How accurately, reproducibly, and efficiently can we measure left ventricular indices using M-mode, 2-dimensional, and 3-dimensional echocardiography in children?

Feasibility of Three-Dimensional Echocardiographic Analysis in Newborns by Novice Observers

Three-dimensional echocardiography (3DE) provides better interobserver agreement than conventional methods. However, more evidence of whether there is good agreement between novice and experienced observers, especially in pediatric 3DE analysis, is required. We conducted 3DE analysis training in novice observers and investigated the agreement when analyzing 3DE images between novice and experienced observers. One experienced and 4 novice observers independently analyzed 60 3DE images obtained from neonates. The left and right ventricular end-diastolic volume (LVEDV and RVEDV), end-systolic volume (LVESV and RVESV), ejection fraction (LVEF and RVEF), left ventricular global longitudinal strain, and global circumferential strain (LVGLS and LVGCS) were calculated. The novices received hands-on instruction in the analysis procedure before the analysis and received further feedback after their first 40 analyses. Agreement between the novices and the experienced observer was evaluated by the intra-class correlation coefficient (ICC) and percentage difference in 3 groups of 20 images each (images 1-20, 21-40, and 41-60). The ICC of LVEDV was > 0.85 from the first 20 images and increased with experience. The ICCs for RVEDV and RVESV were low from the first 20 images but increased linearly, reaching an ICC > 0.9 in 3 of the 4 novice observers in the last 20 images. The range of the percentage difference was small for LVEDV, RVEDV, LVEF, and RVEF. Novices show an experienced level of 3DE analysis capability in LVEDV and RVEDV after analyzing 40 to 60 images. Training of novices is effective for analyzing LVEDV and RVEDV in 3DE images.

Three-dimensional speckle tracking echocardiography for evaluation of ventricular function in patients with systemic lupus erythematosus: relationship between duration of lupus erythematosus and left ventricular dysfunction by using global longitudinal strain

BACKGROUND

Cardiovascular diseases are leading causes of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Cardiac involvement in SLE can often go undetected. Three-dimensional (3D) speckle tracking echocardiography (STE) is a noninvasive imaging technique that can assess the function of the heart's ventricles in an accurate and reproducible way. This makes it an attractive option for detecting early signs of heart disease in SLE patients. By identifying these subclinical cardiac abnormalities, 3D-STE may help reduce the negative impact of cardiovascular diseases in SLE population. Therefore, this study aimed to compare the left ventricular (LV) function between patients with SLE compared to age- and gender-matched controls using two-dimensional (2D) and 3D-STE.

RESULTS

The current study found no significant differences in left ventricle ejection fraction, left ventricle end-diastolic volume, left ventricle end-systolic volume, left ventricle end-diastolic mass, and left ventricle end-systolic mass between the two groups. However, the SLE group exhibited a significantly lower LV global longitudinal strain (GLS) compared to the control group according to all types of echocardiographic assessments, including 3D and 2D long-axis strain, apical 2-chamber, and apical 4-chamber assessments (all P values < 0.05). Furthermore, a good inter-rater reliability and intra-rater reliability were observed regarding the LVGLS measurement with 3D-STE. Additionally, the study identified a significant correlation between LVGLS and SLE duration (r (50) = 0.46, P < 0.001). The use of prednisolone and nephrology disorders was also found to impact LVGLS measurements.

CONCLUSIONS

Despite a normal LVEF in patients with SLE, LVGLS measurements indicated that LV systolic dysfunction was observed more frequently in SLE patients compared to their healthy counterparts. Therefore, advanced 3D-STE techniques may be useful in identifying subtle abnormalities in LV function in SLE patients.

Electrocardiographic manifestations in female team handball players: analyzing ECG changes in athletes

Introduction

Long-term intense training leads to structural, functional, and electrical remodeling of the heart. How different sports affect the heart has not been fully investigated, particularly for female athletes. The aim of the present study was to investigate the morphology of 12-lead resting electrocardiogram (ECG) in elite female handball players compared to non-athlete female subjects. Potential changes will be explored to see if they could be explained by differences in cardiac dimensions and exercise hours.

Materials and methods

A cross-sectional study of 33 elite female team handball players compared to 33 sex and age-matched, non-athletic controls (age range 18-26 years) was performed. All participants underwent a resting 12-lead ECG and an echocardiographic examination. ECG variables for left ventricular hypertrophy and durations were evaluated and adjusted for cardiac dimensions and exercise hours using ANCOVA analysis. A linear regression analysis was used to describe relation between echocardiographic and ECG measures and exercise hours.

