Echocardiographically determined left ventricular mass index in normal children, adolescents and young adults

Left ventricle hypertrophy and re-modeling in children with essential hypertension: does the race matter?

BACKGROUND

This is the first study to report on the impact of race on differences in the prevalence of echocardiographic left ventricular hypertrophy and left ventricular adaptation at the time of diagnosis of essential hypertension in children.

METHODS

This cross-sectional, single-centre study included patients aged 3-18 years who had newly diagnosed essential hypertension. Echocardiography was used to assess left ventricular mass index and left ventricular relative wall thickness. An left ventricular mass index > the 95th percentile for age and gender, and an left ventricular relative wall thickness > 0.42, were used to diagnose left ventricular hypertrophy and concentric adaptation. Various echocardiographic parameters were compared between African Americans and Caucasians.

RESULTS

The study included 422 patients (289 African Americans and 133 Caucasians) diagnosed with essential hypertension at a median age of 14.6 (interquartile range; 12.1-16.3) years. Eighty-eight patients (20.9%) had left ventricular hypertrophy. There was no statistically significant difference in the prevalence of left ventricular hypertrophy between African Americans and Caucasians (22.5% versus 17.3%, p=0.22). The median left ventricular relative wall thickness was 0.35 (0.29-0.43), and 114 patients (27.0%) had an left ventricular relative wall thickness > 0.42. The presence of an left ventricular relative wall thickness > 0.42 was significantly higher among African Americans compared to Caucasians (30.1% versus 20.3%, p = 0.04). The African American race was a strong predictor for an left ventricular relative wall thickness > 0.42 (odds ratio 1.7, p = 0.04), but not for left ventricular mass index > the 95th percentile (p = 0.22). Overweight/obesity was a strong predictor for an left ventricular mass index > the 95th percentile.

CONCLUSIONS

There was no difference in the prevalence of left ventricular hypertrophy in children with essential hypertension of different races. Obesity, rather than being African American, is associated with left ventricular hypertrophy.

A three-dimensional atlas of child's cardiac anatomy and the unique morphological alterations associated with obesity

AIMS

Statistical shape models (SSMs) of cardiac anatomy provide a new approach for analysis of cardiac anatomy. In adults, specific cardiac morphologies associate with cardiovascular risk factors and early disease stages. However, the relationships between morphology and risk factors in children remain unknown. We propose an SSM of the paediatric left ventricle to describe its morphological variability, examine its relationship with biometric parameters and identify adverse anatomical remodelling associated with obesity.

METHODS AND RESULTS

This cohort includes 2631 children (age 10.2 ± 0.6 years), mostly Western European (68.3%) with a balanced sex distribution (51.3% girls) from Generation R study. Cardiac magnetic resonance short-axis cine scans were segmented. Three-dimensional left ventricular (LV) meshes are automatically fitted to the segmentations to reconstruct the anatomies. We analyse the relationships between the LV anatomical features and participants' body surface area (BSA), age, and sex, and search for features uniquely related to obesity based on body mass index (BMI). In the SSM, 19 modes described over 90% of the population's LV shape variability. Main modes of variation were related to cardiac size, sphericity, and apical tilting. BSA, age, and sex were mostly correlated with modes describing LV size and sphericity. The modes correlated uniquely with BMI suggested that obese children present with septo-lateral tilting (R2 = 4.0%), compression in the antero-posterior direction (R2 = 3.3%), and decreased eccentricity (R2 = 2.0%).

CONCLUSIONS

We describe the variability of the paediatric heart morphology and identify anatomical features related to childhood obesity that could aid in risk stratification. Web service is released to provide access to the new shape parameters.

Necropsy Validation of a Novel Method for Left Ventricular Mass Quantification in Porcine Transthoracic and Transdiaphragmal Echocardiography

Introduction

Increased left ventricular mass (LVM) is one of the most powerful predictors of adverse cardiovascular events. Clinical evaluation requires reliable, accurate and reproducible echocardiographic LVM-quantification to manage patients. For this purpose, we have developed a novel two-dimensional (2D) method based on adding the mean wall thickness to the left ventricular volume acquired by the biplane method of disks, which has recently been validated in humans using cardiac magnetic resonance as reference value. We assessed the hypothesis that the novel method has better accuracy than conventional one-dimensional (1D) methods, when compared to necropsy LVM in pigs.

Materials and Methods

Echocardiography was performed during anesthesia in 34 Danish Landrace pigs, weight 47–59 kg. All pigs were euthanized, cardiac necropsy was performed and the left ventricle was trimmed and weighed for necropsy LVM. Trans-thoracic echocardiography was applied for parasternal images. Transdiaphragmal echocardiography was applied for the apical images, which are otherwise difficult to obtain in pigs. We compared the conventional 1D- and 2D-methods and the novel 2D-method to the LVM from cardiac necropsy.

Results

Necropsy LVM was 132 ± 11 g (mean ± SD). The novel method had better accuracy than other methods (mean difference ± 95% limits of agreement; coefficients of variation; standard error of the estimate, Pearson's correlation). Novel (−1 ± 20 g; 8%; 11 g; r = 0.70), Devereux (+26 ± 37 g; 15%; 33 g; r = 0.52), Area-Length (+27 ± 34 g; 13 %; 33 g; r = 0.63), Truncated Ellipsoid (+10 ± 30 g; 12%; 19 g; r = 0.63), biplane endo-/epicardial tracing (−3 ± 2 g; 10%; 14 g; r = 0.57). No proportional bias in linear regression was detected for any method, when compared to necropsy LVM.

Conclusion

We confirm high accuracy of the novel 2D-based method compared to conventional 1D/2D-methods.

Correlation Between Liver Stiffness and Diastolic Function, Left Ventricular Hypertrophy, and Right Cardiac Function in Patients With Ejection Fraction Preserved Heart Failure

Objective: Ejection fraction preserved heart failure (HFpEF) is a common clinical syndrome with a high morbidity, accounting for ~50% of all heart failure patients, and a mortality comparable to that of ejection fraction reduced heart failure (HFrEF). The relationship between liver stiffness (LS) and HFpEF remains unclear. The purpose of this study was to explore the correlation between LS and the severity of HFpEF.

Methods: We performed a prospective observational study. After accepting liver transient elastography on admission, consecutive 150 hospitalized HFpEF patients were divided into three groups based on their liver elasticity value: first-third quartiles. Left ventricular diastolic function, left ventricular hypertrophy degree, right cardiac function and short-term prognosis (≤1 year) were compared among the three groups, and the correlation between liver elasticity and each indicator was analyzed.

Results: The elasticity of the liver was abnormally high in more than two-thirds of cases. The proportion of NYHA class III-IV in the third quartile group was significantly higher than that in the first quartile group (96 vs. 70%, P = 0.013). Significant differences were discovered in the level of lgNT-proBNP between the three groups (2.63 ± 0.65 vs. 2.84 ± 0.44 vs. 3.05 ± 0.71, P = 0.027). In terms of diastolic function and left ventricular hypertrophy, the ventricular septal e′ (5.01 ± 2.69 vs. 6.48 ± 2.29, P = 0.025), lateral wall e′ (6.63 ± 3.50 vs. 8.62 ± 2.73, P = 0.013), mean E/e′ (20.06 ± 7.53 vs. 13.20 ± 6.05, P = 0.001), left atrial volume index (43.53 ± 10.94 vs. 35.78 ± 13.86, P = 0.008), tricuspid regurgitation (TR) peak flow rate (3.16 ± 0.44 vs. 2.75 ± 0.50, P < 0.001), left ventricular mass index (LVMI) in male (163.2 ± 47.6 vs. 131.3 ± 38.0, P = 0.015) and in female (147.4 ± 48.6 vs. 110.6 ± 24.3, P = 0.036) was significantly different between the third quartile and the first quartile. The proportion of patients with diastolic dysfunction in the third quartile was significantly higher than that in the first quartile (70 vs. 36%, P = 0.017). In terms of right cardiac function, right ventricular fractional area change (RVFAC) (30.3 ± 5.4 vs. 36.5 ± 6.8, P < 0.001), tricuspid annular plane systolic excursion (TAPSE) (7.7 ± 5.2 vs. 14.8 ± 5.9, P = 0.010), pulmonary systolic pressure (38.0 ± 10.5 vs. 32.4 ± 10.3, P = 0.005), TR peak flow rate (3.16 ± 0.44 vs. 2.75 ± 0.50, P < 0.001), and inferior vena cava diameter (2.53 ± 0.51 vs. 1.98 ± 0.41, P < 0.001) were significantly different between the third quartile and the first quartile. More than half of HFpEF patients were combined with right ventricular dysfunction (RVD). Compared to HFpEF without RVD, HFpEF with RVD had higher male sex (53.6 vs. 30.3%, P < 0.001), higher NYHA class (3.2 ± 0.6 vs. 2.8 ± 0.6, P = 0.010), higher proportion of atrial fibrillation (45.2 vs. 18.2%, P < 0.001), and higher liver elasticity value (7.95 ± 0.60 vs. 7.31 ± 0.84, P = 0.003). In terms of short-term prognosis, the incidence of adverse cardiovascular events was significantly higher in the third quartile than in the first quartile (P = 0.003) and the second quartile (P = 0.008). Multivariate Cox proportional hazard analysis showed that adverse cardiovascular events were independently associated with NYHA class, atrial fibrillation, lgNT-proBNP and liver elasticity value (HR = 1.208, 95% CI 1.115–1.352, P = 0.002).

