Table 5 Age-related differences in HRV parameters. Values are expressed as median ± IQR. * indicates a t-test p-value < 0.05 compared to the healthy volunteers; ** indicates a t-test p-value < 0.001. + indicates a t-test p-value < 0.05 between COVID-19 and CVD control.
From: Heart rate variability parameters indicate altered autonomic tone in subjects with COVID-19
HRV parameters | Age ≤ 65 years | Age > 65 years | ||||
|---|---|---|---|---|---|---|
COVID-19 | Healthy | CVD | COVID-19 | Healthy | CVD | |
MeanNN (s) | 0.65 ± 0.19**+ | 0.91 ± 0.09 | 0.76 ± 27*+ | 0.8 ± 0.17 | - | 0.73 ± 0.2 |
SDNN (s) | 0.02 ± 0.02** | 0.06 ± 0.03 | 0.03 ± 31.42** | 0.04 ± 0.04 | - | 0.04 ± 0.04 |
RMSSD (s) | 0.02 ± 0.01** | 0.05 ± 0.03 | 0.02 ± 57.30* | 0.03 ± 0.07 | - | 0.03 ± 0.04 |
pNN50 (%) | 0.0 ± 2.83** | 24.67 ± 40.60 | 2.28 ± 7.57+** | 5.83 ± 35.68 | - | 13.1 ± 22.91 |
VLF (%) | 41.51 ± 23.18 | 38.69 ± 25.42 | 35.08 ± 28.93 | 30.4 ± 34.78 | - | 19.66 ± 26.54 |
LF (%) | 9.28 ± 17.70* | 23.30 ± 10.16 | 16.72 ± 17.08* | 20.81 ± 13.58 | - | 20.07 ± 13.98 |
HF (%) | 6.5 ± 14.95** | 22.61 ± 24.67 | 13.39 ± 12.29* | 21.58 ± 24.08 | - | 22.84 ± 23.92 |
LF/HF [n.u.] | 1.47 ± 1.42 | 0.98 ± 1.42 | 0.8 ± 1.35 | 0.88 ± 0.99 | - | 0.84 ± 1 |
SampEn [a.u.] | 1.16 ± 0.75 | 1.73 ± 0.31 | 1.71 ± 0.47 | 1.43 ± 0.65+ | - | 1.57 ± 0.39 |
probAgr [a.u.] | 0.13 ± 0.24** | 0.4 ± 0.07 | 0.14 ± 0.18** | 0.2 ± 0.2 | - | 0.19 ± 0.27 |
SD1 (s) | 0.03 ± 0.02** | 0.08 ± 0.05 | 0.04 ± 99.41** | 0.05 ± 0.12 | - | 0.06 ± 0.06 |
SD2 (s) | 0.05 ± 0.06** | 0.19 ± 0.1 | 0.1 ± 66.52** | 0.11 ± 0.13 | - | 0.13 ± 0.11 |
SD1/SD2 [n.u.] | 0.52 ± 0.35 | 0.38 ± 0.25 | 0.51 ± 0.41 | 0.59 ± 0.37 | - | 0.6 ± 0.25 |
SD2/SD1 [n.u.] | 1.99 ± 1.58 | 2.66 ± 1.19 | 2.04 ± 1.59 | 1.76 ± 1.26 | - | 1.66 ± 0.69 |
