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O Atkov

Publications and source records attributed to O Atkov.

5 recordsLinked to original sources
PubMed2004

ECG voltage modifications as response to gravity changes.

The aim of the study was to analyze ECG (QRS) voltage responses to body fluid shift due to gravity chances. Acute changes in gravity were created by two ways: 1) changes in gravity value during parabolic flights (within 27 subjects 45 ECG have been analyzed); 2) changes in gravity direction due to rotation of the body during postural tests (within 11 subjects 14 ECG have been analyzed). Results and conclusions. Gravity change leads to body fluid shift and changes of intrathoracic organs and tissues electroconduction. It influences on ECG voltage. During parabolic flights in up-right position: R amplitude in Z axis increases in hypergravity (+0.19 mV) and decreases in microgravity (-0.24 mV). During postural tests, R amplitude in Z axis increases in orthostatic position (+0.09 mV) and decreases in antiorthostatic position (-0.025 mV). Changes in QRS voltage during parabolic flights are more important than during postural tests. This could be due to more effective blood redistribution during parabolic flights.

Adult↗
PubMed2001

Parasympathetic activity during parabolic flight, effect of LBNP during microgravity.

BACKGROUND/HYPOTHESIS: During parabolic flight, in the standing position, changes are partly due to an acute shift in fluid between the lower extremities, the head and the thorax (Vaïda P, et al. J Appl Physiol 1997; 82:1091-7; and Bailliart O, et al. J Appl Physiol 1998; 85:2100-5). We hypothesized that modifications of parasympathetic activity associated with changes in hydrostatic pressure gradients induced by changes in gravity could be detected by analysis of short time periods. METHODS: We assessed heart rate variability (HRV) in 11 healthy volunteers by indices of temporal analysis (NN, SDNN, RMSSD) and normalized indices such as coefficients of variation CV-SDNN and CV-RMSSD and ratio SDNN/RMSSD. A lower body negative pressure (LBNP) at -50 mm Hg was randomly applied during the microgravity phase (0 Gz) to counteract the lack of hydrostatic pressure in the lower part of the body. RESULTS: NN, CV-SDNN and CV-RMSSD decreased during hypergravity phases and increased during microgravity and during early normogravity (1 Gz) period at the end of parabolas. With LBNP changes are less pronounced at 0 Gz and in the 1 Gz post parabolic period. CONCLUSION: We concluded that parasympathetic nervous activity is recordable by temporal analysis of HRV during short periods of time. LBNP applied during 0 Gz phase reduced the parasympathetic activation at 0 Gz and post parabolic 1 Gz.

Adult↗
PubMed1999

Echocardiographic evaluation in 485 aeronautical workers exposed to different noise environments.

INTRODUCTION: Vibroacoustic disease (VAD) is a heterogeneous and systemic entity, caused by long term (> or =10 yr) exposure to noise environments characterized by large pressure amplitude and low frequency (LPALF) (> or =90 dB SPL, < or = 500 Hz), and not explained by other possible etiologic agents. The goal of this study was to identify possible structural changes in hearts of men with suspected VAD. METHODS: A total of 485 men were divided into 3 noise groups: no noise exposure (< or =70 dB), n = 48 (Group I); moderate noise exposure, (>70dB and < 90 dB), n = 113 (Group II); and intense noise exposure (> or =90 dB), n = 324 (Group III). Echo-Doppler studies were performed (HP SONOS 1500) and recorded on coded videotapes. Three observers performed blinded evaluations of 26 echo-Doppler parameters. For the purpose of the present study only 12 morphological parameters were compared among the groups: thickening of the mitral, aortic, tricuspid, and pulmonary valves, pericardium and endocardium; mitral valve regurgitation, prolapse and ruptured chordae tendinae; and inflow velocities. Thickness and severity of the applicable parameters were scored in seven-grade scale (0,0.5,1, ...,3). RESULTS: All evaluated parameters were statistically significantly different in Group I vs. Group III, except flow velocity E. Comparison of Group I vs. Group II revealed statistically significant differences in mitral, aortic, tricuspid and pericardial thickening, with the strongest evidence for mitral and pericardial structures. CONCLUSIONS: This confirms the results of previous studies. Occupational exposure to noise environments characterized by LPALF noise causes structural changes in the heart. Mitral valve and pericardial thickening constitute the first signs of VAD.

Adult↗
PubMed1994

Interview with Dr. Oleg Atkov [interview by Winston Huff].

Last summer International Space University (ISU) was held in Huntsville, Alabama. Leading international space experts came to take part in the activities. Dr. Oleg Atkov, a Russian cardiologist who was also a cosmonaut for eight months in 1984, has extensive experience in cardiovascular medicine and first-hand experience in issues of life support, making him a valuable resource. He also serves on the Journal's Advisory Board. Winston Huff took advantage of the unique opportunity of having Valery Aksamentov, Paul Wieland, and Dr. Atkov together in Huntsville to conduct a general discussion of issues important to those studying life support. Dr. Valery Aksamentov was involved for many years in the development of the Russian life support systems. Dr. Aksamentov now leads the only university program specializing in life support at the University of Alabama in Huntsville. His command of both languages and his technical knowledge were critical to the success of this discussion. Paul Wieland from NASA Marshall Space Flight Center is involved with the development of the life support systems for the space station. He and Dr. Aksamentov are topic coordinators for the Journal. The following interview was conducted at the University of Alabama in Huntsville on August 16, 1993.

Ecological Systems, Closed↗