Three-Dimensional Echocardiography Derived Nomograms for Left Ventricular Volumes in Healthy Caucasian Italian Children

Comprehensive Two-Dimensional Pediatric Echocardiographic Nomograms for Coronary Artery Sizes in Caucasian Children and Comparison among Major Nomograms

BACKGROUND

Although coronary artery nomograms in children have been published, data on Caucasian children are lacking. The aim of this study is to provide: (i) a full dataset of coronary artery diameters in healthy children and (ii) a comparison among major previous nomograms.

MATERIALS AND METHODS

We prospectively evaluated 606 healthy subjects (age range, 1 days-<18 years; median age 8.7 years; 62.5% male). Coronary artery measurements in a short-axis view were performed. Age, heart rate, and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. To assess the accuracy of the predictive models of different studies, a Z-score calculator was created using Lopez's nomograms for comparison.

RESULTS

The association with BSA was found to be stronger, and was used for normalization of our data. The best-fit models, satisfying the assumption of homoscedasticity and normality of residuals and showing the highest R2 scores, were logarithmic (ln[y] = a + b*ln[x]). Predicted values and Z-score boundaries by BSA are provided. Our ranges of normality are slightly lower than those, diverging from -0.22 to -0.59 Z-scores for the left main coronary artery and from -0.23 to -0.3 Z-scores for the right coronary artery.

CONCLUSIONS

We report a complete dataset of normal echocardiography coronary artery diameter (including new measures of the proximal origin) values in a large population of healthy children. Our data were statistically like those of north American nomograms.

Characterization of Aortic Flow Patterns by High-Frame-Rate Blood Speckle Tracking Echocardiography in Children

Background Blood speckle tracking echocardiography allows for direct quantification of interventricular and aortic flow profiles, principally in children. Here, we sought to demonstrate the feasibility and reproducibility of blood speckle tracking echocardiography in the aortas of healthy children. Methods and Results One hundred healthy White children evaluated for the screening of congenital heart disease were prospectively enrolled. Echocardiographic examinations were performed using a Vivid E 95 ultrasound system, with blood speckle tracking from a focused and zoomed view of the aortic root and the ascending aorta. Vortex position, height (mm), width (mm), sphericity index, and area (cm2) were measured and indexed by body surface area. Median (interquartile range) age was 8.2 (5.6-11.0) years, median (interquartile range) weight was 28 (19-35) kg, and median (interquartile range) body surface area was 1.01 (0.79-1.16) m2. Vortices were visualized in only a single phase of the cardiac cycle in 25 subjects-14 (56.0%) were evident in early diastole and 11 (44.0%) in late systole. Vortices visualized in diastole had a mean area of 0.27±0.1 cm2/m2, while those in systole had a mean area of 0.34±0.12 cm2/m2. In a subset of 20 patients, inter- and intraobserver coefficient of variation and intraclass correlation coefficients were determined and showed good reproducibility. Conclusions We demonstrate feasibility and reproducibility of blood speckle tracking and identified vortical flow patterns in the aortic root and ascending aorta in healthy children. These data may serve as a baseline for evaluating aortic flow patterns in children with congenital and acquired heart disease.

Echocardiographic scores for biventricular repair risk prediction of congenital heart disease with borderline left ventricle: a review

The aim of this review is to highlight the strengths and limitations of major echocardiographic biventricular repair (BVR) prediction models for borderline left ventricle (LV) in complex congenital heart disease (CHD). A systematic search in the National Library of Medicine for Medical Subject Headings and free text terms including echocardiography, CHD, and scores, was performed. The search was refined by adding keywords for critical aortic stenosis (AS), borderline LV, complex left ventricular outflow tract (LVOT) obstruction, hypoplastic left heart syndrome/complex (HLHS/HLHC), and unbalanced atrio-ventricular septal defects (uAVSD). Fifteen studies were selected for the final analysis. We outlined what echocardiographic scores for different types of complex CHD with diminutive LV are available. Scores for CHD with LVOT obstruction including critical AS, HLHS/HLHC, and aortic arch hypoplasia have been validated and implemented by several studies. Scores for uAVSD with right ventricle (RV) dominance have also been established and implemented, the first being the atrioventricular valve index (AVVI). In addition to AVII, both LV/RV inflow angle and LV inflow index have all been validated for the prediction of BVR. We conclude with a discussion of limitations in the development and validation of each of these scores, including retrospective design during score development, heterogeneity in echocardiographic parameters evaluated, variability in the definition of outcomes, differences in adopted surgical and Interventional strategies, and institutional differences. Furthermore, scores developed in the past two decades may have little clinical relevance now. In summary, we provide a review of echocardiographic scores for BVR in complex CHD with a diminutive LV that may serve as a guide for use in modern clinical practice.

Comprehensive evaluation of left ventricular deformation using speckle tracking echocardiography in normal children: comparison of three-dimensional and two-dimensional approaches

Background

Three-dimensional (3D) speckle tracking echocardiography (STE) can overcome some of the inherent limitations of two-dimensional (2D) STE; however, clinical experience is lacking. We aimed to assess and compare the feasibility, agreement, and reproducibility of left ventricular (LV) global longitudinal (GLS), and regional strain by 3D vs 2D STE in normal children.

Methods

Healthy pediatric subjects (n = 105, age mean = 11.2 ± 5.5 years) were prospectively enrolled. Three-dimensional and 2D LV GLS, as well as regional strain in 16 myocardial segments were quantified. Bland Altman analysis, intra- class correlation coefficients (ICC), percent error and linear regression were used for agreement and correlation between the two techniques. Analysis and acquisition times were compared. Inter- and intra-observer reproducibility was assessed in 20 studies.

