Theory
#Physiological correlates of heart rate variability
The heart rate is largely under the control of the autonomic nervous system. Parasympathetic influence is mediated via the release of acetylcholine. Sympathetic influence is mediated via release of epinephrine (Adrenalin) and norepinephrine. [1]
In some papers, LF is a marker of sympathetic activity and in others, it is a marker for sympathetic and vagal influences (Change of heart Frequence with respiration). During exercise, the LF component is markedly reduced. LF can increase und different conditions: 90° Tilt, standing, mental stress and moderate exercise. An increase in HF can be induced by controlled respiration, cold stimulation of the face, rotational stimuli [1]
Vagal activity (breathing) is the major contributor to the HF component. [1]
Depressed HRV after myocardial infarction (MI) reflect a decrease in vagal activity which leads to cardiac electrical instability. In an acute phase of MI 24h-SDNN is significantly related to left ventricular dysfunction... [1] => Possible detection of MI with 24h-SDNN
Some changes in the HRV values were detected but could not be perfectly linked to diabetic neuropathy. [1]
Reduced HRV with no definite spectral components is reported in patients with a recent heart transplant [1]
Reduced HRV has been consistently observed in patients with cardiac failure (Herzversagen) [1] => Some tips in the app for what a reduced HRV can stand for
It's a growing consensus, that vagal activity can be beneficial and therefore the modification of the HRV. [1] Despite medication, exercise training might decrease mortality and sudden cardiac death [1 -> 126]. Its also capable of modifying the autonomic balance (?) [1 -> 127,128]. => Monitor autonomic balance to see improvements through exercise.
[1]
=> diagnosis of diseases? Tipps on what a certain measurement could stand for.
[1]
Read: [Paper] (https://www.researchgate.net/publication/232532014_Comparing_Parametric_and_Nonparametric_Methods_for_Detecting_Phase_Synchronization_in_EEG)
| Variable | 24h |
|---|---|
| SDNN | 141 +- 39 ms |
| SDANN | 127 +- 35 ms |
| RMSSD | 27 +- 12 ms |
| HRV triangular index | 37 +- 15 |
| Variable | 5min |
|---|---|
| total power | 3466 +- 1018 ms² |
| LF | 1170 +-416 ms² |
| HF | 975 +- 203 ms² |
| LF | 54 +- 4 n.u. |
| HF | 29 +- 3 n.u. |
| LF/HF ratio | 1,5 - 2,0 |
[1] Paper