Table 2. Time and frequency domain parameters in PRE and POST at REST and during STAND over RR, SAP, DAP and RESP variabilities.
| parameter | PRE | POST | ||
|---|---|---|---|---|
| REST | STAND | REST | STAND | |
| μRR [ms] | 944.1±98.4 | 860.3±103.7 | 722.8±128.3* | 690.3±142.5* |
| σ2RR [ms2] | 937.4±1028.0 | 579.8±362.0 | 57.4±51.9* | 62.3±63.8 |
| HFaRR [ms2] | 172.9±249.8 | 114.8±220.1 | 20.5±35.5 | 17.1±16.5 |
| μSAP [mmHg] | 143.3±21.0 | 141.5±24.9 | 139.9±16.6 | 159.5±24.6 |
| σ2SAP [mmHg2] | 23.2±18.5 | 33.7±39.4 | 26.8±19.4 | 32.9±16.0 |
| LFaSAP [mmHg2] | 2.04±2.67 | 2.19±3.20 | 1.46±2.38 | 4.10±4.01 |
| μDAP [mmHg] | 68.6±20.2 | 77.9±18.2 | 75.9±15.0 | 97.6±21.9*§ |
| σ2DAP [mmHg2] | 11.41±9.79 | 16.75±15.64 | 5.62±2.88 | 11.89±7.20 |
| LFaDAP [mmHg2] | 2.45±3.76 | 3.05±4.50 | 0.87±1.15 | 2.63±3.18 |
| fRESP [Hz] | 0.28±0.03 | 0.27±0.04 | 0.29±0.05 | 0.28±0.04 |
LF = low frequency; HF = high frequency; RR = heat period; μRR = RR mean; σ2RR = RR variance; HFaRR = HF power of RR expressed in absolute units; SAP = systolic arterial pressure; μSAP = SAP mean; σ2SAP = SAP variance; LFaSAP = LF power of SAP expressed in absolute units; DAP = diastolic arterial pressure; μDAP = DAP mean; σ2DAP = DAP variance; LFaDAP = LF power of DAP expressed in absolute units; fRESP = respiratory rate derived from the RESP series; PRE = 1 day before surgery; POST = within 7 days after surgery; REST = at rest in supine position; STAND = during active standing. Results are reported as mean±standard deviation. The symbol * indicates p<0.05 versus PRE within the same experimental condition (i.e. REST or STAND). The symbol § indicates p<0.05 versus REST within the same acquisition session (i.e. PRE or POST).