Heart Rate Variability Response to Stressful Event in Healthy Subjects

Abstract

The purpose of this study was to investigate the autonomic nervous system function in healthy subject under stress event by analyzing heart rate variability (HRV). The participants were eight graduate students exposed to a cognitive stress task involving preparation for an oral presentation. Measurements of subjective tension, muscle bound level and electrocardiograms of 5 minutes were obtained at 30 minutes before oral presentation as pretest and at 30 minutes after oral presentation as posttest. R-R intervals of electrocardiogram were calculated, and the R-R intervals’ tracks were analyzed using power spectral analysis to quantify the frequency domain properties of HRV. The results showed that subjective tension, muscle bound level and heart rate were significantly higher in pretest and normalized high frequency power of HRV was significantly lower in pretest, compared with posttest. These findings suggest that stress event will reduce cardiovascular parasympathetic nervous responsiveness and increase sympathetic nervous responsiveness and subjective tension. The normalized high frequency power of HRV can response the affective state under stress event. This psychophysiology measurement will be used for detect human affective state and stress management.