Reference Intervals and Percentile Curves of Echocardiographic Left Ventricular Mass, Relative Wall Thickness and Ejection Fraction in Healthy Children and Adolescents

Impact of a cuff-based device calibration method on the agreement between invasive and noninvasive aortic and brachial pressure

INTRODUCTION

Brachial cuff-based methods are increasingly used to estimate aortic systolic blood pressure (aoSBP). However, there are several unresolved issues.

AIMS

to determine to what extent the scheme used to calibrate brachial records (1) can affect noninvasive obtained aoSBP levels, and consequently, the level of agreement with the aoSBP recorded invasively, and (2) how different ways of calibrating ultimately impact the relationship between aoSBP and cardiac properties.

METHODS

brachial and aortic blood pressure (BP) was simultaneously obtained by invasive (catheterisation) and noninvasive (brachial oscillometric-device) methods (89 subjects). aoSBP was noninvasive obtained using three calibration schemes: 'SD': diastolic and systolic brachial BP, 'C': diastolic and calculated brachial mean BP (bMBP), 'Osc': diastolic and oscillometry-derived bMBP. Agreement between invasive and noninvasive aoSBP, and associations between BP and echocardiographic-derived parameters were analysed.

CONCLUSIONS

'C' and 'SD' schemes generated aoSBP levels lower than those recorded invasively (mean errors: 6.9 and 10.1 mmHg); the opposite was found when considering 'Osc'(mean error: -11.4 mmHg). As individuals had higher invasive aoSBP, the three calibration schemes increasingly underestimated aoSBP levels; and viceversa. The 'range' of invasive aoSBP in which the calibration schemes reach the lowest error level (-5-5 mmHg) is different: 'C': 103-131 mmHg; 'Osc': 159-201 mmHg; 'SD':101-124 mmHg. The calibration methods allowed reaching levels of association between aoSBP and cardiac characteristics, somewhat lower, but very similar to those obtained when considering invasive aoSBP. There is no evidence of a clear superiority of one calibration method over another when considering the association between aoSBP and cardiac characteristics.

Ambulatory blood pressure monitoring in children and adolescents post-hematopoietic stem cell transplantation

BACKGROUND

One of the long-term complications after hematopoietic stem cell transplantation (HSCT) is hypertension (HT). Previous studies showed that 10-15% of children post-HSCT had office HT, but only a few studies used ambulatory blood pressure monitoring (ABPM). The present study was aimed at exploring the frequency and factors associated with ABPM HT in children post-HSCT.

METHODS

Patients aged ≥ 6 years who survived ≥ 2 years after HSCT were enrolled. Clinical and ABPM data were reviewed. ABPM HT was defined according to the 2022 American Heart Association guidelines. Factors associated with HT were analyzed by logistic regression.

RESULTS

Ninety-eight (60 males) patients with a mean age of 15.1 years and a median follow-up time at 4.5 years after HSCT were included. Fifteen patients (15.3%) had ABPM HT (2 ambulatory HT and 13 masked HT). The ABPM HT group had a significantly older age (19 vs. 14 years), a higher proportion of males (87% vs. 57%), a higher office systolic BP index (0.93 vs. 0.85), a higher office diastolic BP index (0.96 vs. 0.82) and a higher proportion of current use of prednisolone and tacrolimus than those in the normal ABPM group. Multivariate analysis revealed that office diastolic BP index was associated with ABPM HT. Left ventricular mass index was significantly correlated with ABPM but not with office BP parameters.

CONCLUSIONS

HT in children post-HSCT was not uncommon and most could not be detected with office BP measurement. A diastolic BP index can be used as a screening tool for HT. A higher resolution version of the Graphical abstract is available as Supplementary information.

Echocardiographic assessment of cardiac function abnormalities and related risk factors in Thai overweight and obese children

Background

Childhood obesity has become a global concern, with its prevalence steadily increasing over the past decade. This condition negatively impacts the cardiovascular system, increasing the risk of morbidity and mortality in adulthood. This study aimed to identify cardiac function abnormalities and related risk factors among overweight and obese Thai children.

