During periods of magnetic storms and sharp fluctuations in the geomagnetic conditions are becomingmorefrequent cases of myocardial infarction and hypertensive crises, an increasing number of cases of sudden death.One of the main "targets" under the influence of the geomagnetic field of the Earth on the human body is the cardiovascular system (I. E. Orange, PG Tsarfis, 1989). During unfavorable heliomagnetic situation is sharply reduced tolerance of the heart to physical exercise, disaspted extracardiac regulation of cardiac function, changes the sensitivity to medication effects. However, it is known that the cardiovascular system is also one of the main "targets" under the influence of the organism to space flight factors (VV Parin et al, 1967, AI Grigor'ev, AD Egorov, 1992 ). Here the disturbing factors are the redistribution of blood in the upper body, reducing the afferent flows from the periphery and a decrease in energy expenditure. Under the influence of prolonged nevesomsti a reduction in baroreflex function and activates adaptive and compensatory mechanisms, elements of which are higher autonomic centers (RMBaevsky, 1995). Thus, both long and short-term weightlessness geomagnetic disturbances practical effect on the same functional systems. Therefore, theoretically, during magnetic storms adverse effects of weightlessness should be strengthened and this can adversely affect the health and performance.According to some authors (VI Kopanev, AV Shakula, 1985; NI Muzalevskaya, 1973; GF Plekhanov, 1978, AS Presman, 1974), the biological effects of geomagnetic fields can be due to their interactions with management information systems of the body, absorb information from the environment and accordingly regulate vital processes. Perturbations of the geomagnetic field, as well as any stress factors affect all body systems, but most of all on the nervous system, providing regulation functions. Under the influence of stress effects arise functional stress regulatory systems (R. Baevsky, 1979). The high sensitivity of the neuro-humoral regulation and cerebral cortex to direct changes in ambient geomagnetic and radiation situation gives grounds to consider it possible to identify these effects on the reaction of regulatory systems. The challenge is to adequately assess the response of a living organism on the impact of changes in the electromagnetic field in space flight, which can not be used sophisticated techniques and bulky equipment. Most effective way to solve this problem would be to study such indicators of regulatory systems, which are the first in the processes of adaptation to the impacts of various environmental factors.In this paper, we investigate the possibility of solving this problem by using a special technology based on mathematical analysis of cardiac rhythm. This technology allows to obtain statistically comparable data on the autonomic regulation of circulation and can be used both on the ground and in space (R. Baevsky, 1979, 1983, 1995; R. Baevsky, OI Kirillov, C . Kletskin Z., 1984, R. Baevsky, GA Nikulina, IG Tazetdinov, 1984). Mathematical analysis of heart rate is used in space medicine, with its first steps. The first results were already obtained during the flight animals on artificial earth satellites and the first manned flight aboard Vostok and to date has accumulated an extensive database that can be a source of retrospective analysis. However, there is extensive literature on the experience of using the mathematical analysis of heart rate and its variability in clinical and applied physiology, preventive medicine (RM Baevskii 1979; R. Baevsky, OI Kirillov, S.Z. Kletskin, 1984; van SM Ravenswaaij-Arts, A. Kollee et al, 1993). Thus, the data obtained in the study of astronauts, canmoreusefully be employed in the practice of preventive health and clinical medicine1. Material and Methods1.1. MaterialThis study used material data bank on the early stages of space flight crew transportation vehicles (TC) "Union" for 1990 - 1995. In forming the initial set of experimental data were selected record an electrocardiogram (ECG) of astronauts on a 32-m coil of each flight mission. The choice of this phase of flight is justified by the fact that, firstly, at all stages of the initial period of flight, which carried out the remote control of physiological functions, there are significant stressor exposure (prelaunch period, the site launch, the first minutes and hours of weightlessness). Secondly, the 32-th round - it is the last round before docking Soyuz "with the orbital station Mir, during which the crew did not perform any particular activity and are quite similar flight conditions, which makes it possible to study the effect of geomagnetic perturbations in the relative stability of other conditions. Total has been selected for the analysis of 30 entries received during the flight crews and members of the main crew visit. Age astronauts ranged from 28 to 54 years. 18 astronauts made their 1 st flight, the rest - the 2 nd or 3 rd.In accordance with the data presented by the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, was allocated an experimental group of astronauts, flying during geomagnetic disturbances. This group was included 12 astronauts. The second experimental group was composed of nine astronauts, for which the 32-th round of the flight took place 1-2 days after magnetic storm. The control group consisted of nine astronauts, a flight which took place in the days, separated from the maximum time a magnetic storm bymorethan 3 days.1.2. Research techniqueThanks to the work carried out in the field of space medicine, the use of the cardiovascular system as an indicator of adaptive reactions of the organism is now considered reasonable, and, in particular,moreandmorecommonplace methods of mathematical analysis of heart rate, developed over 30 years ago as part of Space Cardiology (Parin, Baevskii Volkov, Gazenko, 1967). As is known, the basic information about the state of