[Researches of autonomic regulation of blood circulation in the condition of long-term space flight].

In the article is presented five-year experience of experimentation in autonomic regulation of blood circulation onboard the International space station. The heart rate variability (HRV) analysis was the basic methodical approach in the researches. We described probabilistic approach created on the basis of HRV analysis to an estimation of risk of pathology development in the conditions of long space flight. The individual type of autonomic regulation had essential value during the analysis of results. It is shown that the type of regulation, which is inherent in every cosmonaut in the conditions of weightlessness, remains even during following flights. We obtained the new scientific data on connection of character of adaptable reaction of an organism to the space flight factors with individual type of autonomic regulation. It is shown that staying in weightlessness is connected with changeover of regulatory systems and with transition in a zone of prenosological states. Adaptable reactions in weightlessness are characterized by tension growth of regulatory systems at preservation of sufficient functional reserves. The mobilization of additional resources after returning to the Earth is required and consequently functional reserve of mechanisms of regulation decreases. Cosmonauts with vagotonic and normo-sympatotonic types of autonomic regulation appear to be the most resistant. Knowing the type of autonomic regulation we will be able to foresee possible reaction of the cosmonaut to the factors of space flight. As a result of HRV analysis during the flight of the past few months likelihood estimations were calculated and risk categories were defined. Consequently, 3 groups of risk of pathology development were distinguished. In conclusion, theoretical and applied relevance of the conducted experiments were considered.

[Conception of health: space-earth].

In article the new approach to an estimation of a health state of cosmonauts, sportsmen, pilots, drivers, operators, persons of dangerous trades is considered. It has been created and developed in Institute of biomedical problems of the Russian Academy of Sciences under the direction of academician A.I. Grigoriev. Results of works of last decade, by the Program of Presidium of the Russian Academy of Sciences carried out at support of "Fundamental sciences--are submited to medicine". The new system for an estimation of a functional states of an organism at stressful influences in submitted. The methodology of remote studying of influence of ecological factors on health which has begun a new scientific--practical direction--to telemedical ecology is created. In conclusion of the article it is discussed questions of the further introduction of new concept of health and technologies prenosological diagnostics in practice of public health services.

[Seven-day dry immersion: relations between water-electrolyte and cardiovascular responses].

The paper presents the results of the experiment with 7-day dry immersion. Eight healthy men were studied before, during and after exposure. It is shown that the primary response involves hemodynamic and water-electrolyte changes. The mechanisms of cardiovascular adaptation to immersion conditions are revealed. In particular, some electrophysiological shifts in propagation of myocardial excitation are found, leading to increase in "myocardium" index, estimated by analysis of natural small oscillations in the amplitude of the PQRST complex with dispersion ECG mapping. Revealed significant reduction of functional reserves of the cardiovascular regulatory mechanisms in the process of adaptation to dry immersion is of great practical importance. The results suggest that water-electrolyte shifts induced by dry immersion are the basis and the first phase of the further changes in autonomic regulation and myocardial functional state.

[Indices of electrocardiogram dispersion mapping during 5-day exposure in dry immersion].

The article presents the results of ECG dispersion mapping in the investigation of 13 young healthy people during 5-d dry immersion (DI). This was the first study of 24-hour variations in dispersion of ECG microoscillations. For this purpose, 20-30 min fragments were "cut out" of every hour of Holter monitoring records to analyze their means after averaging over every 4 hours. Heart rate (HR) and QRS-amplitude were analyzed simultaneously. Index of metabolic adaptation (HR(max/MiO(max)) was calculated. Based on the results, alterations in ECG signal became distinct on DI day-3. They started with a considerable rise of the main ECG amplitudes, especially at night (10.00 p.m. to 6.00 a.m.). The myocardium index makes a significant rise in the period from 10.00 p.m. till 2.00 a.m. However, this index reached its maximum values on DI day-5 in the time intervals from 3.00 till 6.00 p.m. and from 10 p.m. till 10.00 a.m. On DI day-5, of particular interest was a marked HR growth from 10.00 p.m. till 02.00 a.m., and in the post-sleep hours (07.00-10.00 a.m.). Consequently, all this looks like a series engagement of first electrical and then energy metabolism processes in the myocardium reaction to DI. Finally, the increased pulse rate suggests an integral nature of the cardiovascular reaction. This picture of alterations provides grounds for hypothesizing energy metabolism genesis of these reactions.

