Table 3 HRV parameters for the COVID-19, CVD, and healthy volunteer groups. There is significant autonomic dysfunction in both COVID-19 and CVD patients, with reduced HRV and parasympathetic activity, and increased sympathetic dominance, particularly in the COVID-19 group. Numbers represent the median and interquartile range (IQR) values. * one way ANOVA p-value < 0.05 compared to the healthy volunteers; ** p < 0.001. + p < 0.05 between COVID-19 and CVD.
From: Heart rate variability parameters indicate altered autonomic tone in subjects with COVID-19
Domain | HRV parameter | COVID-19 | Healthy volunteers | CVD control | p-value |
|---|---|---|---|---|---|
Time | MeanNN (s) | 0.72 ± 0.16** | 0.92 ± 0.1 | 0.75 ± 0.22** | 1.35E− 6 |
SDNN (s) | 0.02 ± 0.02** | 0.06 ± 0.03 | 0.03 ± 0.03** | 3.2E− 4 | |
RMSSD (s) | 0.02 ± 0.02**+ | 0.05 ± 0.03 | 0.03 ± 0.02* | 0.08 | |
pNN50 (%) | 0.79 ± 11.75**+ | 20.99 ± 38.3 | 5.98 ± 17.02* | 5.09E− 4 | |
Frequency | VLF (%) | 37.25 ± 28.76 | 38.69 ± 26.38 | 27.84 ± 31.98 | 0.15 |
LF (%) | 18.47 ± 18.18*+ | 23.30 ± 11.79 | 19.08 ± 13.92* | 8.7E− 5 | |
HF (%) | 13.69 ± 25.80*+ | 22.91 ± 21.86 | 18.87 ± 24.45 | 0.02 | |
LF/HF (n.u.) | 1.038 ± 1.54 | 1.03 ± 0.78 | 0.84 ± 1.08 | 0.065 | |
Regularity | SampEn (a.u.) | 1.51 ± 0.79*+ | 1.67 ± 0.3 | 1.64 ± 0.50 | 0.036 |
probAgr (a.u.) | 0.17 ± 0.28** | 0.40 ± 0.07 | 0.18 ± 0.21** | 4.2E− 15 | |
Nonlinear | SD1 (s) | 0.04 ± 0.04** | 0.08 ± 0.05 | 0.05 ± 0.04* | 0.06 |
SD2 (s) | 0.08 ± 0.07** | 0.17 ± 0.1 | 0.11 ± 0.1** | 4.4E− 5 | |
SD1/SD2 (n.u.) | 0.57 ± 0.35 | 0.39 ± 0.25 | 0.59 ± 0.29* | 0.07 | |
SD2/SD1 (n.u.) | 1.76 ± 1.54* | 2.61 ± 1.31 | 1.73 ± 1.08* | 0.05 |