Results

The female handball players had larger cardiac dimensions and significantly lower heart rate and QTc duration (Bazett's formula) as well as increased QRS and QT durations compared to controls. The 12-lead sum of voltage and the 12-lead sum of voltage ∗ QRS were significantly higher among handball players. Changes in ECG variables reflecting the left ventricle could in part be explained by left ventricular size and exercise hours. Correlation with exercise hours were moderately strong in most of the echocardiographic measures reflecting left ventricular (LV), left ventricular mass (LVM), left atrium (LA) and right atrium (RA) size. Poor to fair correlations were seen in the majority of ECG measures.

Conclusions

Female team handball players had altered ECGs, longer QRS and QT durations, higher 12-lead sum of voltage and 12-lead sum of voltage ∗ QRS as well as shorter QTc (Bazett's formula) duration compared to non-athletic controls. These findings could only partly be explained by differences in left ventricular size. Despite larger atrial size in the athletes, no differences in P-wave amplitude and duration were found on ECG. This suggest that both structural, and to some degree electrical remodeling, occur in the female team handball players' heart and highlight that a normal ECG does not rule out structural adaptations. The present study adds knowledge to the field of sports cardiology regarding how the heart in female team handball players adapts to this type of sport.

Chronic in utero mitral inflow obstruction unloads left ventricular volume in a novel late gestation fetal lamb model

Objective

The in utero no flow/no grow hypothesis postulates that reduced inflow of blood into the left ventricle due to a stenotic mitral valve could lead to ventricular hypoplasia and hypoplastic left heart syndrome. This has been demonstrated in chick embryos, but less so in large animals. We investigated the impact of mitral obstruction on left and right ventricular growth in fetal lambs.

Methods

Twelve pregnant ewes, most bearing twins, were instrumented at 119 ± 1 days gestational age. Carotid artery and jugular vein catheters, an ascending aorta flow probe, and a left atrial deflated balloon catheter were implanted into 1 fetus (left atrial balloon group), and the twin remained an uninstrumented control. The balloon was inflated gradually over 8 days until net antegrade aortic flow was eliminated. Fetal transesophageal echocardiography was performed at the time of surgery and just before termination in both groups.

Results

Terminal fetal body weights were comparable between groups. Terminal heart/body weight ratio was higher in left atrial balloon group fetuses (6.9 ± 0.8 g/kg) compared with controls (5.9 ± 0.6 g, P = .0126). The left ventricular/right ventricular weight ratio was 24% (P = .0077) lower in left atrial balloon group fetuses than in controls. Left ventricular/heart weight (0.24 ± 0.04 g/g vs 0.30 ± 0.04 g/g, P = .0009), left ventricular end-diastolic volume (2.3 ± 0.7 mL vs 7.1 ± 0.8 mL; P = .0012), and left ventricular end-systolic volume (1.01 mL [0.95-1.95 mL] vs 3.38 mL [3.28-3.57 mL], P = .0042) were lower in left atrial balloon group fetuses compared with controls. Right ventricular weight (g/kg), right ventricular end-diastolic volume, and right ventricular end-systolic volume were similar between groups.

Conclusions

In this late-gestation fetal lamb model, in utero obstruction of mitral inflow slowed left ventricular growth and caused right ventricular remodeling.

Comparative Study of 2D-Cine and 3D-wh Volumetry: Revealing Systemic Error of 2D-Cine Volumetry

This study investigates the crucial factors influencing the end-systolic and end-diastolic volumes in MRI volumetry and their direct effects on the derived functional parameters. Through the simultaneous acquisition of 2D-cine and 3D whole-heart slices in end-diastole and end-systole, we present a novel direct comparison of the volumetric measurements from both methods. A prospective study was conducted with 18 healthy participants. Both 2D-cine and 3D whole-heart sequences were obtained. Despite the differences in the creation of 3D volumes and trigger points, the impact on the LV volume was minimal (134.9 mL ± 16.9 mL vs. 136.6 mL ± 16.6 mL, p < 0.01 for end-diastole; 50.6 mL ± 11.0 mL vs. 51.6 mL ± 11.2 mL, p = 0.03 for end-systole). In our healthy patient cohort, a systematic underestimation of the end-systolic volume resulted in a significant overestimation of the SV (5.6 mL ± 2.6 mL, p < 0.01). The functional calculations from the 3D whole-heart method proved to be highly accurate and correlated well with function measurements from the phase-contrast sequences. Our study is the first to demonstrate the superiority of 3D whole-heart volumetry over 2D-cine volumetry and sheds light on the systematic error inherent in 2D-cine measurements.