Conclusion: Increase of liver stiffness is common in HFpEF patients. Increased LS in HFpEF patients was significantly associated with worsen left diastolic function, left ventricular hypertrophy, and the right cardiac function. LS in HFpEF patients may be more than the result of right ventricular dysfunction. Male, atrial fibrillation, poorer NYHA class and increased liver elasticity value were significantly associated with HFpEF combined with RVD. Atrial fibrillation, poorer NYHA class, higher NT-proBNP, and increased liver elasticity value were independent predictors of poor short-term prognosis of HFpEF patients.

Left Ventricular Geometrical Changes in Severely Obese Adolescents: Prevalence, Determinants, and Clinical Implications

Left ventricular hypertrophy (LVH) is independently associated with a higher risk of cardiovascular morbidity and mortality in adults. Adiposity is a risk factor for LVH, independent of blood pressure. Potential causes of this nonhemodynamic pathogenesis identified in adults include adverse body fat distribution, insulin resistance, dyslipidemia, and obstructive sleep apnea syndrome (OSA). In severely obese adolescents, the determinants of obesity-induced changes in left ventricular structure are poorly characterized. Cardiac ultrasonographic, demographic, anthropometric, and comorbidity-related data were prospectively collected in adolescents with severe obesity refractory to conservative treatment who presented for surgical therapy. Differences between adolescents with LVH and without LVH were evaluated using independent samples t, chi-square, or Fisher's exact test. Multivariable linear regression analysis was performed to evaluate associations with left ventricular structural changes, corrected for body mass index (BMI) z score. Forty-three patients entered analysis, of whom 24 (55.8%) showed LVH. The most common geometrical change was eccentric LVH (eLVH), occurring in 21 subjects (48.8%). Demographic and anthropometric variables did not differ between patients with and without LVH. Independent of BMI z score, left ventricular mass index was significantly associated with apnea-hypopnea index (AHI) (regression parameter B = 0.8; 95% CI 0.3 to 1.2). Interventricular septum thickness (IVST) was significantly associated with HOMA-IR values (B = 0.1; 95% CI 0.04 to 0.2), HDL-cholesterol (B = - 1.2; 95% CI - 2.2 to 0.1), and triglyceride levels (B = 0.5; 95% CI 0.001 to 0.9). LVH, especially eLVH, is highly prevalent amongst severely obese adolescents. Adverse changes in cardiac structure, increased IVST in particular, are independently associated with several nonhemodynamic comorbidities that are common in this population, namely OSA, insulin resistance, and dyslipidemia.

Left ventricular mass normalization in child and adolescent athletes must account for sex differences

Background

To assess left ventricular hypertrophy, actual left ventricular mass (LVM) normalized for body size has to be compared to the LVM normative data. However, only some published normative echocardiographic data have been produced separately for girls and boys; numerous normative data for the pediatric population are not sex-specific. Thus, this study aimed to assess whether the LVM normative data should be developed separately for girls and boys practicing sports.

Methods

Left ventricular mass was computed for 331 girls and 490 boys, 5–19 years old, based on echocardiography. The effect of sex on the relationship between LVM and body size was evaluated using a linear regression model. Seven sets of the LVM normative data were developed, using different methodologies, to test concordance between sex-specific and non-specific normative data. Every set consisted of normative data that was sex-specific and non-specific. Upon these normative data, for every study participant, seven pairs of LVM z-scores were calculated based on her/his actual LVM. Each pair consisted of z-scores computed based on sex-specific and non-specific normative data from the same set.

Results

The regression lines fitted to the data points corresponding to LVM of boys had a higher slope than of girls, indicating that sex affects the relationship between LVM and body size. The mean differences between the paired LVM z-scores differed significantly from 0. The percentage of discordant indications, depending on the normalization method, ranged from 66.7% to 100% in girls and from 35.4% to 50% in boys. Application of the LVM normative data that were not sex-specific made relative LVM underestimated in girls and overestimated in boys.

Conclusion

The LVM normative data should be developed separately for girls and boys practicing sports. Application of normative data that are not sex-specific results in an underestimation of relative LVM in girls and overestimation in boys.

Racial Differences in Left Ventricular Mass and Wave Reflection Intensity in Children

The burden of heart failure is disproportionately higher in African Americans, with a higher prevalence seen at an early age. Examination of racial differences in left ventricular mass (LVM) in childhood may offer insight into risk for cardiac target organ damage (cTOD) in adulthood. Central hemodynamic load, a harbinger of cTOD in adults, is higher in African Americans. The purpose of this study was to examine racial differences in central hemodynamic load and LVM in African American and non-Hispanic white (NHW) children. Two hundred sixty-nine children participated in this study (age, 10 ± 1 years; n = 149 female, n = 154 African American). Carotid pulse wave velocity (PWV), forward wave intensity (W1) and reflected wave intensity (negative area, NA) was assessed from simultaneously acquired distension and flow velocity waveforms using wave intensity analysis (WIA). Wave reflection magnitude was calculated as NA/W1. LVM was assessed using standard 2D echocardiography and indexed to height as LVM/[height (2.16) + 0.09]. A cutoff of 45 g/m (2.16) was used to define left ventricular hypertrophy (LVH). LVM was higher in African American vs. NHW children (39.2 ± 8.0 vs. 37.2 ± 6.7 g/m (2.16), adjusted for age, sex, carotid systolic pressure and socioeconomic status; p < 0.05). The proportion of LVH was higher in African American vs. NHW children (25 vs. 12 %, p < 0.05). African American and NHW children did not differ in carotid PWV (3.5 ± 4.9 vs. 3.3 ± 1.3 m/s; p > 0.05). NA/W1 was higher in African American vs. NHW children (8.5 ± 5.3 vs. 6.7 ± 2.9; p < 0.05). Adjusting for NA/W1 attenuated racial differences in LVM (38.8 ± 8.0 vs. 37.6 ± 7.0 g/m (2.16); p = 0.19). In conclusion, racial differences in central hemodynamic load and cTOD are present in childhood. African American children have greater wave intensity from reflected waves and higher LVMI compared to NHW children. WIA offers novel insight into early life origins of racial differences in central hemodynamic load and cTOD.

Subclinical myocardial disease in patients with primary hyperoxaluria and preserved left ventricular ejection fraction: a two-dimensional speckle-tracking imaging study

BACKGROUND

Primary hyperoxaluria (PH) is characterized by progressive chronic kidney disease (CKD) and systemic oxalate deposition. Myocardial dysfunction might be present early in the course of the disease. However, this hypothesis has not yet been tested in the PH population. Therefore, we aimed to determine whether strain imaging using two-dimensional speckle tracking echocardiography (2D-STE) might detect subclinical myocardial disease in otherwise asymptomatic PH patients.

METHODS

Prospective study of pediatric and adolescent PH patients with preserved LV ejection fraction (LV EF) and without renal replacement therapy. Subjects underwent conventional echocardiography and 2D-STE. Global (GLS) and segmental peak systolic LV longitudinal strain (LS) measurements were obtained. Data were compared with age- and gender-matched controls, and Z-scores were calculated as appropriate.

RESULTS

Fifteen PH patients (age 14.1 ± 5.9 years; 13/15 in CKD stages 1-2) were studied. Although LV EF was preserved (63 ± 6%) in patients, GLS was significantly impaired (GLS - 17.1 ± 2.2% vs - 22.4 ± 1.9%, p < 0.001). This was mainly due to decreased LS values in the apical segments (p < 0.05). Echocardiographic indices of ventricular wall thickness were significantly increased in patients compared to controls (all p < 0.03). GLS correlated significantly with Z-scores of diastolic interventricular wall thickness (r = - 0.57, p = 0.025) and moderately with serum creatinine levels (r = 0.53, p = 0.044). No correlation was found between GLS and blood pressure measurements.

CONCLUSIONS

Subclinical myocardial disease is already present early in the course of disease in PH patients with preserved LV EF and some degree of renal dysfunction, but without overt systemic oxalosis. Current recommendations to screen only PH patients with advanced CKD for cardiac disease should be revised accordingly.

Physiological Responses to Exercise in Pediatric Heart Transplant Recipients

INTRODUCTION

Pediatric heart transplant (HTx) recipients have reduced exercise capacity typically two-thirds of predicted values, the mechanisms of which are not fully understood. We sought to assess the cardiorespiratory responses to progressive exercise in HTx relative to controls matched for age, sex, body size, and work rate.

METHODS

Fourteen HTx recipients and matched controls underwent exercise stress echocardiography on a semisupine cycle ergometer. Hemodynamics, left ventricular (LV) dimensions, and volumes were obtained and indexed to body surface area. Oxygen consumption (V˙O2) was measured, and arteriovenous oxygen difference was estimated using the Fick Principle.

RESULTS

At rest, LV mass index (P = 0.03) and volumes (P < 0.001) were significantly smaller in HTx, whereas wall thickness (P < 0.01) and LV mass-to-volume ratio (P = 0.01) were greater. Differences in LV dimensions and stroke volume persisted throughout exercise, but the pattern of response was similar between groups as HR increased. As exercise progressed, heart rate and cardiac index increased to a lesser extent in HTx. Despite this, V˙O2 was similar (P = 0.82) at equivalent work rates as HTx had a greater change in arteriovenous oxygen difference (P < 0.01).

CONCLUSIONS

When matched for work rate, HTx had similar metabolic responses to controls despite having smaller LV chambers and an attenuated increase in hemodynamic responses. These findings suggest that HTx may increase peripheral O2 extraction as a compensatory mechanism in response to reduced cardiovascular function.

Increased asymmetric dimethylarginine in vitamin B12 deficient adolescents

OBJECTIVE

Vitamin B12 deficiency induces hyper-hyperhomocysteinemia by inhibiting intracellular methionine re-methylation. Hyper-hyperhomocysteinemia increases the risk of atherosclerosis. Asymmetric dimethylarginine is an endogenous inhibitor of nitric oxide synthase and its level elevates in cardiovascular diseases. In this study, we aimed to examine the relationship between asymmetric dimethylarginine and arterial stiffness and atherosclerosis in adolescents with vitamin B12 deficiency.

