Effects of Korean traditional herbal remedy on heart rate variability: linear and nonlinear analysis

Heart rate variability was compared in 20 subjects taking traditional herbal remedy (Ondamtanggamibang) or placebo control pill, in placebo controlled design experiment. Herbal remedy group reported more pleasant and clam emotions than did the placebo group. Herbal remedy reduced the heart rate and increased heart rate variability (HRV) as indicated by a reduced low frequency/high frequency power ratio of heart rate variability. With nonlinear analysis, the Poincaré plot index of HRV and approximate entropy was greater in the herbal remedy group than in the control group. These findings suggest that herbal remedy stabilizes the sympathovagal function and cardiac autonomic nervous system by inducing more positive emotions than does placebo therapy. In conclusion, herbal remedy may act by stabilizing both the autonomic nervous system and the emotional state.