Complex Sleep Apnea With Max Pressure Support and Atrial Fib

[rich0]

I've been having some issues lately and I just began to suspect a link to my sleep apnea, so I figured I'd see if anybody knows anything. I plan to contact my doctor first thing tomorrow, but I figured getting more info wouldn't hurt, especially since I understand complex sleep apnea isn't very common and my doctor might not have much experience with this.

A few weeks ago I had an episode of atrial fibrillation with a very high heart rate (somewhere around 200bpm), and a fairly scary episode in the ER while they tried to get it back down.

In the followup they haven't noticed any further afib (24h halter monitor), but they did notice a fair number of PVCs. In an echocardiogram they had concerns about insufficient left ventricular movement and they had me do a stress test with an echocardiogram. In that study they found I had PVCs while at rest, but they went away during exercise, and both before/after exercise they felt my heart was normal. The doctor's sense was that PVCs might have been causing the incomplete contractions, but since I handled the exercise fine he felt I did not have any vascular disease and the PVCs were benign.

However, I'm still having noticeable arrythmias at night mostly. My first afib episode happened while I was awake, but I was deliberately staying up very late so I was quite tired (trying to adjust my sleep schedule for a trip). I read that there is suspicion of issues with the parasympathetic nervous system having a role in triggering afib in some individuals, so maybe that has some bearing on this.

Well, tonight I just woke up and felt a fairly strong sensation of an arrythmia, possibly afib (I could have just had some shivering, but I could swear that I felt a quivering movement in my chest, but my overall heart rate was elevated but reasonable (I'm guessing maybe 90pbm), but somewhat irregular. I also felt a bit short of breath.

So, I just pulled up my data in sleepyhead (I haven't looked at it in a while), and right before I woke up I had maybe 30 seconds of maximum pressure support and a fairly low minute ventilation volume (1-2L/min). My breathing was regular but very shallow on the flow graph. During that period there were no indications of machine-triggered breaths (there were some earlier in the night). I looked back and over the last few weeks (going back to around when this all started) I saw quite a few nights with extended periods of maximum pressure support (25 cm on my PRS1 ASV), sometimes for upwards of 30min. During some of these periods I saw minute ventilation graphs dipping down to 5L/min for an extended period of time. with tidal volumes around 400mL.

So, other than hypertension my cardiologist doesn't think there is anything wrong with my heart. I thought of maybe low potassium being an issue and am about to get a blood test with my primary doctor to check on that. Now I'm seeing central apnea issues.

I am overweight, but my weight has been stable for months and I've been working on slowly getting it down, and I'm probably 20lbs below my max ever (6'1", 270lbs). I'm sure that is contributing to everything over the long term, but I haven't had any short term weight changes except slightly for the better.

The cardiologist doesn't have any concerns for immediate safety/etc, and his general advice is the usual stuff. We're working on getting my blood pressure back down (I've been medicated for a while but it was drifting up into the 140s). So, I'm trying to relax when having episodes and not add anxiety to the mix (and I'm to report to the ER if I have high heart rates like the previous episode).

Does anybody have any ideas here? I've just started to google and am finding papers talking about afib, heart failure, and central apnea, so I'll read those. I'll follow up with my sleep doctor but it might not be something he has experience with. I suppose I could get a second opinion somewhere in the city if he's stumped, but we'll see where he gets. I figured more advice is better than less and if there is a particular type of doctor/etc I should check with I'd be interested in that.

[rich0]

Sorry, one other note. After the original afib episode I was prescribed metoprolol (and blood thinners), so that might also be related to the appearance of the stronger central apnea. Perhaps the medication is causing it? Both the afib and the medication changes happened around the same time...

[Pugsy]

Which machine are you using? It's not showing up the profile (probably broken link)...can you manually add it to the comments section of the profile?

[rich0]

This is a PRS1 AutoSV (950P). I'll see if I can fix the link/etc.

[Pugsy]

You won't be able to fix the link. That model machine is no longer sold at cpap.com and all these links go to what cpap.com sells.
It's broken and can't be fix....so it's best just to manually type in PR S1 ASV model so and so in the comments section.

Are you getting any green PB/CSR flagged times showing up on the events graph?

[rich0]

Are you getting any green PB/CSR flagged times showing up on the events graph?

I occasionally get short bits of that every few nights, but very little in general. There wasn't any during the shallow breathing, and the breaths all look even visually, just shallow. I noticed I had other episodes of breathing that were about as shallow that didn't trigger the pressure support, so I might also be doing this just above whatever its threshold is.

[Pugsy]

PB has to meet certain characteristics plus it has to last at least 2 minutes.

Are you showing many centrals?

[rich0]

Are you showing many centrals?

No, and my AHI as reported in the data is fairly low (1-2, never above 5). The 30 second episode I had wasn't even flagged for hypopnea, and the 30min episode the previous night had 4 hypopnea flags in it, but pressure support was maxing out at the 25cm limit almost the entire time.

So, whether that counts as "many centrals" I'm not sure. I've had it max out at 25cm once in a while for years now, but it seems like it has been doing it all the time lately. I had to disconnect the buzzer internally as it is the one alarm you can't disable and it was impossible to sleep with it, but it was very sporadic originally.

[Pugsy]

I don't know that the machine is going to offer any data to help you out in terms of figuring out what's going on. It's really not designed for that.
I have been sitting here scratching my head wondering what it might have been that you experienced but this stuff is out of my experience zone.
If what you experienced was unrelated to your sleep apnea the the chances of spotting anything on the reports get pretty slim.

Call the doctor tomorrow and share with us what he says or wants to do.