Calculation of Pediatric Left Ventricular Mass: Validation and Reference Values Using Real-Time Three-Dimensional Echocardiography

Association between left ventricular remodeling and lipid profiles in obese children: an observational study

Objective

Childhood obesity has become a prominent issue in the society, which can lead to left ventricular remodeling and severe cardiovascular complications in adulthood. It is beneficial to identify the causes of left ventricular remodeling so that targeted measures can be taken to prevent the cardiovascular disease. Therefore, this study aimed to explore the relationship between left ventricular remodeling and changes in blood lipid indexes in obese children.

Methods

This study was conducted on 40 healthy non-obese children and 140 obese children diagnosed in the pediatric health department of our hospital. Clinical data collected from the two groups were compared. Echocardiography was performed to examine left ventricular configuration and cardiac function. Multiple linear regression analysis was conducted to assess the independent effects of blood lipid levels on echocardiographic parameters. Blood lipid indicators among different left ventricular structural patterns which were classified according to left ventricular mass indexes and relative wall thickness were compared.

Results

Obese children exhibited significantly increased height, weight, body mass index (BMI), body fat percentage (BFP), blood pressure, triglycerides, total cholesterol, left ventricular internal diameter (LVIDd), interventricular septum (IVSd), left ventricular posterior wall diastolic thickness (LVPWd), myocardial mass (LVM) and relative wall thickness (RWT), as well as lower high-density lipoprotein cholesterol (HDL-C) and left ventricular ejection fraction (LVEF) compared to the non-obese children (P < 0.05). Multiple linear correlation analysis showed LVM had a significantly positive correlation with BMI (r = 3.21, P = 0.002) and SBP (r = 2.61, P = 0.01); LVMI had a significantly negative correlation with HDL-C (r = -2.45, P = 0.015); RWT had a significantly positive correlation with SBP (r = 2.50, P = 0.013) but a significantly negative correlation with HDL-C (r = -2.35, P = 0.02). Furthermore, there were significant differences in HDL-C values among children with different ventricular configurations (P < 0.05), with the lowest HDL-C value recorded in the concentric hypertrophy group.

Conclusion

Obese children will develop left ventricular remodeling. The left ventricular configuration indexes are most significantly associated with serum HDL-C. Lower HDL-C level contributes to severer left ventricular hypertrophy, indicating a concentric hypertrophy pattern.

Three-dimensional echocardiography of the athlete's heart: a comparison with cardiac magnetic resonance imaging

Three-dimensional echocardiography (3DE) is the most accurate cardiac ultrasound technique to assess cardiac structure. 3DE has shown close correlation with cardiac magnetic resonance imaging (CMR) in various populations. There is limited data on the accuracy of 3DE in athletes and its value in detecting alterations during follow-up. Indexed left and right ventricular end-diastolic volume (LVEDVi, RVEDVi), end-systolic volume, ejection fraction (LVEF, RVEF) and left ventricular mass (LVMi) were assessed by 3DE and CMR in two-hundred and one competitive endurance athletes (79% male) from the Pro@Heart trial. Sixty-four athletes were assessed at 2 year follow-up. Linear regression and Bland-Altman analyses compared 3DE and CMR at baseline and follow-up. Interquartile analysis evaluated the agreement as cardiac volumes and mass increase. 3DE showed strong correlation with CMR (LVEDVi r = 0.91, LVEF r = 0.85, LVMi r = 0.84, RVEDVi r = 0.84, RVEF r = 0.86 p < 0.001). At follow up, the percentage change by 3DE and CMR were similar (∆LVEDVi r = 0.96 bias - 0.3%, ∆LVEF r = 0.94, bias 0.7%, ∆LVMi r = 0.94 bias 0.8%, ∆RVESVi r = 0.93, bias 1.2%, ∆RVEF r = 0.87 bias 0.4%). 3DE underestimated volumes (LVEDVi bias - 18.5 mL/m², RVEDVi bias - 25.5 mL/m²) and the degree of underestimation increased with larger dimensions (Q1vsQ4 LVEDVi relative bias - 14.5 versus - 17.4%, p = 0.016; Q1vsQ4 RVEDVi relative bias - 17 versus - 21.9%, p = 0.005). Measurements of cardiac volumes, mass and function by 3DE correlate well with CMR and 3DE accurately detects changes over time. 3DE underestimates volumes and the relative bias increases with larger cardiac size.

