[Individual prediction by the analysis of preflight ECG data of cardiac function disorders in cosmonauts during standard deorbit after long-term space flights and in the period of postflight observation].

ECG records of 25 cosmonauts--members of 30 long-term Mir and ISS missions (73- to 197-day long) in the period of 1995-2007 were analyzed. The ECG records were made during medical selection, clinical-physiological investigations (KFO) before launch, insertion and standard descent, and post-flight KFO. No negative trends were discovered in 70% (n=21) of ECG records during insertion and descent of cosmonauts who had not have significant ECG deviations before flight. In 20% of ECG records (n=6) pre-launch individual properties of cardiac rhythm, conduction and end of the ventricular complex became more pronounced in the period of descent persisting after landing. In 10% of ECG records (n=3) the predicted ECG deviations were not found This was the first time when dynamic analysis of ECG records made on the stages of selection and pre-launch training was successful in predicting of 90% (n=27 of 30) of cardiac function deviations during descent. At the start of rehabilitation from long-term missions essentially each of the cosmonauts displayed ECG deviations which were more considerable as compared with the KFO and descent records.

[Prediction of cardiac function deviations (ECG data) in the course of permanent cosmonaut's monitoring starting from selection till return to earth after short-duration space flight].

Analyzed were deviations in cardiac function in 29 cosmonauts with previous aviation and other occupations ranging of 29 to 61 y.o. who made 8- to 30-day space flights (totai number of flights = 34) between 1982 and 2006. The deviations were identified in ECG records collected during clinical selection, clinical physiological examination (CPE) before flight, insertion and deorbit in transport vehicles, and post-flight CPE. Based on the analysis, the cosmonauts were distributed into three groups. The first group (55.2% of the cosmonauts) did not exhibit noticeable shifts and unfavorable trends in ECG at any time of the period of observation. The second group (34.5%) showed some deviations during selection and pre-flight CPE that became more apparent in the period of deorbit and were still present in post-flight ECG records. The third group (10.3%) displayed health-threatening deviations in cardiac function during deorbit. These findings give start to important investigations with the purpose to define permissible medical risks and ensuing establishment and perfection of medical criteria for candidates to cosmonauts with certain health problems.

[Magnetocardiographic markers of functional hemodynamic overloading of the right atrium].

Functional hemodynamic overloading of the right atrium can be caused by some of the dynamic factors in aviation and space flight. Our purpose was to disclose markers of the right atrium functional overloading in 6 normal males during the Stange test and Valsalva maneuver. Computerized magnetocardiography was fulfilled before (resting subjects), during and after (resting subjects) the breathing tests. Testing on a background of the flight dynamic factors resulted in a trend toward a more superficial Z-coordinate of the myocardium signal along the whole or a greater part of the atrial complex as compared with baseline measurements at rest. A supposition has been made that this Z coordinate alteration can be a marker of functional hemodynamic overloading of the right atrium associated with the breathing tests.

[Dynamics of ECG voltage in changing gravity].

Comparative analysis of the QRS voltage response to gravity variations was made using the data about 26 normal human subjects collected in parabolic flights (CNERS-AIRBUS A300 Zero-G, n=23; IL-76MD, n=3) and during the tilt test (head-up tilt at 70 degrees for a min and head-down tilt at-15 degrees for 5 min, n=14). Both the parabolic flights and provocative tilt tests affected R-amplitude in the Z lead. During the hypergravity episodes it was observed in 95% of cases with the mean gain of 16% and maximal--56%. On transition to the horizontal position, the Rz-amplitude showed a rise in each subject (16% on the average). In microgravity, the Rz-amplitude reduced in 95% of the observations. The voltage decline averaged 18% and reached 49% at the maximum. The head-down tilt was conducive to Rz reduction in 78% of observations averaging 2%. Analysis of the ECG records under changing gravity when blood redistribution developed within few seconds not enough for serious metabolic shifts still revealed QRS deviations associated exclusively with the physical factors, i.e., alteration in tissue conduction and distance to electrodes. Our findings can stand in good stead in evaluation of the dynamics of predictive ECG parameters during long-term experiments leading to changes as in tissue conduction, so metabolism.

[Magnetocardiography as a new diagnostic method for cardiologic diseases in occupational medicine].

Magnetocardiography as a new diagnostic method for cardiologic diseases in occupational medicine. The article covers possibilities of magnetocardiography as a promising diagnostic method for cardiologic diseases in occupational medicine. The studies used 7-channels magnetocardiographic complex MKG-6073-M. The authors applied standard exercise tests in 6 apparently healthy examinees.