Autonomic Dysfunction In Children Research Articles

Is there cardiac autonomic dysfunction in children and adolescents with exercise-induced bronchospasm?

ABSTRACT Background The pulmonary impairment in patients with bronchoconstriction induced by eucapnic voluntary hyperpnea(EVH) goes beyond the respiratory system, also impairing autonomic nervous modulation. This study aimed to evaluate the behavior of cardiac autonomic modulation in young asthmatics with and without EIB after the EVH test. Research design and methods A cross-sectional study design using 54 asthmatics(51.9% female), aged between 10 and 19 years, investigated with the EVH test. Forced expiratory volume in one second(FEV1) was measured at 5, 10, 15, and 30 min after EVH. Heart rate variability(HRV) measures of time were assessed pre and 30 min-post EVH. The diagnosis of Exercise-Induced bronchoconstriction with underlying clinical asthma(EIBA) was confirmed by a fall in FEV1 ≥10% compared to baseline. Results Thirty(55.5%) asthmatics had EIBA. Subjects with EIBA have reduced mean of the R-R intervals in relation to baseline until 15 minutes after EVH. Individuals without EIBA had increased parasympathetic activity compared to baseline(rMSSD) from 5 min after EVH(p < 0.05). This parasympathetic activity increase in relation to baseline was seen in individuals with EIBA after 25 minutes (rMSSD = 49.9 ± 5.3 vs 63.5 ± 7.2, p < 0.05). Conclusion Young asthmatics with EIBA present a delay in the increase of the parasympathetic component after EVH when compared to asthmatics without EIBA.

Sleep disordered breathing improvement prevents worsening of autonomic dysfunction in children with Down syndrome

BackgroundResolution of sleep disordered breathing (SDB) in typically developing children normalises heart rate variability (HRV), a measure of autonomic control, to that of non-snoring controls. Children with Down Syndrome (DS) have dampened heart rate variability (HRV) but the effect of treatment is not known. To assess the effect of improvement of SDB on autonomic control we compared HRV in children with DS whose SDB improved over 2 y, to those whose SDB did not improve. Methods24 children (3–19 y) had a baseline and follow-up polysomnographic study 2 y later. Improved SDB was defined as a reduction in obstructive apnea hypopnea index (OAHI) to ≤ 50% of baseline. Children were grouped into Improved (n = 12) and Unimproved (n = 12). Power spectral analysis of the ECG determined low frequency (LF), high frequency (HF) power and the LF/HF ratio. Seven children in the Improved and 2 in the Unimproved group were treated following the baseline study. ResultsIn the Unimproved group at follow-up, LF power was lower compared to baseline during N3 and Total Sleep (p < 0.05 for both). HF power was lower during REM (p < 0.05). HRV remained unchanged between studies in the Improved group. ConclusionAutonomic control worsened as indicated by lower LF and HF power in children whose SDB was not improved. In contrast, in those children with improved SDB, autonomic control remained the same, suggesting improvement in SDB severity prevents further worsening of autonomic control in children with DS.

Evaluation of autonomic nervous system in children with spastic cerebral palsy: clinical and electophysiological study

BackgroundCerebral palsy (CP) is the most prevalent severe motor disability among children. The aim of this work was to assess autonomic dysfunction in children with cerebral palsy clinically and electrophysiologically.ResultsAge of the studied children ranged from 4 to 12 years. Quadriplegic type of spastic cerebral palsy constituted 82.5% of CP children while diplegic type constituted 17.5%. Based on Gross Motor Function Classification System (GMFCS), the majority of children were in levels 4 and 5. The prevalence of autonomic dysfunction symptoms were 80% for thermoregulatory abnormalities (cold extremities), 65% for chronic constipation, 52.5% for sleep disturbance, 47.5% for loss of appetite, 40% for sweating abnormalities, 25% for recurrent nausea and/or vomiting, 22.5% for increased sensitivity to light or dark and 15% for bloating. As regards sympathetic skin response, 19 CP children had unobtainable response in both upper and lower limbs while 5 children had unobtainable response in lower limbs only. All of them were in levels 4 and 5 of GMFCS. Postural hypotension was present in 20% of CP children. Mean Heart rate of CP children was significantly increased more than healthy children upon head tilt test.ConclusionsAutonomic dysfunction has been objectively proven in CP children through absent sympathetic skin response, presence of orthostatic tachycardia and postural hypotension.

