Evaluation of cardiac responses to Stress in healthy individuals A Non invasive evaluation by Heart Rate Variability and Stroop test

Objective and Study Design : Stress is considered as physiological response to the mental, emotional, or physical challenges. Most of the times mental stress provokes body’s “fight or flight” response called as acute stress response. But prolonged or chronic stress can affect numerous physiological functions, such as growth, immune system, metabolism, reproduction and circulation. The Autonomic regulation of the cardiovascular system is most commonly affected by stress and is assessed by means of heart rate variability (HRV) Material and Methods : The aim of this study is to establish mental stress and cardiovascular autonomic Nervous System response to mental stress assessed by combining different physiological parameters using HRV and Stroop test as tool. We compared the mean RR interval, Blood pressure and indices of HRV during the Stroop Color Word Test (SCWT).A total of 50 normal healthy subjects were participated in this study. Results : Statistically significant change in heart rate, RR interval and BP was observed during the stress as compared to resting condition. All the components of HRV (SDNN, RMSSD, NN50, PNN50, LF, HF, LF/HF) were sensitive to stress in all the healthy individuals. Males were more prone to stress when compared to females. Conclusion : The results suggest that there was increased sympathetic activity and reduced parasympathetic activity in HRV performed during the Stroop test and showed statistically significant difference among the genders. Both physical and mental stress influence risk factors that may increase risk for cardiovascular diseases and autonomic imbalance