[Potentiality of building-up the medical operations system for long-duration space missions by noncontact physiological functions recording during sleep time].

Methods of investigating the physiological functions in space crews on extended missions during night sleep are of much fundamental and practical substance. The design of experiment "Sonocard" utilizes the method of seismocardiography. Purpose of the experiment is to validate the procedures of noncontact in-sleep physiological data recoding which are potent to enhance the space crew medical operations system. The experiment was performed systematically by ISS Russian crew members starting from mission-16. The experimental procedure is easy and does not cause discomfort to human subjects. Results of the initial experimental sessions demonstrated that, as on Earth, sleep in microgravity is crucial for the recovery of body functional reserves and that the innovative technology is instrumental in studying the recovery processes as well as person unique patterns of adaptation to extended space mission. It also allows conclusions about sleep quality, mechanisms of recreation, and body functionality. These data may enrich substantially the information used by medical operators of the space missions control centers.

[Prenosological approach to assessing morbidity and mortality].

The paper deals with the morbidity- and mortality-associated problem arising from the processes occurring in the transition period of development of new Russia. It points to the leading role of health care service in this process. The authors show the real health status of the working population, the actual state of affairs with the rendering primary medical care at industrial institutions. Measures are proposed to apply specific science-based health-promoting technologies adopted from Russian space medicine and called prenosological monitoring.

[Parameters of high definition ECG and dispersion ECG mapping on the background of amlodipin and myostimulation during 7-day dry immersion].

The article presents the results of studying electrophysiological changes in the myocardium of normal human subjects during 7-day dry immersion, and modification of the reaction to immersion by amlodipin and myostimulation. The dry immersion effects on the myocardium generally include a succession of electrophysiological shifts first in the ventricles and then in the left atrium due to, probably, blood pooling in the pulmonary vessels. Myostimulation and amlodipin affect the myocardium reaction visibly suggesting involvement of numerous components of the autonomous and central nervous systems. The positive effect of the pharmaceutical--alleviation of myocardium strain--is a result of amlodipin assistance to the coronary blood flow; however, it has a side-effect on orthostatic stability. The positive action of myostimulation is associated with unloading of the right heart and reflected in changed HD ECG parameters and growth of the "myocardium" index.

[The present-day issues of space cardiology].

The author sweeps the history of space cardiology since the first space flights of animals and humans to the on-going missions on the International space station. The material is distributed into four sections in accordance with postulates of the scientific theory described in monograph "Space Cardiology" (1967). The first section deals with adaptation of the blood circulation control system to microgravity. Extended microgravity was shown to cause mobilization of additional functional reserves of organism. During the initial 6 months cardiovascular homeostasis is maintained through the intrasystem control mechanisms; a more extended period of microgravity requires active "intervention" of intersystem mechanisms (suprasegmental components of vegetative control). The second section discusses how the left and right parts of the heart contribute to the cardiovascular adaptation, and the paramount role of the right heart at the beginning of space flight. The third section is concerned with degradation of orthostatic tolerance which became a substantial issue already in the very first piloted missions. The paper presents the results of experiments aboard the ISS indicating the practical value of assessing the reserves of the systems controlling blood circulation. The fourth section provides information about new methods for investigation of the myocardium that stand in line for adoption into the space medical operations system. The paper concludes with introduction of several projects in space cardiology to be performed in new future.

[Investigation into vegetative regulation of blood circulation during 7-day dry immersion].

The paper presents the results of investigations into vegetative regulation of blood circulation and regulation modification by peroral amlodipine and myostimulation during 7-d dry immersion. It was shown that in immersion vegetative regulation readjusted towards predominance of the sympathetic mechanisms. Myostimulation and peroral amlodipine modified regulation substantially mobilizing high level suprasegmentary structures. It should be noted that amlodipine and myostimulation differ in mechanisms of their action on central regulation. Pharmaceutical intervention seems to have a more complex and varying effect on people including side-effects. Presumably, it was the cause of poor orthostatic tolerance of several test-subjects.