Клинические проявления и коррекция вегетативной дисфункции у детей и подростков

Изложены современные представления об этиологии, классификации и терминологии вегетативной дисфункции у детей. Представлены особенности клинических проявлений различных форм заболевания в детском возрасте, диагностика и лечение. Показаны результаты экспериментальных и клинических исследований компонентов препарата Кратал для детей (таурин, боярышник, пустырник). Показана высокая эффективность применения препарата Кратал для детей в лечении нейроциркуляторной и вегетососудистой форм заболевания, что проявилось уменьшением или ликвидацией клинических проявлений вегетативной дисфункции, улучшением вегетативного гомеостаза, показателей функционального состояния сердечно-сосудистой системы и мозгового кровообращения.

Медикаментозная терапия вегетативной дисфункции у детей

В литературном обзоре даны общие представления о расстройствах вегетативной нервной системы, или вегетативной дисфункции, в детском возрасте. Синдром вегетативной дисфункции представляет собой одну из самых распространенных патологий среди популяции детей, которая встречается у каждого третьего ребенка, а у 17–20 % детей со временем может стать основой развития артериальной гипертензии, ишемической болезни сердца, бронхиальной астмы, частых респираторных инфекций. Поздняя диагностика и неадекватное лечение вегетативной дисфункции могут привести к значительному снижению качества жизни и развитию нервно-психических и соматических заболеваний. Лечение синдрома вегетативной дисфункции требует комплексного и индивидуального подхода в каждом конкретном случае. Применение растительных препаратов является одним из эффективных и безопасных методов медикаментозной терапии вегетативной дисфункции у детей и подростков. Множество клинических исследований с использованием фитопрепарата, в состав которого входят таурин, густой экстракт пустырника (Leonurus cardiaca), густой экстракт плодов боярышника (Crataegus oxyacantha L.), при лечении вегетативной дисфункции у детей показали достаточную эффективность и безо­пасность его применения. Влияние терапии вегетативной дисфункции у детей препаратом, в состав которого входят таурин, густой экстракт пустырника (Leonurus cardiaca), густой экстракт плодов боярышника (Crataegus oxyacantha L.), на состояние сердечно-сосудистой системы характеризуется: нормализацией частоты сердечных сокращений, систолического, диастолического и среднего артериального давления, нормализацией циркадного ритма (увеличением числа детей с нормальным циркадным типом артериального давления — dippers), уменьшением вероятности возникновения непароксизмальной тахикардии, восстановлением возбудимости водителя ритма, снижением проявления синдрома ранней реполяризации желудочков. Таким образом, фитопрепарат в состав которого входят таурин, густой экстракт пустырника (Leonurus cardiaca), густой экстракт плодов боярышника (Crataegus oxyacantha L.), можно считать препаратом первичного выбора при лечении синдрома вегетативной дисфункции, который сопровождается склонностью к развитию артериальной гипертензии.

Почки и вегетативная дисфункция у детей и подростков (часть I)

В статье обсуждаются механизмы взаимодействия, развития и прогрессирования сердечно-сосудистых осложнений у детей и подростков с хронической болезнью почек. Подчеркивается главенствующая роль вегетативной дисфункции в развитии сердечно-сосудистых нарушений. Рассматриваются механизмы, с помощью которых повышение активности симпатической части вегетативной нервной системы приводит к поражению почек. Взаимодействие симпатической нервной и ренин-ангиотензиновой систем при формировании нарушений со стороны сердечно-сосудистой системы и почек рассматривается как составляющая адаптационно-приспособительного процесса организма. Универсальным патогенетическим фактором, который непременно сопровождает развитие вегетативных дисфункций и хронической болезни почек у детей и подростков, является активация ренин-ангиотензиновой системы. Общие механизмы развития кардиоренальных нарушений определяют дальнейший однонаправленный подход к диагностике и лечению.

