Table 2.
Basal 5-minues HRV analysis after 10 min of supine rest in tVVS and controls
| Parameter | Syncope (n = 39) | No Syncope (n = 52) | p-value |
|---|---|---|---|
| Maximal RR (ms) | 1041.2 ± 164.5 | 1109.9 ± 212.6 | 0.10 |
| Minimal RR (ms) | 670.1 ± 98.0 | 672.0 ± 105.4 | 0.93 |
| Average RR (ms) | 860.8 ± 118.6 | 886.8 ± 130.4 | 0.33 |
| SDNN (ms) | 61.1 ± 28.0 | 71.4 ± 34.5 | 0.13 |
| RMSSD (ms) | 61.2 ± 49.6 | 69.8 ± 40.8 | 0.37 |
| HRV triangular index | 17.6 ± 6.1 | 18.6 ± 7.2 | 0.47 |
| NN50 (n) | 45.3 ± 34.7 | 55.4 ± 35.4 | 0.18 |
| pNN50 (%) | 13.9 ± 11.4 | 16.7 ± 11.4 | 0.24 |
| VLF (ms2) | 176.8 ± 83.3 | 155.9 ± 84.3 | 0.24 |
| LF (ms2) | 155.8 ± 78.4 | 165.1 ± 66.4 | 0.55 |
| HF (ms2) | 200.6 ± 93.5 | 211.4 ± 88.0 | 0.57 |
| Total power (ms2) | 584.9 ± 99.1 | 575.7 ± 85.2 | 0.64 |
| LF/HF | 1.2 ± 1.4 | 1.0 ± 0.7 | 0.47 |
| ln (NN50) | 3.3 ± 1.4 | 3.6 ± 1.3 | 0.27 |
| ln (pNN50) | 2.1 ± 1.3 | 2.3 ± 1.4 | 0.37 |
| ln (VLF) | 5.0 ± 0.6 | 4.9 ± 0.6 | 0.31 |
| ln (LF) | 4.9 ± 0.6 | 5.0 ± 0.5 | 0.34 |
| ln (HF) | 5.2 ± 0.5 | 5.3 ± 0.5 | 0.42 |
| ln (total power) | 6.4 ± 0.3 | 6.3 ± 0.2 | 0.95 |
| ln (LF/HF) | – 0.3 ± 0.9 | – 0.3 ± 0.8 | 0.89 |
RR time between two successive R-waves, HR heart rate, SDNN standard deviation of NN interval, RMSSD root mean square of successive differences, HRV heart rate variability, NN50 number of times successive heartbeat intervals exceed 50ms, VLF very low frequency, LF low frequency, HF high frequency