Central apnea and syncope

[problemchild]

Hey everyone!

I've been on therapy for eight years and, for the most part, my apnea seems to be controlled.  I'm using a Dreamstation ASV to treat obstructive and central apneas, although most of my obstructives went away when I started sleeping "flat", without bulky pillows tipping my chin forward, and began using a cervical collar to keep my mouth closed and my chin from dropping.  My AHI has been averaging 0.3, especially when I went to a new nasal/mouth mask (instead of the full faced one).  So, things are good. 

The problem I'm still having (and one that I'm beginning to think I've always had) is my tendency toward central apneas and the effect they have on me.

Given that the bulk of my apneas actually *were* obstructives for the first several years of my treatment (until I addressed neck position and chin/mouth issues), and given that my numerous sleep studies have never tested me with those adjustments, it's not surprising that I was diagnosed with OA and that it took years to figure out that I had CA, too (or more likely, complex sleep apnea).  And while the combination of CPAP and ASV adjustments has my AHI numbers almost non-existent, I'm not sure that the CA aspect has been properly diagnosed or recognized.

My first clue is what happens when I'm falling asleep.  I had noted for years times when I'd almost be asleep, then wake up thinking, "Was I breathing then?"  Same thing happens to me when I would crash in the recliner.  Basically, during the process of me falling to sleep, my breathing slows almost to nothing, or stops altogether.  I'm pretty sure I've had some aspect of this all my life, although I notice it a lot more now.  Once I fall completely asleep, these events seem to stop...at least until I reach REM sleep.

On my Dreamstation, the machine actually recognizes these events...but not as apneas.  It'll hit me with a BiPAP-like strong pulse, followed by a shorter one.  That's usually enough to wake me up and get me breathing again.  My doctor sees those events in the data, but doesn't seem to be too concerned about them because they aren't considered OS/CA/HA events.  But to me, they seem like the beginnings of CA events.  I realize that my breathing has slowed or stopped, either from the pulse or just catching it on my own.

The other thing that makes me wonder about this deals with syncope and slow breathing stuff that happens when I'm awake.

I've had several events of syncope over the course of my life...some when I was young and thing.  In most cases, I had viable explanations for it (e.g.  dehydrated from being sick or from being out in the sun all day).  I'd be laying down or asleep, get up to walk around or go to the bathroom, and black out.  I've only completely blacked out a handful of times, but have had enough other instances that I've been able to pin down the process and how it feels as I'm heading toward the point of no return.  The worst time, I was asleep at a friend's house, woke up, climbed a flight of stairs to get to the bathroom, and crashed, face-down on the floor. 

The run-up to what I experience is always the same.  My heart is pounding in my ears (obviously trying to get blood to my brain), my ears start ringing and my vision begins to get fuzzy, and if I'm unable to head it off by breathing carefully (or sitting promptly), the lights can go out.  Understanding how it works and how dehydration and making demands of my body (like going up stairs) before my circulation has had a chance to catch up has helped me avoid it for the most part.  I still have episodes of syncope, but I haven't blacked out in years.

What's new for me is the awareness of how this syncope might tie in to the central-like apneas I get as I'm falling asleep or, more recently, sitting still for a period of time.

The syncope events are very likely some for of orthostatic hypertension, where my circulation slows while I'm relaxed, but my body doesn't properly keep it from plunging when I stand up suddenly and start moving around quickly.  I've been tested for OH a couple of times before, but the tilt table tests and meds they give me to try to trigger an event they can monitor didn't really catch anything, in part, because I'm not in the comfortable, relaxed enough of a state, so I can't demonstrate the process. 

What I'm wondering is if there's a tie-in between the orthostatic hypertension (or whatever is causing the syncope events) and the central-like apnea events I have as I'm relaxing or falling asleep.  Do the central-like apnea events lead my body to become too relaxed, or leave my blood stream in need of cycling out CO2, and when I stand, it can't catch up for awhile?  Or is it a function of orthostatic hypertension, alone?