METHODS

A total of 88 adolescents with age ranging between 11 and 17 years of age were enrolled for this study. Among them, 50 patients had vitamin B12 deficiency 200 pg/ml. In all cases, the levels of asymmetric dimethylarginine were measured with high performance liquid chromatography method. The carotid artery intima media thickness and left ventricular mass index were measured using echocardiography. All these measurements of the study groups were compared.

RESULTS

Both plasma levels of asymmetric dimethylarginine and carotid artery intima media thickness were significantly higher in the vitamin B12 deficiency group than in the control group. Correlation analysis showed significant negative correlation of vitamin B12 with homocysteine, asymmetric dimethylarginine, and carotid artery intima media thickness (p&lt;0.05).

CONCLUSION

Our results suggest that endothelial dysfunction starts in the early stage of adolescent vitamin B12 deficiency, and vitamin B12-deficient adolescents have increased circulating asymmetric dimethylarginine, showing that endothelial dysfunction and increased carotid artery intima media thickness be related to atherosclerosis.

Exposure of immature rat heart to antenatal glucocorticoid results in cardiac proliferation

BACKGROUND

ATP synthesis and cardiac contraction-related protein production are accelerated in the immature fetal heart by antenatal glucocorticoids (GC). This study investigated the structural maturity of the myocardium and underlying signal pathway associated with cardiac growth in fetal rats that received antenatal GC.

METHODS AND RESULTS

Dexamethasone (DEX) was given to pregnant rats for 2 days from day 17 or day 19 of gestation, and the hearts of 19 and 21 day fetuses and 1-day-old neonates were analyzed. Although irregular myofibril orientation was observed morphologically in 19 day fetal hearts, the myofibril components were organized in fetuses after DEX. The cross-sectional area of the myocardium and Ki-67-positive cells were significantly increased in fetal DEX groups, suggesting that cardiac enlargement resulted from myocyte proliferation. Glycogen synthase kinase-3β (GSK-3β) protein was significantly decreased in fetal DEX groups. β-Catenin and vascular endothelial growth factor protein were also significantly increased. Furthermore, increased cardiomyocyte proliferation appeared to be mediated by GC receptors after culture with DEX in vitro.

CONCLUSIONS

Antenatal DEX induces structural maturity accompanying cardiomyocyte proliferation in the premature fetal rat heart, and GSK-3β and β-catenin are thought to contribute to cardiac growth.

Racial Variation in Echocardiographic Reference Ranges for Left Chamber Dimensions in Children and Adolescents: A Systematic Review

Echocardiography plays a critical role in the assessment of cardiac disease. Important differences in echocardiographically derived cardiac chamber dimensions have been previously highlighted in different population groups in adult studies, but this has not been systematically studied in children, whose body size changes throughout childhood. The aim of this study was to review the distribution of available reference ranges for the left cardiac chamber dimensions in older children and adolescents. The following electronic data bases were searched: Medline, Embase and Web of Science were searched to identify studies which have established echocardiographic reference ranges of left heart parameters in children and adolescents from 1975 to December 2017. There was no geographical limitation. All results were imported into Endnote. Retrieved articles were screened and data extracted by two independent reviewers. A total of 4398 studies were retrieved, with 36 studies finally included in this review. 29 (81%) references were from North America and European (Caucasians) populations, with only one study each from Africa and South America. Two-dimensional and M-mode techniques were the most commonly used echocardiography techniques. There were methodological variations in techniques and normalisation of references. Comparison of selected cardiac measures showed significant differences for interventricular septal thickness among Black African, Indian, German and US American children. Available echocardiographic references cannot be generalised to all settings and therefore, there is need for locally relevant reference ranges. Africa and South America are particularly under-represented. Future studies should focus on developing comprehensive echocardiographic reference ranges for children from different racial backgrounds and should use standardised techniques.

Association of Habitual Physical Activity With Cardiovascular Risk Factors and Target Organ Damage in Adolescents and Young Adults

BACKGROUND

We aimed to (1) compare a subjective and objective measure of habitual physical activity (PA), (2) determine the association of PA and cardiovascular risk factors, and (3) test the hypothesis that PA is an independent determinant of target organ damage in youth.

METHODS

Cross-sectional analysis of youth with and without type 2 diabetes [mean age = 22 (3.9) y]. PA was measured with International Physical Activity Questionnaire and Actical accelerometer. Target organ damage was assessed with echocardiography and peripheral arterial testing. Subjects were stratified into tertiles of total PA, and differences were tested by analysis of variance and χ² tests. General linear models tested for independent associations.

RESULTS

The correlation between International Physical Activity Questionnaire and accelerometry was weak (r = .23, P = .0003). Less active subjects had worse cardiovascular risk profiles and target organ damage, including stiffer arteries (P < .01). These outcome differences did not reach statistical significance when adjusted for covariates, such as lipid levels and glycemic control.

CONCLUSION

Survey assessment of PA is complicated by inaccurate reporting. There is a strong association of habitual PA with cardiovascular risk factor clustering. PA may exert its beneficial effect on arterial stiffness in obese youth through improved glycemic control.

Myocardial Deformation Measured by 3-Dimensional Speckle Tracking in Children and Adolescents With Systemic Arterial Hypertension

Systemic arterial hypertension predisposes children to cardiovascular risk in childhood and adult life. Despite extensive study of left ventricular (LV) hypertrophy, detailed 3-dimensional strain analysis of cardiac function in hypertensive children has not been reported. The aim of this study was to evaluate LV mechanics (strain, twist, and torsion) in young patients with hypertension compared with a healthy control group and assess factors associated with functional measurements. Sixty-three patients (26 hypertension and 37 normotensive) were enrolled (mean age, 14.3 and 11.4 years; 54% men and 41% men, respectively). All children underwent clinical evaluation and echocardiographic examination, including 3-dimensional strain. There was no difference in LV volumes and ejection fraction between the groups. Myocardial deformation was significantly reduced in those with hypertension compared with controls. For hypertensive and normotensive groups, respectively, global longitudinal strain was -15.1±2.3 versus -18.5±1.9 (P<0.0001), global circumferential strain -15.2±3 versus -19.9±3.1 (<0.0001), global radial strain +44.0±11.3 versus 63.4±10.5 (P<0.0001), and global 3-dimensional strain -26.1±3.8 versus -31.5±3.8 (P<0.0001). Basal clockwise rotation, apical counterclockwise rotation, twist, and torsion were not significantly different. After multivariate regression analyses blood pressure, body mass index and LV mass maintained a significant relationship with measures of LV strain. Similar ventricular volumes and ejection fraction were observed in hypertensive and normotensive children, but children with hypertension had significantly lower strain indices. Whether reduced strain might predict future cardiovascular risk merits further longitudinal study.

Influence of the Method of Definition on the Prevalence of Left-Ventricular Hypertrophy in Children with Chronic Kidney Disease: Data from the Know-Ped CKD Study

BACKGROUND/AIMS

Children with chronic kidney disease (CKD) have a high risk of cardiovascular disease. Left-ventricular (LV) hypertrophy (LVH) is an early marker of cardiovascular disease in pediatric CKD, and the prevalence of LVH in pediatric CKD is approximately 20-30% in pre-dialysis CKD patients. However, there is no consensus on the ideal method of defining LVH in pediatric CKD patients. Previous studies have typically used the LV mass index (LVMI), which is calculated as LV mass in grams divided by height in meters to the 2.7th power ≥ 38 g/m2.7, to diagnose LVH in children with CKD. Recently, age-specific reference values for LVMI ≥ 95th percentile and LV wall-thickness z-score > 1.64 in children were addressed. The aim of this study was to assess the prevalence and contributing factors of LVH in pediatric CKD patients according to each measurement and evaluate the concordance between each measurement.

METHODS

We used the baseline data of the KoreaN cohort study for Outcome in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD), which is a nationwide, 10-year, prospective, observational cohort study of pediatric CKD. A total of 469 patients were enrolled, and 458 patients were included in the final analysis. Univariate and multiple logistic regression analysis were performed to evaluate the association of the variables with LVH. Kappa statistics were used to analyze the concordance.

RESULTS

According to an LVH diagnosis of LVMI ≥ 38 g/m2.7, 188 patients (41.0%) were diagnosed with LVH, and the prevalence of LVH was high in younger patients (< 2 years of age). Using the age-specific reference values, 116 patients (25.3%) were diagnosed with LVH, and there was no difference in the prevalence of LVH according to age. Thirty-one patients (6.8%) were diagnosed with LVH using an LV wall-thickness z-score > 1.64. There is poor concordance between the diagnosis of LVH using the LV wall-thickness z-score and the LVMI method.

CONCLUSIONS

The results of this study show that there is poor concordance between the diagnosis of LVH using the wall-thickness z-score and the LVMI2.7 criteria. Further investigation is needed to estimate the correlation between LVH and cardiac dysfunction and to find a better method for defining LVH in the pediatric CKD cohort and thereby predicting cardiac dysfunction.

The role of echocardiography in the evaluation of cardiac re-modelling and differentiation between physiological and pathological hypertrophy in teenagers engaged in competitive amateur sports

Aims "Athlete's heart" is a cardiac adaptation to long-term intensive training. The aims of this study were to show the prevalence of left ventricular hypertrophy in teenagers who participate in sports, to define the different types of cardiac re-modelling, and to differentiate between physiological and pathological hypertrophy.

METHOD

Echocardiographic measurements were obtained by M-mode, two dimensional, and Doppler techniques of participants from sports and control groups.

