COMPARATIVE CHARACTERISTIC OF ULTRASOUND CHANGES OF THYROID GLAND IN CHILDREN WITH DISTURBED AND NORMAL HEART RHYTHM

Purpose. Determination and comparative characteristic of ultrasound changes of thyroid gland in child ren with disturbed and normal heart rhythm to justify the need for a ultrasound screening study as a method of early diagnosis and prevention of thyroid pathology. Materials and Methods. The ultrasound examination of the thyroid gland has been carried out for 142 children aged from 3 to 17 years old. Out of these number 118 children with cardiac rhythm disorders, were included in Observation group I, the second Comparative group included 24 children with normal heart rhythm. The ultrasound evaluation of the thyroid gland was performed using the ultrasound machine «Esaote MyLab50» with a linear sensor with a frequency of 7.5–12 MHz according to the generally accepted Brunn method, which consists of determining the three dimensions of the length, width and height of the ultrasound, and the determination of the volume by the formula of ellipse (0,479 × А × В × С). Statistical processing of data was carried out using conventional variational statistical methods using a licensed software package Statistica for Windows 6.1.RU, serial number АХХR712D833214SAN5. We used nonparametric statistical methods: the «2 × 2 Table», the Chi-square (df = 1). statistically significant. pathological thyroid in % ultrasound the thyroid %), decrease of the volume of one of the thyroid lobes (1,7 %), changes in echogenicity of parenchyma (11.02 increased vascular (16.95 In group the 4.17 % of children thyroid volume increase and 8.33 % of children pathological in the thyroid normal heart rhythm. Ultrasound of the thyroid in 25.76 % of child ren 9 years of age % girls and 52.94 % boys) and in 74.24 % of children % аnd in industrial areas of the city and 21.21 % of children living in more environmentally friendly areas. Conclusion. In ultrasound examination, pathological changes of the thyroid gland were recorded in 55.93 % of children with heart rhythm disorders, more often in girls (61.22 %) aged 10 to 17 years of patients living in industrial areas of the city. So, for timely urgent issues timely early diagnostics of endocrine thyroid pathology, including cases of malignant neoplasms, it is necessary to conduct a screening ultrasound examination of the thyroid gland in children, and especially those with heart rhythm disorders living near large industrial enterprises and girls of prepubertal and pubertal age.

Thyroid gland is an endocrine gland, which function influences the work of the whole body, because thyroid hormones support the work of the brain, heart, muscles and bones, the reproductive system and play an important role in the metabolism [1,2]. At the same time, thyroid hormones help to increase the volume of circulating blood and raise the use of oxygen by myocardium, and if its utilization from the blood does not increase herewith, it can lead to a violation of metabolic and enzymatic processes in the myocardium [3,4].
Since every child who comes to the doctor for any reason always undergoes in an objective study auscultation of the heart, the initial diagnosis of cardiac rhythm disturbances presents no big difficulties. However, the true etio-logical factor in the occurrence of arrhythmias in child ren is far more complicated, especially taking into consideration that far more often than cardiac cases, extracardiac causes are recorded, including the side of the endocrine organs.
Therefore, a very important issue is the timely diagnostics of the least changes in the thyroid gland. The examination of the thyroid gland itself includes visual and palpation assessment of its size, shape, consistency. However, pathological changes in the thyroid gland are not always immediately accompanied by a change in the volume or texture of the organ, and changes in the tissue structure of the thyroid gland occur more often than the violation of its function. Therefore, the ultrasound Проблеми ендокринної патології № 1, 2020 Клінічна ендокринологія diagnostics, including morphological analysis, functional dopplerography, color Doppler and energy mapping has become the main non-invasive method of thyroid gland examination [5].
Аlmost all significant violations of the thyroid gland function are reflected in various changes in its structure. These may be diffuse changes in the parenchyma, an increase in the volume of the organ or its lobes, thickening of the isthmus, the presence of inclusions, follic-les, nodules, or just a significant increase in local blood circulation in the gland tissue [6][7][8].
