Atrium pacing (AP) vs ventricle pacing (VP)

AP->VP

by AgentX86 - 2022-02-05 23:15:16

This is something that you should talk to your EP about but it may be nothing.    A pacemaker works by using a timer to measure between to beats.  If the timer expires, the pacemaker inserts a pacing signal.  If the heartbeat occurs before the timer expires, the timer resets and waits for anoter beat.  Thus at a higher pacemaker rate settng is set higher, the percentage of pacing goes up because it doesn't wait as long to see the natureal pacing signal.

VP works in a similar way.  When there is an atrial pace (whether natural or paced) another timer starts.  If this timer expires, a VP is issued.  If the normal A/V node beats the timer, this timer resets and around it goes. One of the settings in the pacemaker controls this timing.

It's entirely possible that you A/V node is failing too.  It wouldn't be shocking if this were the case.  Your sinus node is damaged.  More nerve damage isn't guaranteed but it shouldn't be surprising.

It may be something simpler.  Your EP may be increasing the timer for some reason.  This would increase the VP, the same way a base heart rate increase will increase your AP.

Only your EP knows what's going on.  This is a good reason to learn everything you can about your condition and your PM.  You can then talk intelligently with your EP.  He's more likely to tell you more iif you show you're trying.

Most people fall into one of two categories.  The simplest is where the sinus node is failing and is too low.  This is "sick sinus syndrome" or SSS.  A single atrial lead works if this is the only problem, though a second lead in the RV is usually added because there is a reasonable chance that it'll be used at some point.

The other category is heart block, HB or CHB (complete).  Here the two leads are used with the two timers, above.

Afib is, obviously, a problem with the atria.  It's where andther nerve cell, other than the SI node is starting the beat.  This "ectopic" isunstale so beats at a random (chaotic) rate.  People don't usually get pacemakers for AF, unless it's to support a normal heart rate when taking drugs for AF. Many of these drugs supress the heart rate and higher doses can lower it dangerously.

There are all sorts of other sorts of pacing.  I'm paced 100% V only.  My atria are disabled to "short out" Aflutter and my ventricles get paced without the atria.  There are other weird and unusual reasons and modes for pacemakers but the two above cover probably 99% if pacemaker patients.

100% paced

by sgmfish - 2022-02-07 16:38:43

Thanks for the explanations. The 1 year anniversity of my PM install is coming up this month; so I will be seeing the EP for the 1st time since the surgery period. The PM monitoring system does a report every 3 months (which I can see online), but no one from the EP office has ever called; so I assume they don't see anything serious in these reports. I will certainly discuss all this with the EP when I see him later this month. (Perhaps my PM will need some parameter adjustments.)

One question remains. I often note that folks here sometimes refer to themselves as "100% paced". Is that always a reference to someone who needs 100% VP pacing due to heart block or other condition that causes no natural signal ever reaching the vertricle(s); or do some folks who need 100% pacing in the atrium (like me for SSS), but have a fully functioning AV node and vertricles, also sometimes refer to themsleves as 100% paced?

100% Paced

by AgentX86 - 2022-02-07 21:39:37

I don't understand why your EP hasn't seen you in the year since your surgery. I saw mine every three months for the  first year, then twice the second, once last your and I won't see him again unless something goes wrong.  My cardiologist will do all the routine stuff now.  I see him three or four times a year anyway. Regular in-person checks the first year are important. Remote monitoring is not the same.

"100% paced" could mean either. It doesn't mean that the heart wouldn't beat on its own, just that the timers, mentioned in my first post, are always expiring so the pacemaker starts each beat.  Increase the heart rate 10bpm or increase the A/D delay and that percentage could go down.  Or not. The "or not" part above points to what's called "pacemaker dependent". Even here, the heart will probably beat on its own but at a lower rate.  It may not be fast enought to remain conscious. But "100% paced" doesn't say much by itself.

100% paced

by sgmfish - 2022-02-08 14:02:05

Thanks AgentX86. I guess I'll just assume that when someone in this forum says "100% paced" their ventricle(s) are probably blocked from getting an atrium sourced pulse.

I can only guess that in my situation, an EP visit may be limited by insurance; or more likely it may be because there seems to be a close collaberation btween my cardiologist and the EP (surgeon).....so they just throw the ball back and forth. I did see a tech at the EP's office about a week after the surgery to set the PM's parameters; then the EP's PA (physician's assistant) at 2 months just to see if everything was A-OK (they did an EKG etc). After that I saw the cardiologist at 3 months and 6 months post surgery. The cardio had access to the reports and seems to be the guy who decides what I do or do not need. I have a hard time believing I will see the cardio more than once or twice a year from now on (but then I don't tend to worry about this stuff.....I've never seen doctors all that often in my life unless something is observably wrong).

100%

by AgentX86 - 2022-02-08 22:02:10

It could be cause by a complete heart block or my sick sinus syndrome. Either way the pacer is doing the whole job but it could be because the timer settings are causeing it to pace faster than the "normal" rate.  There could easily be a normal, but slower, natural pace slower than is needed.

It may be that in my case the cause was a more complex rhythm problem and I had an AV ablation at the same time. If my case was simper, I likely wouldn't have seen an EP at all.  My cardiologist does pacemaker surgery so perhaps your case doesn't require close monitoring by an EP.

Insurance is easy to blame but it's not always the problem. Doctors usually know how to get around their roadblocks.  It may take some work but it can be done. Note that I've always had excellent insurance and recently went on Medicare.  I'm surprised any doctors take Medicare at all.  They don't pay doctors anything. Small offices don't.