The functional state of microcirculatory vessels in patients with arterial hypertension I–II degree with different degrees of cardiovascular risk

Aim: to evaluate the main parameters of the microcirculatory blood flow and to determine its reserve capacity in patients with arterial hypertension (AH) and different degrees of cardiovascular risk (CVR).Subjects and methods. We examined 64 subjects aged 47-58 years, of which 27 were healthy volunteers and 37 patients with 1st and 2nd degree arterial hypertension, with medium, high and very high CVR (the antihypertensive therapy was cancelled for 2 weeks before the study). In all subjects laser Doppler flowmetry (LDF) with studing initial perfusion parameters, 2 constrictor and 3 dilatator tests waky perfomed. To assess the status of the tone-shaping «active» and «passive» parts of microcirculatory modulation, analysis of the amplitude and frequency spectrum of LDF- grams was carried out.Results. A significant increase in the rate of «base perfusion» in all hypertensive groups compared with the control group was found. The amplitude of respiratory oscillations was one-third higher in high and very high CVR groups in comparison with the control, the amplitude of the myogenic and neurogenic oscillations were maximal and reached significant values in very high CVR group. A reduction in constrictor response in hypertensive patients with middle and high CVR and its increase in the very high CVR group was shown during constrictor functional tests. The power of perfusion increase was reduced in response to all kinds of dilatator stimulus in hypertensive patients group.Conclusion. The findings indicate a progressive increase in the level of «base perfusion», worsening of venous congestion symptoms in hypertensive patients with the progression in CVR severity. High and very high CVR patients showed a reduction in myogenic tone of microvessels when compared with those with normotension. Dilatator functional tests showed a tendency to lower capillary blood flow reserve in hypertensive patients compared with the control group.