Materials and Methods

A cross-sectional observational study of 70 children with body mass index (BMI) >1 standard deviation above the mean for Thai children was conducted at Naresuan University Hospital. Body fat percentage (%Fat) was measured, and standard transthoracic echocardiography was performed. Metabolic profiles were collected from medical records.

Results

The thickness and diameter of the Left ventricle (LV) wall, including the LV posterior wall, LV internal diameter, and interventricular septum (IVS), were significantly increased in both systolic and diastolic phases in obese children. LV concentric hypertrophy and an abnormal E/E' ratio were found in 27% and 34.3% of participants, respectively. Right ventricular systolic dysfunction indicated by abnormal tricuspid annular plane systolic excursion values was found in 55.7% of all participants. In addition, 27.1% of all obese children had pulmonary hypertension. Significant differences in BMI and %Fat were detected between children with abnormal and normal IVS diastolic (IVSd) (P = 0.016). Our univariate and multivariate correlation analyses revealed a significant positive association between abnormal IVSd and %Fat, with an odd ratio (OR) of 1.13 (95% confidence interval [CI]: 1.01-1.27; P = 0.047) and an adjusted OR of 1.17 (95% CI: 1.01-1.36; P = 0.04).

Conclusions

Cardiac function abnormalities in childhood obesity exhibit a significant positive correlation with BMI and various cardiac dimensions, including ventricular wall thickness. One important related risk factor for increased IVS thickness is %Fat. Therefore, multidisciplinary management of obesity should be initiated as early as possible to prevent future cardiovascular morbidity and mortality.

Whole-Body Magnetic Resonance Imaging Assessment of the Contributions of Adipose and Nonadipose Tissues to Cardiovascular Remodeling in Adolescents

Background Greater body mass index is associated with cardiovascular remodeling in adolescents. However, body mass index cannot differentiate between adipose and nonadipose tissues. We examined how visceral and subcutaneous adipose tissue are linked with markers of early cardiovascular remodeling, independently from nonadipose tissue. Methods and Results Whole-body magnetic resonance imaging was done in 82 adolescents (39 overweight/obese; 36 female; median age, 16.3 [interquartile range, 14.4-18.1] years) to measure body composition and cardiovascular remodeling markers. Left ventricular diastolic function was assessed by echocardiography. Waist, waist:height ratio, and body mass index z scores were calculated. Residualized nonadipose tissue, subcutaneous adipose tissue, and visceral adipose tissue variables, uncorrelated with each other, were constructed using partial regression modeling to allow comparison of their individual contributions in a 3-compartment body composition model. Cardiovascular variables mostly related to nonadipose rather than adipose tissue. Nonadipose tissue was correlated positively with left ventricular mass (r=0.81), end-diastolic volume (r=0.70), stroke volume (r=0.64), left ventricular mass:end-diastolic volume (r=0.37), and systolic blood pressure (r=0.35), and negatively with heart rate (r=-0.33) (all P<0.01). Subcutaneous adipose tissue was associated with worse left ventricular diastolic function (r=-0.42 to -0.48, P=0.0007-0.02) and higher heart rates (r=0.34, P=0.007) but linked with better systemic vascular resistance (r=-0.35, P=0.006). There were no significant relationships with visceral adipose tissue and no associations of any compartment with pulse wave velocity. Conclusions Simple anthropometry does not reflect independent effects of nonadipose tissue and subcutaneous adipose tissue on the adolescent cardiovascular system. This could result in normal cardiovascular adaptations to growth being misinterpreted as pathological sequelae of excess adiposity in studies reliant on such measures.