Purpose Determination and comparative characteristic of ultrasound changes of thyroid gland in children with disturbed and normal heart rhythm to justify the need for a ultrasound screening study as a method of early diagnosis and prevention of thyroid pathology.

MATERIALS AND METHODS
During the work performance the ultrasound examination of the thyroid gland has been carried out for 142 children, including 75 girls and 67 boys aged from 3 to 17 years old. Out of these number 118 children (63 girls and 55 boys) with cardiac activity, namely, cardiac rhythm, confirmed by electrocardiography and Holter monitoring were included in Observation group I, the second Comparative group included 24 children with normal heart rhythm (13 girls and 11 boys). The ultrasound evaluation of the thyroid gland was performed using the ultrasound machine «Esaote MyLab50» with a linear sensor with a frequency of 7.5-12 MHz according to the generally accepted Brunn method, which consists of determining the three dimensions of the length, width and height of the ultrasound, and the determination of the volume by the formula of ellipse (0,479 × А × В × С) [9,10]. Statistical processing of data was carried out using conventional variational statistical methods using a licensed software package Statistica for Windows 6.1.RU, serial number АХХR712D833214SAN5. We used nonparametric statistical methods: the «2 × 2 Table», the Chi-square (df = 1). Differences р < 0.05 were considered statistically significant [11].

RESULTS AND THEIR DISCUSSION
The conducted preliminary analysis of the complaints with which children from the first monitoring group were admitted to a children's hospital is presented in Figure 1. So, most often 65.3 % (77/118) of children complained of a feeling of cardiac rhythm disturbance. Other complaints were registered as well: cardialgia -17 % (20/118) of cases; cephalgia -9.3 % (11/118); increase in blood pressure (hypertension) -4.2 % (5/118); syncopal states -2.5 % Fig. 1. Complaints of children with disturbed heart rhythm.
The organization and timely provision of medical assistance to children as well as diagnostic examination were carried out in accordance with the requirements of the current legislation of Ukraine in the field of health care. All children with complaints of cephalalgia and syncope were examined by a neurologist. Legal support of hospital health workers, children-patients and their parents regarding safe and effective examination and treatment, timely solution of various ethical and legal issues, namely, the mechanism of voluntary informed consent of parents or guardians of children for medical examination or treatment was conducted at the Department of Management and Pharmacy Economics, Medical and Pharmaceutical Commodity Research.
In Abnormality of body weight were in 73.73 % (87/118) children with violations of cardiac activity. Gender traits have also been traced. Thus, girls were more likely to report low body mass indexes than boys: 28.57 % (18/63) against 3.64 % (2/55), р < 0.05. The increase in body weight was also significantly more common in girls: 33.33 % (21/63) against 9.1 % (5/55) in boys. Children from group II had normal body mass.
According to ultrasound findings, ultrasound changes in the thyroid gland have been diagnosed in 55.93 % (66/118) of children with heart rhythm disorders and in 12.5 % (3/24) of children without cardiac disturbance. The results of the ultrasound examination of the thyroid gland are presented in Figure 2.
Thyroid gland volume, which differed from normal values, in relation to body surface area, was registered though significantly more in children with impaired cardiac rhythm than in children from Group II, but not adequate (11.02 % (13/118) against 4.17 % (1/24) of children. Thus, in Group І, an increase in the amount of thyroid gland in relation to the body I II surface area was recorded in 9.32 % (11/118) of children with disturbed heart rhythm and the pronounced asymmetry, when the volume of one lobe less than the volume of the other by 2 times or more was noted in 1.7 % (2/118) of children with disturbed heart rhythm. In one child (4.17 %) of the 2nd group of comparison was visualized thyroid volume increase.
Various pathological inclusions of various echogenicity (anechoic, hypo-, hetero-and hyperheric shadows, as ultrasound signs of follicles, cysts and nodes) were diagnosed in 16.95 % (20/118) of children. In children with normal heart rhythm and asymptomatic course, pathological inclusions were visualized in 8.33 % of cases.