Early Life Stress, Growth and Neurodevelopment in Childhood

Follow up studies of children with congenital heart disease, premature birth, small for gestational age syndrome and attention deficit hyperactivity disorder show significantly reduced 24-hours heart rate variability (HRV) that indicate autonomic dysfunction. The underlying pathophysiological process is of high clinical importance if autonomic dysfunction in these children is related to neurocognitive impairment, an enhanced cardiovascular risk, and a higher risk of short stature. Elevated norepinephrine levels, reduced HRV and MRI imaging indicate brain injury very early in life. We introduce the term autonomic imprinting to explain how early life stress have a lifelong imprinting effect on the autonomic nervous system. Many efforts are done for a careful management of infants in pediatric intensive care units. However, early life stress cannot be prevented if sympathetic activation is part of the underlying disease most of all due to congestive heart failure. We could demonstrate that beside a careful management, pharmacotherapy has a high impact on autonomic dysfunction in children with heart failure, attention deficit disorder and short stature. Moreover, online HRV monitoring is a complete noninvasive tool to monitor early life stress if it uses the data from routine heart rate monitoring. HRV online monitoring on the pediatric intensive care unit and Holter ECG monitoring in a daily life setting are clinical routine in our department for each pharmacotherapy affecting the autonomic nervous system. In the same time as monitoring of early life stress becomes clinically routine, the situation of children will improve if we realize which interventions increase early life stress or improve its detrimental damages in longtime follow up.

Influence of Vitamin B12 Deficiency on Autonomic Nervous System Activity in Children

: Vitamin B12 has an important role in neuronal development of children. Autonomic nervous dysfunction which can be hidden by compensating mechanisms also accompanies vitamin B12 deficiency. However, in children, there is still limited data about this effect of vitamin B12 deficiency. The aim of this study was to evaluate the autonomic activity in vitamin B12 deficient children by analyzing the heart rate variability (HRV) with Holter monitoring. HRV parameters of 37 children who were diagnosed with vitamin B12 deficiency were compared those of 25 age and sex matched healthy controls. All of the heart rate variability parameters (time-domain and frequency-domain) were reduced in the vitamin B12 deficient group compared with controls. The search for factors modifying heart rate variability yielded that serum vitamin B12 level was significantly effective on both time-domain and frequency-domain HRV parameters. A positive correlation was also found between vitamin B12 levels and the mean of the 5 minute RR interval standard deviations (SDNNi), the square root of the mean of the squared differences of two consecutive RR intervals (RMSSD), low-frequency power (LF) parameters (P < 0.05, r: 0.285, 0.262, 0.246, respectively). In conclusion, vitamin B12 deficiency can cause autonomic dysfunction in children.

Evaluation of the Efficiency of the Therapy of Vegetative Disfunction Syndrome in Children Using Adaptol Preparation

Efficacy preparation Adaptol was studied in 30 children and adolescents aged 12-16 years with autonomic dysfunction. Group of patients received Adaptol as monotherapy during 4 weeks. Clinical state of patients was estimated daily, including neurological examination and examination of autonomic nervous system state. Examination showed that Adaptol had distinct thymoleptic, stabilizing and nootropic activity and improved parameters of autonomic homeostasis. These data permit to recommend Adaptol for monotherapy of autonomic dysfunction in children and adolescents.

Discussion on the characteristics of heart rate recovery after primary radical treatment of tetralogy of Fallot

Objective To explore the characteristics of postoperative heart rate recovery (HRR) in children who underwent primary radical repair of tetralogy of Fallot(TOF). Methods A total of 32 patients who underwent primary radical repair of TOF were chosen as the TOF group(18 male, 14 female, aged from 7 to 15 years old, ranged from 5 to 12 years after primary radical repair of TOF), and 86 healthy children were selected as the healthy control group(42 male, 44 female, aged from 6 to 14 years). All children had the treadmill test in Shanghai Children′s Medical Center from January 2013 to December 2015.The data of HRR in 2 groups were reviewed, and the data of HRR were also analyzed in TOF group who had ventricular tachycardia during treadmill test and they were treated with β-blocker.The maximal heart rate(HRmax) at the peak exercise level and the heart rate in 1-6 minute(HRR1-HRR6) in the recovery period were measured and the HRR1-HRR6 was defined as difference between the HRmax and the heart rate in 1-6 minutes during the recovery period. Results The heart rate in first 2 minutes after treadmill exercise showed the rapid recovery in both TOF group and the healthy control group.It recovered slowly after the third minute in two groups.The healthy control group reached the steady HRR period after the fifth minute, whereas TOF group entered the steady HRR period after the sixth minute, and later in the TOF group it reached steady HRR period.There was no difference in HRmax in 2 groups(P>0.05). But there were significant differences in the resting heart rate[(82.3±3.4) times/min vs.(79.0±2.5) times/min], and the levels of HRR1-HRR4 minutes were (25.9±1.5)%, (39.4±1.6)%, (43.0±1.6)%, and(44.7±1.8)% in TOF group, respectively; while in the healthy control group they were (26.3±1.3)%, (40.0±1.1)%, (43.8±0.7)%, and(45.4±1.4)%; the incidence of ventricular premature beat was 18/32 cases(56.3%) and 5/86 cases(5.8%) during treadmill test between 2 groups (t=5.77, 5.59, 10.32, 18.65, 10.66, χ2=37.80, all P<0.05). β-blocker treatment was given to 7 cases who had ventricular tachycardia during treadmill test in TOF group.After treatment, the resting heart rate was (77.6±2.6) times/min, significantly decreased(t=3.93, P=0.01), the level of HRR1-HRR4 was(26.3±1.9)%, (39.8±0.9)%, (43.8±0.8)%, (46.2±1.3)%, respectively, which was significantly increased (t=2.49, 4.63, 8.30, 7.90, all P<0.05). The incidence of ventricular tachycardia(2/7 cases, 28.6%) decreased significantly(χ2=7.78, P=0.02). Conclusions There exists cardiac autonomic dysfunction in children who had the primary radical repair of TOF, which is related to the occurrence of ventricular arrhythmia and may influence the long-term prognosis of TOF.HRR can be used as an important indicator to assess and reassess the cardiac autonomic function in patients after TOF repair. Key words: Heart rate recovery; Tetralogy of Fallot; Sudden cardiac death; Autonomic nervous system; Child