If you've read this far, thanks.  : I'm not really looking for answers, unless someone else has experienced something similar.  I'm mainly trying to coordinate my thoughts for how I can present these associations that I *think* are happening to my cardiologist and/or sleep doctor, to see if they make sense.

Thanks!

[problemchild]

The other aspect of all this that seems to be in play is how I feel when I'm awake.

Even with a good night's sleep and low (or zero) AHI's, I find I'm prone to either crashing during the day on the weekends, or fighting sleep at work. I would say this is a sign that I'm not sleeping well, or enough, but I think that most of the time, it's just me sitting in one place too long. When I start to get sleepy, or have allowed myself to relax for awhile, couch potatoing, I'm thinking my body is trying to shift into "sleep" mode, slowing everything down.

But I'm also guessing that my breathing (or blood pressure) might be slowing, as well, even when I'm still awake, which serves as a force multiplier to trying to recover when I stand up.

[mesenteria]

Syncope is not uncommon in youth who have low heart-rate and who stand suddenly.  It gets worse when one is ill with the flu.  If you haven't experienced it in a couple of decades, it shouldn't crop up again.  Is this something you have raised with a physician if your last experience was less than a year ago?  Normally, climbing a flight of stairs should help to increase blood pressure in response.  I wonder how you made it as far as you did.  And about testing it earlier, the 'white coat' syndrome would be enough to prevent you from having that low BP.

The unfortunate revelation that a good many of us see is that the benefits of discovery and subsequent successful treatment of OSA doesn't necessarily lead to the sensations of youth and unlimited energy; we even feel ourselves turning into middle aged and older inside of a couple of weeks after starting treatment.  Happened to me.  I have gained weight even though I have maintained the same sustained effort of run/walking 30 km or more per week.  I was never sleepy watching TV until the onset of my AFib, diagnosis of OSA when figuring out why the AFiv, and then starting CPAP.  The new medications prescribed by my cardiologist all conspire, with the PAP itself, to slow me down.

That is to say, you are not the only person to experience unwelcome, even disturbing, trends and reduction in your capabilities and in how you feel.  It's surprisingly common...alas.

As for the CAs, they too are common for most of us when we slip into sleep.  Even when we turn over, our machines record a holding of breath that, if extended into the falling asleep, could amount to 15 seconds or more, and they dutifully record them and act on them as they should.  I have two or three such events each night, according to the record, but never have OSAs; the machine prevents them successfully.

We have to get used to the changes that come with the new territory.  If our AHI count is under 5, and especially if they are routinely under 2, we are doing pretty darned well.

[StevesSp]

These stories of low AHI yet debilitating daytime tiredness are depressingly familiar and I too suffer the same problem. Like the OP, I also suffer from CAs, which I am trying to combat through better understanding of my data, and how CPAP works. The advice in this forum and others is of huge value in this respect.

Also like the OP, I frequently stop breathing as I fall asleep, so much so that it usually prevents me from taking daytime naps, when those 'falling asleep CAs' seem to be more prevalent. I find that, in order to fall asleep during the day, I have to successfully exploit a very narrow window of opportunity, dropping off at the first attempt, when everything falls into place just right. If however, just as I'm nodding off, a noise or other disturbance (such as a significant CA) halts the nodding-off, that's it. I've had it. I don't get two goes and I might as well give up.

Another phenomenon more recently has been the length and depth of CAs when I am properly asleep. These can be so prolonged that it wakes me up as though an explosion has gone off and I am suddenly aroused in panic, desperately short of breath and with a racing heart. This never used to happen before my diagnosis, before I started CPAP. My apnea was typical before official diagnosis - though I was 'awakened', I wasn't aware of it happening, I guess because i didn't fully awake. These major CAs also come with nightmares, when my brain tries to make sense of my breathlessness, usually by crafting a scenario of extreme danger, such as drowning or being pursued.

Sorry, I starting a novel here and hijacking the thread. Suffice to say that I am concerned that so many people, like the OP, say that CPAP may well control their AHI, but they simply don't achieve refreshing sleep. There's something going on here that nobody has so far explained and, if the PAP machine manufacturers know what's wrong, they're not letting on.