Pediatric Normal Values and Z Score Equations for Left and Right Ventricular Strain by Two-Dimensional Speckle-Tracking Echocardiography Derived from a Large Cohort of Healthy Children

BACKGROUND

Strain values vary with age in children and are both vendor and platform specific. Philips QLAB 10.8 and TomTec AutoSTRAIN are two widely used strain analysis platforms, and both incorporate recent European Association of Cardiovascular Imaging/American Society of Echocardiography/Industry Task Force to Standardize Deformation Imaging guidelines. The aims of this study were to establish normal strain values and Z scores for both platforms using a large data set of healthy children and to compare values among these two platforms and a previous version, QLAB 10.5, which predated the task force guidelines.

METHODS

Echocardiograms from 1,032 subjects <21 years old with structurally and functionally normal hearts were included. Images were obtained on the Philips EPIQ platform. Left ventricular (LV) and right ventricular (RV) strain was analyzed using QLAB 10.8 and AutoSTRAIN, and measurement reliability was assessed. Z score equations were derived as a function of age for QLAB 10.8 (LV longitudinal and circumferential strain) and AutoSTRAIN (LV and RV longitudinal strain). A subset (n = 309) was analyzed using QLAB 10.5. Strain values were compared among the three platforms.

RESULTS

For both of the newer platforms, strain varied with age, with magnitude reaching a maximum at 4 to 5 years. For LV longitudinal strain, the largest differences in value were observed in the youngest patients when using QLAB 10.5; the other two platforms were similar. LV circumferential strain measurements (QLAB 10.5 vs QLAB 10.8) were different for all ages, as were measurements of RV longitudinal strain (QLAB 10.8 vs AutoSTRAIN). Reliability was greater for AutoSTRAIN than for QLAB 10.8 and greater for LV than for RV strain.

CONCLUSIONS

Normal RV and LV strain values and Z scores were generated from a large cohort of children for two commonly used platforms in pediatric echocardiography laboratories. Following the incorporation of task force guidelines, the greatest improvement in standardization was seen in infants. Small differences persist between modern platforms; however, these results support the cautious consideration of comparing interplatform measurements.

Changes in myocardial work associated with pediatric kidney transplantation: A pilot study of short-term postoperative effect

The study was mainly to evaluate the changes of left ventricular (LV) myocardial work (MW) in children with CKD stage 5 within 3 months after kidney transplantation (KTx). Forty-three successful KTx recipients (mean age 10.6 years, 58% male) in childhood and 28 healthy children were enrolled. General clinical characteristics and laboratory parameters were collected. Cardiac structure, function, and LV MW were assessed by echocardiography before and after KTx. The results showed that significantly improvement was observed in LV global MW index (GWI), constructive MW (GCW), and wasted MW (GWW) (p < .01), but not in MW efficiency (GWE) and global longitudinal strain (GLS) (p > .05). Besides, blood pressure (BP), renal graft function, LV ejection fraction (LVEF), and LV mass index (LVMi) had obviously improved after KTx (p < .05). Nevertheless, compared with healthy children, higher BP, LVMi, GWW, more deteriorated LV diastolic function and lower GWE were still observed in patients after KTx. The ratio of dialysis duration to CKD course were negatively correlated with the improvements of GWE (p = .004), GWI (p = .01), and GCW (p = .01). In conclusion, a portion of LV MW parameters were obviously improved in children received KTx. Thus, LV MW was superior to GLS in evaluating LV systolic function recovery in these patients. Those patients with insignificant MW improvement should be closely monitored, and adjusted the treatment strategies timely to avoid serious and irreversible myocardial injury after KTx.

Advanced Imaging and New Cardiac Biomarkers in Long-term Follow-up After Childhood Cancer

OBJECTIVES

Pathologic ejection fraction (EF), shortening fraction (FS), and standard heart failure biomarkers (high sensitive troponin T and N-terminal brain natriuretic peptide) during follow-up after childhood cancer have been associated with irreversible cardiac damage. We aimed to evaluate strain imaging values by echocardiography and new biomarkers for heart failure with preserved ejection fraction (HFpEF) as potential more sensitive parameters for cardiac deterioration in childhood cancer survivors (CCS).