Results

There was good to excellent agreement for 2D and 3D global longitudinal strain (ICC =0.82) and modest agreement for regional strain (ICC range 0.43–0.71). Both methods had high feasibility (88.6% for 2D vs 85.7% for 3D, p = 0.21), although 3D STE required significantly shorter acquisition and analysis time than 2D STE (acquisition time 1 ± 1.2 mins vs 2.4 ± 1 mins; p = 0.03, analysis time = 3.3 ± 1 mins vs 8.2 ± 2.5 mins; p = 0.001, respectively). Inter and intra-observer reproducibility was excellent for GLS by the two techniques (ICC = 0.78–0.93) but moderate to poor for regional strain (ICC = 0.21–0.64).

Conclusion

Three-dimensional global LV strain is as feasible and reproducible as 2D strain, with good agreement yet significantly more efficient acquisition and analysis. Regional strain is less concordant and 2D and 3D values should not be used interchangeably. 3D LV GLS may represent a viable alternative in evaluation of LV deformation in pediatric subjects.

1. Adequate feasibility of 3D STE in pediatrics; comparable to 2D STE.

2. Significantly shorter acquisition and analysis time for 3D GLS compared to 2D GLS.

3. Excellent agreement between 3D and 2D LV GLS and moderate to poor agreement between regional strain values.

4. Excellent inter and intra-observer reproducibility for GLS by the two techniques, and fair to poor reproducibility for regional strain (higher for apical than basal regions).

Left ventricular vortex analysis by high-frame rate blood speckle tracking echocardiography in healthy children and in congenital heart disease

Background

High-frame rate blood speckle tracking (BST) echocardiography is a new technique for the assessment of intracardiac flow. The purpose of this study was to evaluate the characteristics of left ventricular (LV) vortices in healthy children and in those with congenital heart disease (CHD).

Methods

Characteristics of LV vortices were analyses based on 4-chamber BST images from 118 healthy children (median age 6.84 years, range 0.01-17 years) and 43 children with CHD (median age 0.99 years, range 0.01-14 years). Both groups were compared after propensity matching. Multiple linear regression was used to identify factors that independently influence vortex characteristics.

Results

Feasibility of vortex imaging was 93.7% for healthy children and 95.6% for CHD. After propensity matching, there were no overall significant differences in vortex distance to apex, distance to interventricular septum (IVS), height, width, sphericity index, or area. However, multiple regression analysis revealed significant associations of LV morphology with vortex characteristics. Furthermore, CHD involving LV volume overload and CHD involving LV pressure overload were both associated with vortices localized closer to the IVS.

Conclusions

LV vortex analysis using high-frame rate BST echocardiography is feasible in healthy children and in those with CHD. As they are associated with LV morphology and are modified in some types of CHD, vortices might yield diagnostic and prognostic value. Future studies are warranted to establish applications of vortex imaging in the clinical setting.

A multicenter study of three-dimensional echocardiographic evaluation of normal pediatric left ventricular volumes and function

BACKGROUND

Three-dimensional echocardiography (3DE) evaluation of left ventricular (LV) volume and function in pediatrics compares favorably with cardiac magnetic resonance imaging. The aim of this study was to establish from a multicenter, normal pediatric z-score values of 3DE left ventricular volumes and function.

METHODS

Six hundred and ninety-eight healthy children (ages 0-18 years) were recruited from five centers. LV 3DE was acquired from the 4-chamber view. A vendor-independent software analyzed end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) using semi-automated quantification. Body surface area (BSA)-based z-scores were generated. Intraobserver and interobserver variability were calculated using intraclass correlation (ICC) and repeatability coefficient (RC).

RESULTS

Z-scores were generated for ESV, EDV, and SV. The ICC for intraobserver variability for EDV, ESV, and SV was 0.99, 0.99, and 0.99, respectively. The ICC for interobserver variability for EDV, ESV, and SV was 0.98, 0.94, and 0.98, respectively. The RC for intraobserver and interobserver variability for LV EF was 4.39% (95% CI: 3.01, 5.59) and interobserver was 7.08% (95%CI: 5.51, 8.42).

CONCLUSIONS

We report pediatric z-scores for normal LV volumes using the semi-automated method from five centers, enhancing its generalizability. 3DE evaluation of LV volumes and EF in pediatric patients is highly reproducible.

Pediatric nomograms for left ventricle biplane 2D volumes in healthy Caucasian children

BACKGROUND

Left ventricular (LV) volumes are basic parameters used to estimate ventricular size and function; however, normal values are not available in children. The aim of our study is to provide normal values for LV volumes (measured with the biplane Simpson method) in healthy children.

MATERIALS AND METHODS

We prospectively studied 1320 healthy Caucasian Italian children (age 0 days-17 years, 49.4% female). Echocardiographic measurements on LV volumes were performed. Age, heart rate (HR), and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement.

RESULTS

Models with exponential (ln[y] = a + b*ln[x]) equations resulted in the best fit for LV volumes. The association with BSA was found to be stronger than the association of HR and age. Thus BSA was used for normalization of our data. Predicted values and Z-score boundaries by BSA are provided.

CONCLUSIONS

We report normal values for 2D biplane LV volumes in a population of healthy children. These data cover a gap in current pediatric echocardiographic nomograms and may serve as baseline for evaluation of children with cardiac defects characterized by LV dilatation or hypoplasia.