Hao W Y, Zhang L F, Wu X Y, Bai J
Lab of Biomedical Engineering, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China.
Space Med Med Eng (Beijing). 2001 Aug;14(4):253-6.
To study the effects of depressed myocardial contractility induced by microgravity on cardiovascular response to orthostatic stress, and to investigate the role played by the changes of myocardial contractility in the mechanism of cardiovascular deconditioning and orthostatic intolerance induced by space weightlessness.
On the basis of our previous model used to simulate the cardiovascular response to lower body negative pressure (LBNP), the factor of changes of myocardial contractility was incorporated into the model by multiplying a coefficient to the maximum elastance of the heart working sub-model. By decreasing the coefficient progressively, then the changes of heart rate (HR), blood pressure (BP), and cardiac output (CO) during LBNP after 0 - 30% of myocardial contractility depression combined with 12% decrease of total blood volume were simulated.
Simulation results indicated that depressed myocardial contractility induces more augment of HR, and more decrease of BP and CO during LBNP.
The depression of myocardial contractility degenerated cardiovascular response to orthostatic stress.
研究微重力诱导的心肌收缩力降低对心血管系统体位性应激反应的影响，探讨心肌收缩力变化在太空失重诱导的心血管脱适应和体位性不耐受机制中的作用。
在我们之前用于模拟心血管系统对下体负压（LBNP）反应的模型基础上，通过将一个系数乘以心脏工作子模型的最大弹性，将心肌收缩力变化因素纳入模型。通过逐步降低该系数，模拟了心肌收缩力降低0 - 30%并伴有总血容量减少12%后LBNP期间心率（HR）、血压（BP）和心输出量（CO）的变化。
模拟结果表明，心肌收缩力降低会导致LBNP期间HR增加更多，BP和CO降低更多。
心肌收缩力降低会使心血管系统对体位性应激的反应退化。
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