Schumacher Autumn M, Zbilut Joseph P, Webber Charles L, Schwertz Dorie W, Piano Mariann R
Department of Physiological and Technological Nursing, School of Nursing at the Medical College of Georgia, Augusta, 30912, USA.
Biol Res Nurs. 2006 Jul;8(1):55-66. doi: 10.1177/1099800406289775.
Cardiac variability can be assessed from two perspectives: beat-to-beat performance and continuous performance during the cardiac cycle. Linear analysis techniques assess cardiac variability by measuring the physical attributes of a signal, whereas nonlinear techniques evaluate signal dynamics. This study sought to determine if recurrence quantification analysis (RQA), a nonlinear technique, could detect pharmacologically induced autonomic changes in the continuous left ventricular pressure (LVP) and electrographic (EC) signals from an isolated rat heart-a model that theoretically contains no inherent variability. LVP and EC signal data were acquired simultaneously during Langendorff perfusion of isolated rat hearts before and after the addition of acetylcholine (n = 11), norepinephrine (n = 12), or no drug (n = 12). Two-minute segments of the continuous LVP and EC signal data were analyzed by RQA. Findings showed that%recurrence,%determinism, entropy, maxline, and trend from the continuous LVP signal significantly increased in the presence of both acetylcholine and norepinephrine, although systolic LVP significantly increased only with norepinephrine. In the continuous EC signal, the RQA trend variable significantly increased in the presence of norepinephrine. These results suggest that when either the sympathetic or parasympathetic division of the autonomic nervous system overwhelms the other, the dynamics underlying cardiac variability become stationary. This study also shows that information concerning inherent variability in the isolated rat heart can be gained via RQA of the continuous cardiac signal. Although speculative, RQA may be a tool for detecting alterations in cardiac variability and evaluating signal dynamics as a nonlinear indicator of cardiac pathology.
逐搏表现和心动周期中的连续表现。线性分析技术通过测量信号的物理属性来评估心脏变异性，而非线性技术则评估信号动态。本研究旨在确定一种非线性技术——递归定量分析（RQA），能否检测离体大鼠心脏连续左心室压力（LVP）和心电图（EC）信号中药物诱导的自主神经变化，该模型理论上不存在固有变异性。在添加乙酰胆碱（n = 11）、去甲肾上腺素（n = 12）或不添加药物（n = 12）的情况下，对离体大鼠心脏进行Langendorff灌注时，同时采集LVP和EC信号数据。通过RQA分析连续LVP和EC信号数据的两分钟片段。结果显示，在乙酰胆碱和去甲肾上腺素存在的情况下，连续LVP信号的%递归率、%确定性、熵、最大线长和趋势均显著增加，尽管收缩期LVP仅在去甲肾上腺素作用下显著增加。在连续EC信号中，去甲肾上腺素存在时RQA趋势变量显著增加。这些结果表明，当自主神经系统的交感神经或副交感神经分支一方压倒另一方时，心脏变异性的潜在动态变得稳定。本研究还表明，通过对连续心脏信号进行RQA，可以获得有关离体大鼠心脏固有变异性的信息。尽管具有推测性，但RQA可能是一种检测心脏变异性改变并将信号动态作为心脏病理非线性指标进行评估的工具。
