The features of autonomic nervous system homeostasis and adaptive potential in children with syncope

The investigation of the nature of syncope shows that it is caused by failure of compensatory reflex mechanisms of the autonomic nervous system. Therefore, the determination of specific parameters of autonomic nervous system homeostasis and adaptive potential improves the approach to determining the clinical predictors of the syncope and facilitate its early diagnosis. Purpose — to determine the nature and compare of autonomic dysregulation and functional changes of in children with syncope of different genesis, to identify the circumstances for the formation of insufficient autonomic regulation. Materials and methods. The enrolled subjects were 125 children with syncope, aged 8–17 years, and 41 controls. Children were divided into three groups for analysis: 81 — with vasovagal syncope, 25 — with syncope due to orthostatic hypotension, 19 — with cardiogenic syncope. All children underwent a clinical and functional examination of the cardiovascular system to identify features of autonomic homeostasis. Results. Autonomic imbalance with a predominance of sympathetic autonomic regulation was detected in children of all study groups. The results of functional tests and quantitative integrative indicators showed significantly increased autonomic reactivity with depletion of adaptive potential in all study groups (p<0.05). Children with vasovagal syncope had excessive levels more often (p<0.05), and children with syncope due to orthostatic hypotension had insufficient levels of autonomic support (p<0.05). Violations of cardiorespiratory inter systemic connections were found in children with vasovagal and cardiogenic syncope significantly more often, compared to the control group (p <0.05). Correlations were found between the parameters of the initial autonomic balance, autonomic support of the circulatory system, and the manifestations of syncope in children. Conclusions. The correlation between pathological types of autonomic response and the frequency and duration of syncopal episode indicates a pathogenetic relationship between the state of autonomic support and the ability of the circulatory system to respond to triggers. Therefore, indicators of the autonomic homeostasis and adaptive potential can be applied for predicting the occurrence of syncopal episodes and monitoring of effective management of syncope in children. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of all participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the authors. Key words: children, syncope, autonomic nervous system homeostasis, adaptive potential.

Parameters of autonomic regulation in patients with focal frontal and temporal epilepsy

Aim. This study aimed to investigate the mechanisms of autonomic regulation and autonomic support in focal frontal and temporal lobe epilepsy. Materials and Methods. Thirty-six individuals were examined (19 men and 17 women; mean age 33.71.4 years) in the control group (without history of epileptic seizures) and 68 patients (32 men and 36 women, 34.11.5 years) with focal epilepsy (36 patients with frontal lobe epilepsy, of which 32 had temporal lobe epilepsy). Physiological parameters of heart rate variability and of skin sympathetic evoked potentials were evaluated. Results. Predomination of sympathetic influences in both groups of patients was found. According to the analysis of skin sympathetic evoked potentials, a high activity of the suprasegmental autonomic centers was determined in patients with epilepsy. Based on the results of the correlation analysis, the initial state in patients with temporal lobe epilepsy was characterized by greater intrasystemic tension that reflects the high level of physiological costs. The logit regression analysis model makes it possible to distribute patients with focal epilepsy into groups with different disease courses on the basis of the parameters of the autonomic support of the activity. Conclusion. In patients with focal epilepsy, predomination of sympathetic influences was observed, as well as greater activity of the suprasegmental centers of the autonomic regulation. Intrasystemic ratios of autonomic regulation parameters demonstrate an increase in the intrasystemic tension and a limitation of functional reserves in patients with temporal lobe epilepsy. A complex of parameters of autonomic support allows, based on the logit regression analysis, to distribute patients into groups with different courses of focal epilepsy.

Peculiarities of vegetative provision and disorders of tolerance to exercise in children with endocrine and cardiac pathology

Annotation. The aim – to find out the features of autonomic support and exercise tolerance of the cardiovascular system in children with chronic non-infectious diseases, in the future will be able to improve the results of diagnosis and rehabilitation of patients, as well as differentially regulate the mode of the exercise regime for patients. The study included 58 children aged 10-17 years, with cardiac and endocrine pathology: group 1 – 23 children with endocrine pathology (type 1 diabetes mellitus), group 2 – 23 children with cardiac pathology (AH stages I-II). The study included clinical examinations, anthropometry, a questionnaire of physical activity by MAOFA, ECG, ultrasound examination of the heart and Rufier's test were performed. Assessment of the state of the autonomic nervous system was carried out using the Kerdo index and COT. Statistical analysis was performed using s/n program SPSS 17 4a 180844250981. It was found that there is a tendency to outstrip the normative values and increased body weight indicators in the examined children with chronic pathology of the endocrine and cardiovascular systems. According to the Rufier test, it was found that in the group of children with diabetes mellitus, 69.5±9.6% of the examined had low results. Among children with hypertension, 30.7±10.4% of the test indicators were regarded as weak, and in 26.9±5.8% – unsatisfactory. The results of Rufier's test were significantly lower in children with endocrine pathology, both in comparison with the group of children with cardiac pathology (p<0.05) and with the control group (p≤0.001). In 70.0±15.3% of cases, weak and unsatisfactory indicators of the Ruffier test were observed against the background of hyperdiastolic autonomic support. In physically nonactive adolescents, asympathicotonic and hyperdiastolic types of COT were observed. Thus, almost 70% of children with diabetes mellitus and 57% of children with arterial hypertension have reduced exercise tolerance. This is associated with hyperdiastolic autonomic support. Physical activity has a positive effect on the state of the autonomic nervous system in children with arterial hypertension and diabetes mellitus.

Autonomic support of the activity in children with small cardiac abnormalities

The aim of the study was to investigate vegetative maintenance (VM) in children with small cardiac abnormalities (SCA) using a wedge-orthostatic test (WOT). The article describes the research results of 170 children with SCA. VM was estimated with clinic orthostatic test (COT). The group of patients consisted of 106 children with mitral valve prolapse (MVP) and 64 children with false tendons (FT) in the left cardiac ventricular. We used absolute and relative statistical methods with Microsoft Excel program for this study. We found out that hypersympathycotonic type of VM was prevalent at MVP (57,6%). For FT it was only 37,5%. Pathologic type of VM with insufficient activation of sympathetic adrenal system was noted only in 21,2% of patients with SCA. This species is more common with FT (23.4%) than with MVP (19.8%). Hyper diastolic type was present only in 9,4% patients with MVP and in 3,1% with FT, respectively. Mixed types were rare noted at SCA without specification for MVP or FT (4.7% for MVP and 3.2% for FT). Thus, the revealed types of COT show the disorder of VM, which characterizes the reducing of adaptive capacity in such children.