MATERIALS AND METHODS

Prospective study with 50 CCS (median 16.2 y) at a median follow-up of 13 years. In addition to standard echo and laboratory parameters for heart failure, strain measurements and new biomarkers, including myocardial inflammation (interleukin 6), extracellular matrix (ECM) remodeling (C-telopeptide for type I collagen, intact N-terminal propeptide of type III procollagen), and other heart failure biomarkers (galectin 3, solutable ST2, growth differentiation factor 15), were obtained and compared with 50 healthy controls.

RESULTS

No significant differences in EF, FS, high sensitive troponin T, N-terminal brain natriuretic peptide, interleukin 6, solutable ST2, and galectin 3 were found between study and control groups. In contrast, strain imaging showed significant differences between both groups (global longitudinal strainGLS -16.1% vs. -20.4%, P<0.0001; global circumferential strain -14.3 vs. -21.4%, P<0.0001), detecting 66% (global longitudinal strain) and 76% (global circumferential strain) of patients with pathologic values in contrast to 6% (EF) and 16% (FS) for standard parameters. Markers for disturbances of ECM remodeling (C-telopeptide for type I collagen, intact N-terminal propeptide of type III procollagen, each P<0.0001) and growth differentiation factor 15 (P<0.0001) were significantly different between the groups.

CONCLUSION

Strain imaging and new cardiac biomarkers used in HFpEF focusing on ECM remodeling appear to be more sensitive in detecting early remodeling processes in CCS than standard echo and laboratory parameters.

Aortic Pressure Levels and Waveform Indexes in People Living With Human Immunodeficiency Virus: Impact of Calibration Method on the Differences With Respect to Non-HIV Subjects and Optimal Values

Background: There are scarce and controversial data on whether human immunodeficiency virus (HIV) infection is associated with changes in aortic pressure (aoBP) and waveform-derived indexes. Moreover, it remains unknown whether potential differences in aoBP and waveform indexes between people living with HIV (PLWHIV) and subjects without HIV (HIV-) would be affected by the calibration method of the pressure waveform.

Aims: To determine: (i) whether PLWHIV present differences in aoBP and waveform-derived indexes compared to HIV- subjects; (ii) the relative impact of both HIV infection and cardiovascular risk factors (CRFs) on aoBP and waveform-derived indexes; (iii) whether the results of the first and second aims are affected by the calibration method.

Methods: Three groups were included: (i) PLWHIV (n = 86), (ii) HIV- subjects (general population; n = 1,000) and (iii) a Reference Group (healthy, non-exposed to CRFs; n = 398). Haemodynamic parameters, brachial pressure (baBP; systolic: baSBP; diastolic: baDBP; mean oscillometric: baMBPosc) and aoBP and waveform-derived indexes were obtained. Brachial mean calculated (baMBPcalc=baDBP+[baSBP-baDBP]/3) pressure was quantified. Three waveform calibration schemes were used: systolic-diastolic, calculated (baMBPcalc/baDBP) and oscillometric mean (baMBPosc/baDBP).

Results: Regardless of CRFs and baBP, PLWHIV presented a tendency of having lower aoBP and waveform-derived indexes which clearly reached statistical significance when using the baMBPosc/baDBP or baMBPcalc/baDBP calibration. HIV status exceeded the relative weight of other CRFs as explanatory variables, being the main explanatory variable for variations in central hemodynamics when using the baMBPosc/baDBP, followed by the baMBPcalc/baDBP calibration.

Conclusions: The peripheral waveform calibration approach is an important determinant to reveal differences in central hemodynamics in PLWHIV.

Subclinical cardiac dysfunction in pediatric kidney transplant recipients identified by speckle-tracking echocardiography

BACKGROUND

Kidney transplantation (KTx) improves prognosis in children with kidney failure; still, these patients are prone to cardiovascular damage due to multiple risk factors. Our aim was to assess myocardial structure and function in pediatric KTx by conventional and speckle-tracking echocardiography (STE) in association with established cardiovascular risk factors.

