RESUMEN
Physiological reactions to +Gx loads of 10 nonprofessional members of 8 to 12-d. missions to the ISS some of whom had partial health defciency were compared with data about space station MIR cosmonauts (n=10) who participated in flights of similar duration but were qualified as essentially healthy. Age of the ISS visitors varied between 29 and 60 years, whereas the MIR cosmonauts were 31 to 49 years old. Based on analysis of objective information, the ISS visitors were distinguished by much more pronounced sinus tachycardia and tachypnea during insertion and re-entry. There were several instances of pre-launch extrasystole arrhythmias that persisted during insertion and were, as a rule, more serious during re-entry. Also, descent from orbit caused more frequent cardiac rhythm disturbances, polymorphism and severity in these space flyers in comparison with the MIR cosmonauts. Particularly grave ECG deviations were observed in two 60-y.o. crew members. However, all these disturbances were episodic by character. These results suggest that development of individual programs of medical risk mitigation for nonprofessional flyers to the ISS should give regard for the status of cardiac rhythm regulation as re-entry g-loads may affect ECG dramatically. Besides, the analysis highlighted the necessity of more rigorous selection of aged candidates for ISS missions with partial health deficiency