Left ventricular mass estimation by real-time 3D echocardiography favourably competes with CMR in congenital left ventricular disease

Assessment of left ventricular mass (LVM) is important in the evaluation of patients with congenital heart disease (CHD) and cardiac magnetic resonance imaging (CMR) is the gold standard. Recent software allows LVM calculation by real-time 3-dimensional echocardiography (RT3DE). We investigated the impact of different software analysis tools on LVM determination by CMR or RT3DE in a cohort of patients with heterogeneous left ventricular (LV) disease. 37 subjects (17 patients, mean age 18.7 y; 20 controls, mean age 13.2 y) underwent CMR and RT3DE. CMR LVM and RT3DE calculations were done using two different LV-analysis software packages for each modality: CMR i) customized software “CMR HDZ”, CMR ii) “CMR ISP”; RT3DE i) “Toshiba”, RT3DE ii) “Tomtec”, 4D LV-Analysis Version 3.1 (built 3.1.0.258661). Intra- and interobserver variabilities were calculated. Only RT3DE-derived LVM showed significant software-dependent differences. RT3DE-derived LVM (both softwares) was significantly higher than CMR-derived LVM (both softwares). The two different methods and four evaluation software packages for LVM assessment were well correlated with each other. Intra- and interobserver variability of LVM as assessed by each single modality or software was low. Despite software dependency and overestimation of RT3DE-assessed LVM by 5 to 10%, RT3DE still competes with the gold standard, CMR, even in patients with various forms of LV disease. The use of optimized software, especially for RT3DE, should improve the accuracy of LVM assessment, overcoming LVM overestimation.

The developing athlete's heart: a cohort study in young athletes transitioning through adolescence

Background

Athlete's heart is a term used to describe physiological changes in the hearts of athletes, but its early development has not been described in longitudinal studies. This study aims to improve our understanding of the effects of endurance training on the developing heart.

Methods

Cardiac morphology and function in 48 cross-country skiers were assessed at age 12 years (12.1 ± 0.2 years) and then again at age 15 years (15.3 ± 0.3 years). Echocardiography was performed in all subjects including two-dimensional speckle-tracking strain echocardiography and three-dimensional echocardiography. All participants underwent cardiopulmonary exercise testing at both ages 12 and 15 years to assess maximal oxygen uptake and exercise capacity.

Results

Thirty-one (65%) were still active endurance athletes at age 15 years and 17 (35%) were not. The active endurance athletes had greater indexed maximal oxygen uptake (62 ± 8 vs. 57 ± 6 mL/kg/min, P < 0.05) at follow-up. There were no differences in cardiac morphology at baseline. At follow-up the active endurance athletes had greater three-dimensional indexed left ventricular end-diastolic (84 ± 11 mL/m2 vs. 79 ± 10 mL/m2, P < 0.05) and end-systolic volumes (36 ± 6 mL/m2 vs. 32 ± 3 mL/m2, P < 0.05). Relative wall thickness fell in the active endurance athletes, but not in those who had quit (–0.05 ΔmL/m2 vs. 0.00 mL/m2, P = 0.01). Four active endurance athletes had relative wall thickness above the upper reference values at baseline; all had normalised at follow-up.

Conclusion

After an initial concentric remodelling in the pre-adolescent athletes, those who continued their endurance training developed eccentric changes with chamber dilatation and little change in wall thickness. Those who ceased endurance training maintained a comparable wall thickness, but did not develop chamber dilatation.

Morphological changes and myocardial function assessed by traditional and novel echocardiographic methods in preadolescent athlete’s heart

Background

Athlete’s heart is a term used to describe the morphological and functional changes in the hearts of athletes. Recent studies suggest that these changes may occur even in preadolescent athletes. This study aims to improve our understanding of the changes occurring in the preadolescent athlete’s heart.

Design and methods

Cardiac morphology and function in 76 preadolescent cross-country skiers (aged 12.1 ± 0.2 years) were compared with 25 age-matched non-competing preadolescents. Echocardiography was performed in all subjects, including 2D speckle-tracking strain echocardiography and 3D echocardiography. All participants underwent cardiopulmonary exercise testing to assess oxygen uptake and exercise capacity.

Results

Athletes had greater indexed VO2 max (62 ± 7 vs. 44 ± 5 mL/kg per min, p < 0.001), indexed left ventricular end-diastolic volume (79 ± 7 vs. 68 ± 7 mL/m2, p < 0.001), left ventricular mass (69 ± 12 vs. 57 ± 13 g/m2, p < 0.001), indexed right ventricular basal diameter (28.3 ± 3.0 vs. 25.4 ± 3.5 mm/m2, p < 0.001) and right atrial area (10.6 ± 1.4 vs. 9.7 ± 1.2 cm2/m2, p < 0.01). There was no difference in left ventricular ejection fraction, global longitudinal strain, and global circumferential strain and right ventricular fractional area change between the groups. Controls had higher right ventricular global longitudinal strain (−28.1 ± 3.5 vs. −31.1 ± 3.3%, p < 0.01). VO2 max was highly correlated to left ventricular end-diastolic volume ( r = 0.76, p < 0.001).

Conclusion

Athletes had greater left ventricular mass and greater left and right ventricular chamber dimensions compared with controls, while left ventricular function did not differ. Interestingly, right ventricular deformation was significantly lower compared with controls. This supports the notion that there is physiological, adaptive remodelling in preadolescent athlete’s heart.