METHODS

Forty-two KTx and 39 healthy age- and gender-matched children were evaluated. KTx recipients were further categorized according to the control of hypertension assessed by 24-h ambulatory blood pressure monitoring (ABPM). Subjects underwent pulse wave velocity (PWV) measurement, conventional echocardiography, and 2-dimensional STE. Left and right ventricular (LV, RV) global longitudinal strain (GLS), and LV circumferential strain (GCS) were measured. Glomerular filtration rate (eGFR) was calculated according to the Schwartz formula.

RESULTS

KTx patients had increased blood pressure and arterial stiffness. LV ejection fraction (EF) was preserved along with elevated LV mass index (LVMi) while LVGLS was significantly lower, whereas LVGCS and RVGLS were increased in KTx. Uncontrolled hypertensives had lower LVGLS compared to those with controlled hypertension. Using multiple forward stepwise regression analysis, 24-h SBP and relative wall thickness (RWT) were independent determinants of LVMi, whereas antihypertensive therapy, eGFR, and HOMA-IR were independent determinants of LVGLS.

CONCLUSIONS

Cardiac morphology and function show distinct changes after KTx. Along with comparable ventricular volumes, LV hypertrophy and subclinical myocardial dysfunction are present. Control of hypertension and kidney graft function are major factors of LV performance. STE may be useful to reveal early myocardial dysfunction in pediatric KTx. A higher resolution version of the Graphical abstract is available as Supplementary information.

High Fibroblast Growth Factor 23 as a Biomarker for Severe Cardiac Impairment in Children with Chronic Kidney Disease: A Single Tertiary Center Study

INTRODUCTION

Left ventricular hypertrophy (LVH) is the most common cardiac abnormality in chronic kidney disease (CKD). Changes in cardiac geometry and functions may occur in an early stage and worsen as CKD progresses. Recently, the role of fibroblast growth factor 23 (FGF23) is being highlighted and investigated in CKD-related cardiomyopathy. However, only a few studies have reviewed the utilization of FGF23 as a diagnostic biomarker in the pediatric CKD population.

PURPOSE

This study aimed to identify the role of FGF23 as a biomarker in assessing cardiac changes in children with CKD.

PATIENTS AND METHODS

We conducted a cross-sectional study that involved children aged 2 to 18 years old with CKD stages 2 to 5D in Dr. Sardjito General Hospital, Yogyakarta, Indonesia. The level of FGF23 was measured using an immunometric enzyme-linked immunosorbent assay. LVMI, RWT, and left ventricular ejection fraction (LVEF) were assessed with echocardiography. Receiver-operating characteristic (ROC) analyses were conducted to assess the diagnostic performance of FGF23 in detecting LVH with impaired contractility.

RESULTS

A total of 43 children with CKD stages 2 to 5D were included, among whom the prevalence of LVH diagnosis was 95.35%. The area under the curve (AUC) of FGF23 to assess LVH and systolic dysfunction was 0.82 (95% CI 0.62-1.0), and the optimal cutoff point was 1413 RU/mL (sensitivity 80%, specificity 78.95%). The median concentration of FGF23 increased with the decreasing eGFR and the increasing LVMI although the systolic and diastolic functions were preserved.

CONCLUSION

FGF23 might be used as an early biomarker to detect cardiac changes in pediatric CKD patients, particularly for LVH and impaired systolic function among children with CKD stage 2 and higher.

Association Between Central-Peripheral Blood Pressure Amplification and Structural and Functional Cardiac Properties in Children, Adolescents, and Adults: Impact of the Amplification Parameter, Recording System and Calibration Scheme

INTRODUCTION

Systolic blood pressure (SBPA) and pulse pressure amplification (PPA) were quantified using different methodological and calibration approaches to analyze (1) the association and agreement between different SBPA and PPA parameters and (2) the association between these SBPA and PPA parameters and left ventricle (LV) and atrium (LA) structural and functional characteristics.

