Is it true that AT/AF includes more than just AFib?

It is my understanding that the AT/AF data recorded by my pacemaker (previously a Medtronic, and now a Boston Scientific) includes more than just AFib -- it can include other atrial misbehavior. Can anyone confirm or disconfirm?

Earlier this year I had a period of near-constant palpitations. When I went to the doctor, the folks who read my pacemaker said I was having AFibs. But the doctor read the EKG and said no: it's not AFibs, it's actually Atrial Premature Contractions. So apparently these APCs were showing up in my pacemaker's AT/AF data. What I'm getting at with this little story is: I suspect that people tend to assume AT/AF means AFib, when the real situation could be more complicated.

Can anyone confirm or disconfirm?




AT/AF data does not include atrial premature contraction episodes

by Gemita - 2022-08-26 13:34:26

Mark, the AT/AF data log will contain other atrial tachy arrhythmias like Atrial Flutter, SVT, Multi Focal Atrial Tachycardia but not atrial premature contractions since these are not atrial tachy arrhythmias.  

Your pacemaker arrhythmia logs will include all important tachy arrhythmias like Atrial Fibrillation, Atrial Flutter, Atrial Tachycardia and there will also be a separate log for ventricular tachy arrhythmias like VT.  Any significant tachy arrhythmia will be recorded when the arrhythmia has met the threshold set by your EP for its recording and storage. For example, he may only be interested in a tachy arrhythmia episode when it reaches a certain heart rate and duration.

In the pacemaker AT/AF log, atrial tachyarrhythmias are grouped under the same umbrella but any pacemaker stored EKG will usually confirm the actual arrhythmia seen, although a surface EKG may sometimes still be needed to confirm the occurrence of a more complex atrial tachy arrhythmia like Multi Focal Atrial Tachycardia.  

Since premature atrial contractions are not atrial tachyarrhythmias they will not be stored/recorded in the pacemaker AT/AF log, but the pacemaker can be set to record the total ectopic percentage burden.  You could ask for a copy of your settings so you will know what is set up for you personally.  My pacemaker does not routinely record ectopic episodes since they would run out of storage space.  Ectopics are essentially benign and not of interest to my EP even though they can cause extremely difficult symptoms. 

The situation can get complicated when atrial ectopics develop into atrial tachy arrhythmias like AF, then back to ectopic beats, but if the AF episode is significant in duration and rate, it will be recorded and they will see how the AF starts and ends.  My clinic was able to confirm that one of my AF episodes started and ended with ectopic beats, and the pacemaker recorded the exact start and finish time of the AF episode.

Perhaps at the time of your EKG which only takes seconds to record, you slipped out of AF into ectopics?  An in clinic surface EKG is all too brief and may miss an arrhythmia episode.  

Thanks Gemita for that comprehensive reply!

by AbNormative - 2022-08-28 22:42:07

Thanks Gemita for that comprehensive reply!

So AT/AF includes more types of atrial tachycardias than just AFib, but it does NOT include PACs.

I take your point that I could have AFib at some times and PACs at other times.

That doctor visit that I described took place during a 10-day spell of near-constant heart weirdness of a type that seemed new to me. It was very noticeable and unpleasant. In the course of a single inhalation I would feel my heart 3-4 times, grabbing my attention as if there were some emergency I needed to respond to. It was quite a relief when it stopped.

That doesn't seem to fit with AFIb because, when I've had AFib before, I didn't notice it.

But PACs were new for me. I never had PACs before this episode, at least not that anyone ever identified. So maybe what I was experiencing was mainly a lot of PACs, with some periods of AFib mixed in? But from what I read about PACs it sounds like they are usually isolated, whereas whatever was going on with me was near constant, so I don't know.