RESULTS

The echocardiographic examinations included 100 healthy teenagers taking part in dynamic sports such as football and basketball and 100 healthy teenagers taking part in static sports such as karate and judo. The control group (n=100) included healthy, sedentary teenagers. Sports participants had significantly higher left ventricular mass when compared with the control group, (p0.05). Respondents from both groups had E/A ratios (transmitral flow velocity ratio)>1, preserved diastolic function, and statistically they did not differ from the control group.

CONCLUSION

Echocardiographic parameters show that physiological hypertrophy and cardiac re-modelling are present in teenagers who play sports. Unexpectedly, the prevalence of concentric and eccentric types of re-modelling is equally possible in the group of static sports participants.

Cardiovascular Disease Risk Factors and Left Ventricular Hypertrophy in Girls and Boys With CKD

BACKGROUND AND OBJECTIVES

Prior studies suggested that women with CKD have higher risk for cardiovascular disease (CVD) and mortality than men, although putative mechanisms for this higher risk have not been identified. We assessed sex differences in (1) CVD risk factors and left ventricular hypertrophy (LVH), and (2) the relationship of left ventricular mass (LVM) with different measures of body size in children with CKD.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

The study population comprised 681 children with CKD from the Chronic Kidney Disease in Children cohort, contributing 1330 visits. CVD risk factors were compared cross-sectionally by sex. LVH was defined as LVM/height2.7 >95th percentile and LVM relative to estimated lean body mass (eLBM) >95th percentile for age and sex. Differences in LVM by sex were assessed by adjusting for age, weight, height, and eLBM using bivariate and multivariate regression models.

RESULTS

Girls were less likely to have uncontrolled hypertension (26% versus 38%, P=0.001), had lower diastolic BP z-scores (+0.3 versus +0.6, P=0.001), and had lower prevalence of high triglycerides (38% versus 47%, P=0.03) compared with boys. When LVH was defined by LVM indexed to height, girls had higher prevalence of LVH (16% versus 9%, P=0.01); when LVH was defined by LVM relative to eLBM, prevalence of LVH was similar between girls and boys (18% versus 17%, P=0.92). In regression models adjusting for eLBM, no sex differences in LVM were observed.

CONCLUSIONS

Despite lack of increased prevalence of CVD risk factors, indexing LVM to height showed a higher proportion of LVH among girls, while estimates of LVH based on eLBM showed no sex differences. Indexing LVM to eLBM may be an alternative to height indexing in children with CKD.

Cardiac Abnormalities in Youth with Obesity and Type 2 Diabetes

Childhood obesity has been linked to cardiovascular disease (CVD) risk in adulthood. Of great concern is the expected increase in the population's CVD burden in relation to childhood obesity. This is compounded by the risk related to chronic hyperglycemia exposure in youth with type 2 diabetes. We herein provide an overview of the spectrum of early cardiovascular disease manifestation in youth with obesity and type 2 diabetes, in particular abnormalities in cardiac structure and function. Cardiac remodeling and adverse target organ damage is already evident in the pediatric age group in children with obesity and type 2 diabetes. This supports the importance of intensifying obesity prevention efforts and early intervention to treat comorbidities of obesity in the pediatric age group to prevent cardiac events in early adulthood.

Association between left ventricular mass, androgens, adiposity and insulin resistance in girls with precocious pubarche: a case-control study

OBJECTIVE

Precocious pubarche (PP) has been linked to higher prevalence of metabolic disturbances and polycystic ovary syndrome (PCOS). The aim of the study was to assess echocardiographic parameters in PP girls and to analyse their relationship with androgens and insulin resistance (IR).

DESIGN

Case-control study.

PATIENTS

Thirty-five PP girls and 35 healthy age-matched controls.

MEASUREMENTS

Clinical, hormonal and metabolic profiles, echocardiography, body composition and oral glucose tolerance test.

RESULTS

Chronological age (10·04 ± 2·6 years in PP vs 10·13 ± 2·56 years in controls, P = 0·227), and pubertal stage at the time of the study were similar between the groups. PP girls had higher free androgen index (FAI) [1·39 (0·48-3·64) vs 1·06 (0·39-1·7), P = 0·005] and QUICKI (0·58 ± 0·08 vs 0·63 ± 0·12, P = 0·021). However, HOMA-IR was not significantly different between the groups [2·79 (1·84-4·05) vs 2·15 (1·09-3·23), P = 0·085]. After adjusting for total body fat, left ventricular mass (LVM) was higher in the PP group (97·31 ± 33·37 vs 81·25 ± 19·06 g, P = 0·017) as well as A' wave (5·66 ± 1·34 vs 5·09 ± 0·98 cm/s, P = 0·025), a measurement of diastolic function. FAI and total body fat were independent predictors of higher LVM and together with HOMA-IR contributed 72% of LVM variability in the PP group.

CONCLUSION

In this study with PP girls, greater LVM, associated with higher androgen levels, IR and total body fat, occurred early in pubertal development.

New Reference Centiles for Left Ventricular Mass Relative to Lean Body Mass in Children

BACKGROUND

Echocardiographic measurement of left ventricular (LV) mass is routinely performed in pediatric patients with elevated cardiovascular risk. The complex relationship between heart growth and body growth in children requires normalization of LV mass to determine its appropriateness relative to body size. LV mass is strongly determined by lean body mass (LBM). Using new LBM predictive equations, the investigators generated sex-specific LV mass-for-LBM centile curves for children 5 to 18 years of age.

METHODS

This retrospective study used M-mode echocardiographic data collected from 1995 through 2003 from 939 boys and 771 girls between 5 and 18 years of age (body mass index < 85th percentile for sex and age) to create smoothed sex-specific LV mass-for-LBM reference centile curves using the Lamda Mu Sigma method. The newly developed reference centiles were applied to children with essential hypertension and with chronic kidney disease, groups known to be at high risk for LV hypertrophy (LVH). The identification of LVH using two different normalization approaches was compared: LV mass-for-LBM and LV mass index-for-age percentiles.

RESULTS

Among 231 children at risk for LVH, on average, relative LV mass was higher using the LV mass index-for-age percentile method than the LV mass-for-LBM percentile method. LVH was more likely to be diagnosed among overweight children and less likely among thin children.

CONCLUSIONS

This study provides new LV mass reference centiles expressing LV mass relative to LBM, the strongest determinant of LV mass. These reference centiles may allow more accurate stratification of cardiovascular risk in children.

The effects of sports participation on the development of left ventricular mass in adolescent boys

OBJECTIVES

To examine the contribution of body size, biological maturation, and nonelite sports participation to longitudinal changes of left ventricular mass (LVM) in healthy boys.

METHODS

One hundred and ten boys (11.0-14.5 years at baseline) were assessed biannually for 2 years. Stature, body mass, and four skinfolds were measured. Lean body mass (LBM) was estimated. Biological maturation was assessed as years from age at peak height velocity (APHV). Sports participation was assessed by questionnaire. LVM was obtained from M-mode echocardiograms using two-dimensional images. To account for the repeated measures within individual nature of longitudinal data, multilevel random effects regression analyses were used in the analysis.

RESULTS

LVM increased on average 42 ± 18 g from 11 to 15 years (P < 0.05) and 76 ± 14 g from 3.5 years pre-APHV to 1.5 years post-APHV (P < 0.05). The multilevel model with the best statistical fit (Model B) showed that changes of 1 cm in stature, 1 year post-APHV, and 1 kg of LBM predicts 4.7, 0.5, and 1 g of LVM (P < 0.05), respectively.

CONCLUSIONS

Among healthy, male adolescents aged 11-15 years individual differences in growth and biological maturation influence growth of LVM. Subcutaneous adiposity and sports participation were not associated with greater LVM.

Insulin resistance, dyslipidemia and cardiovascular changes in a group of obese children

Introduction

Obesity-related comorbidities are present in young obese children, providing a platform for early adult cardiovascular disorders.

Objectives

To compare and correlate markers of adiposity to metabolic disturbances, vascular and cardiac morphology in a European pediatric obese cohort.

Methods

We carried out an observational and transversal analysis in a cohort consisting of 121 obese children of both sexes, between the ages of 6 and 17 years. The control group consisted of 40 children with normal body mass index within the same age range. Markers of adiposity, plasma lipids and lipoproteins, homeostasis model assessment-insulin resistance, common carotid artery intima-media thickness and left ventricular diameters were analyzed.

Results

There were statistically significant differences between the control and obese groups for the variables analyzed, all higher in the obese group, except for age, high-density lipoprotein cholesterol and adiponectin, higher in the control group. In the obese group, body mass index was directly correlated to left ventricular mass (r=0.542; p=0.001), the homeostasis model assessment-insulin resistance (r=0.378; p=<0.001) and mean common carotid artery intima-media thickness (r=0.378; p=<0.001). In that same group, insulin resistance was present in 38.1%, 12.5% had a combined dyslipidemic pattern, and eccentric hypertrophy was the most common left ventricular geometric pattern.

Conclusions

These results suggest that these markers may be used in clinical practice to stratify cardiovascular risk, as well as to assess the impact of weight control programs.

Associations between childhood body size, composition, blood pressure and adult cardiac structure: the Fels Longitudinal Study

Objectives

To determine whether childhood body size, composition and blood pressure are associated with adult cardiac structure by estimating childhood “age of divergence.”

Methods

385 female and 312 male participants in the Fels Longitudinal Study had echocardiographic measurements of left ventricular mass, relative wall thickness, and interventricular septal thickness. Also available were anthropometric measurements of body mass index, waist circumference, percentage body fat, fat free mass, total body fat, and systolic and diastolic blood pressures, taken in both childhood and adulthood. The age of divergence is estimated as the lowest age at which childhood measurements are significantly different between patients with low and high measurements of adult cardiac structure.

