Complex sympathetic regulation in adolescent mitral valve prolapse.

Mitral valve prolapse (MVP) belongs to cardiac disorders characterized by impaired closure of mitral leaflets. We studied adolescent group of patients with MVP suffering from symptomatology that cannot be explained by mitral regurgitation alone. Several studies suggested that symptoms can be explained by autonomic, in particular sympathetic-linked dysfunction. Thus, we assessed non-invasive sympathetic indices of blood pressure and heart rate variability and electrodermal activity (EDA). Fifty-three adolescents with MVP (age: 15.1+/-0.4 years) and 43 healthy age- and gender-matched adolescents (age: 14.9+/-0.4 years) were examined. Blood pressure, heart rate and EDA were continuously recorded during 6-min rest. Evaluated parameters were: low frequency band of systolic blood pressure variability, systolic, diastolic and mean blood pressure, mean RR interval, cardiac sympathetic indices: symbolic dynamics (0V%), left ventricular ejection time (LVET), pre-ejection period (PEP), and EDA. Our findings revealed significantly higher systolic, diastolic, and mean blood pressure values, shortened mean RR interval, increased 0V%, and shortened LVET in MVP patients vs. controls (p=0.028, p<0.001, p=0.002, p<0.001, p=0.050, p<0.001; respectively). Our study revealed enhanced cardiovascular sympathetic regulation in adolescent MVP patients. We suggest that evaluation of non-invasive sympathetic parameters could represent potential biomarkers for early diagnosis of cardiovascular complications associated with MVP already at adolescent age.

Respiratory Sinus Arrhythmia as an Index of Cardiac Vagal Control in Mitral Valve Prolapse.

Respiratory sinus arrhythmia (RSA), i.e. heart rate (HR) variations during inspiration and expiration, is considered as a noninvasive index of cardiac vagal control. Mitral valve prolapse (MVP) could be associated with increased cardiovascular risk; however, the studies are rare particularly at adolescent age. Therefore, we aimed to study cardiac vagal control indexed by RSA in adolescent patients suffering from MVP using short-term heart rate variability (HRV) analysis. We examined 12 adolescents (girls) with MVP (age 15.9±0.5 years) and 12 age and gender matched controls. Resting ECG was continuously recorded during 5 minutes. Evaluated HRV indices were RR interval (ms), rMSSD (ms), pNN50 (%), log HF (ms(2)), peak HF (Hz) and respiratory rate (breaths/min). RR interval was significantly shortened in MVP group compared to controls (p=0.004). HRV parameters-rMSSD, pNN50 and log HF were significantly lower in MVP compared to controls (p=0.017, p=0.014, p= 0.015 respectively). Our study revealed reduced RSA magnitude indicating impaired cardiac vagal control in MVP already at adolescent age that could be crucial for early diagnosis of cardiovascular risk in MVP.

Cardiac Vagal Control and Depressive Symptoms in Response to Negative Emotional Stress.

We aimed to study complex cardiovagal control using heart rate variability (HRV), linear and nonlinear analyses at rest and during negative emotional stress in healthy students with varying depressive symptoms. ECG recording in 20 students was performed at baseline, negative emotional stress, and recovery period. The HRV parameters evaluated were the following: RR interval, spectral power in high-frequency band (HF-HRV), and symbolic dynamics index 2LV%. The subjects were divided into two groups based on the score of the Beck Depression Inventory (BDI) - normal mood (BDI: 0.6 ± 0.2) and mild mood disturbance (BDI: 14.3 ± 1.4). We found significantly lower logHF-HRV during emotional stress in mild mood disturbance compared with normal mood (p = 0.047). No significant differences were found in the remaining parameters. We conclude that negative emotional stress attenuated the cardiovagal control during mood disturbance, which points to discrete abnormalities in the neurocardiac reflex system associated with depressive symptoms. Hampered cardiovagal control could represent a potential pathomechanism leading to depression-linked cardiovascular complications.

Alterations in vagal-immune pathway in long-lasting mental stress.