Growth of Cardiovascular Structures from the Fetus to the Young Adult

The size, hemodynamics, and function of cardiovascular structures change dramatically from the early fetal life to late adolescence. The principal determinants of cardiovascular dimensions are related to the blood flow needed to meet metabolic demands. This demand is in turn tightly related to body size and body composition, keeping in mind that various tissues may have different metabolic rates. There is no simple model that links cardiac dimensions with a single body size measurement. Consequently, despite abundant scientific literature, few studies have proposed pediatric reference values that efficiently and completely account for the effect of body size. Other factors influence cardiovascular size and function in children, including sex. The influence of sex is multifactorial and not fully understood, but differences in body size and body composition play an important role. We will first review the determinants of cardiovascular size and function in children. We then explore the evaluation and normalization of cardiovascular size and function in pediatric cardiology in relation to the growth of cardiovascular structures during childhood, with a particular focus on sex differences.

Centile Curves for Velocity-Time Integral Times Heart Rate as a Function of Ventricular Length: The Use of Minute Distance Is Advantageous to Enhance Clinical Reliability in Children

BACKGROUND

The generation of velocity-time integrals (VTIs) from Doppler signals is an essential component of standard echocardiographic investigations. The most effective algorithm to compensate for growth in children has, however, not yet been identified. This study was initiated to establish pediatric reference values for VTI and to enhance the interpretability of those values, considering technical and physiological factors.

METHODS

The echocardiographic data sets of healthy children and adolescents (N = 349; age range, 0-20 years) were recorded in a prospective approach and subsequently analyzed. In a pilot study, aortic and pulmonary VTIs were set in relation to the physiologic parameters of heart size as possible influencing parameters in a subgroup of children with comparable physical characteristics. The ratio with the smallest SD was taken as the base to generate centile curves using the LMS method. The clinical utility of the model was tested by examining patients (n = 80) with shunt lesions such as patent ductus arteriosus and atrial septal defect.

RESULTS

Feasibility was 94.6% for aortic VTI and 92.8% for pulmonary VTI. The pilot study identified ventricular length and heart rate as suitable parameters with the lowest relative SDs and high correlations with VTI. Gender differences were not relevant for children <7 years of age, and with increasing age, SD increased because of higher stroke volume variations. The detection of increased aortic VTI was possible with sensitivity of 73% for patients with patent ductus arteriosus with moderate or large hemodynamically significant ductus arteriosus. Patients with atrial septal defects with enlarged right ventricles could be identified as having increased pulmonary VTI with sensitivity of 84%.

CONCLUSIONS

These new reference values for VTI times heart rate as a function of ventricular length may be of specific clinical value to improve the assessment of cardiac function, therapeutic decision making, and follow-up in pediatric patients with heart disease.

Cardiac Imaging in Heart Failure with Comorbidities

Imaging modalities stand at the frontiers for progress in congestive heart failure (CHF) screening, risk stratification and monitoring. Advancements in echocardiography (ECHO) and Magnetic Resonance Imaging (MRI) have allowed for improved tissue characterizations, cardiac motion analysis, and cardiac performance analysis under stress. Common cardiac comorbidities such as hypertension, metabolic syndromes and chronic renal failure contribute to cardiac remodeling, sharing similar pathophysiological mechanisms starting with interstitial changes, structural changes and finally clinical CHF. These imaging techniques can potentially detect changes earlier. Such information could have clinical benefits for screening, planning preventive therapies and risk stratifying patients. Imaging reports have often focused on traditional measures without factoring these novel parameters. This review is aimed at providing a synopsis on how we can use this information to assess and monitor improvements for CHF with comorbidities.

Tacrolimus Predose Concentration Is Associated With Hypertension in Pediatric Liver Transplant Recipients

BACKGROUND

The aim of the study was to analyze the incidence of hypertension in pediatric liver transplantation (LT) recipients using ambulatory blood pressure measurements (ABPM) and to identify factors associated with hypertension. We also investigated whether hypertension or tacrolimus predose concentration (TAC C0) was associated with increased left ventricular (LV) wall thickness.

PATIENTS AND METHODS

On a retrospective longitudinal base, we included 39 pediatric LT recipients. Median time since transplantation was 65 months (range: 11-183). Two consecutive ABPM were analyzed with a median time interval of 13 months. Data from echocardiographic evaluation parallel to the baseline ABPM were analyzed. All patients except 1 were prescribed tacrolimus. The median TAC C0 was 4 ng/mL (range 0.9-11.2). Univariate and multivariate logistic regression models were fitted to identify factors associated with systolic and diastolic hypertension and LV wall thickness.

RESULTS

Twenty-two of 39 children were hypertensive at baseline and 19 of 32 were hypertensive at follow-up. At baseline 10 (26%) children had masked systolic hypertension. TAC C0 was associated with systolic (P = 0.007, Exp(B) 2.02, 95% CI 1.2-3.3) and diastolic (P = 0.044, Exp(B) 1.48, 95% CI 1.0-2.2) hypertension. LV wall thickness was increased in children after LT compared with healthy population, but it was not associated with hypertension or TAC C0.

CONCLUSIONS

Given the high prevalence of masked hypertension, ABPM should be performed in all pediatric LT recipients. Systolic and diastolic hypertension is associated with TAC C0; therefore, children with a higher target TAC C0 require a more intensive blood pressure surveillance.