Peculiarities of functional test of the cardiovascular system in children with increased level of arterial pressure

Abstract

Assessment of the functional state of the cardiovascular system in children and adolescents is one of the most important areas in pediatrics, since its criteria are basic in terms of determining and predicting somatic health, physical status, as well as the possible limitations of certain types of motor activity. Functional disorders of the cardiovascular system are mainly represented by fluctuations of blood pressure, impaired repolarization and conduction of the heart, etc. To assess the condition of the cardiovascular system in schoolchildren usually use screening studies: measure the level of blood pressure, record electrocardiography, conduct functional tests (Rufier, Shtange, Gench, etc.). The purpose of the work. To evaluate the features of functional tests in children with high level of blood pressure. Material and methods. 90 children of school age residents of Chernivtsi region and Chernivtsi city were examined. The children were divided into two groups: the main group (45 people) was referred to children with high blood pressure level, the control group (45 people) consisted of clinically healthy children. Measurement of blood pressure was performed three times with an interval of 3 minutes on the left arm using an automatic tonometer. Measurement results were evaluated using percentile nomograms for age, gender, and height of children. To assess the functional state of the cardiovascular system, children fulfilled Ruffier, Shtange and Gench tests. Results. Assessing the level of blood pressure in schoolchildren of the main group obtained the following results: in 33 children, the level of blood pressure was within the corridor 90–95%, which is estimated as arterial prehypertension; at 12 — exceeded 95%, and was in the range between 95% and 95% +12 mm Hg, which was regarded as arterial hypertension of 1 degree. In all children of the control group, blood pressure indicators corresponded to percentile corridors of 25–75%, 75–90% (up to 90th percentile), which was regarded as normal blood pressure level. Estimating the Rufier index, it was found that in most children with hypertension, the reserve capacity of the cardiovascular system and exercise tolerance are significantly lower than those of their peers with normal blood pressure. Analyzing the data obtained from the samples of Shtange and Gench tests showed significantly worse results in children with hypertension than in the comparison group. This indicates a lower resistance to hypoxia in these children, which is due to the pathophysiological mechanisms that occur in the microcirculatory bed of the lungs, heart and brain. Conclusions. 1. According to the results of functional tests in children with arterial hypertension, exercise tolerance and resistance to hypoxia are significantly lower than in their peers with normal blood pressure. 2. These features in children with arterial hypertension may be the result of pathophysiological disorders both at the level of central hemodynamics and at the level of the microcirculation.