Weighting coefficients of the original variables
| Variables | PC1 | PC2 |
|---|---|---|
| MRR | 0.25 | 0.60 |
| SDNN | 0.23 | 0.91 |
| RMSSD | 0.37 | 0.89 |
| pNN50 | 0.48 | 0.79 |
| LF | –0.93 | –0.35 |
| HF | 0.93 | 0.35 |
| LF/HFNormlog | –0.92 | –0.36 |
Where MRR is the mean of the normal sinus (NN) intervals; SDNN is the standard deviation of all NN intervals; RMSSD is the root mean square of the successive differences between adjacent NN intervals; pNN50 is the percentage of times that the change in consecutive normal sinus intervals exceeded 50 ms; LF is low frequency; HF is high frequency, and LF/HFNormlog is normalized LF/HF by logarithmic transformation. The scores are latent factors or eigenvectors of factor analysis