Results

Childhood body mass index is significantly associated with adult left ventricular mass (indexed by height) in men and women (ages of divergence: 7.5 years and 11.5 years, respectively), and with adult interventricular septal thickness in boys (age of divergence: 9 years). Childhood waist circumference indexed by height is associated with left ventricular mass (indexed by height) in boys (age of divergence: 8 years). Cardiac structure was in general not associated with childhood body composition and blood pressure.

Conclusions

Though results are affected by adult body size, composition and blood pressure, some aspects of adult cardiac structure may have their genesis in childhood body size.

Geometry-independent inclusion of basal myocardium yields improved cardiac magnetic resonance agreement with echocardiography and necropsy quantified left-ventricular mass

OBJECTIVES

Left-ventricular mass (LVM) is widely used to guide clinical decision-making. Cardiac magnetic resonance (CMR) quantifies LVM by planimetry of contiguous short-axis images, an approach dependent on reader-selection of images to be contoured. Established methods have applied different binary cut-offs using circumferential extent of left-ventricular myocardium to define the basal left ventricle (LV), omitting images containing lesser fractions of left-ventricular myocardium. This study tested impact of basal slice variability on LVM quantification.

METHODS

CMR was performed in patients and laboratory animals. LVM was quantified with full inclusion of left-ventricular myocardium, and by established methods that use different cut-offs to define the left-ventricular basal-most slice: 50% circumferential myocardium at end diastole alone (ED50), 50% circumferential myocardium throughout both end diastole and end systole (EDS50).

RESULTS

One hundred and fifty patients and 10 lab animals were studied. Among patients, fully inclusive LVM (172.6±42.3g) was higher vs. ED50 (167.2±41.8g) and EDS50 (150.6±41.1g; both P<0.001). Methodological differences yielded discrepancies regarding proportion of patients meeting established criteria for left-ventricular hypertrophy and chamber dilation (P<0.05). Fully inclusive LVM yielded smaller differences with echocardiography (Δ=11.0±28.8g) than did ED50 (Δ=16.4±29.1g) and EDS50 (Δ=33.2±28.7g; both P<0.001). Among lab animals, ex-vivo left-ventricular weight (69.8±13.2g) was similar to LVM calculated using fully inclusive (70.1±13.5g, P=0.67) and ED50 (69.4±13.9g; P=0.70) methods, whereas EDS50 differed significantly (67.9±14.9g; P=0.04).

CONCLUSION

Established CMR methods that discordantly define the basal-most LV produce significant differences in calculated LVM. Fully inclusive quantification, rather than binary cut-offs that omit basal left-ventricular myocardium, yields smallest CMR discrepancy with echocardiography-measured LVM and non-significant differences with necropsy-measured left-ventricular weight.

Detection of early diastolic alterations by tissue Doppler imaging in untreated childhood-onset essential hypertension

The aim of the study was to determine the presence of preclinical diastolic dysfunction in hypertensive children relative to normotensive children by Tissue Doppler Imaging (TDI). We prospectively enrolled children with untreated essential hypertension in absence of any other disease and a matched healthy control group with normal blood pressure (BP); both groups confirmed by clinic BP and a 24-hour ambulatory BP monitoring. Echocardiographic diastolic parameters were determined using spectral transmitral inflow Doppler, flow propagation velocity, TDI, and systolic parameters were determined via midwall shortening fraction and ejection fraction. A total of 80 multiethnic children were prospectively enrolled for the study: 46 hypertensive (median age, 13 years; 72% males) and 34 control (median age, 14 years; 65% males). The only echocardiography parameters that had a statistically significant change compared with the control children, were regional mitral Ea, Aa, and the E/Ea ratio by TDI. In comparison with controls, hypertensive children had lower Ea and Aa velocities of anterior and posterior walls and higher lateral wall E/Ea ratio. The decrease in posterior wall Ea and Aa remained significant after adjustment for gender, age, body mass index, ethnicity, and left ventricular hypertrophy on multivariate analysis. The lateral and septal wall E/Ea ratios correlated significantly with fasting serum insulin levels on similar multivariate analysis. Decreased regional TDI velocities were seen with preserved left ventricular systolic function even when other measures of diastolic dysfunction remained unchanged in untreated hypertensive children. Hypertension and serum insulin levels had strong associations with preclinical diastolic alterations in children.

Regression of left ventricular hypertrophy in children following the Ross procedure

OBJECTIVES

Left ventricular hypertrophy (LVH) frequently accompanies the progression of aortic valve disease in children. The extent of LVH regression following surgical relief of aortic valve disease in children has not been clearly elucidated. We hypothesized that significant regression of LVH will occur in children following the Ross procedure.

METHODS

We examined LVH over time in children <18 years of age who underwent the Ross procedure. Left ventricular mass index (LVMI) and corresponding z scores were calculated based on height, age and gender. Left ventricular hypertrophy was defined as an LVMI of > 39 g/m(2.7) and a z score of >1.6.

RESULTS

Twenty-five children underwent the Ross procedure. The left ventricular mass increased proportionally with the growth of the child from baseline to the latest follow-up at 7.3 ± 2.9 years (121.1 ± 81.5 vs 133.1 ± 79.8 g, P = 0.4). However, 96% (24/25) of children demonstrated LVMI regression from baseline. Mean LVMI decreased from 70.8 ± 31.2 to 41.8 ± 16.6 g/m(2.7) (P < 0.001). Similarly, LVMI z scores decreased from 2.2 ± 1.2 to 0.2 ± 1.9 (P < 0.001). Freedom from LVH was 83% at 10 years. Examination of LVMI and z scores over time demonstrated that the largest decrease occurred after the first year, with continued gradual decline over 10 years of follow-up.

CONCLUSIONS

The Ross procedure is effective in reversing LVH in children with aortic valve disease.

Concordance of measures of left-ventricular hypertrophy in pediatric hypertension

The American Academy of Pediatrics (AAP) recommends that any child diagnosed with hypertension have an echocardiogram to evaluate for the presence of left-ventricular (LV) hypertrophy (LVH) and advocates that LVH is an indication to initiate or intensify antihypertensive therapy. However, there is no consensus on the ideal method of defining LVH in the pediatric population. Many pediatric cardiologists rely on wall-thickness z-score of the LV posterior wall and/or interventricular septum to determine LVH. Yet, the AAP advocates using LV mass indexed to 2.7 (LVMI(2.7)) ≥ 51 g/m(2.7) to diagnose LVH. Recently, age-specific reference values for LVMI ≥ 95% were developed. The objective of the study was to determine the concordance between diagnosis of LVH by wall-thickness z-score and diagnosis by LVMI(2.7) criteria. A retrospective chart review was performed for subjects diagnosed with hypertension at a single tertiary care center (2009-2012). Echocardiogram reports were reviewed, and assessment of LVH was recorded. Diagnosis of LVH was assigned to each report reviewed according to three criteria: (1) LV wall-thickness z-score > 2.00; (2) age-specific reference values for LVMI(2.7) > 95th percentile; and (3) LVMI(2.7) > 51 g/m(2.7). Cohen's kappa statistic was used as a measurement of agreement between diagnosis by wall-thickness z-score and diagnosis using LVMI(2.7). A total of 159 echocardiograms in 109 subjects were reviewed. Subjects included 31 females and 77 males, age 13.2 ± 4.4 years, and 39 (42%) with a diagnosis of secondary hypertension. LVH was diagnosed in 31 cases (20%) based on increased wall-thickness z-score. Using LVMI(2.7) > 95%, LVH was found in 75 (47%) cases (mean LVMI(2.7)42.3 ± 17.2 g/m(2.7) [range 11.0-111 g/m(2.7)]). The wall-thickness z-score method agreed with LVMI(2.7) > 95% diagnosis 71% of the time (kappa 0.4). Using LVH criteria of LVMI(2.7) ≥ 51 g/m(2.7), 33 (21%) subjects were diagnosed with LVH. There was 79% agreement in the diagnosis of LVH between the wall-thickness z-score method and LVMI(2.7) > 51 g/m(2.7) (kappa 0.37). There is poor concordance between the diagnosis of LVH on echocardiogram reports using wall-thickness z-score and diagnosis of LVH using LVMI(2.7) criteria. It is important to establish a consensus method for diagnosing LVH because of the high frequency of cardiovascular complications in children with hypertension.

Effects of obesity and race on left ventricular geometry in hypertensive children

BACKGROUND

Like left ventricular hypertrophy (LVH), abnormal left ventricular (LV) geometry increases cardiovascular risk, but little data utilizing age and sex-specific norms are currently available on LV geometry in hypertensive children.

METHODS

This was a cross-sectional study of 141 hypertensive children aimed at determining the prevalence of LVH and abnormal LV geometry in the patient population and whether clinical characteristics associated with these findings differ by race. LVH was defined as an LV mass index of ≥95th percentile or cardiologist diagnosis. Abnormal geometry was defined as the presence of LVH or a relative wall thickness of >0.41.

RESULTS

The prevalence of LVH was 35 % overall. According to race, LVH prevalence was 49 % among African-Americans (AA) versus 30 % among non-AA (p < 0.05). Overweight/obesity was also highly prevalent among AA compared to non-AA (87 vs. 71 %, respectively; p = 0.03). After multivariable adjustment, the body mass index (BMI) z-score and 95 % diastolic blood pressure (BP) index were the sole independent predictors of LVH. Of the 141 hypertensive children, 40 % had abnormal LV geometry; 63 % among AA vs. 32 % among non-AA (p = 0.001). Multivariable analyses revealed a 3.8-fold increased odds of abnormal geometry among AA (p = 0.002).

