Table 3.
Correlation among all indices under study. Pearson correlation coefficients (n = 50) among all baseline heart rate values and between baseline heart rate values and respiration rate.
| HR (beats/min) | HR variability (SDRR) | RSA (beats/s2) | LF (ms2/Hz) | HF (ms2/Hz) | LF/HF | D2 | |
|---|---|---|---|---|---|---|---|
| HR variability (SDRR) | r = −.121 | ||||||
| RSA (ms2) | r = −.147 | r = .517*** | |||||
| LF (ms2/Hz) | r = .048 | r = .446*** | r = .036 | ||||
| HF (ms2/Hz) | r = −.101 | r = .605*** | r = .699*** | r = .431** | |||
| LF/HF | r = .119 | r = −.108 | r = −.436** | r = .524*** | r = −.410** | ||
| D2 | r = −.013 | r = −.504*** | r = −.044 | r = −.528*** | r = −.150 | r = −.342* | |
| Respiration rate (Hz) | r = .046 | r = −.154 | r = −.194 | r = −.320* | r = −.260 | r = −.022 | r = .279 |
Abbreviations: BL, baseline; HR, heart rate; SDRR, standard deviation of the mean R-R interval; RSA, respiratory sinus arrhythmia; LF, low frequency band power; HF, high frequency band power; D2, correlation dimension.
*
p ≤ .05 (two-tailed).
**
p ≤ .01 (two-tailed).
***
p ≤ .001 (two-tailed).