Table 1.
Effect of speech task stress on heart rate and various measures of heart rate variability. Mean (±S.D.) baseline and speech task of heart rate and various measures of heart rate variability. Repeated-measures ANCOVA considering the influence of respiration rate change was used to assess the effect of speech task (F value and degrees of freedom).
| Baseline | Speech task | F (1, 45) | |
|---|---|---|---|
| HR (beats/min) | 74.2 ± 9.46 | 87.4 ± 15.32 | 44.259*** |
| HR variability (SDRR) | 33.2 ± 23.83 | 96.0 ± 86.64 | 16.047*** |
| RSA (beats/s2) | 3.3 ± 2.5 | 3.6 ± 2.1 | 0.569 |
| LF (ms2/Hz) | 8.0 ± 5.93 | 19.7 ± 15.65 | 15.237*** |
| HF (ms2/Hz) | 6.9 ± 4.89 | 15.8 ± 17.83 | 7.54** |
| LF/HF | 1.5 ± 1.11 | 1.8 ± 1.20 | 0.863 |
| D2 | 3.5 ± 0.27 | 3.2 ± 0.33 | 32.935*** |
Abbreviations: 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; HR, heart rate.
**
p ≤ .01 (two-tailed).
***
p ≤ .001 (two-tailed).