21d头低位卧床期间心功能的变化及最后一周下体负压锻炼的影响  

Changes of Cardiac Function during 21 d Head down Tilt Bed Rest and the Effect of Lower Body Negative Pressure in the Last Week.

作　　者：孙喜庆[1] 姚永杰[1] 吴兴裕 郝卫亚[1] 姜世忠[2] 乔宗林 

机构地区：[1]第四军医大学航空航天医学系,西安710032 [2]航天医学工程研究所,北京100094 [3]空军临潼疗养院,临潼710600

出　　处：《航天医学与医学工程》2001年第1期22-26,共5页Space Medicine & Medical Engineering

基　　金：8 63资助项目!( 863 2 4 2 4)

摘　　要：目的观察 2 1d头低位卧床期间被试者心功能的变化及最后一周下体负压锻炼 (LBNP)的影响。方法 1 2名健康男性志愿者 ,随机分为对照组和LBNP组 ,每组 6人 ,均参加头低位倾斜卧床实验。对照组在卧床期间不做任何处理 ,LBNP组在卧床最后一周 ,每天进行 1h、- 4.0kPa的下体负压锻炼。测量心脏收缩和泵血功能等指标。结果在卧床期间 ,两组的心输出量、心指数及每搏输出量较卧床前均显著降低或有降低趋势 ,射血前期 (PEP)均显著延长 ,总外周阻力、等容收缩时间 /左室射血时间(LVET)、PEP/LVET均显著升高或有升高趋势 ,起床后第 2天基本恢复。LBNP组PEP和PEP/LVET在第 2 1天及起床后第 2天较对照组显著升高。结论 2 1d头低位卧床可引起心脏泵血和收缩功能显著降低 ;在 2 1d头低位卧床的最后一周进行下体负压锻炼 ,不能有效对抗头低位卧床模拟失重引起的心脏泵血和收缩功能的降低 ,但对提高立位耐力有利。Objective To investigate the change of cardiac function during 21 d head down tilt (HDT) bed rest and the effect of lower body negative pressure(LBNP) in the last week in human. Method 12 healthy male served as subjects which were randomly divided into control and LBNP groups, with 6 in each group. All of them were exposed to -6° HDT for 21 d. The LBNP group received -4.0 kPa LBNP training 1 h/d in the last week of the test. The cardiac pump function and cardiac systole function were measured before, during and after HDT. Result Cardiac output,cardiac index and stroke volume decreased significantly, whereas total peripheral resistance, pre ejection period(PEP), isovolumetric contraction time/left ventricular ejection time(LVET) and PEP/LVET increased significantly during HDT in both control and LBNP groups, compared to pre HDT values, and they returned to normal level on day 2 post HDT. PEP and PEP/LVET in LBNP group were significantly higher than those in control group on day 21 of HDT and day 2 post HDT. Conclusion The reduction of cardiac pump function and cardiac systole function induced by 21 d HDT could not be prevented by LBNP training in the last week of 21 d HDT.

关 键 词：失重模拟 下身负压 心功能 卧床试验 

分 类 号：R852.22[医药卫生—航空、航天与航海医学]