We studied a potential impact of chronic psychosocial load on the allostatic biomarkers--cardiac vagal activity, inflammation, and oxidative stress in healthy undergraduate students. Continuous resting ECG signals were monitored in a group of 16 female healthy students (age: 23.2±0.2 years, BMI: 20.9±0.5 kg/m2) at two time periods: right after holiday (rest period) and a day before final exams (stress period). Vagal activity was quantified by spectral analysis of heart rate variability at high frequency band (HF-HRV). The immune response was assessed from the level of tumor necrosis factor-alpha (TNF-α) in plasma. In addition, mean RR intervals were evaluated. We found that HF-HRV was significantly reduced and the TNF-α was increased in the stress period compared with the rest period. No significant changes were found in the RR interval. In conclusion, allostatic load induced by stress and the accompanying greater immune response decreased cardiovagal regulation in healthy young subjects. These findings may help understand the pathway by which stress can influence health and disease.

Complexity and time asymmetry of heart rate variability are altered in acute mental stress.

We aimed to study the complexity and time asymmetry of short-term heart rate variability (HRV) as an index of complex neurocardiac control in response to stress using symbolic dynamics and time irreversibility methods. ECG was recorded at rest and during and after two stressors (Stroop, arithmetic test) in 70 healthy students. Symbolic dynamics parameters (NUPI, NCI, 0V%, 1V%, 2LV%, 2UV%), and time irreversibility indices (P%, G%, E) were evaluated. Additionally, HRV magnitude was quantified by linear parameters: spectral powers in low (LF) and high frequency (HF) bands. Our results showed a reduction of HRV complexity in stress (lower NUPI with both stressors, lower NCI with Stroop). Pattern classification analysis revealed significantly higher 0V% and lower 2LV% with both stressors, indicating a shift in sympathovagal balance, and significantly higher 1V% and lower 2UV% with Stroop. An unexpected result was found in time irreversibility: significantly lower G% and E with both stressors, P% index significantly declined only with arithmetic test. Linear HRV analysis confirmed vagal withdrawal (lower HF) with both stressors; LF significantly increased with Stroop and decreased with arithmetic test. Correlation analysis revealed no significant associations between symbolic dynamics and time irreversibility. Concluding, symbolic dynamics and time irreversibility could provide independent information related to alterations of neurocardiac control integrity in stress-related disease.

Attention deficit/hyperactivity disorder (ADHD) is associated with altered heart rate asymmetry.

Attention deficit/hyperactivity disorder (ADHD) is associated with complex neurocardiac integrity. We aimed to study heart rate time asymmetry as a nonlinear qualitative feature of heart rate variability indicating complexity of cardiac autonomic control at rest and in response to physiological stress (orthostasis) in children suffering from ADHD. Twenty boys with ADHD and 20 healthy age-matched boys at the age of 8 to 12 years were examined. The continuous ECG was recorded in a supine position and during postural change from lying to standing (orthostasis). Time irreversibility indices - Porta's (P%), Guzik's (G%) and Ehlers' (E) - were evaluated. Our analysis showed significantly reduced heart rate asymmetry indices at rest (P%: 49.8 % vs. 52.2 %; G%: 50.2 % vs. 53.2 %; p<0.02), and in response to orthostatic load (P%: 52.4 % vs. 54.5 %, G%: 52.3 % vs. 54.5 %; p<0.05) associated with tachycardia in ADHD children compared to controls. Concluding, our study firstly revealed the altered heart rate asymmetry pattern in children suffering from ADHD at rest as well as in response to posture change from lying to standing (orthostasis). These findings might reflect an abnormal complex cardiac regulatory system as a potential mechanism leading to later cardiac adverse outcomes in ADHD.

Epicardial adipose tissue and cardiometabolic risk factors in overweight and obese children and adolescents.