The variability of 2D and 3D transthoracic echocardiography applied in a general population : Intermodality, inter- and intraobserver variability

Assessment of the left ventricular (LV) function by three-dimensional echocardiography (3DE) is potentially superior to 2D echo echocardiography (2DE) for LV performance assessment. However, intra- and interobserver variation needs further investigation. We examined the intra- and interobserver variability between 2 and 3DE in a general population. In total, 150 participants from the Copenhagen City Heart Study were randomly chosen. Two observers assessed left ventricular ejection fraction (LVEF), end-diastolic (EDV) and end-systolic volumes (ESV) by 2DE and 3DE. Inter-, intraobserver and intermodality variabilities are presented as means of difference (MD), limits of agreement (LoA), coefficient of correlation (r), intraclass correlation coefficients (ICC). The lowest MD and LoA and highest r- and ICC-values was generally seen among the 3D acquisitions, with the 3D EDV interobserver as the best performing estimate (r = 0.95, ICC = 0.94). The largest MD, LoA and lowest r- and ICC-values was found in the interobserver 2D LVEF (r = 0.76, ICC = 0.63. For the intraobserver analysis, there were statistically significant differences between observations for all but 3DE EDV (p = 0.06). For interobserver analysis, there were statistically significant differences between observers for all estimates but 2DE EDV (p = 0.11), 3D ejection fraction (p = 0.9), 3DE EDV (p = 0.11) and 3D ESV (p = 0.15). Three-dimensional echocardiography is more robust and reproducible than 2DE and should be preferred for assessment of LV function.

Echocardiographic Findings and Correlation with Laboratory Values in Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19

Cardiac involvement is a common and serious problem in multisystem inflammatory syndrome in children (MIS-C). Echocardiographic evaluation of systolic and diastolic function by traditional, tissue Doppler and three-dimensional (3D) echocardiography was performed in consecutive 50 MIS-C patients during hospitalization and age-matched 40 healthy controls. On the day of worst left ventricular (LV) systolic function (echo-1), all left and right ventricular systolic function parameters were significantly lower (p < 0.001), E/A ratio was significantly lower, and averaged E/e' ratio was significantly higher (median 1.5 vs. 1.8, p < 0.05; 8.9 vs. 6.3, p < 0.001 respectively) in patients compared to control. Patients were divided into 2 groups according to 3D LV ejection fraction (LVEF) on the echo-1: Group 1; LVEF < 55%, 26 patients, and group 2; LVEF ≥ 55%, 24 patients. E/e' ratio was significantly higher in group 1 than group 2 and control at discharge (median 7.4 vs. 6.9, p = 0.005; 7.4 vs. 6.3, p < 0.001 respectively). Coronary ectasia was detected in 2 patients (z score: 2.53, 2.6 in the right coronary artery), and resolved at discharge. Compared with group 2, group 1 had significantly higher troponin-I (median 658 vs. 65 ng/L; p < 0.001), NT-pro BNP (median 14,233 vs. 1824 ng/L; p = 0.001), procalcitonin (median 10.9 vs. 2.1 µg/L; p = 0.009), ferritin (median 1234 vs. 308 µg/L; p = 0.003). The most common findings were ventricular systolic dysfunction recovering during hospitalization, and persisting LV diastolic dysfunction in the reduced LVEF group at discharge. Coronary artery involvement was rare in the acute phase of the disease. Also, in MIS-C patients, the correlation between LV systolic dysfunction and markers of inflammation and cardiac biomarkers should be considered.

Measurement of Left Ventricular Dimensions and Ejection Fraction in Neonates by Three-Dimensional Echocardiography: A Comparative Study Between Philips QLAB and TOMTEC Software-Are the Values Interchangeable?