Syndrome of autonomic dysfunction in children and adolescents

To study clinical and pathophysiological symptoms of autonomic dysfunction syndrome in children and adolescents and assess the efficacy of its treatment with nooclerin. Fifty-three patients, aged from 10 to 15 years, with autonomic dysfunction syndrome were examined. All patients underwent neurological examination, assessment with the A.M. Vein's questionnaire of autonomic disorders, the 10 point Visual Analogous scale for headache and fatigue, the Spielberger-Khanin scale for anxiety, Kerdo index, Hildebrandt's coefficient, electrocardiography with clinoorthostatic test, electroencephalography, and TOVA psychophysiological test. The signs of the asthenic-autonomic syndrome were characteristic of the clinical picture of disease. EEG results demonstrated the deficit of activation effects, predominance of synchronized effects of thalamic structures which led to the insufficient activation of cortical structures. These data support the high efficacy of nooclerin.

TO THE QUESTION OF VEGETATIVE BACKGROUND IN CHILDREN WITH CHRONIC GASTRODUODENAL PATHOLOGY

Summary. It is proved that the vegetative dysfunction, which originated in childhood or adolescence, becomes an unfavorable background and a harbinger of many diseases, including chronic ones. In connection with the increase in the frequency of autonomic dysfunction in children, there is a need in recent years to study this problem. Objective. To study the state of the autonomic nervous system in children with chronic gastroduodenal pathology.Materials and methods. 120 school-age children were examined, who were hospitalized in the gastroenterological department of the city children's clinical hospital in Chernivtsi. Children are divided into two groups: the main one (60 people with chronic gastroduodenal pathology), and the control group (60 people with functional diseases of the gastrointestinal tract).During the questioning of children, using the questionnaire ofWayne, the state of the vegetative nervous system was evaluated. To determine the nature of autonomic dysfunction with a predominance of sympathetic or parasympathetic departments, the vegetative Kerdo index was used. All children were also electrocardiographically examined.Results. Children with chronic gastroduodenal pathology were twice as likely to have autonomic dysfunction as compared to the comparison group. Estimating the Curdo index in children from the main group, the prevalence of the sympathetic tone of the vegetative system was significantly higher (85.6 ± 0.2%, vs. 50.8 ± 0.3% in the control group and significantly less pronounced in them eutonia - 4.4 ± 0 4%, against 41.0 ± 0.2% in the control group, p &lt;0.05.Conclusions. The predominance of the frequency of autonomic dysfunction in children of the main group can be explained by the effect of autonomic dysregulation and organic lesions of the gastroduodenal zone in them.