PACs can be constant

by Gemita - 2022-08-29 01:40:03

Mark PACs can be constant for me and go on for hours.  They are far from "isolated".  In my case when they are constant they invariably trigger other atrial tachy arrhythmias including AF.  When my PACs start I know I am in for a rough ride.  Also you might be getting ventricular ectopics too (PVCs) which will cause more symptoms.

If it happens again, longer term additional external monitoring (Zio patch or holter monitor) might catch the little pest.  Just message me if you need to chat.  Good luck

Sounds similar

by AbNormative - 2022-08-29 15:40:15

Thanks Gemita.

Sounds like I could have something very similar going on.

The episode that I described was in February of this year (2022). Since then I've had a couple of similar but milder episodes. I'm worried that it will get more frequent.

If I'm having a lot of PACs, is there any treatment for that? I tried metoprolol but it didn't have any noticeable effect.

The pacemaker that I had in February was a Medtronic that I got in 2011. (They just replaced it a few weeks ago (finally) with a Boston Scientific.) I wonder if its AT/AF tracking could have been more primitive than newer pacemakers?


Treatment for PACs

by Gemita - 2022-08-29 19:30:16

Mark I have always found a higher base rate setting (mine is set at 70 bpm) can be effective in "outpacing" slow, pausing, irregular ectopic beats.  Not sure what yours is set at?  I take a low dose beta blocker (Bisoprolol) to calm any high heart rates during AF but if I take too much, it worsens all my arrhythmias.  If your heart rate is always well controlled, I would take only a low dose beta blocker, or even consider taking nothing at all.  Some arrhythmia sufferers find a calcium channel blocker like Diltiazem more helpful than a beta blocker in the treatment of their rhythm disturbances.  It will be trial and error until you find the best med.

You sound as though you have received a better pacemaker for athletes in the Boston Scientific than you had in the Medtronic and yes with every device upgrade you will get better software and functions, so hopefully you will see improvements not only in your capacity to exercise but in your arrhythmia control.

I have a Medtronic implanted in 2018.  It seems very basic to me without any special anti tachycardia pacing therapies but it has a superb mode switch facility when I am in AFib so that my fast arrhythmias are not tracked.  Perhaps when you approached the end of battery life, some of the Medtronic functions were not fully operational in order to preserve battery.  No doubt some pacing therapies would have automatically reduced to conserve energy.  Perhaps that is when you noticed a deterioration in your arrhythmias?  But there are so many triggers that can start ectopics/AF.  It is important to get to know what yours are? Dehydration, tiredness, wine are known triggers for me.  I no longer drink wine with my main meal.

I hope the Boston Scientific works well for you and keeps those irregular beats under better control.


by FJ - 2022-08-31 13:59:08

This is all so helpful, thank You Gemita and all. I am relatively new to the family having received my Medtronic Azure MRI single wire in April 2022. I am dealing with lightheadedness that is very frustrating. My 2nd intervention is in Sept. I am hoping they can do something for me. Thank You again. 



PACs, beta blockers, alcohol

by AbNormative - 2022-09-05 10:24:20

Gemita, my new pacemaker has a lower rate limit of 60. I don't know how they arrived at that. My previous pacemaker was set at 55, which seemed perfectly adequate. But maybe they were applying your strategy of outpacing some PACs.

They prescribed the beta blocker metoprolol around day 3 or 4 of my first experience with a high frequency of PACs, which went on for about 10 days. Unfortunately, it didn't seem to have any effect. I stopped taking metoprolol a few days after the PACs went away. Since then my periods of PACs have not been as intense. But frequent PACs are so unpleasant that I would definitely be willing to try beta blockers again. Trying different beta blockers is a good idea I'll keep in mind.

That was back in Feb, well before that old Medtronic pacemaker's long awaited demise.

You mentioned wine as a trigger for ectopics/AF. I just yesterday came across research from 2021 that nails down alcohol as a trigger, for AF at least. The New York Times had a good write-up of it: I normally have a few beers over the course of a week, but that research probably spells the end of alcohol for me. 


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