Three-dimensional echocardiography is being used to evaluate left ventricular dimensions and ejection fraction in clinical practice. The validity and normal values have been established in a large group of normal adults, children and neonates. The aim of this study was to compare left ventricular dimensions and ejection fraction obtained from the same 3-dimensional echocardiography datasets using 2 commercially available applications: Philips QLAB and Tomtec 4D LEFT VENTRICLE-ANALYSIS. Fifty consecutive newborns or neonates coming to their first newborn visit within the first 3 weeks of live, were recruited. 38 babies underwent full Echocardiographic evaluation, including the acquisition of several 3-dimensional datasets, while naturally sleeping. Left ventricular dimensions, volumes and ejection fraction were measured using Philips QLAB version 9.0 and results were compared to results of the same datasets, analysed using TomTec 4D LV software. Mean left ventricular diastolic, and systolic volumes indexed to body surface area and ejection fraction were: 24.7 ± 3.6 ml/m², 9.2 ± 1.3 ml/m² and 62 ± 3.8% using TomTec and 26.6 ± 3.8 ml/m², 10.4 ± 2 ml/m² and 63 ± 3.1% using QLAB, respectively. Mean indexed left ventricular diastolic, and systolic volumes measured with QLAB were significantly higher as compared to TomTec with insignificant difference in the ejection fraction. Normal left ventricular indices obtained from 3-dimensional echocardiography datasets were established, using Philips QLAB and TomTec 4D LV ANALYSIS software. Measurements obtained were significantly different between those venders, and hence, may not be used interchangeably.

Usefulness of three-dimensional echocardiography for assessment of left and right ventricular volumes in children, verified by cardiac magnetic resonance. Can we overcome the discrepancy?

INTRODUCTION

The role of three-dimensional echocardiography (3D-ECHO) chamber quantification in children is still underestimated.

MATERIAL AND METHODS

In 43 children 3D-ECHO measurements of end-diastolic (EDV) and end-systolic ventricular volumes (ESV) were compared to cardiac magnetic resonance (CMR) using Bland-Altman analysis and linear regression. The values of left and right ventricular volumes calculated in 3D-ECHO were compared with each other and verified by CMR.

RESULTS

The values of LV-EDV and LV-ESV measured in 3D-ECHO showed highly significant correlations with CMR (for LV-EDV r = 0.892, p < 0.00001; for LV-ESV r = 0.896, p < 0.00001). In the case of the right ventricle the correlation of 3D-ECHO results with CMR was still high (RV-EDV r = 0.848, p < 0.00001, RV-ESV r = 0.914, p < 0.00001), although mean RV-EDV and RV-ESV in 3D-ECHO were underestimated compared to CMR (by 38% for RV-EDV and 45% for RV-ESV). Correction of 3D-ECHO results using the coefficient of 1.38 and 1.45 for RV-EDV and RV-ESV, respectively, significantly improved the consistency of the results with CMR. 3D-ECHO offered lower mean values of right ventricular volumes compared to the left ventricle. The discrepancy was again reduced by the calculated coefficients.

CONCLUSIONS

3D-ECHO is a valuable tool for assessment of left ventricular volume, which strongly correlates and agrees with CMR. The right ventricular volumes calculated in 3D-ECHO tend to be significantly underestimated in comparison to CMR and corresponding left ventricular volumes obtained from 3D-ECHO. The use of coefficients developed by the study improves the consistency of right ventricular volumes measured by 3D-ECHO with results obtained by CMR and reduces the volumetric discrepancy between ventricles in 3D-ECHO.

Echocardiographic Left Ventricular Mass Estimation: Two-Dimensional Area-Length Method is Superior to M-Mode Linear Method in Swine Models of Cardiac Diseases

Echocardiography offers rapid and cost-effective estimations of left ventricular (LV) mass, but its accuracy in patients with cardiac disease remains unclear. LV mass was measured by M-mode-based linear method and two-dimensional echocardiography (2DE)-based area-length method in pig models and correlation with actual LV weight was assessed. Twenty-six normal, 195 ischemic heart disease (IHD), and 33 non-IHD HF pigs were included. A strong positive linear relationship to the actual LV weight was found with 2DE-based area-length method (r = 0.82, p < 0.001), whereas a moderate relationship was found with M-mode method in the overall population (r = 0.68, p < 0.001). Two correlation coefficients were significantly different (p < 0.001), and were driven mainly by incremental overestimation of LV mass in heavier hearts using the M-mode method. IHD and LV dilation were the factors contributing to overestimation using M-mode method. 2DE-based area-length method provides a better estimation of LV weight in swine models of HF, particularly in those with IHD.

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.

