Functional characteristics of the autonomic nervous system and hemodynamics in primary arterial hypertension in children

The dissertation is devoted to the study of the functional characteristics of the autonomic nervous system and hemodynamics in children with primary arterial hypertension. The research is aimed at systematizing the clinical-functional and neurovegetative manifestations of the disease in pediatric practice and at developing diagnostic criteria that make it possible to distinguish the neurovegetative variants of the course of this pathology.

The work examines the prevalence and structure of primary arterial hypertension in children, analyzes the interrelation of the disease with the familial and hereditary history, characteristics of antenatal development, and the physical development of the child. Particular attention is paid to the assessment of the autonomic status of patients, to the study of hemodynamic parameters, and to accompanying functional cardiopathies. On the basis of a comprehensive clinical-functional examination, neurovegetative variants of blood pressure regulation are substantiated, and recommendations are proposed for individualizing the diagnosis, treatment, and rehabilitation of patients.

In recent decades, the structure of cardiovascular pathology in pediatric practice has undergone significant changes. In particular, an increase has been observed in functional vaso- and cardiopathies pathogenetically associated with autonomic dysfunctions. It is these conditions that frequently form the basis for the development of cardiovascular pathology in adults, since under certain conditions (familial and hereditary determination, micro- and macrosocial living conditions, dietary characteristics, self-destructive forms of behavior) they transform into hypertensive disease, hypotensive disease, ischemic heart disease, and other disorders.

At the same time, cardiovascular diseases occupy the leading position in the structure of non-infectious human pathology, being one of the main causes of impaired quality of life (72) and mortality at various age periods (16, 17, 11, 15, 54, 93).

At the same time, it is well known that effective intervention in the child's organism is possible precisely during childhood, at the stage of functional changes, which allows preventing or delaying the development of diseases at a more mature age (41).

Recently, interest has grown in the problem of primary arterial hypertension in children. Many authors classify it among functional vasopathies pathogenetically associated with the sympathicotonic variant of the autonomic dysfunction syndrome. Interest in this problem is caused, first of all, by the increasing prevalence of this pathology, its earlier onset, and the possibility of subsequent transformation into hypertensive disease (15, 16, 17).

However, at present, both in practical public health and among researchers, there remains a lack of clarity regarding the terminology of elevated blood pressure in children; there is no precise definition of this very concept, no unified, approved, and officially recommended classification of primary arterial hypertension, and its clinical-functional and neurovegetative variants, which would allow predicting the outcome and the probability of either regression or further progression, have not been developed.

The above circumstances prompted us to undertake the present study.

Aim of the work: To study the functional state of the autonomic nervous system and hemodynamics in children with primary arterial hypertension and to develop diagnostic criteria for its neurovegetative variants.

In accordance with the stated aim, the following specific tasks were addressed:

1. The interrelation of primary arterial hypertension with the familial and hereditary history, characteristics of the course of the antenatal period of development, and indicators of physical development was investigated;

2. The functional state of the autonomic nervous system in children with primary arterial hypertension was studied;

3. The functional state of the cardiovascular system in children with primary arterial hypertension and the structure of accompanying functional cardiopathies were assessed;

4. Diagnostically significant criteria for various neurovegetative variants of primary arterial hypertension were substantiated.

Scientific novelty of the study:

• On the basis of a comprehensive study of the autonomic status and the functional state of the cardiovascular system in primary arterial hypertension, the existence of three neurovegetative variants of blood pressure regulation has been substantiated: sympathicotonic, mixed, and vagotonic. Their vegetological and hemodynamic criteria have been developed. It has been shown that in the sympathicotonic and mixed variants of primary arterial hypertension, the elevation of blood pressure is based on a hyperkinetic type of hemodynamics, whereas in the vagotonic variant it is based on a true increase in total peripheral vascular resistance, which indicates the pathogenetic heterogeneity of primary arterial hypertension in children and adolescents.

• The structure of functional cardiopathies in children with primary arterial hypertension and their pathogenetic interrelation have been studied.

Practical significance of the work.

A comprehensive plan for the examination of children with primary arterial hypertension has been developed and introduced into the practice of the pediatric cardiological service of the city of Yaroslavl; it allows an adequate assessment of the anamnestic, clinical, hemodynamic, and neurovegetative factors responsible for the elevation of blood pressure in a particular patient. Amendments have been introduced into the scheme for formulating the diagnosis of primary arterial hypertension, taking into account the neurovegetative variant and hemodynamic characteristics. Recommendations have been substantiated for determining the autonomic status of children with arterial hypertension, including the assessment of its functional state. It has been proposed to individualize the schemes of treatment and rehabilitation of patients with primary arterial hypertension, taking into account the neurovegetative variant and hemodynamic characteristics of the particular child.