METHODS

In 269 healthy subjects, LV and LA parameters were echocardiography-derived. SBPA and PPA parameters were quantified using: (1) different equations (n = 9), (2) methodological approaches (n = 3): brachial sub-diastolic (Mobil-O-Graph®) and supra-systolic oscillometry (Arteriograph®) and aortic diameter waveform re-calibration (RCD; ultrasonography), and (3) using three different calibration schemes: systo-diastolic (SD), calculated mean (CM) and oscillometric mean (OscM).

RESULTS

SBPA and PPA parameters obtained with different equations, techniques, and calibration schemes show a highly variable association level (negative, non-significant, and/or positive) among them. The association between SBPA and PPA with cardiac parameters were highly variable (negative, non-significant, or positive associations). Differences in BPA parameter data between approaches were more sensitive to the calibration method than to the device used. Both, SBPA and PPA obtained with brachial sub-diastolic technique and calibrated to CM or OscM showed higher levels of association with LV and LA structural characteristics.

CONCLUSIONS

Our data show that many of the parameters that assume to quantify the same phenomenon of BPA are not related to each other in the different age groups. Both, SBPA and PPA obtained with brachial sub-diastolic technique and calibrated to CM or OscM showed higher levels of association with LV and LA structural characteristics.

Cardiac Function is Preserved in Adolescents With Well-Controlled Type 1 Diabetes and a Normal Physical Fitness: A Cross-sectional Study

OBJECTIVES

Cardiovascular diseases and exercise intolerance elevate mortality in type 1 diabetes (T1D). Left ventricular systolic and diastolic function are already affected in T1DM adolescents, displaying poor glycemic control (glycated hemoglobin [A1C]>7.5%) and exercise intolerance. We investigated to the extent to which left ventricular function is affected by disease severity/duration and whether this is related to exercise capacity.

METHODS

Transthoracic echocardiography was performed in 19 T1DM adolescents (14.8±1.9 years old, A1C 7.4±0.9%) and 19 controls (14.4±1.3 years old, A1C 5.3±0.2%), matched for age and Tanner stage. Diastolic and systolic (ejection fraction [EF]) function were assessed. Cardiopulmonary exercise testing was used to evaluate exercise capacity, as measured by peak oxygen uptake (VO_2peak).

RESULTS

VO_2peak and left ventricular systolic and diastolic function were similar in both groups. Within the T1D group, EF was negatively associated with disease duration (r=-0.79 corrected for age, standardized body mass index, glucose variability and VO_2peak; p=0.011). Regression analyses revealed that 37.6% of the variance in EF could be attributed to disease duration.

CONCLUSIONS

Although left ventricular systolic and diastolic function are preserved in T1D with adequate exercise capacity, disease duration negatively affects EF. The detrimental effects of T1D seem to be driven by disease duration, rather than by disease severity, at least during adolescence. Young T1D patients may, therefore, benefit from cardiovascular evaluation in order to detect cardiovascular abnormalities early in the disease course, and therefore, improve long-term cardiovascular health.

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.

Division of Myocardial Enzyme Reference Intervals in Population Aged 1 to <18 Years Old Based on Fisher's Optimal Segmentation Method

Background

Reference interval (RI) research is to make it a concise, effective, and practical diagnostic tool. This study aimed to establish sex- and age-specific RI for myocardial enzyme activity in population aged 1–<18 years old in Changchun, China.

Methods

Healthy subjects (n = 6,322, 1–<18 years old) were recruited from communities and schools. Aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and creatine kinase isoenzyme (CKMB) were measured using an automatic biochemical analyzer. Fisher's optimal segmentation method was used to partition by including percentiles as impact factors, aiming at minimizing the sum of the squares of the total dispersion into groups as splitting sequence of ordered data.