Left Ventricular Mass Quantification by Two-Dimensional Echocardiography in a Pediatric Population: Correlation with Cardiac Magnetic Resonance Imaging

Quantification of left ventricular (LV) mass by echocardiography has not been validated against the gold standard of cardiac magnetic resonance imaging (CMR) in the pediatric population. The purpose of this study was to compare LV mass by two-dimensional and conventional M-mode echocardiography versus CMR in children. Consecutive CMR studies were paired with echocardiograms and retrospectively analyzed in children age ≤ 16 years (3 days old to 16 years old). Studies performed > 3 months between modalities and single ventricle anatomy were excluded. Unindexed LV mass was calculated using M-mode, area-length (AL), and truncated ellipsoid (TE) methods via echocardiography, and compared to cine stack CMR images. There were 46 patients included in the study (both MRI and echocardiography). Good correlations were observed for LV mass measured by CMR and all echocardiographic methods: M-mode (R = 0.965), AL (R = 0.975), and TE (R = 0.975). There was a significant overestimation using TE echocardiography, by a mean of 10.5 g (95% confidence interval 5.7-15.2 g, p < 0.05). There was no significant over- or underestimation of LV mass observed by M-mode or AL echocardiographic measurements, with tight limits of agreement when compared to CMR (95% confidence interval - 5.2 to 4.4 g and - 1.5 to 6.7 g, respectively). Interobserver agreement was good for each of the echocardiographic measurements, but inferior with M-mode (ICC, 0.89) compared to two-dimensional methods (ICC, 0.97). Echocardiographic estimates of LV mass have good correlation with CMR in children. Performance comparison showed AL echocardiographic method provides the most accurate measurement of LV mass with the best reproducibility compared to other methods.

Left ventricular volumes and ejection fraction quantification using an automated three-dimensional adaptive analytic echocardiographic algorithm in pediatric population

INTRODUCTION

The quantitative measurement of the left ventricle by echocardiography is a fundamental tool in the diagnosis and prognosis of acquired and congenital diseases in the pediatric population. The objective of this study was to validate an automated three-dimensional adaptive analytic echocardiographic algorithm, the so-called Heart Model^® (HM) in the pediatric population, using as comparators the left atrial and left ventricular volumes and left ventricular ejection fraction obtained by means of conventional 2D and 3D echocardiography.

METHODS

Pilot study, where a population comprised of 75 consecutive patients aged 6-17 years who attended a pediatric cardiology clinic, was evaluated. Every patient underwent a conventional 2D and 3D echocardiography and an analysis using HM. Conventional 3D echo was used as the reference method.

RESULTS

Seventy-five patients were analyzed. Mean age was 11.2 (4.0) years (52.2% women). The intraclass correlation coefficient of HM vs 2D echo was poor, but it was good for the agreement between HM and 3D echo for left ventricular end-diastolic volume (ICC: 0.98; 95% CI: 0.97-0.99; P < 0.001), left ventricular end-systolic volume ICC: 0.98; 95% CI: 0.96-0.99; P = 0.001), and left ventricular ejection fraction (ICC: 0.87; 95% CI: 0.78-0.92; P < 0.001). The agreement was also good for the three parameters when the analysis was performed according to body weight.

CONCLUSIONS

Heart Model^® is a feasible and accurate tool for the evaluation of left atrial and left ventricular volumes and left ventricular ejection fraction in pediatric population aged above 6 years.

Innovation in 3D Echocardiographic Imaging

PURPOSE OF REVIEW

The purpose of this review is to detail three-dimensional echocardiographic (3DE) innovations in pre-surgical planning of congenital heart disease, guidance of catheter interventions such as fusion imaging, and functional assessment of patients with congenital heart disease.

RECENT FINDINGS

Innovations in 3DE have helped us delineate the details of atrioventricular valve function and understand the mechanism of atrioventricular valve failure in patients with atrioventricular septal defect and single ventricle post repair. Advancement in holographic display of 3D datasets allows for better manipulation of 3D images in three dimensions and better understanding of anatomic relationships. 3DE with fusion imaging reduces radiation in catheter interventions and provides presentations of 3DE images in the similar fashion as the fluoroscopic images to improve communication between cardiologists. Lastly, 3DE allows for quantitative ventricular volumetric and functional assessment. Recent innovations in 3DE allow for pre-surgical planning for congenital heart disease, reduce radiation using fusion imaging in catheter interventions, and enable accurate assessment of ventricular volume and function without geometric assumptions.