systems that regulate heart rhythm, is contained in the "scatter function" duration cardio.There are three groups of methods aimed at, respectively, to investigate the average heart rate, its variability and transients. Central to this classification occupy methods for studying heart rate variability. These methods can be divided into three groups: 1) methods for estimating common statistical characteristics, and 2) methods to assess the relationship between cardio and 3) methods for detection of latent periodicity of the dynamic series cardio. Methods of assessing the general statistical characteristics of the dynamic series cardio include calculating the expectation (M) and heart rate (HR, HR-Heart Rate), the standard deviation (SDNN), coefficient of variation (CV) and parameters variation pulsometry (fashion - Mo, the amplitude Fashion - AMO and the variational scale, or the difference between the maximum and minimum duration of RR-intervals, - MxDMn). Variation pulsometry called the method of analysis of heart rate variability based on the use of data on the distribution of cardio on the selected range. According to the variation pulsometry evaluated a number of derived indicators. The most informative is the index of tension of regulatory systems (Stress Index - SI). This figure is computed using the formula SI = AMo / (2Mo * MxDMn). Strain index reflects the degree of centralization of cardiac rhythm management and characterizes cummarnuyu sympathetic activity of autonomic nervous system. Among the statistical estimates made by Western researchers, is RMSSD, which reflects well the state of the parasympathetic autonomic nervous system.As a method of revealing hidden periodicity of the time series of cardio most often used spectral analysis. In this opredelyalyutsya spectral power in the high range (High Frequency-HF), nihkih (Low Frequency - LF) and very low (Very Low Frequency-VLF) frequencies. We devote to estimate VLF frequency range from 0.04 to 0,015 Hz. (25-70 s). It is important to assess the activity of the subcortical cardiovascular center that has in its composition three nuclei (center) and Vascular accelerating and inhibitory (folk, Neil, 1983). In this case, the vascular (or vasomotor), the center operates in the frequency range of about 0.1 Hz. And regulating sympathetic activity of the autonomic nervous system, accelerating and inhibitory centers are characterized by a low-frequency vibrations. Oscillations with frequencies below 0.015 Hz. (> 70 sec.) According to available data in the literature (Sayers, 1973) reflect the state of the centers of thermoregulation and the renin-angiotensinic system (van Ravenswaaij-Arts, Kollee et al, 1993). Thus, the power spectra of slow waves of the first and second order indicates the activity of various levels of central regulation. In this case, slow waves of the first order reflect the state of the vasomotor center, and a wave of second order - sympathetic activity of autonomic nervous system. Total power of all waves in the range of 0.4 to 0,015 Hz (2.5 - 70 sec.) Characterizes the overall activity of intra-(level in central regulation) and autonomous regulatory mechanisms. It should be noted that the decrease in total power can be seen as the result of activation of higher levels of regulation, resulting in suppressed activity nizhelezhashih centers. It should be noted that the values of individual components of the spectasm are calculated both in absolute values (HFs, LFs, VLFs in MC2), and in relative units (HF%, LF%, VLF% as a percentage relative to total power). According to the spectral analysis of heart rate calculated two integral index: an index of centralization (Index of Centralization - IC) and an index of activation of the subcortical nervous centers (Subcortical Nervous Centers Activation-SNCA). To calculate them, the following formula: IC = VLF + LF / HF, SNCA = LF / VLF. The physiological meaning of IC is that it reflects the ratio between the central and autonomous control loop heart rhythm. SNCA to evaluate cardio-vascular subcortical nerve center in terms of relations specific baroreflex (vascular) component of the regulation and nonspecific sympathetic influences (stress components).Statistical significance of differences between heart rate variability in different groups was determined by pairwise comparison by Student's t-test and stepwise discriminant analysis method with the constasction of mathematical models of phenomena under study.2.Rezultaty and discussionThe results of the mathematical analysis of heart rate variability as srednegasppovyh values with an estimate of the reliability of their differences in F-Fisher test are presented in Table. 1.The data obtained suggest that during the magnetic storm observed other changes in autonomic regulation than in the 1-2-th day after the storm. During a magnetic storm, a simultaneous decrease in heart rate (HR) and a shift in autonomic balance toward sympathetic level of regulation (reduction in HF%, HFs, CV, MxDMn, pNN50, RMSSD; growth of SI, VLFs) talk about the activation of the subcortical cardiovascular center. Rises in SNCA and LFs / HFs suggests that there are specific changes in vascular regulation. This is confirmed by the growth rate LFt. Physiologically, these changes can be interpreted as the activation of the vasomotor center and the deceleration time of reception and processing of information in it. Thus, observed during a magnetic storm changes clearly show that the main "targets" the impact of geomagnetic disturbances are central nervous system and neural regulation of vascular tone.Several authors have noted that the most significant deviations of physiological functions occur 24-48 hours after a magnetic storm and are expressedmoreoften in high blood pressure and vascular dystonia (Muzalevskaya, 1973, Orange, Tsarfis, 1989). In this study we have also seen a significant change in heart rate variability in 1-2-days after a magnetic storm. These changes are shown