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.

心理压力可能会产生有害的生理影响并导致健康状况恶化。急性心理压力也会影响心脏自主神经调节，并可能导致心跳间期序列的非平稳性。我们解决了固定 RR 间期序列计算心率变异性 (HRV) 频域参数的要求，并使用源自 RR 间期差异的二进制符号动力学来克服这一障碍。24 名健康受试者（12 名女性，20-35 岁）完成了以下程序：等待期、特里尔社会压力测试诱发急性心理压力、恢复期。在整个过程中记录心电图并计算九个 5 分钟的 HRV 参数。RR 间期系列的非平稳性在所有时期都存在。在急性压力期间，与压力测试前后的休息相比，平均 RR 间期和 SDNN 降低。与休息相比，低频振荡 (LF)、高频振荡 (HF) 和 LF/HF 都不能明确反映急性应激期间的变化。源自二元符号动力学的模式类别清楚地确定了急性压力和伴随的心脏自主调节的改变。应该首选基于 RR 间隔差异的方法，如二进制符号动态，以克服与非平稳性相关的问题。源自二元符号动力学的模式类别清楚地确定了急性压力和伴随的心脏自主调节的改变。应该首选基于 RR 间隔差异的方法，如二进制符号动态，以克服与非平稳性相关的问题。源自二元符号动力学的模式类别清楚地确定了急性压力和伴随的心脏自主调节的改变。应该首选基于 RR 间隔差异的方法，如二进制符号动态，以克服与非平稳性相关的问题。