短期和长期太空飞行后超声心动图变化的比较。
Comparison of echocardiographic changes after short- and long-duration spaceflight.
作者信息
Martin David S, South Donna A, Wood Margie L, Bungo Michael W, Meck Janice V
机构信息
Wyle Laboratories, Houston, Texas, USA.
出版信息
Aviat Space Environ Med. 2002 Jun;73(6):532-6.
BACKGROUND
Previous echocardiographic studies of astronauts before and after short-duration (4-17 d) missions have demonstrated a decrease in resting left ventricular stroke volume, but maintained ejection fraction (EF) and cardiac output. Similar studies before and after long-duration (129-144 d) spaceflight have been rare and their overall results equivocal.
METHODS
Echocardiographic measurements (M-mode, 2-D, and Doppler) were obtained from short-duration (n = 13) and long-duration (n = 4) crewmembers to evaluate cardiac chamber sizes and function.
RESULTS
Compared with short-duration astronauts, long-duration crewmembers had decreases in EF (+6+/-0.02 vs. -10.5+/-0.03%, p = 0.005) and percent fractional shortening (+7+/-0.03 vs. -11+/-0.07%, p = 0.015), and an increase in left ventricular end systolic volume (-12+/-0.06 vs. +39+/-0.24%, p = 0.011).
CONCLUSIONS
These data suggest a reduction in cardiac function that relates to mission duration. As the changes in BP and circulating blood volume are reported to be similar after short- and long-duration flights, the smaller EF after longer spaceflights may be due to a decrease in cardiac function rather than altered blood volume.
背景
先前针对宇航员在短期（4 - 17天）任务前后进行的超声心动图研究表明，静息左心室每搏输出量减少，但射血分数（EF）和心输出量保持不变。而针对长期（129 - 144天）太空飞行前后进行的类似研究较少，且总体结果不明确。
方法
对短期（n = 13）和长期（n = 4）的机组人员进行超声心动图测量（M型、二维和多普勒），以评估心腔大小和功能。
结果
与短期宇航员相比，长期机组人员的EF降低（+6±0.02%对 - 10.5±0.03%，p = 0.005），缩短分数百分比降低（+7±0.03%对 - 11±0.07%，p = 0.015），左心室收缩末期容积增加（-12±0.06%对 +39±0.24%，p = 0.011）。
结论
这些数据表明心脏功能的降低与任务持续时间有关。由于据报道短期和长期飞行后血压和循环血容量的变化相似，长时间太空飞行后较小的EF可能是由于心脏功能下降而非血容量改变所致。
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