Results

AST decreased gradually and was partitioned as 1, 2∼<10 and 10∼<18 years old. LDH presented disparate descending rate among 1∼<4, 4∼<12, and 12∼<18 years old. CK stood quite stable with the same RI in all ages. CKMB began to differ at 6 years of age sexually and then remained stable during 6∼<14 years old for male while it continued to decline in female. Cardiac development was partitioned as 1∼<6, 6∼<13, and 13∼<18 years old using multiple percentiles from massive data that reflect characteristics of totality as impact factors.

Conclusions

Fisher's optimal segmentation method excelled for multidimensionality, continuity, and loop calculating as dealing with RIs for myocardial enzymes activity and cardiac development process despite limitations. In future, impact of partition on the overall interval should be delved into.

Enzyme Replacement Therapy Decreases Left Ventricular Mass Index in Patients with Hunter Syndrome?

Although enzyme replacement therapy (ERT) has shown benefit in improving cardiac systolic function in a murine model of cardiomyopathy associated with Hunter syndrome, few studies have analyzed its effect in humans. We evaluated the effect of ERT on patients with Hunter syndrome-related cardiomyopathy. We performed a retrospective analysis of serial transthoracic echocardiograms performed before and over the first 5 years after treatment initiation, in 14 patients with Hunter syndrome. An important cardiac remodeling occurred in all patients in this study. There was a significant reduction in left ventricular mass index from 70.88 to 26.75 g/m^2.7 (p = 0.003), with a trend towards a decrease in relative wall thickness from 0.515 at baseline to 0.370 after 5 years of enzyme therapy (p = 0.140). No differences were observed in aortic root diameter, left atrial diameter, left ventricular diastolic and systolic diameters, left ventricular ejection fraction, or myocardial performance index. Our findings demonstrate that ERT contributes to reducing left ventricular mass index in patients with Hunter syndrome.

Left ventricular mass normalization for body size in children based on an allometrically adjusted ratio is as accurate as normalization based on the centile curves method

BACKGROUND

Normalization for body size is required for reliable left ventricular mass (LVM) evaluation, especially in children due to the large variability of body size. In clinical practice, the allometrically adjusted ratio of LVM to height raised to the power of 2.7 is often used. However, studies presenting normative LVM data for children recommend centile curves as optimal for the development of normative data. This study aimed to assess whether the allometrically adjusted LVM-to-height ratio can reliably reproduce the results of LVM normalization for height based on the centile curves method.

METHODS

Left ventricular mass was computed for 464 boys and 327 girls, 5-18 years old, based on echocardiographic examination. Normalized data representing LVM for height were developed using the centile curves construction method and two variants of the allometrically adjusted ratio method: one variant with the allometric exponents specific to the study groups, and one variant with the universal exponent of 2.7. The agreement between the allometric methods and the centile curves method was analyzed using the concordance correlation coefficient, sensitivity, and specificity.

RESULTS

For both the specific allometric variant and the universal variant, the analysis of concordance has indicated high reproducibility compared to the centile curves method. The respective coefficient values were 0.9917 and 0.9916 for girls, and 0.9886 and 0.9869 for boys. The sensitivity and specificity test has also shown high agreement. However, for girls, the sensitivity was higher for the specific variant (100% vs. 90.9%).

CONCLUSION

The results of the study show that allometric scaling of LVM for height can very reliably reproduce the results of LVM normalization for height based on the centile curves method. However, the analysis of sensitivity and specificity indicates greater agreement for the allometric normalization with the group-specific allometric exponents.

Impact of Methodological and Calibration Approach on the Association of Central and Peripheral Systolic Blood Pressure with Cardiac Structure and Function in Children, Adolescents and Adults

INTRODUCTION

Peripheral and aortic systolic blood pressure (pSBP and aoSBP) were measured using different methodological and calibration approaches to analyze the association and agreement between pSBP and/or aoSBP, and the association of pSBP and aoSBP with left ventricle (LV) and atrium (LA) structural-functional characteristics.