CONCLUSIONS

While LVH, abnormal geometry and overweight/obesity are more prevalent among AA hypertensive children, after multivariable adjustment, BMI and race were independently associated with LVH and abnormal geometry, respectively. This result suggests that both race and obesity have important roles in the development of end-organ damage among children with primary hypertension.

Myocardial tissue remodeling in adolescent obesity

BACKGROUND

Childhood obesity is a significant risk factor for cardiovascular disease in adulthood. Although ventricular remodeling has been reported in obese youth, early tissue-level markers within the myocardium that precede organ-level alterations have not been described.

METHODS AND RESULTS

We studied 21 obese adolescents (mean age, 17.7±2.6 years; mean body mass index [BMI], 41.9±9.5 kg/m(2), including 11 patients with type 2 diabetes [T2D]) and 12 healthy volunteers (age, 15.1±4.5 years; BMI, 20.1±3.5 kg/m(2)) using biomarkers of cardiometabolic risk and cardiac magnetic resonance imaging (CMR) to phenotype cardiac structure, function, and interstitial matrix remodeling by standard techniques. Although left ventricular ejection fraction and left atrial volumes were similar in healthy volunteers and obese patients (and within normal body size-adjusted limits), interstitial matrix expansion by CMR extracellular volume fraction (ECV) was significantly different between healthy volunteers (median, 0.264; interquartile range [IQR], 0.253 to 0.271), obese adolescents without T2D (median, 0.328; IQR, 0.278 to 0.345), and obese adolescents with T2D (median, 0.376; IQR, 0.336 to 0.407; P=0.0001). ECV was associated with BMI for the entire population (r=0.58, P<0.001) and with high-sensitivity C-reactive protein (r=0.47, P<0.05), serum triglycerides (r=0.51, P<0.05), and hemoglobin A1c (r=0.76, P<0.0001) in the obese stratum.

CONCLUSIONS

Obese adolescents (particularly those with T2D) have subclinical alterations in myocardial tissue architecture associated with inflammation and insulin resistance. These alterations precede significant left ventricular hypertrophy or decreased cardiac function.

Systemic blood pressure after stent management for arch coarctation implications for clinical care

OBJECTIVES

The goal of this study was to prospectively assess blood pressure (BP) and echocardiographic parameters to delineate the incidence and nature of the hypertension burden in this cohort.

BACKGROUND

Few data are available on the long-term outcomes of aortic stenting.

METHODS

Thirty-one patients with successfully stented coarctation during childhood (mean age 12.4 years) underwent 24-h ambulatory BP monitoring (ABPM), exercise BP measurement, and echocardiographic assessment.

RESULTS

Mean time after stent implantation was 5.3 ± 4 years. Hypertension was noted on one-off right-arm BP assessment in 3 patients (10%), but on the basis of the 24-h ABPM assessment in 14 patients (45%). Twenty-four of 31 patients (80%) had an abnormally elevated exercise BP response. Peak exercise BP correlated with left ventricular mass index (r = 0.51; p < 0.05), which was also significantly increased in the entire cohort (mean = 91.3 g/m(2); p < 0.05). In patients with significant somatic growth since implantation, the indexed diameter of the stent (to aortic diameter) had significantly decreased from the 48th percentile at the implantation to the 4th percentile during the study (p < 0.05). There was no difference in any parameter between patients with native or those with recurrent coarctation.

CONCLUSIONS

Hypertension is endemic in patients with stented coarctation, irrespective of the absence of residual obstruction. Due to abnormal BP homeostasis, hypertension should be aggressively pursued by ABPM assessment and exercise stress testing in this population. Relative hypoplasia of the stented arch after somatic growth may contribute to this tendency and should provoke consideration of elective serial redilation of coarctation stents.

Prevalence and long-term predictors of left ventricular hypertrophy, late hypertension, and hypertensive response to exercise after successful aortic coarctation repair

Controversial data exist about the long-term results of aortic coarctation (AC) repair. This study explored the prevalence and predictors of left ventricular (LV) hypertrophy, late hypertension, and hypertensive response to exercise in 48 subjects (age, 15.1 ± 9.7 years) currently followed in the authors' tertiary care hospital after successful AC repair. Data on medical history, clinical examination, rest and exercise echocardiography, and ambulatory blood pressure monitoring were collected. The time from AC repair to follow-up evaluation was 12.9 ± 9.2 years. The prevalence of LV hypertrophy ranged from 23 to 38 %, based on the criteria used to identify LV hypertrophy, and that of concentric geometry was 17 %. One sixth of the patients without residual hypertension experienced late-onset hypertension. One fourth of those who remained normotensive without medication showed a hypertensive response to exercise. Age at AC repair was the strongest independent predictor of LV hypertrophy, defined using indexation either for body surface area (odds ratio [OR], 1.03; p = 0.0090) or for height(2.7) (OR 1.02; p = 0.029), and it was the only predictor of late hypertension (OR 1.06; p = 0.0023) and hypertensive response to exercise (OR 1.09; p = 0.029). The risk of LV hypertrophy was 25 % for repair at the age of 3.4 years but rose to 50 and 75 % for repair at the ages of 5.9 and 8.4 years, respectively. Similar increases were found for the risk of late-onset hypertension and hypertensive response to exercise. A considerable risk of LV hypertrophy, late hypertension, and hypertensive response to exercise exists after successful AC repair. Older age at intervention is the most important predictor of these complications.

Ambulatory and home blood pressure monitoring in children and adolescents: diagnosis of hypertension and assessment of target-organ damage

The prevalence of elevated blood pressure in children and adolescents is more common than previously believed and often represents the early onset of essential hypertension, particularly in adolescents. The definition of hypertension in children is based on distribution criteria and normalcy tables that provide blood pressure percentiles for each measurement method (office, ambulatory and home) according to the individual's age, gender and body size. Owing to the white coat and masked hypertension phenomena, ambulatory blood pressure monitoring is indispensable for the diagnosis of hypertension in children. Home blood pressure monitoring in children has been less well studied, and at present, treatment decisions should not be based solely on such measurements. Hypertension-induced preclinical target-organ damage (mainly echocardiographic left ventricular hypertrophy) is not uncommon in children and should be evaluated in all hypertensive children. Other indices of target-organ damage, such as carotid intima-media thickness, pulse wave velocity and microalbuminuria, remain under investigation in pediatric hypertension.

Pregnancy is associated with decreased cardiac proteasome activity and oxidative stress in mice

During pregnancy, the heart develops physiological hypertrophy. Proteasomal degradation has been shown to be altered in various models of pathological cardiac hypertrophy. Since the molecular signature of pregnancy-induced heart hypertrophy differs significantly from that of pathological heart hypertrophy, we investigated whether the cardiac proteasomal proteolytic pathway is affected by pregnancy in mice. We measured the proteasome activity, expression of proteasome subunits, ubiquitination levels and reactive oxygen production in the hearts of four groups of female mice: i) non pregnant (NP) at diestrus stage, ii) late pregnant (LP), iii) one day post-partum (PP1) and iv) 7 days post-partum (PP7). The activities of the 26 S proteasome subunits β1 (caspase-like), and β2 (trypsin-like) were significantly decreased in LP (β1∶83.26±1.96%; β2∶74.74±1.7%, normalized to NP) whereas β5 (chymotrypsin-like) activity was not altered by pregnancy but significantly decreased 1 day post-partum. Interestingly, all three proteolytic activities of the proteasome were restored to normal levels 7 days post-partum. The decrease in proteasome activity in LP was not due to the surge of estrogen as estrogen treatment of ovariectomized mice did not alter the 26 S proteasome activity. The transcript and protein levels of RPN2 and RPT4 (subunits of 19 S), β2 and α7 (subunits of 20 S) as well as PA28α and β5i (protein only) were not significantly different among the four groups. High resolution confocal microscopy revealed that nuclear localization of both core (20S) and RPT4 in LP is increased ∼2-fold and is fully reversed in PP7. Pregnancy was also associated with decreased production of reactive oxygen species and ubiquitinated protein levels, while the de-ubiquitination activity was not altered by pregnancy or parturition. These results indicate that late pregnancy is associated with decreased ubiquitin-proteasome proteolytic activity and oxidative stress.

White coat hypertension in children: not rare and not benign?

The clinical significance of white coat hypertension (WCH) remains uncertain. We aimed to evaluate the target organ damage (TOD) in children with essential hypertension (HTN) and WCH. We retrospectively analyzed the body mass index (BMI) and ambulatory blood pressure monitoring (ABPM) in 183 untreated children aged 5 to 19 years who were referred for assessment of hypertension and had secondary hypertension ruled out. Left ventricular mass index (LVMi) and carotid intima media thickness (CIMT) were analyzed in a subset of 106 children. WCH was found in 54/183 children (29.5%) who had normal mean arterial pressure (MAP), MAP load, and MAP day/night ratio. However, the mean+/-SD LVMi (g/m(2.7)) was identical in HTN and WCH patients (38.2+/-10.9 vs. 37.0+/-11.3, P=.59); it exceeded the 95th percentile in 40% HTN and 36% WCH patients (NS). The mean CIMT was significantly higher compared with normal, but not different between HTN and WCH; it exceeded the 95th percentile in 26% HTN and 29% WCH patients. WCH was found in up to 30% of children referred for HTN. Patients with WCH have TOD comparable to that found in HTN patients despite similar BMI, significantly lower average BP and BP load and a well-preserved BP dipping pattern.

Genetics of the renin-angiotensin system with respect to cardiac and blood pressure phenotypes in healthy newborn infants

INTRODUCTION

Left ventricular mass (LVM) is a strong predictor of various heart diseases. We examine the association between the G(-6)A AGT, I/D ACE, A1166C AGTR1, T(-344)C CYP 11β2, A538G MR and A10631G REN polymorphisms and LVM and blood pressure in newborn infants.

