Table 3.
Intra-researcher reproducibility of HRV parameters derived from short-term recordings.
| 1st processing Mean ± stand. deviation |
2nd processing Mean ± stand. deviation |
Mean difference ± stand. deviation |
95% Limits of agreement | ICC (95% CI) | CV (%) | RMSE | |
|---|---|---|---|---|---|---|---|
| Children with overweight/obesity (n = 99) | |||||||
| RMSSD (ms) | 59.76 ± 30.66 | 59.86 ± 30.93 | 0.32 ± 2.47 | − 4.52; 5.15 | 0.997 (0.995;0.998) | 1.1 | 2.48 |
| pNN50 (%) | 29.98 ± 19.75 | 30.18 ± 20.07 | 0.29 ± 2.35 | − 4.32; 4.89 | 0.998 (0.998;0.999) | 1.2 | 1.09 |
| SDNN (ms) | 57.74 ± 24.53 | 57.56 ± 24.28 | 0.09 ± 1.11 | − 2.09; 2.28 | 0.995 (0.993;0.997) | 1.0 | 2.35 |
| FFT_HF (ms2) | 1767.70 ± 1744.89 | 1813.02 ± 1813.98 | 3.58 ± 158.87 | − 307.80; 314.97 | 0.996 (0.994;0.997) | 3.0 | 157.31 |
| AR_HF (ms2) | 1756.60 ± 1698.83 | 1772.00 ± 1728.91 | 19.41 ± 275.68 | − 520.92; 559.75 | 0.987 (0.981;0.992) | 2.4 | 274.97 |
| FFT_LF (ms2) | 1674.03 ± 1557.16 | 1674.92 ± 1,590.28 | − 24.25 ± 266.75 | − 547.08; 498.58 | 0.985 (0.978;0.990) | 4.3 | 266.50 |
| AR_LF (ms2) | 1566.66 ± 1,371.32 | 1,520.93 ± 1,333.45 | 30.66 ± 247.76 | − 454.93; 516.26 | 0.983 (0.975;0.988) | 3.7 | 248.40 |
| FFT_LF/HF | 1.28 ± 0.82 | 1.25 ± 0.80 | 0.02 ± 0.26 | − 0.48; 0.52 | 0.952 (0.930;0.968) | 3.9 | 0.24 |
| AR_LF/HF | 1.18 ± 0.69 | 1.15 ± 0.68 | 0.03 ± 0.22 | − 0.40; 0.45 | 0.950 (0.926;0.966) | 3.9 | 0.22 |
| Young adults (n = 73) | |||||||
| RMSSD (ms) | 60.20 ± 31.49 | 59.27 ± 29.23 | − 0.46 ± 2.77 | − 4.96; 5.88 | 0.995 (0.993;0.997) | 1.8 | 2.90 |
| pNN50 (%) | 34.07 ± 21.90 | 33.88 ± 20.96 | 0.44 ± 2.22 | − 3.90; 4.79 | 0.994 (0.991;0.996) | 3.0 | 2.25 |
| SDNN (ms) | 53.89 ± 23.95 | 52.71 ± 22.01 | 0.50 ± 3.11 | − 5.94; 6.59 | 0.990 (0.984;0.994) | 2.1 | 3.13 |
| FFT_HF (ms2) | 1,700.78 ± 1814.40 | 1584.71 ± 1948.83 | − 8.49 ± 327.44 | − 650.27; 633.29 | 0.986 (0.977;0.991) | 8.5 | 325.24 |
| AR_HF (ms2) | 1675.50 ± 1717.53 | 1592.50 ± 1737.96 | − 38.89 ± 156.37 | − 345.38; 267.59 | 0.996 (0.993;0.997) | 4.6 | 160.06 |
| FFT_LF (ms2) | 1,350.06 ± 1,493.56 | 1,251.76 ± 1,394.01 | 52.20 ± 384.82 | − 701.05; 805.46 | 0.965 (0.945;0.978) | 10.9 | 402.13 |
| AR_LF (ms2) | 1,349.15 ± 1,464.88 | 1,278.26 ± 1,376.76 | 22.24 ± 262.34 | − 491.95; 536.42 | 0.982 (0.971;0.989) | 7.7 | 272.81 |
| FFT_LF/HF | 1.15 ± 1.02 | 1.25 ± 1.12 | − 0.03 ± 0.38 | − 0.77; 0.70 | 0.943 (0.910;0.964) | 10.5 | 0.38 |
| AR_LF/HF | 1.12 ± 0.87 | 1.15 ± 0.94 | 0.01 ± 0.28 | − 0.53; 0.56 | 0.955 (0.928;0.971) | 7.9 | 0.28 |
| Middle-aged adults (n = 39) | |||||||
| RMSSD (ms) | 32.43 ± 19.54 | 32.04 ± 18.28 | − 0.87 ± 2.96 | − 6.67; 4.92 | 0.985 (0.972;0.992) | 3.8 | 3.06 |
| pNN50 (%) | 13.25 ± 16.22 | 12.72 ± 14.97 | − 0.82 ± 3.13 | − 6.96; 5.33 | 0.976 (0.955;0.987) | 10.9 | 3.20 |
| SDNN (ms) | 31.36 ± 13.94 | 31.77 ± 13.59 | 0.04 ± 3.25 | − 6.32; 6.41 | 0.972 (0.948;0.985) | 4.3 | 3.21 |
| FFT_HF (ms2) | 492.49 ± 617.23 | 479.04 ± 598.83 | − 21.53 ± 112.43 | − 241.90; 198.84 | 0.982 (0.966;0.990) | 12.2 | 113.05 |
| AR_HF (ms2) | 488.12 ± 585.05 | 503.54 ± 649.73 | − 47.62 ± 177.95 | − 396.40; 301.17 | 0.976 (0.953;0.987) | 7.4 | 181.94 |
| FFT_LF (ms2) | 505.92 ± 463.28 | 571.89 ± 516.77 | − 9.56 ± 166.45 | − 335.80; 316.69 | 0.951 (0.909;0.974) | 13.7 | 164.58 |
| AR_LF (ms2) | 505.27 ± 459.28 | 541.69 ± 471.18 | 33.80 ± 127.73 | − 216.55; 284.16 | 0.966 (0.936;0.982) | 8.8 | 130.54 |
| FFT_LF/HF | 2.03 ± 2.88 | 2.39 ± 3.58 | − 0.07 ± 0.35 | − 0.76; 0.62 | 0.995 (0.990;0.997) | 10.8 | 0.36 |
| AR_LF/HF | 2.08 ± 2.79 | 2.23 ± 3.17 | 0.24 ± 0.91 | − 1.54; 2.03 | 0.957 (0.919;0.977) | 10.4 | 0.93 |
HRV heart rate variability, RMSSD the square root of the mean of the sum of the squares of differences between adjacent R–R intervals, pNN50 percentage (%) of the total pairs of R–R intervals that differ by more than 50 ms, SDNN standard deviation of all normal R–R intervals, FFT fast Fourier Transformation algorithm, HF high frequency (0.15–0.4 Hz) index of parasympathetic activity, LF low frequency (0.04–0.15 Hz) mix index of sympathetic and parasympathetic activity, AR autoregressive algorithm, ms milliseconds, CV coefficient of variation, ICC intraclass correlation coefficient, RMSE root mean square error.