Are pulse rate changes significant during sleep?

[UsuallyTired]

For healthy sleep, how much should our pulse rate fluctuate throughout the night? 

I saw 1 respiratory therapist online who notes anything above a 3 beat/minute change, but I have no idea if that's a based on real evidence. 

I'd love to hear any rules of thumb or better, any sources to read about the significance of pulse rate changes while sleeping. 

The screenshot is a typical night of sleep for me. I set OSCAR to flag pulse rate changes of > 6bpm within 8s. I used the Viatom O2Ring. I have literally hundreds of PR changes, and I suspect that's significant, but I'm not sure. What does the graph of a healthy / treated person look like? 

Note: You may want to recommend increasing my CPAP pressure. I have tested that extensively, and it ends up creating new problems for me. It does not end up helping my SpO2 or PR much. 

   

[Jay51]

There is one more major variable to add to your equation IMO - you live at 5,600 feet.  That high elevation may have something to do with it.  

The first big thing I have learned from research from pulse rate changes is that it should remain relatively steady all night for a normal person sleeping.  The great thing about OSCAR is that you can "line up" pulse rate changes on your graph with events to see cause and effect.  

I see one cluster of flow limitations that decreases your SPO2 down to 90 and slightly below.  But, at other times, you have some pulse rate spikes that don't line up with anything.  When a pulse rate spike lines up with a flow limitation, H, or O, or even CA, etc. that is the most likely probably reason.  

This is only one night also.  It would probably be best to upload more charts to see if any trend can be established.  

That is what I see here.  Others may have comments on this as well.

Oh, and your tidal volume of exactly 300 (median) is lower than normal.  This may be altitude related or not.  This could certainly contribute to heart rate spikes (lower amount of oxygen being consumed with every breath).

[UsuallyTired]

Thanks, Jay51. 

Thanks for pointing out the altitude. I'm glad you saw that. I meant to put it in my original post. 

NOTE: These results include me using 1lpm of O2 (via O2 concentrator plugged into my CPAP line)! 

It's hard to line up my O2/PR rate w/ my CPAP data, but I think they're within ~15 seconds of each other -- if I did my calculations correctly. 

My PR and O2 are consistently all over the place; this one night was not an exception. 

My tidal volume is consistently low, and I've noticed that, too. When I've mentioned it before, I haven't gotten much response other than to keep adjusting my CPAP. I do suspect it's another piece to the puzzle. 

My hypothesis, and I think your comments support it, is that I have UARS and some sort of consistent resistance in my airway. I have recently had scans done, and I do have narrowing both in my nasal passageway and in my throat. (I nearly always have some sort of congestion in my nose.) I also suspect that this is why modifying my CPAP settings doesn't seem to help.  

This may all be moot as I'm about to start palatal expansion (via MARPE). I'm just intrigued by trying to learn as much as possible about all this, and I only recently learned that erratic PR may be another sign of problems.

* I can post another night if you think that'd be helpful, but I don't think there will be much difference. I don't usually import my O2/PR data, so it takes a bit more effort to get that included.

[Jay51]

Thank you for sharing that information.  You don't have to upload any more charts because you have enough to see the trend.  

The best plan seems to be to wait and see the results after surgery.  Hopefully it goes well.

[UsuallyTired]

Thanks! 

I meant to respond to this: 

Oh, and your tidal volume of exactly 300 (median) is lower than normal.  This may be altitude related or not.  This could certainly contribute to heart rate spikes (lower amount of oxygen being consumed with every breath).

So, this gave me the idea to look at my OSCAR when I visited a lower altitude with my CPAP but without O2. Interestingly, my Tidal Volume and other stats were unchanged. 

I also suspect that my Respiratory Rate (16.8-17) is a bit fast. I don't know what other people experience at night, but that seems fast for me at rest. When I'm awake and at rest, I don't think it's nearly this fast.  I suspect that my Respiratory Rate is elevated to compensate for the low Tidal Volume. 

I am also hypothesizing that this further increases sympathetic nervous system response and causes further symptoms for me.

[THEVGE]

I am, like you, tracking SpO2/HR in OSCAR. I see pretty clear trends, where positive trends is minimal 3 % / 4 % SpO2 dips (I have once achieved 4% events < 1/hr) and if that happens, HR events go down as well (<< 10/hr). Not sure yet what is a good value, just started.

In your case I see a lot of residual flow limitation and pretty low SpO2 dips. My advice would be to slowly increase pressure and see if your feeling improves together with a reduction in SpO2/HR events.

[Jay51]

Normal respiratory rate during sleep is roughly 12 to 20 (and that can even vary normally).  You are close to the middle of this range.  No problem with this IMO.  

You are correct, too, in that minute ventilation is most important.  Usually, when respiratory rate goes up, tidal volume goes down a little, and vice versa to compensate and try to equalize minute ventilation.