[Software for polygraphs used in scientific research].

Polygraphs--devices for simultaneous detection of several physiological parameters--are currently used in medicine in psychology. Special polygraphs are also used in scientific research. The process of data acquisition and processing in such polygraphs is usually computer-controlled. The goal of this work was to describe software for detection of polygraph signals used in cardiorespiratory system research. The software supports the experiment script language, allows hyperventilation testing, and makes it possible for the examination subject to control the data detection process.

[Diagnostic and prognostic validity of high-resolution electrocardiography under the conditions of space flight].

Applicability of high-resolution ECG used in clinics for predicting the probability of life-threatening arrhythmias in cardiovascular patients for the space flight environment was investigated in A 7-d bedrest experiment was to verify HR ECG displayed electrophysiological shifts in myocardial atriums and ventricles. Clearly seen changes in R-amplitude and time course seem to have reflected the volumetric loading and altered sympathetic activity during bed rest QRS-complex had increased the time of low-amplitude signals at the end of the last 40 ms but was short in duration which may point to delayed ventricular depolarization. Prognostically meaningful is exaggerated electrical instability of the myocardium during the standing test on completion of the bedrest period. Results of the investigation allow recommend HR ECG integration into the spacecrew health monitoring system.

[Estimation and prediction of functional changes in organisms in space flight].

The article is devoted to theoretical and applied problems of estimation of the organism functional state and a level of health. Transitive states between health and illness, between norm and a pathology, so-called prenosological states are considered. The level of health is determined by adaptable opportunities of an organism, a degree of regulatory systems tension and their functional reserve. As the basic methodical approach to an estimation of a degree of regulatory systems tension the method of heart variability analysis is described. The applied aspect of a considered problem is submitted by results of the researches which have been carried out in conditions of space flight. Changes of organism functional state at different stages of adaptation to conditions of long weightlessness are described. The mathematical model of functional states is submitted. Four types of the vegetative regulation, differing on the adaptive reactions in conditions of space flight are allocated. Results of researches of crew members of the International space station are submitted.

[Assessment and prediction of health status of the Mars mission crew members].

The scientific concept of health assessment and prediction in a piloted mission to Mars has been built on the principles of pre-nosologic diagnostics, i.e., identification of the norm-pathology borderline states. The article deals with the medical care policy for the mission, and specific techniques and technologies. A three-level system of health assessment and prediction is proposed. Innovative approaches to evaluation of the body control systems during long exposure in microgravity have a footing of ground-based and space experimental investigations. Namely, these include evaluation of the cardiorespiration autonomous regulation and body functional reserve assessment by noninvasive recording of physiological signals in sleeping crewmembers before and after mission.

Assessment of electrophysiological state of heart in astronauts in terms of decartographic and conventional electrocardiographic characteristics.

Long-term observation of the heart state during specialized professional activities plays an important part in preventive medicine. This study is aimed at assessment of electrophysiological state of heart in astronauts by common electrocardiography, vectorcardiography, and dipole electrocardiotopography (DECARTO technique). The subjects observed were two astronauts performing a long-term flight at the Mir orbital station. DECARTO technique was used to obtain an intelligible-pictorial representation of the data in the form of so-called decartograms for visual and quantitative analysis. The observations showed rather stable chronotopography of the heart depolarization process. However, there was an increase of the maximal magnitude of the electric heart vector and a decrease of the ventricular gradient vector in the middle part of the flight. Just upon landing, a pronounced decrease of the ventricular gradient magnitude, followed by a fast restoration of its value was observed in both subjects. The DECARTO technique used in combination with vectorcardiography facilitated the detailed visual analysis of the electrocardiographic data. (Fig. 3, Ref. 3.)

[Effect of geomagnetic activity on the functional status of the body]. / Vliianie geomagnitnoi aktivnosti na funktsional'noe sostoianie organizma.

