450 likes | 922 Views
中国宇航员 太空飞行后心脏自主功能分析 Autonomic control after spaceflight 2005. Liexin Liu, Frank Beckers, Bart Verheyden, Kurt Couckuyt , André Aubert. Laboratory of Experimental Cardiology Univ. Hospital Gasthuisberg, & Interdisciplinary Center for Space Studies (ICSS), K.U.Leuven, Leuven, Belgium.
E N D
中国宇航员 太空飞行后心脏自主功能分析 Autonomic control after spaceflight 2005 Liexin Liu,Frank Beckers, Bart Verheyden, Kurt Couckuyt , André Aubert Laboratory of Experimental Cardiology Univ. Hospital Gasthuisberg, & Interdisciplinary Center for Space Studies (ICSS), K.U.Leuven, Leuven, Belgium
Wan Hu (16th cent Ming Dynasty) He had a chair built with forty-seven rockets attached. On the day of lift-off, Wan, splendidly attired, climbed into his rocket chair and forty seven servants lit the fuses and then hastily ran for cover. There was a huge explosion. When the smoke cleared, Wan and the chair were gone. He was never seen again.
背景情况 Background
Cardiovascular system resting • No effort for moving • No liquid transfer • No flow redistribution • No stimulation of 1G reflexes When returning to 1G redistribution of flow towards brain less efficient risk for syncope
Experiment science objectives • Autonomic cardiovascular control before, during and after space flight • ECG and BP measurements • Respiration • Induce changes: head flexion • Orthostatic intolerance • Stand test
Brains sympathetic Parasympathetic (vagal) + - Heart rate cardiac output Blood pressure Model of cardiovascular regulation Simplified scheme
Model of cardiovascular variability BRAIN STEM symppara Baroreflex Sensitivity - + BAROREFLEX - () n. vagus + (-) + - + VASOMOTOR TONE HEART RATE SV arterial baroreceptors TPR CO BLOOD PRESSURE Heart Rate Variability Blood Pressure Variability
HRV, BPV are influenced by: • Baroreceptor • Chemoreceptor • Atrial stretch receptors • Position (supine, standing) • Interventions: • Respiration • Valsalve • Carotis massage • Stress (Gravity…) • …
HRV and BPV indices can be used to quantify autonomic cardiovascular modulation
从心电、血压 到心率变异、血压变异 及压力反射敏感性 From HR & BP to HRV, BPV & BRS
研究方法 Method
Experiment Hardware Ground BDC’s / postflight
Parameters • ECG (electrocardiogram) • BP (continuous blood pressure) • Respiration with pressure sensor
Heart Rate Variability & Blood Pressure Variability ( ms ) 816 848 784 832 864 800 704 976 880 768 800 944 ( mmHg ) 120 117 115 120 122 119 119 120 115 109 113 115 112 Time
BP(mmHg) RR RR RR RR Time BRS BPV HRV HRV & BPV ECG
分析方法 Analysis
Tachogram & Systogram FFT • HRV: • Low Frequencypower (LF) [0.04-0.15 Hz] ~ sympathetic modulation + BRS+ Vagal modulation • High Frequency power (HF) [0.16-0.4 Hz] ~ vagal modulation • Total power[0.0078-0.5 Hz] ~ global autonomicmodulation • BPV: • Low Frequencypower (LF) [0.04-0.15 Hz] ~ sympathetic modulation • High Frequency power (HF) [0.16-0.4 Hz] ~ mechanical effect of respiration
RR BP Algorithms to evaluate cardiovascular autonomic function- Baroreflex sensitivity (BRS) • Calculation of the slope between dynamic HR responses to systolic BP changes: index of dynamic baroreflex sensitivity (BRS) • Sequence method: at least 3 sequences • Other methods: alpha method, statistical dependency, cross correlation…
Results HRV standing Sympathetic modulation Vagal modulation Beckers et al. J Gravit Phys, 2003
中国航天员研究 Chinese Astronauts Study 2005
Putting on Equipment FLEXION FREQ_1 FREQ_2 BASELINE supine 10 min 1 min 5 min 5 min sitting Check cables, check signals FREQ_2 FREQ_1 BASELINE standing 5 min 5 min 10 min Putting off Equipment China experimental protocol Recording 1 Freq1 : 5 seconds breathing in – 5 seconds breathing out Freq2 : 3 seconds breathing in – 3 seconds breathing out Recording 2
结果 Result
心率变异 HRV
HR Supine: heart rate decreases, stabilized at R+7 Standing: heart rate remains similar -23% -12%
LF Supine: increase post-flight with stabilization at R+7 +312% -6%
LF% Supine: small decrease, but most likely not significant -13% -27%
HF Supine: increase postflight with stabilization at R+7 +218% +145%
HF% HF% shows contrasting evolution between astronauts -33% +90%
LF/HF Stable post-flight (high percentages due to low values) +30% -62%
血压变异 BPV
BP After space flight, in both astronauts SBP had no obvious alteration at supine position, as well as at stand position. -1% +27%
LF Supine: increase immediately post-flight, but rather fast normalization +104% +340%
压力反射敏感性 BRS
BRS Rather stable evolution post-flight +44% -12%
Results: • In the Chinese group there was no difference in pre- and post-flight HRV parameters • Similar differences after 10 day flights of ESA and Russian cosmonauts were between 13% and 54%. • No evolution until R+9. • Similar behavior was observed for BPV parameters.
结论 Conclusion
Conclusion: • No significant differences were found between pre and post flight in the Chinese group in contrast to the ESA/Russian group • No evolution post-flight until R+9 in the Chinese group • This different behavior could be due to specific training methods and/or nutrition methods?
初步结果: • 在短期航天飞行后,中国宇航员的心血管自主神经功能变化情况与俄罗斯宇航员、欧洲宇航员存在着明显的差异。 • 中国宇航员经过5天的短期太空飞行返回地面后,心率、血压稳定;迷走神经张力有一过性升高。
可能因素: • 太空飞行时间短。目前欧洲、美国的短期载人航天飞行一般都在10天左右。以前的研究结果大多数都是建立在这个时间基础上的。 • 训练水平高。也许因为中国航天员的训练方法更加有效。 • 药物因素。太空飞行结束后,服用中药可能对航天员的心血管功能恢复有帮助。 • 基因差异。
相关问题: • 返回10天之后,是否还继续监测心电图和血压情况?情况怎样? • 杨利伟的飞行时间更短,是否可以做一参照,对其血压、心率及心脏自主神经功能进行回顾性的研究? • 两名航天员的飞行前后体重情况? • 应对另外4个航天员的基础检测数据进行参照分析,已得到基础情况,以便进行统计学分析。