Cardiovascular Autonomic Dysfunction in Children and Adolescents With Rett Syndrome

BackgroundAutonomic dysfunction is common in children with Rett syndrome. They usually manifest with agitation, persistent screaming, constipation, gastroesophageal reflux, aerophagia, hyperventilation, and breath-holding episodes. Cardiovascular autonomic dysfunction may result in fatal a arrhythmia. Many of these events are mistaken for seizures and treated with antiepileptics. MethodsThe present study was conducted in a tertiary care teaching hospital in north India for more than a six month period. MeCP2 mutation positive, 24 cases with Rett syndrome and 24 age-matched healthy girls were evaluated for cardiovascular autonomic dysfunction (heart rate variability, head-up tilt test, and cold pressor test). ResultsThe mean age was 9.06 years (±3.4) and 9.75 years (±3.13) for patients and control subjects, respectively. The heart rate variability contributed independently by parasympathetic and sympathetic nervous system was significantly reduced in cases compared with control subjects (P = 0.033 and P = 0.001, respectively). There was significant sympathovagal imbalance with sympathetic overactivity in cases compared with control subjects (P = 0.001). The mean longest QTc interval was significantly prolonged in cases compared with control subjects (P = 0.001). Cold pressor test and head-up tilt test could be done in 16 Rett syndrome patients (because of poor cooperation) and in all 24 control subjects. The change in blood pressure during cold pressor test and head-up tilt test was not significantly different in cases and control subjects. ConclusionsChildren with Rett syndrome exhibited significant cardiovascular autonomic dysfunction in the form of sympathetic overactivity, parasympathetic underactivity, and sympathovagal imbalance. These findings have potentially important therapeutic- and outcome-related implications.

Heart Rate Variability in Children with Attention-Deficit/Hyperactivity Disorder: A Pilot Study

Background: Attention deficit/hyperactivity disorder (ADHD) is a common childhood neuropsychiatric disorder. Autonomic nervous system plays a vital role in attention, self-regulation, emotional stability and social affiliation, which are affected in ADHD. The prefrontal cortex, which is vital for attention, motor control, emotional regulation and higher order autonomic control, is hypofunctional in ADHD. In addition, catecholamine dysregulation is there. Purpose: We hypothesized that there is autonomic dysfunction: reduction in overall heart rate variability (HRV) and sympathovagal imbalance in children with ADHD. Methods: Study criteria were drug-naïve ADHD children who were 7-12 years of age of either gender who fulfilled DSM-IV criteria for ADHD and did not have any associated comorbid psychiatric/neurological/medical disorders. Two hundred and seventy ADHD children were screened out of which only 12 were found eligible and 10 participated. Sample size was 20 (cases = 10, age- and gender-matched healthy controls = 10). Short-term HRV of both time and frequency domains were assessed by recording lead II electrocardiogram after using Tell-Show-Do, a behavior shaping technique. Comparison between groups was done using Mann-Whitney and Wilcoxon test. Demographic variables like age, height, weight and body mass index were similar between groups. Results: Among time domain parameters, SD of all NN intervals, square root of the mean of the sum of squares of differences between adjacent NN intervals and percentage of count of number of pairs of adjacent NN intervals differing by more than 50 ms were reduced in ADHD group with p < 0.05. Among frequency domain parameters, total power was reduced in ADHD group with p < 0.05, high frequency power (HF) was reduced in ADHD group with p < 0.01 and low frequency power to HF ratio was higher in ADHD group with p < 0.01. Conclusion: There is autonomic dysfunction in children with ADHD - reduction in overall HRV with sympathovagal imbalance with sympathetic dominance.

Abstract P041: Impaired Autonomic Control of Heart Rate at Rest and Slower Post-exercise Heart Rate Kinetics in Children with Congenital Heart Defects

