Table 4.
Sensitivity, specificity, ROC curve and cutoff points of heart rate variability indices with ROC curve > 0.65
| Indices | SEN | SPE | ROC | Cutoff point |
|---|---|---|---|---|
| RMSSD | 0.66 [0.49 - 0.80] | 0.81 [0.66 - 091] | 0.79 [0.69 - 0.87] | 37.00 |
| SDNN | 0.57 [0.40 - 0.73] | 0.88 [0.74 - 0.96] | 0.80 [0.70 - 0.88] | 41.90 |
| PNN50 | 0.71 [0.55-0.85] | 0.72 [0.56-0.84] | 0.77 [0.66-0.85] | 18.50 |
| LF (ms2) | 0.79 [0.63 - 0.90] | 0.69 [0.53 - 0.82] | 0.75 [0.64 - 0.84] | 711.00 |
| HF (ms2) | 0.82 [0.66 - 0.92] | 0.55 [0.39 - 0.70] | 0.74 [0.63 - 0.83] | 826.00 |
| RRTri | 0.69 [0.52 - 0.83] | 0.76 [0.61 - 0.88] | 0.76 [0.65 - 0.85] | 12.66 |
| SD1 | 0.66 [0.49 - 0.80] | 0.79 [0.64 - 0.90] | 0.78 [0.68 - 0.87] | 26.20 |
| SD2 | 0.61 [0.44 - 0.76] | 0.88 [0.74 - 0.96] | 0.80 [0.70 - 0.88] | 55.60 |
SEN: sensitivity; SPE: specificity; RMSSD: square root of the mean of the squares of successive differences between normal RR intervals in a time interval (ms); SDNN: standard deviation of normal RR intervals in a time interval (ms); LF: low-frequency component; HF: high-frequency component; RRTri: triangular index; SD1: standard deviation of the instantaneous RR intervals; SD2: long-term variability of continuous RR intervals.