Abstract
Psychological stress may have harmful physiological effects and result in deteriorating health. Acute psychological stress acts also on cardiac autonomic regulation and may lead to nonstationarities in the interbeat interval series. We address the requirement of stationary RR interval series to calculate frequency domain parameters of heart rate variability (HRV) and use binary symbolic dynamics derived from RR interval differences to overcome this obstacle. 24 healthy subjects (12 female, 20–35 years) completed the following procedure: waiting period, Trier Social Stress Test to induce acute psychological stress, recovery period. An electrocardiogram was recorded throughout the procedure and HRV parameters were calculated for nine 5-min periods. Nonstationarities in RR interval series were present in all periods. During acute stress the average RR interval and SDNN decreased compared to rest before and after the stress test. Neither low frequency oscillations (LF), high frequency oscillations (HF) nor LF/HF could unambiguously reflect changes during acute stress in comparison to rest. Pattern categories derived from binary symbolic dynamics clearly identified acute stress and accompanying alterations of cardiac autonomic regulation. Methods based on RR interval differences like binary symbolic dynamics should be preferred to overcome issues related to nonstationarities.
Highlights
Psychological stress may have harmful physiological effects and result in deteriorating health
The median visual analogue scale (VAS)-score increased from the waiting period T1 (5) to the Trier Social Stress Test (TSST) test-period, where the maximum was observed at the end of the TSST at T5 (59) directly after the arithmetic task
The VAS-score at T4 and T5 were statistically different from all other analysis periods before and after the stress exposure
Summary
Psychological stress may have harmful physiological effects and result in deteriorating health. Functioning as a co-factor, this includes diseases of all severities, ranging from the common cold[3] up to severe diseases, such as atherosclerosis[4], coronary heart disease, rheumatoid arthritis, peptic ulcer diseases, ulcerative colitis and even malignant diseases such as breast c ancer[7], as well as a sthma[6], diabetes m ellitus[5], or several more Such harmful stress effects have already been investigated for the field of neuronal diseases as well as mental and psychiatric disorders such as schizophrenia or major depressive disorders (MDD)[7]. Sympathetic activity of cardiac autonomic regulation is often calculated using low frequency (LF) power of spectral analysis of HRV whereas parasympathetic activity may be assessed using high frequency (HF) power or the root of the mean squares of differences between adjacent RR intervals (RMSSD) in the time d omain[17]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call