Variability of skin microcirculation in case of arterial hypertension from the view of distributional responses of blood flow

Abstract

The aim of the study. To evaluate individual variability of skin microcirculation (MC) in patients with arterial hypertension (AH) and characteristics of microvascular (MV) reaction to hypotensive impact from the view of blood distribution. Material and methods. Microcirculation of forearm skin in 176 patients with AH stage 2 was studied by laser doppler flowmetry (LDF). All the patients were divided into 2 groups: 1 - with low (n=46) value of MV resistance and 2 - with high (n=130) value of MV resistance. 90 patients out of the total amount (also divided into the same 2 groups - 25 people in the first group and 65 people in the second) had another study of MC after sublingual taking of 20 mg of corinfar. Results. The results revealed controversial MC skin picture with high blood filling of MV canal and reduced MV tone in the first group and high value of MV tone with hemoperfusion limitation in the second group in patients with AH and the same blood pressure (BP). Reduction in the first group can be caused by redistribution of a minute blood volume kept on a high level in the condition of elevated total peripheral resistance (TPR) (the so called central blood bypass). In this case the skin where a part of a cardiac output goes to serves as a depot. Increase of intravascular resistance in the skin of patients from the second group is caused by prevalence of TPR in hemodynamic mechanisms of BP elevation. Whereas constriction of microcirculation vessel is observed not only in the abdominal vessel area (which is the main area responsible for TPR formation) but also in the other areas, particularly in the skin. Corresponding BP decrease in groups of patients under the influence of corinfar was accompanied by bidirectional shifts of MC values: vasodilation in the second group and vasoconstriction in the first group of patients. It happens due to more balanced bloodflow distribution in the vessel areas more responsible for TPR formation as a result of vasodilation under the influence of corinfar.