Sloan R P, Shapiro P A, Bagiella E, Bigger J T, Lo E S, Gorman J M
Division of Clinical Psychobiology, Columbia-Presbyterian Medical Center, New York, NY 10032, USA.
Psychosom Med. 1996 Jan-Feb;58(1):25-31. doi: 10.1097/00006842-199601000-00005.
Heart rate increases during psychological stress are the product of cardiac sympathetic activation and parasympathetic withdrawal. Levels of plasma epinephrine (E) and norepinephrine (NE) have a long history as indicators of cardiac adrenergic activity and, accordingly, generally increase in response to psychological challenge. Recently, several investigators have suggested that indices derived from power spectral analysis of heart period variability (HPV) also may provide estimates of cardiac sympathetic nervous system activity. These indices include power in the low frequency band (0.04-0.15 Hz, LF), and the ratio of low to high frequency (0.15-0.50 Hz, HF) power (LF/HF). The relationship between spectral and neurohumoral indices during psychological stress has not been investigated. This issue was addressed by studying spectrally defined measures of HPV and levels of plasma E and NE in 34 normal subjects who participated in a study of responsiveness to a psychologically challenging arithmetic task. Heart rate (HR), LF and HF power, the LF/HF ratio, and blood pressure were measured during the 5-minute baseline and 5-minute task periods. Integrated samples of forearm venous blood were collected for both periods. E and NE were analyzed by high performance liquid chromatography. The task produced significant increases in HR, systolic and diastolic pressures, and NE. Of the 12 Pearson correlation coefficients used to examine the relationships between power spectral measures and catecholamines for the baseline, task, and delta values, none achieved statistical significance, suggesting little relationship between neurohumoral and spectral estimates of cardiac sympathetic activity. We conclude that under conditions of psychological stress, LF power provides no useful information about cardiac sympathetic activity, both because power in this frequency band falls whereas HR rises and because there is no relationship between LF power and plasma NE.
心理应激期间心率增加是心脏交感神经激活和副交感神经撤 退的结果。血浆肾上腺素（E）和去甲肾上腺素（NE）水平作为心脏 肾上腺素能活动的指标由来已久，因此通常会随着心理挑战而升高。 最近，一些研究人员提出，从心率变异性（HPV）功率谱分析得出 的指标也可能提供心脏交感神经系统活动的估计值。这些指标包括 低频带（0.04 - 0.15Hz，LF）功率以及低频与高频（0.15 - 0.50Hz， HF）功率之比（LF/HF）。心理应激期间频谱指标与神经体液指标 之间的关系尚未得到研究。本研究通过对34名正常受试者进行研 究，探讨了HPV的频谱定义测量指标与血浆E和NE水平之间的关 系，这些受试者参与了一项对具有心理挑战性的算术任务的反应性 研究。在5分钟的基线期和5分钟的任务期内测量心率（HR）、LF 和HF功率、LF/HF比值以及血压。在这两个时期都采集了前臂静脉 血的综合样本。通过高效液相色谱法分析E和NE。该任务使HR、 收缩压和舒张压以及NE显著升高。在用于检查基线、任务和差值 的功率谱测量指标与儿茶酚胺之间关系的12个Pearson相关系数 中，没有一个达到统计学显著性，这表明心脏交感神经活动的神经 体液估计值与频谱估计值之间几乎没有关系。我们得出结论，在 心理应激条件下，LF功率无法提供有关心脏交感神经活动的有用 信息，这既是因为该频段的功率下降而HR上升，也是因为LF功率 与血浆NE之间没有关系。
