Measures of heart rate and heart rate variability in patients with Parkinson's disease (PD) and control subjects
| Variable | PD Patients (n=54) | Control subjects (n=47) | p Value (Mann-Whitney) |
| RRI (ms) | 849 (102) | 846 (99) | 0.905 |
| SDNN (ms) | 93 (24) | 102 (24) | 0.024 |
| VLF (ms2) | 1332 (1046) | 1899 (1192) | 0.001 |
| LF (ms2) | 607 (691) | 764 (570) | 0.009 |
| HF (ms2) | 312 (432) | 367 (387) | 0.004 |
| SD1 (ms) | 17 (7) | 20 (10) | 0.053 |
| SD2 (ms) | 142 (47) | 156 (53) | 0.186 |
| Slope of HRV | −1.41 (0.18) | −1.28 (0.19) | 0.002 |
Values are presented as mean (SD). RRI=RR interval; SDNN=SD of all RRIs; VLF=very low frequency; LF=low frequency; HF=high frequency; SD1=instantaneous beat to beat RRI variability; SD2=long term continuous RRI variability; slope of HRV=slope of power law relation.