MATERIAL AND METHODS

The study included 211 healthy newborn infants. Two-dimensional M-mode echocardiography was used to assess LVM between days 3-4 after birth. Polymorphisms were determined by polymerase chain reaction - restriction fragment length polymorphism (PCR-RLFP).

RESULTS

AGTR1 genotype was significantly associated with neonatal systolic blood pressure (≥90 percentile). LVM indexes (LVMIs) were tested for association with genotypes in multivariate analysis. The carriers of the A allele of the AGT polymorphism had significantly higher LVM/body length (BL) values when compared with newborn infants homozygous for the G allele (p adjusted=0.03). The higher LVM/BL values were seen in the carriers of the A alleles of the AGTR1 polymorphism (p adjusted=0.046). All examined indexes (LVM/body surface area (BSA), LVM/BL, LVM/bodyweight (BW)) were associated with CYP11B polymorphism. The newborn infants homozygous for the T allele had significantly higher values of LVM/BSA, LVM/BL, and LVB/BW compared to non-TT-homozygous neonates (p adjusted=0.003; p adjusted=0.003; p adjusted=0.004 respectively).

CONCLUSION

The AGT, AGTR1, CYP11β polymorphisms are associated with increased LVMIs in newborns. This observation indicates that genetic factors may be modulating LVM at birth.

Cardiac vulnerability to ischemia/reperfusion injury drastically increases in late pregnancy

Although the murine late pregnant (LP) heart is speculated to be a better functioning heart during physiological conditions, the susceptibility of LP hearts to I/R injury is still unknown. The aims of this study were to investigate the cardiac vulnerability of LP rodents to ischemia/reperfusion (I/R) injury and to explore its underlying mechanisms. In vivo female rat hearts [non-pregnant (NP) or LP] or ex vivo Langendorff-perfused mouse hearts were subjected to I/R. The infarct size was approximately fourfold larger in LP animals compared with NP both in vivo and ex vivo. The heart functional recovery was extremely poor in LP mice compared with NP (~10% recovery in LP vs. 80% recovery in NP at the end of reperfusion, P < 0.01). Interestingly, the poor functional recovery and the larger infarct size in LP were partially restored one day post-partum and almost fully restored 1 week post-partum to their corresponding NP levels. Mitochondrial respiratory function and the threshold for opening of the mitochondrial permeability transition pore were significantly lower in LP compared with NP when they both were subjected to myocardial I/R injury [Respiratory control ratio = 1.9 ± 0.1 vs. 4.0 ± 0.5 in NP, P < 0.05; calcium retention capacity (CRC) = 167 ± 10 vs. 233 ± 18 nmol/mg protein in NP, P < 0.01]. Cardiac reactive oxygen species (ROS) generation, as well mitochondrial superoxide production, was approximately twofold higher in LP compared with NP following I/R. The phosphorylation levels of Akt, ERK1/2, and STAT3, but not GSK3β, were significantly reduced in the hearts from LP subjected to I/R. In conclusion, increased mitochondrial ROS generation, decreased CRC as well as impaired activation of Akt/ERK/STAT3 at reperfusion are the possible underlying mechanisms for higher vulnerability of LP hearts to I/R.

Comparing Height-Adjusted Waist Circumference Indices: The Fels Longitudinal Study

OBJECTIVES

While researchers are increasingly recognizing the importance of adjusting waist circumference (WC) for height, no standard has yet been established. In this study we contrast three standard methods for indexing WC by height (using height, root-height and height-squared) via comparisons with age-specific optimal indices.

STUDY DESIGN AND SETTING

Measurements from 722 male and 746 female Caucasian participants in the Fels Longitudinal Study were used. The three standard waist-circumference indices (as well as an optimal index) were determined for ages 2 through 18, and for every decade thereafter to 70 years of age. Pearson correlations were used to assess the suitability of all indices.

RESULTS

The three standard indices remain correlated with the original WC measures, though each was associated with height at some ages. Waist-to-height ratio is suitable for some childhood ages (boys: 5 - 9, 13 - 16; girls: 4 - 7, 9, 11 - 14) but not for adult ages; Root-height works well mostly for older teenage children and adults but not in early childhood and adolescence; Height-squared is nowhere suitable. In both men and women, the optimal indexing factor ranged between root-height and height-squared in childhood, and is close to root-height in adulthood.

CONCLUSIONS

No one index is most suitable, as WC indexed by root-height is suitable for use with measurements from teenage children and adults, while waist-to-height ratio is generally suitable for use in children. WC indexed by height-squared is nowhere suitable.

Oxidative stress in hypertensive children before and after 1 year of antihypertensive therapy

BACKGROUND

The relation between primary hypertension (PH), target organ damage (TOD) and oxidative stress (SOX) is not known.

METHODS

We assessed SOX in 86 children with PH before and after 12 months of standard non-pharmacological and pharmacological therapy based on renin-angiotensin system blockade.

RESULTS

Patients with left ventricular hypertrophy (LVH) and with carotid intima-media thickness (cIMT) >2SDS had higher thiobarbituric acid reactive substances (TBARS) concentrations in comparison to patients without LVH or with normal cIMT. Patients with metabolic syndrome (MS) had lower activity of gluthatione peroxidase, higher asymmetric dimethyloarginine (ADMA) and oxidized LDL cholesterol (oxyLDL) in comparison to patients without MS. TBARS correlated with left ventricular concentric hypertrophy, cIMT, albuminuria and SBP/24 h. ADMA and oxyLDL correlated with CRP and TG/HDL ratio. After 1 year of antihypertensive treatment blood pressure, TOD and prevalence of MS decreased. TBARS decreased and glutathione concentrations increased. The decrease of TBARS concentration correlated with the decrease of body mass index (BMI). Decrease of oxyLDL and ADMA correlated with increased insulin sensitivity, however markers of SOX did not correlate with BP decrease.

CONCLUSION

SOX in children with PH correlates with TOD, metabolic abnormalities, changes in fat amount and improvement of insulin sensitivity, but not with BP decrease.

Improved left ventricular mass quantification with partial voxel interpolation: in vivo and necropsy validation of a novel cardiac MRI segmentation algorithm

BACKGROUND

Cardiac magnetic resonance (CMR) typically quantifies LV mass (LVM) by means of manual planimetry (MP), but this approach is time-consuming and does not account for partial voxel components--myocardium admixed with blood in a single voxel. Automated segmentation (AS) can account for partial voxels, but this has not been used for LVM quantification. This study used automated CMR segmentation to test the influence of partial voxels on quantification of LVM.

METHODS AND RESULTS

LVM was quantified by AS and MP in 126 consecutive patients and 10 laboratory animals undergoing CMR. AS yielded both partial voxel (AS(PV)) and full voxel (AS(FV)) measurements. Methods were independently compared with LVM quantified on echocardiography (echo) and an ex vivo standard of LVM at necropsy. AS quantified LVM in all patients, yielding a 12-fold decrease in processing time versus MP (0:21±0:04 versus 4:18±1:02 minutes; P<0.001). AS(FV) mass (136±35 g) was slightly lower than MP (139±35; Δ=3±9 g, P<0.001). Both methods yielded similar proportions of patients with LV remodeling (P=0.73) and hypertrophy (P=1.00). Regarding partial voxel segmentation, AS(PV) yielded higher LVM (159±38 g) than MP (Δ=20±10 g) and AS(FV) (Δ=23±6 g, both P<0.001), corresponding to relative increases of 14% and 17%. In multivariable analysis, magnitude of difference between AS(PV) and AS(FV) correlated with larger voxel size (partial r=0.37, P<0.001) even after controlling for LV chamber volume (r=0.28, P=0.002) and total LVM (r=0.19, P=0.03). Among patients, AS(PV) yielded better agreement with echo (Δ=20±25 g) than did AS(FV) (Δ=43±24 g) or MP (Δ=40±22 g, both P<0.001). Among laboratory animals, AS(PV) and ex vivo results were similar (Δ=1±3 g, P=0.3), whereas AS(FV) (6±3 g, P<0.001) and MP (4±5 g, P=0.02) yielded small but significant differences with LVM at necropsy.

CONCLUSIONS

Automated segmentation of myocardial partial voxels yields a 14-17% increase in LVM versus full voxel segmentation, with increased differences correlated with lower spatial resolution. Partial voxel segmentation yields improved CMR agreement with echo and necropsy-verified LVM.

The renin-angiotensin system, blood pressure, and heart structure in patients with hereditary vitamin D-resistance rickets (HVDRR)

Vitamin D deficiency has been linked to hypertension and an increased prevalence of cardiovascular risk factors and disease. Studies in vitamin D receptor knockout (VDR KO) mice revealed an overstimulated renin-angiotensin system (RAS) and consequent high blood pressure and cardiac hypertrophy. VDR KO mice correspond phenotypically and metabolically to humans with hereditary 1,25-dihydroxyvitamin D-resistant rickets (HVDRR). There are no data on the cardiovascular system in human HVDRR. To better understand the effects of vitamin D on the human cardiovascular system, the RAS, blood pressure levels, and cardiac structures were examined in HVDRR patients. Seventeen patients (9 males, 8 females, aged 6 to 36 years) with hereditary HVDRR were enrolled. The control group included age- and gender-matched healthy subjects. Serum calcium, phosphorous, creatinine, 25-hydroxyvitamin D [25(OH)D],1,25-dihydroxyvitamin D(3) [1,25(OH)(2) D(3) ], parathyroid hormone (PTH), plasma rennin activity (PRA), aldosterone, angiotensin II (AT-II), and angiotensin-converting enzyme (ACE) levels were determined. Ambulatory 24-hour blood pressure measurements and echocardiographic examinations were performed. Serum calcium, phosphorus, and alkaline phosphatase values were normal. Serum 1,25(OH)(2) D(3) and PTH but not PRA and ACE levels were elevated in the HVDRR patients. AT-II levels were higher than normal in the HVDRR patients but not significantly different from those of the controls. Aldosterone levels were normal in all HVDRR patients. No HVDRR patient had hypertension or echocardiographic pathology. These findings reveal that 6- to 36-year-old humans with HVDRR have normal renin and ACE activity, mild but nonsignificant elevation of AT-II, normal aldosterone levels, and no hypertension or gross heart abnormalities.

