Guitarsoup said:
I had a strange question: My garmin quantix 7 watch tracks HRV when I sleep. My baseline was between 30-40ms prior to the CPAP. Since starting the CPAP, my HRV has measured in the mid-20s each night. Last night was an average of 24 with a low of 12 and high of 39. Should I worry about that at all?
Oh, crap, now you're making me work.
Huge caveat/disclaimer ahead of this answer: I am not a cardiologist.
All I know about HRV comes from Peter Attia, to whose Podcast I subscribe.
Loosely paraphrased, it appears HRV over 14.7 is ASSOCIATED with less cancer, heart attack, and overall cardiovascular disease than lower. A HRV over 22.3 appears to give another "bump".
I am not sure how well the Garmin tracks HRV. That being said, a much easier metric to follow would be your O2 saturation. Time below 90% is important. Track that. Understand, also, that you drop a couple of percentages from your baseline as you go to sleep, then a few percentage points again when you enter REM sleep. And, just as with a home pulse oximeter, it's not uncommon to get a spurious reading here and there. Don't be shocked if you get an O2 minimum of 72% with only 3% of your night spent below 90%. That's likely artifact and not real.
IF you have a cardiologist, ask them what the think of the HRV data.