Comparative evaluation of cardiac hemodynamics and endothelium-dependent reactive hyperemia in arterial hypertension in those living in high-altitudeand plain areas

Aim. To reveal the specific features of cardiac hemodynamics and endothelial function in high-altitude
native dwellers with arterial hypertension (AH).
Materials and methods. 90 native dwellers from high-altitude and plain areas, who had Stages I and
II AH, were examined. To assess cardiac contractility, central and peripheral hemodynamics, the authors used electrocardiography, echocardiography, tetrapolar impedance rheoplethysmography. The
functional status of the endothelium was evaluated by the reproduction of endothelium-dependent reactive hypermia in the antebrachial vessels.
Results. The patients with Stages I and II AH who live in high-altitude area have been found to have
less pronounced peripheral vasocontriction due to the less suppression of pump and contractile functions of the heart. Total peripheral resistance in high-altitude dwellers with Stage II AH is practically
similar to that in plain inhabitants with Stage I AH. The extended vasodilator reserve in high-altitude
inhabitants with AH is also shown by the data obtained in the reproduction of reactive hyperemia in
the antebrachial vessels. A less marked decrease in this vascular reaction in patients with AH who live
in high-altitude areas may be due to additional production and/or release of nitric oxide in order to
increase the vasodilator reserve in moderate hypoxia.
Conclusion. The course of AH in high-altitude dwellers is marked by less suppression of cardiac pump
and contractile functions and less peripheral vasoconstriction. This may be accounted for by compensatory activation of endothelial vasodilator mechanisms aimed at preserving adequate tissue perfusion
and at optimally providing the body with oxygen in moderate hypoxia.

arterial hypertension, cardiac contractile and pump functions, vasodilatative reserve, reactive hyperemia, hypoxia, high-altitude area