A complicated nonlinear biological system should be in principal more sensitive to the external factors activity including geomagnetic disturbances. The complex of experimental studies based on this hypothesis were done simultaneously in two hospitals in Moscow as well as in condition of space orbital station, where just above-mentioned conditions are the case. This studies revealed that the reaction of astronauts to the geomagnetic storm involves a mobilization and activation of all centers of the sympathetic link, and as a result,--a significant increase and stabilization of pulse (heart rate), decrease of the heart rhythm variability and the power of respiratory waves. This nonspecific adaptation stress-reaction was accompanied by variations in the regulation of vascular tonus which is correspond to specific adaptation stress-reaction. The results of clinical examinations of healthy people and patients with the ischemic heart disease lead us to the conclusion that the reaction to the geomagnetic disturbances are mainly of one type and manifests themselves in deterioration of the physiological status, rheologic blood characteristics and the heart rate disturbances similar to ones observed in astronautes.

[Effect of geomagnetic activity on the human body in extreme conditions and correlation with data from laboratory observations]. / Vozdeistvie geomagnitnoi aktivnosti na organizm cheloveka, nakhodiashchegosia v ékstremal'nykh usloviiakh, i sopostavlenie s dannymi laboratornykh nabliudenii.

It was hypothesized based on previous laboratory observations and theoretical concepts that astronauts working at the "Mir" station under zero gravity conditions exhibit enhanced sensitivity to geomagnetic disturbances. The result of studies made it possible to reveal the dynamics of changes in cardiovascular characteristics separately in the main phase and the phase of storm restoration. A similar dynamics of cardiac activity was observed in experimental rabbits during geomagnetic storms.

[Use of the variation pulsimetry in the evaluation of diurnal dynamics of cardiac rhythm in patients with ischemic heart disease and functional disorders of the cardiovascular system]. / Primenenie variatsionnoi pul'sometrii v otsenke sutochnoi dinamiki serdechnogo ritma u bol'nykh ishemicheskoi bolezn'iu serdtsa i s funktsional'nymi narusheniiami serdechno-sosudistoi sistemy.

The results of employing the method of variation pulsimetry and dynamic electrocardiography in 30 patients are discussed. Analysis of the circadian dynamics of the statistical characteristics of cardiac rhythm showed that the activity of the sympathetic part of the vegetative nervous system was higher in patients with ischemic heart disease than in those with functional disorders. Disbalance of neurohumoral control of cardiac rhythm in various types of arrhythmias was disclosed.

[Cybernetic analysis of the heart rhythm in the measured physical loading test with crew members of the Saliut-6 orbital station]. / Kiberneticheskii analiz serdechnogo ritma pri probe s dozirovannoi fizicheskoi nagruzkoi u chelnov ekipazhei orbital'noi stantsii "Saliut-6".

The authors report on the study of the members of four lengthy expeditions on the orbital station "Saliut-6" in the exercise test with the bicycle ergometer at the station. The cybernetic analysis of the cardiac rhythm during its adaptation to weightlessness shows the definite changes of the controlling systems of the body. It is shown that the "cost" od adaptation to exercise is determined by the results of the cybernetic analysis of the cardiac rhythm.

[Use of mathematical analysis of the cardiac rhythm in evaluation of the functional state of a patient in surgical interventions]. / Primenenie matematicheskogo analiza serdechnogo ritma v otsenke funktsional'nogo sostoianiia bol'nogo pri khirurgicheskikh vmeshatel'stvakh.

In 112 patients mathematical analysis of the cardiac rhythm indices and a biochemical investigation were effected during operative interventions with diverse types of endotracheal anesthesia. The correlation analysis of the cardiac rhythm parameters showed that at the most traumatic moment of the operation the synchronization of the functional links aimed at maintaining homeostasis was going up. Pharmacological block of adrenergic receptors results in weakening correlational interlinks. By analyzing the degree of synchronization marking functional links of the cardiac rhythm parameters that characterize the vegetative homeostasis it becomes possible to obtain information as to the level of the level of the adaptive-regulatory mechanisms tension and the correspondence of the depth of anesthesia to the seriousness of the operation trauma at different stages of surgery.