What is already known about this subject The prevalence of childhood obesity has increased markedly in the past 2 decades. Abdominal fat is a better predictor of risk than body mass index. Waist circumference (WC) as a measure of abdominal fat has limited sensitivity and specificity. What this study adds Epicardial adipose tissue (EAT) as measured by echocardiography represents a simple and reliable marker of visceral adiposity. In children, both body mass index and EAT show a similar or better correlation with markers of cardiometabolic risk than does waist circumference. BACKGROUND: Epicardial adipose tissue (EAT) is the visceral fat deposit around the heart and is commonly increased in obese subjects. EAT is related to cardiometabolic risk factors and non-alcoholic fatty liver disease (NAFLD) in adults, but this relationship is not well known in children. OBJECTIVES: Echocardiographic assessment of EAT and its association with cardiometabolic risk factors in overweight and obese children. STUDY GROUPS AND METHODS: In 25 (mean age 13.0 ± 2.3) overweight and obese subjects and 24 lean controls, blood pressure (BP), WC, fasting plasma glucose and insulin, lipids, uric acid and hepatic enzymes were measured. EAT thickness was measured by transthoracic echocardiography. RESULTS: In overweight and obese subjects, EAT was significantly higher compared to normal weight children. Overweight and obese children had significantly higher body mass index (BMI), WC, BP, triglycerides (TAG), low-density lipoprotein and total cholesterol, hepatic enzymes alanine aminotransferase (ALT) and γ-glutamyl transferase, and lower high-density lipoprotein cholesterol (HDL-C). EAT correlated significantly with BP, TAG, uric acid, HDL-C, apoprotein B and ALT. Correlation coefficients were similar or better than for WC, but similar or lower than for BMI. CONCLUSION: EAT thickness in children is associated with an unfavourable cardiometabolic risk profile including biochemical signs of NAFLD and hyperuricaemia, but is not a stronger indicator than BMI.

Left ventricular systolic and diastolic function in children with overweight and obesity.

OBJECTIVES: Several studies have found an association between obesity and heart failure. The purpose of our study was to identify the influence of the severity of obesity in children on structural and functional changes of the left ventricle and parameters of the systolic and diastolic function. METHODS: This was a prospective controlled study carried out between February 1 and October 31, 2010, involving 21 children with overweight and obesity and 23 healthy controls. Following parameters were evaluated: nutritional status, intermittent and continuous ambulatory blood pressure monitoring, echocardiographic examination including aortal root diameter, left atrial diameter, interventricular septum thickness, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left ventricular posterior wall thickness, left ventricle mass, relative wall thickness, left ventricular mass/height index and ejection fraction. RESULTS: In overweight and obese children, systolic blood pressure, diastolic blood pressure, average day-time SBP were higher than in controls. Also, left ventricular size was increased and diastolic dysfunction with preserved systolic function was present in overweight children. CONCLUSIONS: In our study we have found that in obese and overweight children signs of early myocardial damage, both structural and functional, are detectable mainly as the alteration of the left ventricular diastolic function, despite preserved global systolic function. These changes seem to be intensified by the severity of obesity (Tab. 3, Ref. 39).

Doppler-derived myocardial performance index in healthy children.

The myocardial performance index (MPI) is a simple quantitative, non-geometric index of ventricular function and is readily applicable for evaluation of the right and left ventricle function. The aim of the study was to assess normal MPI values in healthy children. We studied 38 healthy children from 3 to 18 years of age. The normal values of both, the left ventricular and right ventricular MPI were 0.32 +/- 0.07 and 0.27 +/- 0.09, respectively. Measurement of the MPI is non-invasive and easily obtainable and does not prolong the time required for examination. It is independent from ventricular geometry, blood pressure, heart rate and it appears to be of great prognostic value in many different clinical settings (Tab. 2, Fig. 1, Ref. 14). Full Text in free PDF www.bmj.sk.

[Metastatic involvement of the heart and pericardium--MR case reports]. / Metastatické postihnutie srdca a perikardu-- MR kazuistiky.

Secondary metastatic tumors of the heart and pericardium are in comparison with primary cardiac tumors more common, but their overall prognosis is very poor. Metastases can occur in every part of the heart and pericardium. The most common source are tumors--lung cancer, breast cancer, melanoma and lymphoma. In this case report we described two patients with metastatic involvement of the heart. We are pointing out the possibilities of diagnostic imaging of cardiac tumors using echocardiography and magnetic resonance.

Moebius syndrome associated with hypoplastic left heart syndrome.

The authors present a newborn infant from the second pregnancy whose mother experienced influenza A infection in the first trimester. The birth was at term without complications, but 11 hours later, cyanosis and tachypnoe developed. The final diagnosis was hypoplastic left heart syndrome with simultaneous Moebius Syndrome. In conclusion the authors indicate that echocardiography is of great importance in the diagnosis of this complex heart disease as it helps to analyze in detail the options in the diagnosis of rare Moebius Syndrome (Fig. 2, Ref. 8).

Cardiac autonomic control in adolescents with primary hypertension.

