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Biomedical subjects

V V Chestukhin

Publications and source records attributed to V V Chestukhin.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

[Hemodynamic characteristics of the EMIKS disk artificial heart valves].

Analysis of the intracardiac hemodynamics have been made in 16 patients before and after making prosthetic appliance of the mitral valve EMIKS. The examination of the patients carried out 8.3 +/- 0.4 months after the operation showed that significant improvement of the intracardiac hemodynamics took place in patients with mitral valvular disease after the implantation of the EMIKS valves. With the cardiac output of 5.62 +/- 0.121/min the diastolic gradient with the EMIKS valves is 3.33 +/- 0.31 mm of M.C. and the effective opening area is 2.62 +/- 0.08 cm2.

Heart Valve Prosthesis↗
PubMedDate not supplied

[Effect of short-term antiorthostatic hypokinesia on the pressure in various parts of the healthy human cardiovascular system].

Before and after 5-day head-down tilting (-4.5 degrees) blood pressure was measured in different cardiovascular compartments by the technique of selective catheterization: the upper bulb of the internal jugular vein, superior and inferior venae cavae, hepatic, renal and iliac veins, right atrium and right ventricle, coronary sinus, pulmonary and radial arteries. After exposure the pressure in extrathoracic vessels increased by 1.4 mm Hg on the average: in the internal jugular vein it rose by 1.7 mm Hg whereas in the iliac vein by 1.0 mm Hg. The blood pressure in the intrathoracic vessels of the systemic circulation increased, as a rule, by no more than 0.5--0.8 mm Hg. This elevation was characteristic of diastolic regions of the pressure curve (x- and y-collapse). The pressure in pulmonary vessels--pulmonary artery and left atrium--showed a trend for a decrease of 1.3 mm Hg. The factors that may be responsible for the dissimilar changes of pressure in different cardiovascular compartments under the influence of short-term simulated weightlessness are discussed.

Adult↗
PubMedDate not supplied

[Central circulation in the healthy human being during 7 days of head-down tilt and decompression of different body areas].

The effect of 7-day head-down tilt (-15 degrees) and decompression of various body parts (lower body-LBNP, upper body in the area of the hydrostatically indifferent point-UBNP, and local negative pressure applied to both calves-LNP) on central circulation was investigated on eight healthy test subjects who, for 10 days, had catheters (Swan-Ganz) implanted into the pulmonary and radial arteries. It was shown that, when calculated by square centimeter of the decompression area, the effect of UBNP on central venous pressure (CVP) and pulmonary artery pressure (PAP) was 3-4 times greater than that of LBNP or LNP. This indicates a high sensitivity of this body part to the exposure. During the 7-day study, CVP and PAP showed the most distinct changes. By the 7th hour of the head-down tilt study, CVP remained unchanged and systolic PAP increased by 5.5 mm Hg (27%) (p less than 0.05). This was paralleled by a decrease of plasma aldosterone and renin. By the 2nd day of the study, CVP and PAP were close to the pretest level; on the 3rd day, they began to decline and remained about 3 mm Hg lower than the pretest values to the end of the study (p less than 0.05). During this same period, the contractility of the right heart (the mean rate of right ventricular pressure increment) decreased by 34% (p less than 0.05) and its work by 27% (p less than 0.05). By the 24th hour after the study (the recovery period), CVP and PAP were close to the pretest values, whereas heart rate, cardiac index and oxygen tension in the mixed venous blood were significantly higher than the pretest values (p less than 0.05). The factors responsible for these changes and the potential application of the catheterization technique in biomedical investigations during real space flight are discussed.

Adult↗
PubMedDate not supplied

[Water content of the lungs during 7-day anti-orthostatic hypokinesia].

The time-course variation of the water content of the lungs of seven male volunteers were examined during 7-day head-down tilt (at -15 degrees). As compared to the horizontal subjects, the tilted subjects showed a significant increase in the water content from 557 +/- 19 ml to 612 +/- +/- 63 ml by the 7th hour of the tilt. Later on the parameter gradually declined and on tilt day 7 almost returned to the pretest level, i.e., 567 +/- 46 ml. This increase in the water content during the first hours of the exposure can be attributed to the hydrostatic factors: higher pulmonary artery pressure and higher cardiac output. The increase in the water content on tilt days 3-7 can be associated with changes in the permeability of lung capillaries, drainage function of the lymphatic system of the lungs, and colloidal-osmotic pressure in the perivascular space of the lungs.

Adult↗