Sleep apnea and CPAP use and it’s effect on HRV and Sleep Quaility

[tinyobject]

Does anyone know about Sleep Apnea and it’s effect of HRV? Or CPAP and it’s affect on HRV? 

I ask out of curiosity after monitoring my 02, HRV and Heart rate over 6 months especially at nights with and without my CPAP machine (with observed apneas by my partner).

If I have understood what I’ve read, heathy HRV should be at its highest at night when you are asleep especially after 2am - when using a CPAP machine that’s not what I’ve observed for myself.

If I use my CPAP my HRV drops down to 34ms on average (73ms max) and my heart rate sits around 61 bpm average (55bpm lowest)… and I feel more almost stressed when i wake up usually falling asleep again after I remove the mask.
   

However if I don’t use my CPAP my HRV is around 66ms average (100ms max) and my heart rate drops to around 58 bpm average (55 bpm lowest); i wake up almost instantly and the morning I feel decent but crash as the day progresses.
   

As I understand it, the HRV should be at it highest in sleep.

Note about above examples : the example for the one using CPAP, I used the CPAP for most of the night only removing it at 7:30am and falling asleep again, the other one I didn't use the CPAP at all that night.

Thank you

[Jay51]

Hello tinyobject, 

I just purchased a HRV watch myself.  I did some research on it.  Greater HRV is supposed to be seen during sleep.  I can already tell the same thing will most likely happen when I record with it that happened to you.  

HRV is the ability of the autonomic nervous system to change back and forth from sympathetic to parasympathetic and then back when necessary.  It is a sign of a good, healthy heart.  The increased air coming into the body is a new and foreign stimulus (thus pushing the body into more sympathetic to deal with the new, novel experience of cpap, etc.).  My heart rate that I have recorded is about 5 or so beats faster at night when I use my ventilator as opposed to not using it.  It forces my heart to work a little harder to pump more blood to circulate the extra oxygen provided by the cpap.  

Without a doubt though for me, the benefits of using the ventilator at night far outweigh the small decrease in HRV.  Far less chance of any hypoxia to tissues, etc.  So I plan on keeping on using it.  

It seems like the higher the pressure and the more variable the pressure is, the more it stimulates the sympathetic nervous system.  Just my observations.