BACKGROUND: Impairment in cardiovascular autonomic regulation participates in the onset and maintenance of primary hypertension. OBJECTIVE: The aim of the present study was to evaluate cardiac autonomic control using long-term heart rate variability (HRV) analysis in adolescents with primary hypertension. SUBJECTS AND METHODS: Twenty two adolescent patients with primary hypertension (5 girls/17 boys) aged 14-19 years and 22 healthy subjects matched for age and gender were enrolled. Two periods from 24-hour ECG recording were evaluated by HRV analysis: awake state and sleep. HRV analysis included spectral power in low frequency band (LF), in high frequency band (HF), and LF/HF ratio. - RESULTS: In awake state, adolescents with primary hypertension had lower HF and higher LF and LF/HF ratio. During sleep, HF was lower and LF/HF ratio was higher in patients with primary hypertension. CONCLUSIONS: A combination of sympathetic predominance and reduced vagal activity might represent a potential link between psychosocial factors and primary hypertension, associated with increased cardiovascular morbidity.

Heart rate variability changes in children after cardiac transplantation.

BACKGROUND: Heart rate variability analysis is a modern, non-invasive, precise and sensitive method of the assessment of cardiovascular systemic functions. OBJECTIVES: Find out changes in parameters of time-domain analysis of heart rate variability (HRV) in children after cardiac transplantation. METHODS: Twenty-two subjects were enrolled and examined in this study--2 subjects after cardiac transplantation (14 and 5 years of age) and 2 control groups of healthy subjects (10 subjects at age from 14 to 16 and 10 subjects at age from 5 to 7 y). Five parameters of HRV from 24-hour Holter monitoring have been analysed (NN intervals, SD, pNN50, rMSSD, triangular index). GiOtto ECG Holter monitor (Medatron) was used in each child. Time domain analysis parameters have been controlled and compared by using percentile range obtained from healthy individuals (Pl0-P90). RESULTS: rMSSD, pNN50, triangular index were below 10th percentile in a 14-year-old girl. rMSSD, SD were below the 10th percentile in a 5-year-old boy. CONCLUSION: Total heart rate variability (described by triangular index and SD parameter) and parameters describing parasympathetic activity (pNN50 and rMSSD) were decreased in both patients after cardiac transplantation. Considering the still unclear mechanism of heart innervation, it is necessary to continue in the research. Authors are planning to check the changes in the future also by means of frequency analysis of heart rate variability. (Tab. 3, Ref. 22.)

Echocardiographic evaluation of left ventricle postnatal growth in newborns and infants.

BACKGROUND: During intrauterine life is the volume stimulation of the left ventricle low and it's cardiac output in comparison to the right ventricle is about 50%. Before and also after birth the right ventricle is dominant. Postnatally low-resistance placenta is excluded from the systemic circuit, leading to an abrupt pressure elevation and to its further increase. AIM OF STUDY: The authors performed echocardiographic evaluation of healthy children from newborn age to 6 month of age. METHODS: Fifty randomly selected healthy mature infants were included in this study. Echocardiographic examination was performed at the age of 5 days, 1 month and 6 months respectively. Data obtained at the age of 5 days were compared to those at 1 month and 6 months. RESULTS: The authors confirmed a significant increase in the left ventricular volumes (LVESV, LVEDV, SV) developed early newborn in the period to 6 months of age. There was a significant increase in EF in the period age of 5 days to 1 month of age. Mean LVM on the 5th day after birth was 8.13+/-1.50 g. It increased to 11.39+/-2.33 g after 1 month and to 16.61+/-2.75 g after 6 months. They confirmed significant LVMVI decrease to 1.38+/-0.25 g/ml (6 months) from 1.56+/-0.33 (1 month). The authors found significant decrease in RWT values at the age of 6 months compared with the 5th day. CONCLUSION: Left ventricular parameters confirm postnatal left ventricle growth in healthy infants. The results are useful in interpretation of echocardiographic examinations in newborns and infants.

[Dynamics of hemodynamic parameters in the early neonatal period]. / Dynamika niektorých hemodynamických parametrov vo vcasnom novorodeneckom období.

