Question for ALL my TECH SAVY Pacers!

You may be right

by crustyg - 2020-09-30 17:50:28

Hi Alejandro:

You may be correct that your PM is not completely synch'd to your natural rhythm.  Let me illustrate from my own experience.  My SA node is useless and my PM only drives my RA lead (long story).  My AV-node produces a very slow resting rate, now about 28-30BPM, *BUT* it can still drive my ventricles up to about 110BPM - not enough for real living, hence the PM.  My AV-node shows very little retrograde conduction, and as the ventricular lead isn't used, my PM can't sense when my AV-node is driving fast.

So when I wake in the night from a dream (lots of Sympathetic nervous system drive to the AV-node), I have an irregular rhythm as the PM delivers 50BPM (no input to the RR algorithm) while my AV-node is driving my ventricles much faster with no synchronisation between the two sources.  Would be potentially lethal except that the AV-node has a refractory period so that any PM-derived atrial impulses that would tend to provoke VF by colliding with the natural stimulation from the AV-node don't actually make it to the ventricles.  As I calm down my rate slows and becomes regular again.

Back to you: my recollection is that there is strong suspicion that you could get by without a PM.  Your symptoms sound a lot like a 'fight' between your natural rhythm (from wherever) and your PM.

Remind me: when was the last time the EP techs briefly turned off your PM (one of two routine checks for many PM patients)?  Could you survive without pacing?

Funny you ask!

by arent80 - 2020-09-30 18:09:11

I saw an outside EP recently. He is TWO years older than me (I'm 40). Harvard grad, real cocky. He told me I wouldn't have put a PM in you. Said my heart works fine with exception of these sleep apnea related electrical issues. However it was proven I was having nightly pauses confirmed by both zio patches. I had pausing NIGHTLY up to 11 seconds and intermittent 2nd degree AV Mobitz Block 1 (Wenckebach). In the hospital they did a sleep study. I needed more pressure from my CPAP. Originally I was at level 8 out of 20. After sleep study I needed a pressure range from 13-20. This brought nightly pausing DOWN UNDER 5 seconds. This was confirmed by a 30 day cardiac event monitor worn for 30 days after released from the hospital. My heart rate would drop dangerously low as well when these pauses would take place. Lowest recorded was 21BPM. So the EP at the VA decided a PM was my only option being that sleep apnea was treated and pausing did not stop. 
 

After PM was first put in I didn't notice much. Ever since they started with the CLS, Accelerometer and other tweaks I've felt HORRIFIC! At first CLS was activated to 140BPM. This was too much. Then they reduced it to 120BPM this was better. Based on a Cardiopulmonary Exercise Test it was determined I didn't need the CLS feature, maybe just the Rate Response (Accelerometer). That caused a lot more issues. Especially in the ventricles. Now I had them turn off any feature related to CLS or Rate Response and I'm better. 

The question now is why? Like I said I only notice anything bad when my heart rate is at the minimum and the PM is working. My last zio after the PM in May 2020 indicated retrograde conduction with Intermittent av block with programmed AV Delay hysteresis. I am now certain the PM is to blame BUT WHAT IS THE FIX? Seeing docs tomorrow morning. Wish me luck!!!

Retrograde conduction is the key component to PMT

by crustyg - 2020-09-30 18:22:40

If your EP-doc & techs start from a hypothetical assumption that you're getting some episodes of PMT they ought to be able to use the various delays and features of your PM to reduce the rate at which your HR is driven up and potentially eliminate PMT episodes.  They can also perform a test which attempts to set you up for PMT and then watch your ECG in realtime to determine if it's happening, which might be a diagnostic step onwards.  If that's proven then, armed with that information, they can make the necessary changes.

Best wishes.

Thank you!

by arent80 - 2020-09-30 19:01:32

CrustyG- THANK YOU! I'll be sure to mention this tomorrow. The more info I have the better. You all are amazing! I can't thank you enough. 

Good luck

by Gemita - 2020-09-30 20:32:54

Alejandro, I wish you luck and an answer in the very near future.  Please post an update when you can.  

Despite all your setbacks you have never stopped believing in yourself, in your ability to identify that missing ingredient.  We have one by one eliminated many possibilities, work that we had to get through to narrow the possibilities down.  I think we may have finally arrived.  

We always felt that retrograde conduction was at the heart 💓 of your problems due to pacemaker settings.  Stay with this as you move forward.  Learn as much as you can about this area and don't allow your doctors to change the subject and steer you in another direction.  They need to keep monitoring you as your pacemaker settings are changed and perhaps do another sleep study to see what is happening when you are at rest, when you appear to be most symptomatic

Understanding the PM

by Old_Mainer - 2020-10-18 23:09:04

Alejandro,

Puzzling and frustrating!!  I have a long tale similar to yours but different enough that it is difficult to be helpful.  However, I suggest a strategy for knowing a lot more. 

If you have a smartphone invest in a Kardia portable EKG.  I have the $89 Kardia Mobile.  It helped me enormously to understand what was happening.  I can quickly run an EKG of from a few seconds to 5 minutes and see what my heart and pcemaker are doing. 

Early on I started getting clouds of Premature Ventricular Contractions (PVCs) after strenuous exercise - the rhythms you describe sound silmilar.

Hope this is helpful.