HRV Spectral Analysis

[willtaylor]

Wanting to open up some discussion regarding HRV spectral analysis, for folks focussing on this, including Kubios users (using session data exported from Alive), to make some sense out of what can be found in the literature regarding the physiologic implications.

[willtaylor]

To begin - I've been somewhat puzzled by the commonly-repeated suggestion that Parasympathetic influence is represented in the classically-defined High Frequency band of HRV (>.15hz), with the classically-defined Low-Frequency band (0.04 - 0.15 Hz) representing primarily Sympathetic, or a mixture of Sympathetic & Parasympathetic influence, such that the LF/HF ratio might reflect Sympathetic dominance (e.g., https://www.ncbi.nlm.nih.gov/pmc/articl ... 0-0007.pdf. There appears to be a failure in the historical literature to attend to respiratory rate and its influence on the Respiratory Sinus Arrhythmia as a variable. The reported "average" adult respiratory rate of 12-20 breaths/minute would result in a vagaly-mediated RSA of 0.2-0.33 hz, in the classically-defined High Frequency band, explaining the placement of Parasympathetic influence here, but only as an artifact of aroused breathing patterns in the study population. More physiologically-appropriate respiratory rates of 6-10 breaths/minute would bring the RSA down to 0.1-0.16 hz, in the upper range of the classically-defined Low-Frequency band. I'm sure this is obvious to the folks who've developed the algorithm for "smoothness" & "coherence," & the power spectrum feedback in Alive, so thanks for indulging my curiosity here.
I'm intrigued to explore the physiologic nature of other components of the HRV power spectrum.