Introduction: A slow recovery in heart rate (HR) following exercise is due to autonomic dysfunction and is associated with increased cardiovascular event risk. Children with congenital heart defects (CHD) display autonomic dysfunction as shown by a reduction in HR variability (HRV). Whether children with CHD have impairment in post-exercise HR recovery is unknown. Hypothesis: We tested the hypothesis that children with CHD would have reduced HRV at rest and slower HR recovery kinetics following 6-minute walk testing (6MWT) compared to healthy controls. Methods: Twenty-five children with CHD (11±2 years; males=14; females=11) and 21 age- and sex-matched controls (11±3 years; males=10; females=11) were studied. CHD diagnoses included Tetralogy of Fallot (n=7), pulmonary or aortic stenosis (n=3), hypoplastic left or right heart syndrome (n=5), Ebstien’s anomaly (n=1), atrial or ventricular septal defect (n=3), transposition of the great arteries (n=1), double inlet left ventricle (n=1), tricuspid atresia (n=1), coarctation of the aorta (n=2), single ventricle (n=1), and dilated cardiomyopathy (n=1). HRV was determined following 10 min supine rest using a 5 min surface ECG recorded epoch. Post-exercise HR kinetics were determined over a 4-min period following the 6MWT using telemetry-based HR. Mono-exponential modeling was used to derive a HR recovery time constant, tau (time to reach 63% change). Analyses were completed using unpaired t -tests with P &lt; 0.05 being significant. Data are mean ± SD. Results: Children with CHD had a lower 6MWT distance (513±75 vs. 599±81 m; P &lt; 0.001) and lower average exercise HR (122±15 vs. 139±18 beats/min; P = 0.001) compared to controls. Time domain HRV parameters revealed a reduction in the standard deviation of normal R-R intervals (55.9±40.4 vs. 92.1±24.5 ms), the root mean square of successive R-R interval differences (57.4±53.0 vs. 101.1±40.0 ms), and the percentage of consecutive normal R-R intervals that differ by more than 50 ms (24.6±28.7 vs. 53.2±14.0 %) in children with CHD vs. controls, respectively (all P &lt; 0.01). Power spectral HRV analyses revealed no difference in low frequency (LF) power (30±16 vs. 25±16 %; P &gt; 0.05), but significant differences in high frequency (HF) power (34±19 vs. 49±14 %) and the LF/HF ratio (1.4±1.5 vs. 0.6±0.3 %) in children with CHD vs. controls, respectively (all P &lt; 0.05). Post-exercise HR kinetics were slower in children with CHD (tau = 34±15 s) compared to controls (tau = 24±8 s; P = 0.01), indicating a longer recovery time for HR. Conclusions: Children with CHD have autonomic dysfunction as measured by a reduction in HRV and greater LF/HF ratio. Slower HR kinetics in children with CHD may be due to a reduction in parasympathetic activation during the post-exercise recovery period. Our findings suggest that autonomic dysfunction in children with CHD functionally alters HR control during or immediately following exercise.

P wave dispersion on 12-lead electrocardiography in adolescents with neurocardiogenic syncope.

PurposeNeurocardiogenic syncope (NCS) is the most frequent cause of fainting during adolescence. Inappropriate cardiovascular autonomic control may be responsible for this clinical event. The head-up tilt test has been considered a diagnostic standard, but it is cumbersome and has a high false-positive rate. We performed a study to evaluate whether P-wave dispersion (PWD) could be a useful electrocardiographic parameter of cardiac autonomic dysfunction in children with NCS.MethodsFifty-four patients with NCS (28 boys and 26 girls; mean age, 12.3±1.4 years) and 55 age- and sex-matched healthy controls were enrolled. PWD was obtained as the difference between maximum and minimum durations of the P wave on standard 12-lead electrocardiography in all patients and controlsResultsThe value of PWD was significantly higher in the syncope group than in the control group (69.7±19.6 msec vs. 45.5±17.1 msec, respectively; P<0.001). The minimum duration of P wave was shorter in the syncope group than in the control group (43.8±16.8 msec vs. 53.5±10.7 msec, respectively; P<0.001). Left atrial volume was not different between the groups on transthoracic echocardiographyConclusionPWD on echocardiography could be used as a clinical parameter in patients with NCS.

Respiratory and autonomic dysfunction in children with autism spectrum disorders

IntroductionCardiac parasympathetic hypofunction has been reported in autism spectrum disorders (ASD). This usually is linked to respiratory dysrhythmia which has been documented in some children with ASD. ObjectivesThis study evaluated the cardiorespiratory functions in ASD to elucidate the physiologic basis of behaviors. MethodsNineteen children with ASD and 18 age matched controls underwent autonomic function monitoring at a defined resting state using the NeuroScope. The non-invasive real time beat-to-beat blood pressure was measured by Portapres and fed into the NeuroScope where heart rate, cardiac vagal tone and cardiac sensitivity to baroreceptor were derived from the EKG and blood pressure waveforms using the Vagosoft software; and respiratory rate and rhythm were measured simultaneously by plethysmograph. Respiration was analyzed breath by breath using our prior published methods. ResultsVarious respiratory dysrhythmias, particularly Biot’s and Cheyne–Stokes respiration, were detected in children with ASD, who also exhibited greater variability in respiratory rhythm and amplitudes than controls. The respiratory dysrhythmia in children with ASD was associated with a lower cardiac vagal activity. ConclusionThe Biot’s breathing and Cheyne–Stokes respiration coupled with cardiac vagal hypofunction in ASD suggest a brainstem dysfunction consistent with our previous findings. The low parasympathetic activity could explain in part the chronic sensory hyperarousal state in children with ASD.

