Table 2.
Definition of the variables (ANS proxies) employed in the study.
| Vars. | Units | Definition |
|---|---|---|
| HR | beat/min | Heart Rate |
| RR Mean | msec | Average of RR interval from tachogram |
| RR TP | msec2 | RR variance from tachogram |
| RR LFa | msec2 | Absolute power(a) of Low Frequency (LF) component of RR variability (V) |
| RR HFa | msec2 | Absolute power(a) of High Frequency (HF) component of RRV |
| RR LFnu | nu | Normalized power(nu) of Low Frequency (LF) component of RRV |
| RR HFnu | nu | Normalized power(nu) of High Frequency (HF) component of RRV |
| RR LF/HF | – | Ratio between absolute values of LF and HF |
| RR LFHz | Hz | Center frequency of LF |
| RR HFHz | Hz | Center frequency of HF, providing a measure of respiratory rate |
| ΔRRLFnu | nu | Difference in LF power in nu between stand and rest |
| α index | msec/mmHg | Frequency domain measure of baroreflex gain |
| SAP | mmHg | Systolic arterial pressure by sphygmomanometer |
| DAP | mmHg | Diastolic arterial pressure by sphygmomanometer |
| SAP Mean | mmHg | Average of systogram (i.e., systolic arterial pressure variability by Finometer) |
| SAP LFa | mmHg2 | Absolute power of LF component of systogram |