BACKGROUND: The fetal circulation is subdued to alteration after birth. Fetal vascular communications enclose (ductus arteriosus Botalli and foramen ovale) and vascular resistance of the lungs and pressure in the pulmonary artery decrease. Low-resistance placenta is excluded from the systemic circuit, leading thus to abrupt pressure elevation and to its further increase. OBJECTIVES: The aim of the study is to judge the dynamics of alterations during the postnatal period by means of Doppler's echocardiography:--the left ventricular ventricle,--parameters characterizing circulation in the pulmonary bed. METHODS: 23 healthy randomly selected newborn infants born at full term were examined on the 1st and 2nd day of their life. RESULTS: Parameters of the left ventricular function did not change between the 1st and 2nd days of life. Parameters from the outflow tract of the right ventricle on the 5th day of life of infants: the ratio of PEP (preejection period) to AT (acceleration time) significantly decreased, the ratio of PEP to ET(ejection time) did not change. Parameters of the pulmonary artery on the 5th day of life of infants: significant decrease of the ratio PEP/AT, as well as of PEP/ET, the peak and mean velocity of blood flow significantly increased. CONCLUSIONS: The left ventricular function is not subdued to alterations during early postnatal period. The parameters characterizing the pulmonary circulation prove a decrease of pressure in the pulmonary bed on the 5th day of life. MEANING FOR PRACTICE AND THEORY: The results are utilizable in interpretation of echocardiographic examination in postnatal age. (Fig. 8, Ref. 19.).

[Architectonics of pulmonary vessels in pulmonary stenosis]. / Architektonika pl'úcnych ciev pri pulmonálnych stenózach.

The authors aimed their work on the study of the architecture of pulmonary blood vessels and blood flow via pulmonary vascular network in patients with Fallot malformation. In 34 children with valvular stenosis of a. pulmonalis and in 12 children with Fallot tetralogy they analysed in detail their angiograms, paying attention to evaluation of the architecture of truncus pulmonalis and its branches, the discharging part of the right ventricle, and the state of the arterial phase of the pulmonary vascular network. On the basis of their results the authors explain the preferential blood distribution in Fallot's tetralogy by the displacement of the outflow part of the right ventricle to the right and by a greater amanation angle between the right branch of a.pulmonalis and its truncus. Better routing of blood into the left lung in patients with pulmonary valvular stenosis is according to the authors due to a greater emanation angle between the left branch of a.pulmonaris and its truncus. The authors analyse also the mechanism of formation of poststenotic dilatation of truncus pulmonaris and the left branch of a.pulmonaris in cases of valvular stenosis in infant age. (Fig. 4, Ref. 12.)

[Radionuclide scintigraphy in the diagnosis of Meckel's diverticulum]. / Vyuzitie rádionuklidovej scintigrafie pri diagnostike Meckelovho divertiklu.

In the submitted case-history the authors draw attention to the advantage of radionuclide diagnosis of ectopic gastric mucosae located in Meckel's diverticula. Diagnosis with 99mTc is according to the authors the treatment of choice in acute haemorrhage into the GIT with an obscure aetiology.

[Invasive diagnosis of abnormal muscular hypertrophy in the right ventricular cavity]. / Invazívna diagnóza abnormálnej hypertrofie svaloviny v dutine pravej komory.

The authors elaborated the problem of abnormal hypertrophy of the musculature of the right ventricular cavity. From a total number of 534 children subjected to complete cardiological examination in 28 (5.2%) they made the diagnosis of an inborn anomaly of the musculature of the right ventricle localized beneath the infundibulum. The classification of this pathological entity is based on angiocardiographic and catheterization findings. The patients were divided into three groups: group I comprised 6 patients with an associated defect of the ventricular septum. Obstruction caused by hypertrophy of the muscle bundles created a morphological and functional right ventricle with two cavities. Group II comprised 15 patients where the authors confirmed by catheterization and angiocardiography an obstruction at the site of the hypertrophic musculature. Group III comprised 7 patients where they proved hypertrophy of the musculature by angiocardiographic examination but were unable to confirm the obstruction by catheterization.

[Treatment of a patent duct in neonates]. / Liecba otvoreného duktu v novorodeneckom veku.

The authors analyze clinical and laboratory aspects of Indomethacin treatment of neonates with a patent ductus arteriosus. From June 1987 to November 1990 the authors treated 19 neonates with a patent ductus arteriosus with Indomethacin. The drug was administered, 0.1-0.3 mg/kg body weight, by the oral route three times/24 or 36 hours. In 17 infants after Indomethacin treatment the duct closed, in two infants the duct did not close during Indomethacin treatment, in three infants the authors observed oliguria which improved after discontinuation of treatment.