HEMODYNAMIC FLUCTUATIONS AND BAROREFLEX SENSITIVITY IN HUMANS - A BEAT-TO-BEAT MODEL
HEMODYNAMIC FLUCTUATIONS AND BAROREFLEX SENSITIVITY IN HUMANS - A BEAT-TO-BEAT MODEL
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DOI：
10.1152/ajpheart.1987.253.3.h680
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发表时间：
1987-09-01
影响因子：
--
通讯作者：
STRACKEE, J
中科院分区：
文献类型：
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作者：
DEBOER, RW;KAREMAKER, JM;STRACKEE, J
建立了一个心血管系统的逐搏模型，用于研究人体静息状态下动脉血压（BP）和心率（HR）数据的自发短期变异性。该模型由一组表示以下机制的差分方程组成：1）通过压力反射控制HR和外周阻力，2）全身动脉树的Windkessel特性，3）心肌的收缩特性（Starling定律和恢复），以及4）呼吸对BP的机械效应。该模型进行了测试，通过比较功率谱和交叉谱的模拟数据从模型与光谱的实际数据从休息科目。为了使来自模拟数据和来自实际数据的频谱吻合，必须假设静息时的呼吸性窦性心律失常是由快速迷走神经介导的压力反射将呼吸BP变异性转换为HR变异性引起的。所谓的10-s心率和血压的节奏似乎是一种共振现象，由于压力感受器反射的交感神经控制回路的延迟。该模型的模拟响应施加的BP增加显示对应于BP和HR的反应后，患者的BP增加的药物，如苯丙氨酸。它的结论是，该模型正确地描述了一些重要功能的心血管系统。讨论了差分方程模型的数学性质。
A beat-to-beat model of the cardiovascular system is developed to study the spontaneous short-term variability in arterial blood pressure (BP) and heart rate (HR) data from humans at rest. The model consists of a set of difference equations representing the following mechanisms: 1) control of HR and peripheral resistance by the baroreflex, 2) Windkessel properties of the systemic arterial tree, 3) contractile properties of the myocardium (Starling's law and restitution), and 4) mechanical effects of respiration on BP. The model is tested by comparing power spectra and cross spectra of simulated data from the model with spectra of actual data from resting subjects. To make spectra from simulated data and from actual data tally, it must be assumed that respiratory sinus arrhythmia at rest is caused by the conversion of respiratory BP variability into HR variability by the fast, vagally mediated baroreflex. The so-called 10-s rhythm in HR and BP appears as a resonance phenomenon due to the delay in the sympathetic control loop of the baroreflex. The simulated response of the model to an imposed increase of BP is shown to correspond with the BP and HR response in patients after administration of a BP-increasing drug, such as phenylephrine. It is concluded that the model correctly describes a number of important features of the cardiovascular system. Mathematical properties of the difference-equation model are discussed.