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Biomedical subjects

A D Egorov

Publications and source records attributed to A D Egorov.

67 records · Page 4Linked to original sources
PubMedDate not supplied

[Study of the cardiovascular system in long-term space flights].

During the Salyut-6 space flights cardiac bioelectrical and mechanical activity, blood content and tone of cerebral and limb vessels, systemic arterial and venous pressure were measured in 10 primary crewmembers. The measurements were taken at rest and during LBNP and ergometry tests. The study has shown that the circulation changes are adaptive reactions of the body to a new environment, particularly weightlessness. Cardiovascular responses to the provocative tests were changes and more marked, probably, due to blood redistribution.

Adaptation, Physiological↗
PubMedDate not supplied

[Main results of the medical research in the Saliut 6-Soiuz program].

In 1977-1981 the Soviet Union launched 18 manned space missions under the Salyut-6--Soyuz program which included five flights of prime crews for 96, 140, 175, 185, and 75 days and eleven flights of visiting crews. Altogether 30 cosmonauts, including 9 crewmembers from other than the USSR socialist countries, took part in the program. Emphasis was given to the medical investigations, since their purpose was not only to assess the health status of the crewmembers and to investigate their responses to prolonged weightlessness, but also to identify the maximum allowable flight time.

Body Weight↗
PubMedDate not supplied

[Dynamics of the phasic structure of left ventricular systole on prolonged (140-185 days) space flights].

Kinetocardiographic studies of the left ventricular systolic time intervals at rest in space flights of 140, 175 and 185 days in duration revealed functional changes reflecting cardiovascular adaptation to weightlessness. The typical changes were: shortening of isometric contraction, decrease of the tension index, irregular decline of the ejection time, and a slight increase in the intrasystolic index. These changes in the systolic time intervals are indicative of an enhanced strength of cardiac contraction. This may in turn be associated with cephalad fluid shifts and reduced activity of the peripheral muscular heart.

Humans↗
PubMedDate not supplied

[Results of vectorelectrocardiographic examinations during and after long space flights aboard the orbital complex "Sal'iut-6"--"Soiuz"].

In long-term space flights cardiac bioelectric activity was measured by vector-electrocardiography using ECG in 12 standard leads. Most marked changes in the form of a decrease in the integral spatial repolarization vector were seen postflight. This parameter did not return to normal during one month postflight. Depolarization vector and vector orientation remained essentially unchanged.

17-Hydroxycorticosteroids↗
PubMedDate not supplied

[Changes in the body weight of cosmonauts during a 140-day space flight].

During 140-day space flight body mass changes of the Commander and Flight-Engineer were measured. No correlation between body mass losses and flight duration was found. Greatest body mass losses occurred on MD 44--59 in Commander (2.3--2.4 kg), and on MD 86 in Flight-Engineer (5.4 kg). Later the losses decreased. The results suggest that body mass changes varied on an individual basis and depended on many spaceflight factors.

Body Weight↗
PubMedDate not supplied

Preliminary results of medical investigations during piloted flights in the Salyut-6 program.

The changes observed during flight on the whole corresponded with the preflight prognosis and reflected the phase nature of the processes of adaptation. They were shown by blood redistribution symptoms, fluctuations in the main indices of hemodynamics at rest not going beyond the limits of the physiological norm, an increase in the pulse-filling of the head with blood, and a decrease in that of the shank. The reaction of the blood circulation to a physical load and the application of negative pressure varied, and in a number of investigations during flight it was more pronounced than on Earth. The changes observed after the flight appeared regular for the period of readaptation of the reactions of the organism. These reactions bore a functional nature and qualitatively did not differ from reactions observed after other flights, and after the 140-day flight they were, on the whole, less pronounced than after the 96-day flight. In the postflight period to accelerate the process of adaptation a complex of restorative-healing measures was carried out, including mainly a regulation of motor activity, restorative massage of the muscles, remedial physical culture and aquatic procedures. The flight lasting 140 days revealed no contraindications to a further regular increase in the time of cosmic flights and demonstrates once again the possibility of the planned control of the state of a healthy subject in flight and the readiness of the organism for a return to the terrestrial force of gravity.

Blood Circulation↗
PubMedDate not supplied

[Results of studying the hemodynamics and phase structure of the heart cycle in a functional test with lower body negative pressure exposure on an 140-day flight on the Saliut-6 station].

The two members of the 140-day permanent Salyut-6 space flight were exposed to 5 LBNP tests at -25 and -35 mm Hg for 2 and 3 min, respectively. Circulation responses to the LBNP tests were measured with respect to the heart rate, arterial pressure, chronocardiogram and cardiac output. As compared to the preflight data, inflight responses were characterized by a greater tachycardia, preload insufficiency, and vascular tone in the absence of orthostatic intolerance. Possible mechanisms of the changes in the circulation responses are discussed.

Cardiovascular Physiological Phenomena↗
PubMedDate not supplied

[Dynamics of the diastolic phase structure in an 140-day space flight].

The kinetocardiographic study of the diastolic structure demonstrated its consistent changes. In the first flight month they included an increased time of total diastole, filling and diastasis periods. Later these parameters shortened. The phase of isometric relaxation was reduced whereas that of rapid filling was enlarged throughout the flight. These changes seem to be associated with fluid redistribution, shift in the pressure gradient and enhancement of the sucking activity of the heart.

Diastole↗
PubMedDate not supplied

[Study of hemodynamics and the phase structure of the cardiac cycle of members of the second crew of orbital station "Salyut-6" at rest].

During the 140-day flight of the Salyut-6 station cardiovascular examinations were carried out at rest. They showed blood redistribution and hyervolemia of the upper body. They also demonstrated increases in the circulating blood volume and pulse blood filling of cerebral vessels, development of the phase preload syndrome and simultaneous decrease in blood filing of leg vessels. These changes varied phasically in the course of flight. Weightlessness of up to 140 days did not cause any pathologies in the cardiovascular system.

Aorta↗
PubMedDate not supplied

[Electrocardiographic examination of the crew of the 2d "Saliut-4" expedition].

The inflight electrocardiograms in 12 leads of the cosmonauts P.I. Klimuk and V.I. Sevastyanov showed a trend towards a decrease of the atrio-ventricular and an increase of the intraventricular conduction as well as a decrease of the T voltage. These changes seemed to be adaptive and developed as a result of the positional changes of the heart. Metabolic changes in the myocardium should not be, however, ruled out.

Electrocardiography↗