Evaluation of electrocardiographic parameters for early diagnosis of autonomic dysfunction in children and adolescents with type‐1 diabetes mellitus

The aim of this study was to identify the sensitivity of electrocardiogram (ECG) in early diagnosis of cardiac autonomic function disorder in children with type 1 diabetes mellitus. A total of 150 children and adolescents with type 1 diabetes mellitus were enrolled between June 2009 and June 2010, as well as 100 age- and sex-matched healthy control children. Twelve-lead ECG was done in all cases and heart rate, QT and QTc interval, dispersion of P wave (Pd), and of QT (QTd) and QTc interval (QTcd) were measured. The clinical and demographic features such as age, gender, duration of follow up and level of HbA1c and fasting glucose were obtained and the effects of these parameters on ECG measurements were investigated. The mean age of the patients and controls was 11.61 ± 3.72 years and 10.92 ± 3.2 years, respectively. QT and QTc interval and QTcd interval were significantly higher in diabetic children compared to healthy controls but these ECG findings were not associated with the duration of diabetes or glycemic state. Pd was significantly higher in the diabetic patients with HbA1c >7.5% compared to control, and this was also found in patients that were followed up >1 year. Cardiac autonomic function disorder, which is one of the most important causes of morbidity and mortality, may emerge in the course of type 1 diabetes mellitus. It can be diagnosed on ECG even when the patients are asymptomatic.

Relationship of hypoglycemia and glucose variability with autonomic dysfunction in children and adolescents with type 1 diabetes

Aim. Glucose variability (GV) and hypoglycaemia frequency and duration, depending on cardiovascular autonomic dysfunction, in children and adolescents with type 1 diabetes mellitus (T1DM) were evaluated. Materials and methods. One hundred and thirty T1DM patients, aged 6?18 years, were included in this study. The study included 3 tests:. continuous glucose monitoring (CGM) with GV evaluation, frequency and duration of hypoglycaemia;24-h ECG monitoring with automatic calculation of QTc interval and heart rate variability (HRV) parameters;cardiovascular autonomic tests.Results. The estimated prevalence of cardiovascular autonomic neuropathy (CAN) was 19.2%. CAN positive (CAN+) patients had lower values from cardiovascular autonomic tests and HRV and longer QTc intervals compared with CAN negative (CAN-) patients (p

Cardiac autonomic functions in children with familial Mediterranean fever.

Familial Mediterranean fever (FMF) is the most common inherited autoinflammatory disease in the world. The long-term effects of subclinical inflammation in FMF are not well recognized. Some studies have suggested that FMF is associated with cardiac autonomic dysfunction in adult FMF patients. The objective of this study was to investigate the cardiac autonomic functions in pediatric FMF patients by using several autonomic tests. Thirty-five patients with FMF and 35 healthy controls were enrolled in this cross-sectional study. Demographic data, disease-specific data, and orthostatic symptoms were recorded. In all participants, 12-lead electrocardiography (ECG), 24h ambulatory electrocardiographic monitoring, transthoracic echocardiography, treadmill exercise test, and head upright tilt-table (HUTT) test were performed. The heart rate recovery (HRR) indices of the two groups were similar. Also, chronotropic response was similar in both groups. The time-domain parameters of heart rate variability (HRV) were similar in both groups, except mean RR (p = 0.024). Frequencies of ventricular and supraventricular ectopic stimuli were similar in both groups. There were no statistically significant differences between the groups in average QT and average corrected QT interval length, average QT interval dispersion, and average QT corrected dispersion. There was no significant difference between the two groups regarding the ratio of clinical dysautonomic reactions on HUTT. However, we observed a significantly higher rate of dysautonomic reactions on HUTT in patients with exertional leg pain than that in patients without (p = 0.013). When the fractal dimension of time curves were compared, FMF patients exhibited significantly lower diastolic blood pressure parameters than controls in response to HUTT. Cardiovascular autonomic dysfunction in children with FMF is not prominent. Particularly, patients with exertional leg pain are more prone to have dysautonomic features. Further studies are needed to elucidate the exact mechanisms leading to impaired cardiac autonomic functions in FMF.