhythmia

for me it sound like

by new to pace.... - 2023-11-14 20:28:56

Maybe you might want to avoid Gluten for a while and see how you feel.  I know after eating Pizza sometimes i stagger and certainly have brain fog.  I know it will be hard now since this is the US thanksgiving with all the stuffing and pies and leftover turkey sandwhiches.  Also Barley and other grains.                                                                                                                    Wish you luck in finding out what is going on.                                     new to pace


by Penguin - 2023-11-15 08:37:18

Would it be helpful to re-cap on what's been tried so far to get rid of diagnosed RNRVAS?: 

1. You were switched from DDD to AAI only pacing.

2. AAI had to be changed back to DDD because there was some AVB and a need for some v.pacing. You felt better initially and for quite some time afterwards.

3. The symptoms have come back recently and worsened, so they have now extended your PVARP.

4. The PVARP extension has resulted in v.little v.pacing for AVB (type?).

5. Your symptoms have improved but are still coming on with exercise / activity. 

6. You also have suspected PSVT but it didn't show up on recent holter monitoring.

7. You are having symptoms which may indicate lack of blood flow to your brain.

Is that right?

I feel your "condition" has changed but that your settings are still not ideal

by Gemita - 2023-11-15 09:57:30

Gotrhythm, during an ER check earlier this year when you were last having intolerable symptoms, you asked specifically whether your symptoms could be due to RNRVAS - a pacemaker-mediated tachycardia that is seen in patients with retrograde ventriculoatrial conduction.  Your question and knowledge shocked your treating doctors who confirmed "There is no algorithm to test for it, but it can be observed."  When they looked for it, they found it.  

In the absence of any other cause for your current new symptoms, in your shoes, I would continue to look at RNRVAS as a continuing trigger for your sudden deterioration in symptoms.  Your EP, while suggesting that you seek advice from your PCP has also clearly “theorized” that you are still having RNRVAS and he has therefore widened the PVARP setting, making it so that you are practically never pacing in the ventricle.  

Your personal experience perhaps confirms what my searches have revealed that in patients with VA conduction, the recommendation seems to be to avoid RNRVAS predisposing settings.  New algorithms for the diagnosis, prevention and suppression of RNRVAS are urgently needed in all current manufacturer devices.  Studies have shown (see links below) a number of predisposing causes from a loss of atrial capture to other potential triggers like PVCs that conduct retrogradely to the atria.

Certain adjustments in device programs may prevent or terminate RNRVAS and it is recommend that as many of these modifications as possible be included in any upcoming device algorithms. (i) Decreasing lower rate limit, (ii) short AV delay or automatically shortening AV delay, (iii) decreased sensor indicated upper rate or turning off R mode, (iv) shortening PVARP or programming a rate dependent PVARP; (v) programming non‐competitive atrial pacing, (vi) programming ventricular pacing decreasing algorithms when the patient's AV conduction is functional (MVP, AAI‐SafeR, or RhythmIQ). Medtronic devices have noncompetitive atrial pacing algorithm which is programmable and may eliminate RNRVAS . It is also recommend that meticulous measurement of atrial threshold and programming the pace amplitude for safety margins be made to prevent loss of atrial capture.

I hope you find something of interest in the links below, but take your time to read them when any brain fog has lifted.  My feeling is that your settings are still not quite right because of the complexity of your rhythm disturbance and you may need to work closely with a manufacturer technician to adjust them.  I feel your condition has changed but that your settings have not been adjusted appropriately for you.  I hope that your intermittent symptoms can be stabilised Gotrhythm and that you will soon be feeling so much better

I feel so bad for you

by PacedNRunning - 2023-11-15 21:30:48

I'm so sorry this is all going on with you.  I personally find it hard to believe RVRNAS is causing this (Ive had this). It's usually from long AV delays that should be fixed easily with adjustments.  Perhaps a lead is oversensing causing the device to track non cardiac signals.  Have they ever looked at your RA or RV sensitivity?  My second guess would be you need more RV pacing even though they are trying to minimize pacing.  I have exercise AV delays, which means on exertion my AV delays shortnes as my HR increases.  If you have fixed AV delays, at higher HR's it may not be enough of a AV delay to keep up with your heart rate.  

I too had RVRNAS, classically caught on my kardia. But at the time, I had long AV delays to avoid V pacing.  Fixed with AV delay adjustments. BUT! what happend with me is my AV block worsened and I became symptomatic. I honestly didn't realize how bad I felt until they adjusted my settings. They kept trying to minimize pacing as well and that only made my symptoms worse.  I was very short of breath (I'm a runner), felt alot of chest continous palpitations and just felt awful.  My symptoms only came on when I exerted myself. I'm sure they have looked at these things.  I recently had a zio that showed 3rd degree HB, HR dropped to 32bpm for 14 seconds.  My device had oversensing or EMI, to they adjuted my PM to avoid oversensing. I had been experiencing strong bouts of sudden nausea and lightheadness.  Another option, probably not ideal but has been offered to me by my EP when I had symptoms was a loop recoerder. I know we have PM's but they don't catch everything.  They only catch significant events that need attention.  That  may be an option as well. Have they watched you walk in real time with the device programmer to see exactly how the PM is responding to your hearts activity?  I really hope they find a solution. I'm sorry this is going on and i hope it can be fixed soon.


by Penguin - 2023-11-17 14:39:05

May I ask a question?  

You say that your RNRVAS was caught on Kardia mobile.  Did it say ' RNRVAS' or did you recognise the rhythm disturbance yourself? 

Many thanks

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