Abstract: | Patients with congenital heart diseases (CHD) aged 4 months to 12 years, hospitalized for surgical treatment, were examined. Complex viscosity of the blood and the constituents of this parameter (dynamic viscosity and elastic component) were evaluated in the range of shift strain corresponding to the range of shift velocities 0.37-500 s-1 at a frequency of 2 Hz. The threshold blood fluidity was estimated for evaluating the conditions under which erythrocyte disaggregation begins. The relationship between blood rheology and morphofunctional characteristics of blood cells was evaluated. In accordance with the findings, the patients were divided into 3 groups with different suspension stability of the blood. In group 1 the threshold fluidity approximated the norm. In group 2 with normal blood rheology the shifts were compensated and regulation of rheology was in general intact. In group 3 the hematocrit values, mean erythrocyte volume, mean concentration of hemoglobin in erythrocyte, leukocyte counts, and complex viscosity of the blood were the highest, while the suspension stability was the lowest, which indicates depletion of the adaptive potential of the organism. Hence, blood rheology in patients with CHD differs by the type of regulation, mechanisms and compensation of changes, and depend largely on the mean erythrocyte volume, mean hemoglobin concentration in erythrocytes, and leukocyte counts. |