[Counteracting effect of hypoxia and Qigong on cardiac rhythm during orthostatic test post simulated weightlessness]

Objective: To try to find a new method for countermeasuring the effect of simulated weightlessness. Methods: The study was carried out in fifteen male healthy subjects, 19-22 years, -6 degrees head-down bed rest (-6 degrees HDBR) for 21 d was used as a weightlessness simulation model. The subjects were divided into three groups: control group (-6 degrees HDBR), hypoxia group (-6 degrees HDBR + inhalation of hypoxic gas mixture two times a day, 20 min each time) and Qigong group (-6 degrees HDBR + Qigong, three times per day, 45 min each time). Orthostatic test (+75 degrees 20 min) was conducted on each subject pre- and post-HDBR. Results: Cardiac rhythm during the orthostatic test was normal pre-HDBR but sinus cardiac arrhythmias were observed in two subjects of the control group and nodal cardiac arrhythmias were observed in two subjects in Qigong group after HDBR. No cardiac arrhythmia was found in hypoxia group. Conclusion: Hypoxia is more effective in countermeasuring orthostatic intolerance after weightlessness than Qigong.