Only in children with heart rhythm disorders ultrasound changes with an alternation in the echogenicity of the parenchyma of the thyroid gland were recorded in 11.02 % (13/118) of cases and an increase in vascular pulsation with additional Doppler examinationin 16.95 % (20/118) of patients.
The results of ultrasound examination of the thyroid gland, depending on the nature of violations of cardiac activity, are presented in tables 1, 2, 3. Thus, pathological inclusions of the thyroid gland were significantly more often registered in children with malodorous heart rhythm disturbances (21.92 %). Also, the ultrasound changes in the thyroid gland were far more often registered in children with sinus tachycardia than in children with sinus arrhyth mia (82.76 % versus 31.25), р < 0.05.
Depending on age, among children with cardiac impairment and ultrasound changes in the thyroid gland, pathology of the thyroid gland was observed in 25.76 % (17/66) of child ren under the age of 9 years and in 74.24 % (49/66) of children from 10 to 17 years (p < 0.05). That is, ultrasound pathological changes of the thyroid gland were much more often registered among children from 10 years.
The prevalence of ultrasound changes in the thyroid gland in young children was approximately the same for patients of different sexes and amounted to 47.06 % for girls and 52.94 % for boys. From 10 years of age,of changes in the thyroid gland much more commoned in girls (61.22 %), which could be attributed to increased thyroid load in prepubertal and puberty periods than in boys (38.78 %).
Comparison of results of ultrasound examination of thyroid gland, taking into account the place of residence of patients, made it possible to draw attention to the fact that any violations in the ultrasound picture of the glands are often associated with living in an ecologically unfavorable area of the city. Thus, pathological changes in the thyroid gland were observed at  Note. * the authenticity of the difference between the respective groups of children (р < 0.05). Consequently, the evaluation of ultrasound changes in the thyroid gland in children with cardiac activity in different age groups has shown that it is worth increasing the intensity of diagnostic and preventative measures aimed at timely detection and prevention of thyroid gland diseases, and especially in children of prepubertal and pubertal age, who live in the most environmentally polluted areas.

DISCUSSION
The results of our studies are confirmed by the data of other scientists, namely that the patients with thyroid pathology often have symptoms indicating changes in the cardiovascular system, and complaints about heart rhythm di-sturbances (sinus tachycardia (42-78 %), supraventricular extrasystole (5-7 %), flutter (1.4 %), atrial fibrillation (5-7 %), other supraventricular and ventricular arrhythmias, bradycardia may be the only signs of the disease [12].

Клінічна ендокринологія
Having performed an ultrasound examination in 52 children with paroxysmal vegetative insufficiency, which was also characterized by a violation of the heart rhythm, Maydannyk V.H. with colleagues diagnosed and registered the thyroid gland heterogeneity in 66.7 % of patients; changes in echogenicity -in 59.8 %; hypoechoic or hyperechoic inclusions -in 48 %, and macro-follicular masses or nodes -in 53 % [13].
Although the frequency of occurrence of nodules of the thyroid gland in children is much lower than in adults, nevertheless, the frequency of cases of malignant neoplasms of the thyroid gland with an increased risk of metastasis and relapse in children reaches 25 % [14].
Today, Patrick Hanley and authors review the diagnostic capabilities of non-invasive ultrasound examination of the thyroid gland are quite high, since specialist see very good the inhomogeneous areas in the gland tissue, the foci of densification, cysts, thyroid hypoplasia or thyroid aplasia. For example, the prevalence of thyroid nodules increases with age; however, in contrast to adults, there is a higher rate of malignancy for nodules diagnosed in a patient younger than 19 years of age (20 %-25 % vs 10 %-15 %, respectively) [15].
Maria Segni also believes that ultrasound diagnostics provide enough information in case of nodal changes in the thyroid gland. Thus, in a study of 154 children and adults with goiter, nodules were diagnosed in 13 %. At the same time, papillary thyroid carcinoma sized up to 1.2-2.6 cm in diameter was diagnosed in 2.5 % of cases, and biopsy was performed with the node sizes > 0.5 cm [16].
