Table 1.
Spontaneous cardiovascular variability under resting conditions
| Variables | Young, n = 10 | Elderly, n = 8 |
|---|---|---|
| SBP, mmHg | 120±10 | 143±14* |
| DBP, mmHg | 68±10 | 70±6 |
| HR, beats/min | 71±16 | 71±14 |
| RF, Hz | 0.29±0.06 | 0.27±0.09 |
| ETCO2, mmHg | 37±4 | 38±3 |
| SBPVLF, mmHg2 | 13±9 | 16±16 |
| SBPLF, mmHg2 | 8±5 | 10±13 |
| SBPHF, mmHg2 | 2±1 | 3±3 |
| RRVLF, ms2 | 908±812 | 133±62* |
| RRLF, ms2 | 845±619 | 226±372* |
| RRHF, ms2 | 369±357 | 88±88* |
| Gain-VLF, ms/mmHg | 5.7±4.4 | 2.6±1.7 |
| Gain-LF, ms/mmHg | 9.3±4.0 | 3.7±2.4* |
| Gain-HF, ms/mmHg | 11.9±7.7 | 5.2±4.6* |
| Gain-SF, ms/mmHg | 9.8±3.8 | 3.6±2.2* |
| Phase-VLF, rads | −0.9±0.6 | −0.9±1.0 |
| Phase-LF, rads | −0.9±0.4 | −1.3±0.3 |
| Phase-HF, rads | −0.1±0.4 | −0.3±0.5 |
| Phase-SF, rads | −0.9±0.3 | −1.4±0.5* |
| Coherence-VLF | 0.38±0.11 | 0.45±0.13 |
| Coherence-LF | 0.65±0.09 | 0.62±0.15 |
| Coherence-HF | 0.61±0.10 | 0.48±0.15 |
| Coherence-SF | 0.70±0.18 | 0.66±0.16 |
Values are means ± SD. SBP and DBP, systolic and diastolic blood pressure. HR, heart rate. RF, respiratory frequency. ETCO2, end-tidal CO2. SBPVLF, SBPLF, SBPHF, RRVLF, RRLF and RRHF, spectral power of SBP and R-R interval at the very low (VLF), low (LF), and high frequencies (HF). Transfer function gain, phase, and coherence were estimated in the VLF, LF, and HF ranges and in the specific frequency range from 0.078 to 0.125 Hz (SF).
*
P < 0.05, comparisons between the young and elderly.