Cardiovascular impact of the pediatric obesity epidemic: higher left ventricular mass is related to higher body mass index

OBJECTIVE

To compare secular changes in body mass index (BMI) and left ventricular mass (LVM) in today's children versus children of a generation earlier.

STUDY DESIGN

All healthy patients aged 2 to 19 years who underwent echocardiography at a single US academic medical center in 1986 to 1989 (prior era) and 2008 (current era) were included in this retrospective cross-sectional study. BMI, BMI z score, LVM indexed to height (LVMI), LVM z score, and relative wall thickness were calculated. Cardiac geometries were assigned based on LVM z score and relative wall thickness and classified as normal, concentric hypertrophy, eccentric hypertrophy, or concentric remodeling. Stepwise regression analysis was performed to identify determinants of LVMI.

RESULTS

There were 350 subjects in the prior era and 350 age- and sex-matched subjects in the current era. Mean BMI and LVMI were both significantly higher in the current era than in the prior era (BMI, 19.9 ± 5.6 kg/m(2) vs 18.1 ± 3.8 kg/m(2), P = .0004; LVMI, 32.7 ± 7.8 g/m(2.7) vs 31.5 ± 8.1 g/m(2.7); P = .02). Determinants of LVMI in both eras were BMI z score, younger age, male sex, and African-American race.

CONCLUSIONS

Today's children have higher BMI, LVMI, and predicted cardiovascular risk than their counterparts a generation earlier. Reversal of these trends is needed, and intervention is required.

Relationships between serial childhood adiposity measures and adult blood pressure: The Fels longitudinal study

OBJECTIVES

Several studies have shown that causes of adult hypertension arise in childhood, and obesity may be a potential cause or at least a mitigating factor in this development. Body mass index is a well studied obesity metric, yet other potential adiposity measures such as percent body fat and waist circumference have been somewhat less considered. The purpose of this study is to determine associations between these alternative serial childhood adiposity measures and adulthood blood pressure.

METHODS

Measurements from participants in the Fels Longitudinal Study were used to summarize childhood adiposity, represented by childhood measurements of percent body fat and height-adjusted waist circumference. These subjects also provided systolic and diastolic blood pressure as adults. Childhood adiposity levels were categorized as high or low as compared to the respective upper quartile, and associations with adult blood pressure were measured using Poisson regression to estimate the number of expected occurrences of elevated adiposity during childhood. Adult lifestyle covariates and adiposity were accounted for using multiple linear regression.

RESULTS

Summary indices of the childhood adiposity measures were significantly associated with both adult blood pressure metrics in men and women, though some of these associations were altered or reduced in the presence of adult lifestyle characteristics and adult adiposity measures.

CONCLUSIONS

Childhood measures of percent body fat and height-adjusted waist circumference have an effect on adult blood pressure, though the effect can be mitigated by adult lifestyles.

Change in left ventricular geometry during antihypertensive treatment in children with primary hypertension

The pattern of the left ventricle (LV) has important significance in adults with hypertension. The aim of the present study was to analyze changes and determinants of LV geometry after 1 year of antihypertensive treatment in children with primary hypertension (PH) in relation to metabolic abnormalities and anthropometrical parameters. In 86 children (14.1 ± 2.4 years) with newly diagnosed PH, LV geometry and biochemical parameters before and after 12 months of standard antihypertensive therapy were assessed. At baseline, normal LV geometry (NG) was found in 42 (48.9%), concentric remodeling (CR) in 4 (4.6%), concentric hypertrophy (CH) in 8 (9.3%), and eccentric hypertrophy (EH) in 32 (37.2%) patients. The prevalence of NG in patients with severe hypertension was significantly lower than in patients with ambulatory hypertension. There were no differences in dipping status in relation to LV geometry. Patients with CH and EH were more viscerally obese than patients with NG. Patients with CH had higher diastolic blood pressure in comparison with EH patients (p < 0.05). The main predictor of relative wall thickness (RWT) was the triglycerides to high density lipoprotein cholesterol (TG/HDL) ratio (R(2 ) = 0.319, β = 0.246, p = 0.004). Patients received 12 months of antihypertensive treatment, either lifestyle modification only (n = 37) or lifestyle modification plus antihypertensive medications (n = 49) if severe ambulatory hypertension or target organ damage were present. After 12 months of treatment the prevalence of EH (37.2% vs 18.6%, p = 0.003) decreased but prevalence of CH did not change. Patients in whom RWT decreased also decreased waist circumference and TG/HDL; the main predictor of RWT decrease was a decrease of the TG/HDL ratio (β = 0.496, R (2) = 0.329, p = 0.002). In adolescents with PH, LV geometry is related to central obesity and insulin resistance. Decrease of abdominal obesity and insulin resistance are the most important predictors of normalization of LV geometry, however CH has lower potential to normalize LV geometry.

Sex-specific approach to gated SPECT volumetric analysis after stress and at rest to detect high-risk coronary artery disease

OBJECTIVES

To determine the role of quantitative analysis of poststress and resting left ventricular function using sex-specific criteria to detect high-risk coronary artery disease (CAD) as defined by the Duke CAD Prognostic Index.

METHODS AND RESULTS

Stress technetium-99m-sestamibi-gated single-photon emission computed tomography and coronary angiography were performed in 407 consecutive patients (300 men, 107 women) with suspected CAD. The cut-off point for high-risk CAD was defined as a Duke CAD Prognostic Index of 42. The stress-to-rest ratios of end-diastolic volume (rEDV) and end-systolic volume (rESV) were analyzed. In 102 patients with high-risk CAD, the summed difference scores, rEDV and rESV, were greater than in 305 patients with low-risk to intermediate-risk CAD. The receiver operating characteristic curves revealed that the optimal cut-off points for rEDV and rESV to detect high-risk CAD were 1.10 and 1.11, respectively. Sex-specific rEDV was 1.08 in men, 1.11 in women, and sex-specific rESV was 1.09 in men and 1.20 in women. Multivariate discriminant analysis showed that the combination of sex-specific rEDV, sex-specific rESV, and summed difference scores greater than or equal to 8 best identified high-risk CAD, with a sensitivity of 75% and specificity of 76%.

CONCLUSION

The addition of a sex-specific approach to left ventricular functional analysis using gated single-photon emission computed tomography on conventional perfusion analysis, may help better identify patients with high-risk CAD as defined by the Duke CAD Prognostic Index.

Left ventricular hypertrophy and diastolic dysfunction in children with sickle cell disease are related to asleep and waking oxygen desaturation

Premature death and cardiac abnormalities are described in individuals with sickle cell disease (SCD), but the mechanisms are not well characterized. We tested the hypothesis that cardiac abnormalities in children with SCD are related to sleep-disordered breathing. We enrolled 44 children with SCD (mean age, 10.1 years; range, 4-18 years) in an observational study. Standard and tissue Doppler echocardiography, waking oxygen saturation averaged over 5 minutes, and overnight polysomnography were obtained in participants, each within 7 days. Eccentric left ventricular (LV) hypertrophy was present in 46% of our cohort. After multivariable adjustment, LV mass index was inversely related to average asleep and waking oxygen saturation. For every 1% drop in the average asleep oxygen saturation, there was a 2.1 g/m(2.7) increase in LV mass index. LV diastolic dysfunction, as measured by the E/E' ratio, was present in our subjects and was also associated with low oxygen saturation (sleep or waking). Elevated tricuspid regurgitant velocity (> or = 2.5 m/sec), a measure of pulmonary hypertension, was not predicted by either oxygen saturation or sleep variables with multivariable logistic regression analysis. These data provide evidence that low asleep and waking oxygen saturations are associated with LV abnormalities in children with SCD.

Myocardial performance after successful intervention for native aortic coarctation

Coarctation of the aorta is associated with increased risk for hypertension in adulthood, despite successful repair. The intrinsic mechanisms underscoring hypertension and left ventricular performance in these patients, however, remains to be determined. Our objective was to evaluate left ventricular performance by means of echocardiographic and biochemical parameters at midterm follow-up in normotensive children who have had undergone successful surgical or catheter interventional treatment of coarctation with a residual gradient of less than 20 mmHg at rest. We studied prospectively 14 patients with native aortic coarctation who underwent surgery or balloon angioplasty, the cohort made up of equal numbers of boys and girls, and having a mean age of 8.5 plus or minus 4 years. We also studied 30 age-matched healthy subjects, measuring mitral inflow pulsed wave signals, isovolumic relaxation and contraction times, myocardial performance index parameters, and levels of B-type natriuretic peptide and endothelin-1 in both groups. We found no differences in systolic blood pressure at rest between the patients and their controls. The ventricular septal diastolic dimensions, left ventricular posterior wall dimensions, mitral valve E wave, deceleration time, isovolumic relaxation time, isovolumic contraction time and myocardial performance index were all significantly increased in the patients. Levels of plasma B-type natriuretic peptide and endothelin-1 were also significantly higher in the patients when compared to the control group. We conclude that aortic coarctation is a chronic disease characterized by persistency of myocardial and vascular alterations. The elevated levels of plasma b-type natriuretic peptide and endothelin-1 may be indicative of late onset hypertension after successful treatment of native coarctation in early childhood.