METHODS

In healthy subjects (n = 269, age: 9-85 years; n = 147, age < 24 years) LV and LA parameters were echocardiography-derived. pSBP and aoSBP were obtained by brachial sub-diastolic (Mobil-O-Graph^®) and supra-systolic oscillometry (Arteriograph^®) and aortic diameter waveform re-calibration (RCD; ultrasonography), using three calibration schemes: systo-diastolic (SD), calculated mean (CM), and oscillometric mean (OscM).

RESULTS

Always pSBP and aoSBP were positively associated; aoSBP obtained with the Mobil-O-Graph^® and calibrated to CM or OscM were the ones that showed the lowest levels of association with the remaining forms of aoSBP and pSBP. Bland-Altman related mean errors varied noticeably (e.g. - 27, - 23, - 17, - 12 or 8 mmHg when aoSBP obtained with MOG (OscM) was compared with data from other methodological and calibration schemes). The aoSBP data obtained with Mobil-O-Graph^® (calibration: CM and OscM) showed the highest levels of association with cardiac structural characteristics. aoSBP values obtained calibrating to OscM were higher than those obtained calibrating to SD or CM.

CONCLUSIONS

aoSBP obtained with Mobil-O-Graph^® and calibrated to CM or OscM showed (1) lower association with other forms of aoSBP and pSBP determination and (2) higher levels of association with LV and LA structural characteristics. Differences in aoSBP data between approaches were more sensitive to the calibration method than to the device used.

Subclinical Organ Damage in Children and Adolescents with Hypertension: Current Guidelines and Beyond

High blood pressure (BP) is becoming a growing health issue even in children and adolescents. Moreover, BP elevation in youth frequently translates into children and adult hypertension contributing to the development of cardiovascular disease. The detection of early markers of vascular damage, potentially leading to overt cardiovascular disease, is important for clinical decisions about if and how to treat hypertension and can be useful in monitoring the effectiveness of the treatment. The purpose of this review is to summarize the actual knowledge about subclinical organ damage (SOD) in hypertensive children and adolescents and its association with cardiovascular disease in children and young adults. Our focus is especially put on left ventricular mass, pulse wave velocity, carotid intima-media thickness and microalbuminuria. We also want to address the scientific evidence about possible regression of SOD and cardiovascular risk with the use of behavioural and specific anti-hypertensive therapy. Indications from current guidelines are critically discussed.

Percentile curves for left ventricle structural, functional and haemodynamic parameters obtained in healthy children and adolescents from echocardiography-derived data

BACKGROUND

Transthoracic echocardiography is the most common non-invasive technique for the study of the left ventricle (LV) and the proximal aorta. Despite the clinical value, there is scarcity of data about reference intervals (RIs) and percentiles for thoracic aorta dimension and LV structural and functional parameters, obtained from population-based studies in children and adolescents. The aim was to generate RIs for LV, haemodynamic and thoracic aorta parameters obtained from transthoracic echocardiography in healthy children, adolescents and young adults from a South-American population.

METHODS

One thousand ninety-five healthy subjects (5-24 years) were studied (M-mode, B-mode and Doppler echocardiography).

RESULTS

RIs for LV structural (diameters, volumes and wall thickness) and functional (stroke volume, cardiac output, cardiac index, transmitral E and A flow waves velocities) parameters; systemic vascular resistance and aortic root diameter were obtained using parametric regression analyzes based on fractional polynomials. Covariate analysis (i.e., adjusting for age, body surface) showed that specific sex-specific RIs were necessary. Then, age, body height (BH), body weight (BW), body surface area (BSA), and sex-specific 1st, 2.5th, 5th, 10th, 25th, 50th, 75th, 90th, 95th, 97.5th and 99th percentiles were obtained. Our results were in agreement with and complimentary to available international databases.

CONCLUSION

This study provides RIs for echocardiography-derived haemodynamic, LV (structural and functional) and aortic parameters in children, adolescents and young adults considering data obtained from the largest Argentinean database. In early stages of life an adequate interpretation of echocardiography-derived LV and aortic parameters requires considering age, BH, BW, BSA and/or sex-specific RIs.