a significant increase in the values of parameters IC, VLF%, VLFs. To a lesser extent increases LF, but significantly reduced HF. All this goes to centralize the management of cardiac rhythm involving the process of suprasegmental brain stasctures. However, attention is drawn to a significant increase in IARS and a significant increase in arrhythmias (NArr). Together with a significant lengthening of the period of vasomotor waves (LFt) and an increase in the total power of low-frequency oscillations with respect to high (LFs / HFs), these changes point to the phenomenon of imbalance in the central regulation on the further development of vascular changes in the system of regulation. Particular attention should be given the fact a significant increase in the number of arrhythmias.Physiological interpretation of the revealed during a magnetic storm, and especially over the next 24-48 hours the changes shows that there are deviations beyond the normal physiological limits. The changes of the heart (the appearance of arrhythmia) and cardiovascular system (lengthening the time the regulation of vascular tone and functional power vasomotor center) can be considered as risk factors for possible deviations with a pathological character.Fig. 1 shows three concrete examples of analysis of heart rate variability in astronauts in each of the groups. As can be seen, cardiointervalograms cosmonauts during and after magnetic storms differ reduced variability, the virtual absence of high tidal waves. Autocorrelation functions of different smoothness and a slower decline. In the spectral features of the astronauts of these groups is dominated by slow waves of order 2. These results show that the system autonomic circulatory regulation responsive to the geomagnetic disturbances. Revealed that the astronauts who committed 32 first round of the flight during geomagnetic storms in the next 1-2 days after their completion, the activity of regulatory systems has been higher, and autonomic balance was significantly shifted towards increased sympathetic activity level. This result is consistent with the available literature data on the high sensitivity of the autonomic nervous system to radiation and geomagnetic effects (Muzalevskaya, 1973, Orange, Tsarfis, 1989, Plekhanov, 1978; Presman, 1974).ConclusionIn the present work shows the presence of specific influence of geomagnetic disturbances on the system autonomic regulation of circulation in the cosmonauts during the flight. It can be concluded that the magnetic storms, both during their direct impact, and during the after-effect (the next 24 h) caused significant changes in the autonomic regulation of heart rate in astronauts during flight. The results show that the observed changes are consistent with previously hypothesized that one of the "targets" under the influence of the geomagnetic field of the Earth on the human body during space flight is a system of regulation of vascular tone. Therefore, changes in the indicators characterizing the activity of the vasomotor center, can be qualified as special. Changes in the indicators reflecting the state of the tone of the sympathetic and parasympathetic system, are secondary and can be regarded as nonspecific. However, the so-called specific and nonspecific changes are single coherent response mechanism?? In the regulation of blood flow to an external stress factor - the magnetic storm.The question of sensitivity and specificity of autonomic response to the influence of the magnetic storm of great scientific and practical interest. This question is closely connected with the problem of developing criteria to judge the magnitude of individual response to geomagnetic disturbances. One of the first steps in this direction is to separate the two components of the body's response to the impact of geomagnetic disturbances. Nonspecific component is characterized by activation of the sympathetic part of autonomic nevnoy system and flows according to the type of general adaptation syndrome (Selye, 1961). A similar response can be obtained by other influences, such as physical or psycho-emotional stress. Specific component of the reaction are changing autonomic balance with the activation of the baroreflex or the parasympathetic parts of the regulation. Changes of this type are characteristic for meteotropnyh reactions are described in many papers devoted to the study of magnetic storms (Muzalevskaya, 1963, Orange, Tsarfis, 1989, Plekhanov, 1978; Chizhevsky, 1976).Corresponding alteration of regulatory mechanisms in response to magnetic storms, in particular, readjustment of the subcortical cardiovascular center, led to the development of general nonspecific stress reaction, which is characterized by increased tone of the sympathetic nervous system (increased heart rate, reduced heart rate variability, decreased spectral power tidal waves, etc.) and possible inclusion in the regulation of higher levels of control physiological functions. At the transformation of regulatory processes under the action of a magnetic storm may occur instability of the sinus node to increase the number of arrhythmic contractions.Due to the influence of magnetic storms on the activities of the mechanisms of circulatory regulation and the possibility of arrhythmia need to emphasize applied aspect of the results. He, in particular, on the one hand points to the usefulness of supplementing the medical monitoring of astronauts forecast of probable geomagnetic disturbances as a reaction to geomagnetic disturbances can be summed with voltage regulation systems. On the other hand, these data are of interest to specialists cardiologists in terms of predicting the possibility of arrhythmias in the respective groups of patients.ReferencesBaevsky RM Prediction of the states on the verge of norm and pathology. Moscow: Medicine. 1979. 295.Baevsky RM, Kirillov OI, Kletskin SZ Mathematical analysis of heart rate during stress. 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