Brindle Ryan C, Ginty Annie T, Phillips Anna C, Fisher James P, McIntyre David, Carroll Douglas
School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.
Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Psychophysiology. 2016 Apr;53(4):465-72. doi: 10.1111/psyp.12576. Epub 2015 Nov 20.
Correlation dimension (D2), a measure of heart rate (HR) complexity, has been shown to decrease in response to acute mental stress and relate to adverse cardiovascular health. However, the relationship between stress-induced changes in D2 and HR has yet to be established. The present studies aimed to assess this relationship systematically while controlling for changes in respiration and autonomic activity. In Study 1 (N = 25) D2 decreased during stress and predicted HR reactivity even after adjusting for changes in respiration rate, and cardiac vagal tone. This result was replicated in Study 2 (N = 162) and extended by including a measure of cardiac sympathetic activity; correlation dimension remained an independent predictor of HR reactivity in a hierarchical linear model containing measures of cardiac parasympathetic and sympathetic activity and their interaction. These results suggest that correlation dimension may provide additional information regarding cardiac stress reactivity above that provided by traditional measures of cardiac autonomic function.
关联维数（D2）是心率（HR）复杂性的一种度量，已被证明会因急性精神压力而降低，并与不良心血管健康状况相关。然而，压力引起的D2变化与心率之间的关系尚未确立。本研究旨在在控制呼吸和自主神经活动变化的同时，系统地评估这种关系。在研究1（N = 25）中，D2在压力期间降低，即使在调整呼吸频率和心脏迷走神经张力变化后仍能预测心率反应性。这一结果在研究2（N = 162）中得到了重复，并通过纳入一项心脏交感神经活动测量指标进行了扩展；在包含心脏副交感神经和交感神经活动及其相互作用测量指标的分层线性模型中，关联维数仍然是心率反应性的独立预测指标。这些结果表明，关联维数可能提供有关心脏应激反应性的额外信息，超出传统心脏自主神经功能测量指标所提供的信息。
