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本文探讨了人体在下体负压应激下心脏收缩间期和其它心血管功能的变化。观察对象为43名健康学员,平均年龄为21.5岁。受试者分为两组,第一组的负压制度为-20和-40mmHg,各暴露8分钟;第二组的负压制度为-50mmHg,暴露14分钟。两组在除负压后各观察10分钟。实验前、中、后同步记录心阻抗图、阻抗微分图、心电图、心音图,然后分析心脏收缩间期各时相、心输出量以及心率、血压等参数的变化。结果表明:下体负压作用下心脏收缩间期的主要参数都有明显的改变(P<0.001),如射血前期率串校正指数延长、左室射血期心串校正指数缩短、射血前期/左室射血期增大,而总电机械收缩期心率校正指数却保持不变。其它心血管功能参数也有明显变化,如在-40mmHg作用6～8分钟时,心搏量减少42.5％,每分输出量减少26.9％。
This article explores the changes in systolic and other cardiovascular functions in the body under negative pressure. Subjects for the 43 healthy students, the average age of 21.5 years old. Subjects were divided into two groups. The first group had a negative pressure regime of -20 and -40 mmHg, each for 8 minutes; the second group had a negative pressure regime of -50 mmHg and a 14-minute exposure. In addition to negative pressure after the two groups observed for 10 minutes. Heart impedance plots, impedance differential plots, electrocardiogram (ECG) and phonocardiogram were recorded simultaneously before, during and after the experiment. Changes of cardiac output, cardiac output and heart rate, blood pressure and other parameters were then analyzed. The results showed that the major parameters of cardiac systolic interval under the negative pressure of the lower body were significantly changed (P <0.001). For example, the pre-ejection rate correction index was prolonged, the correction index of left ventricular ejection phase was shortened, / Left ventricular ejection fraction increased, while the total mechanical contraction heart rate correction index remained unchanged. Other cardiovascular function parameters also have significant changes, such as the role of -40mmHg 6 to 8 minutes, the stroke volume decreased 42.5%, a decrease of 26.9% per minute output.