In case of autoimmune thyroiditis, heart problems also occur. Marco Cappa et al. showed that at ultrasound examination of the thyroid gland, the autoimmune thyroiditis was characterized by structural abnormalities in the form of generalized hypoechogenicity, and at a later stage of the disease -by diffuse fibrosis. This article reports that the single nodules were visualized in 60 % of children with autoimmune thyroiditis, 40 % of children had multiple nodules and only 3 % of children had papillary carcinoma, although the incidence of thyroid cancer at autoimmune thyroiditis ranged from 1 to 30 % [17].
In addition to node visualization, an ultrasound examination often also shows an increase in the volume of the thyroid gland. However, Jozef Szczyrski and colleagues demonstrated that obese patients had a larger thyroid volume. Also, in obese children, the decreased echogenicity of the thyroid gland was recorded in 61 % of cases, the echostructural changes in combination with the altered echogenicity -in 33 %, the isolated changesonly in 9.2 % of cases and the increase in blood flow -in 7 %.
The correlation was also found between the thyroid volume with body mass index and waist circumference, and after 6 months of diet and weight loss, the thyroid volume also decreased by 10 % [19].
The presented data showed the importance and the need for screening ultrasound in children, especially those with heart rhythm disturbances being the first symptoms of thyroid diseases, including malignant tumors.
К л ю ч е в ы е с л о в а : щитовидная железа, ультразвуковая диагностика, ритм сердца, дети. Purpose. Determination and comparative characteristic of ultrasound changes of thyroid gland in child ren with disturbed and normal heart rhythm to justify the need for a ultrasound screening study as a method of early diagnosis and prevention of thyroid pathology. Materials and Methods. The ultrasound examination of the thyroid gland has been carried out for 142 children aged from 3 to 17 years old. Out of these number 118 children with cardiac rhythm disorders, were included in Observation group I, the second Comparative group included 24 children with normal heart rhythm. The ultrasound evaluation of the thyroid gland was performed using the ultrasound machine «Esaote MyLab50» with a linear sensor with a frequency of 7.5-12 MHz according to the generally accepted Brunn method, which consists of determining the three dimensions of the length, width and height of the ultrasound, and the determination of the volume by the formula of ellipse (0,479 × А × В × С). Statistical processing of data was carried out using conventional variational statistical methods using a licensed software package Statistica for Windows 6.1.RU, serial number АХХR712D833214SAN5. We used nonparametric statistical methods: the «2 × 2 Table», the Chi-square (df = 1). Differences р < 0.05 were considered statistically significant. Results. The pathological changes of the thyroid gland were recorded in 55.9 % of children with heart rhythm disorders (more often with sinus tachycardia) and in 12.5 % of children with normal heart rhythm. In children with heart rhythm disturbances, the following ultrasound changes in the thyroid gland were diagnosed: increased volume (9.32 %), asymmetric decrease of the volume of one of the thyroid lobes (1,7 %), pathological inclusions in the form of shadows of different echogenicity (16.95 %), changes in echogenicity of parenchyma (11.02 %), increased vascular pulsation (16.95 %). In group II, the 4.17 % of children with thyroid volume increase and 8.33 % of children with pathological inclusions in the thyroid gland, had normal heart rhythm. Ultrasound abnormalities of the thyroid gland were in 25.76 % of child ren under 9 years of age (47.06 % in girls and 52.94 % in boys) and in 74.24 % of children aged 10 to 17 years (61.22 % in girls and 38.78% in boys) аnd diagnosed in 78.79 % of patients living in industrial areas of the city and 21.21 % of children living in more environmentally friendly areas. Conclusion. In ultrasound examination, pathological changes of the thyroid gland were recorded in 55.93 % of children with heart rhythm disorders, more often in girls (61.22 %) aged 10 to 17 years of patients living in industrial areas of the city. So, for timely urgent issues timely early diagnostics of endocrine thyroid pathology, including cases of malignant neoplasms, it is necessary to conduct a screening ultrasound examination of the thyroid gland in children, and especially those with heart rhythm disorders living near large industrial enterprises and girls of prepubertal and pubertal age.
K e y w o r d s : thyroid gland, ultrasound diagnostics, heart rhythm, children.