[Physiological aspects of analysis of the indexes of the variability of cardiac rhythm in adolescents with latent hypothyrosis].

Abstract

We studied the parameters of variability of cardiac rhythm in adolescents with the latent hypothyrosis and in healthy individuals and the interrelationship of these parameters with the indexes of the thyroid system (hormonal status, dimensions of thyroid, median ofioduria). It has been revealed that iodine deprivation leads to vegetative dystonia with the decreased activity of the sympathetic nervous system. This is accompanied by the narrowing of the range of adaptive capabilities of the organism, exhaustion of the regulatory influences in comparison with healthy children. The analysis of the indexes of the variability of cardiac rhythm after the correction by iodide-100 detected the decrease of the influence of the parasympathetic nervous system on cardiac rhythm regulation and stabilization of the sympathetic component. The correlation link between the content of thyroid hormones and the indexes of the variability of cardiac rhythm has been determined. Such tendency proves the essential role of T3 and FT4 for the maintaining of the functional capability of Autonomic Nervous system in adolescents. The pathophysiologic patterns of vegetative profile of the variability of cardiac rhythm in latent hypothyrosis have been substantiated.