Left Ventricular Dilation: When Pediatric Meet Adult Guidelines

Measuring and grading left ventricular (LV) size is essential for diagnostic, treatment, and prognostic purposes. Guidelines for quantifying LV size exist for pediatric and adult patients via M-mode measurements, but no data exist determining how well they agree with one another. The goal of this study was to determine the agreement between pediatric echocardiographic readers (PER), pediatric guidelines, and adult guidelines in assessing LV dilation. A retrospective review of all noncongenital echocardiograms from 9/2002 to 11/2015 that had a left ventricular end-diastolic diameter (LVEDD) >5.8 cm for males and >5.2 cm for females was performed. LV size was graded as normal (Z-score ≤ 2), mild (2 < Z-score ≤ 3), moderate (3 < Z-score ≤ 4), or severe (4 < Z-score) based on pediatric and adult guidelines. PER interpretation was also recorded. Agreement between LV size assessments was determined for these three interpretations. A total of 1489 echocardiograms met the inclusion criteria (654 males:835 females). Males were 19.0 ± 6.9 years old and had a BSA of 1.9 ± 0.3 m², and LVEDD was 6.3 ± 0.5 cm. Females were 18.7 ± 8.3 years old and had a BSA of 1.8 ± 0.3 m², and LVEDD was 5.7 ± 0.5 cm. There was a 63.91% agreement for males and an 81.8% agreement for females between PER and pediatric guidelines in assessing LV size. There was a 39.14% agreement for males and a 14.13% agreement for females between PER and adult guidelines in assessing LV size. There was a 41.44% agreement for males and a 14.49% agreement for females between adult and pediatric guidelines in assessing LV size. These agreement percentages did not change significantly when separating the population into greater than or less than 18 years of age cohorts. Pediatric echocardiographic readers were more consistent in following pediatric guidelines than adult guidelines in assessing LV size. The agreement for PER and pediatric guidelines was poor, especially for females, in relation to adult guidelines when assessing LV size. Further standardization and guidelines are needed for pediatric patients that are adult size.

Three-dimensional Echocardiography in Congenital Heart Disease: An Expert Consensus Document from the European Association of Cardiovascular Imaging and the American Society of Echocardiography

Three-dimensional echocardiography (3DE) has become important in the management of patients with congenital heart disease (CHD), particularly with pre-surgical planning, guidance of catheter intervention, and functional assessment of the heart. 3DE is increasingly used in children because of good acoustic windows and the non-invasive nature of the technique. The aim of this paper is to provide a review of the optimal application of 3DE in CHD including technical considerations, image orientation, application to different lesions, procedural guidance, and functional assessment.

Interpreting measurements of cardiac function using vendor-independent speckle tracking echocardiography in children: a prospective, blinded comparison with catheter-derived measurements

BACKGROUND

Adult studies demonstrate that echocardiographic measurements of cardiac function using speckle tracking correlate with invasive measurements, but such data in the pediatric population are sparse. Our aim was to compare speckle-derived measures of cardiac function to measurements routinely obtained by cardiac catheterization in children.

METHODS

Echocardiograms were performed on the day of cardiac catheterization. Using Tomtec 2D Cardiac Performance Analysis, longitudinal strain (LS), longitudinal strain rate (LSR), early diastolic LSR, and ejection fraction (EF) for the right and left ventricle (RV and LV) were calculated via speckle tracking. Global LS and LSR were calculated for the LV. These results were compared to cardiac index, maximum ventricular dp/dt (max dp/dt), ventricular end-diastolic pressure (EDP), and pulmonary capillary wedge pressure (PCWP) obtained by fluid-filled catheters. A blinded observer performed all echo measurements.

RESULTS

Fifty studies were performed on 28 patients ages 4 months to 20 years old. Their diagnoses included cardiac transplant (48 studies), repaired AV septal defect (1), and dilated cardiomyopathy (1). RVEDP ranged from 2 to 22 mm Hg (median=6) and PCWP ranged from 6 to 32 mmHg (median 10). LV global LS and LV 2-chamber LSR by speckle-tracking negatively correlated with LV max dp/dt (LV global LS R=-.83, P=.001; LV 2-chamber LSR R=-.69, P=.009). RV LS weakly correlated with max dp/dt (R=.363, P=.002). Early diastolic strain rate did not correlate with EDP in either ventricle.

CONCLUSION

Speckle-derived measurements of function in the LV have stronger correlation than the RV to catheter-derived measures. LV global LS has the strongest correlation with invasive function measures in children.

Critical Review of Current Approaches for Echocardiographic Reproducibility and Reliability Assessment in Clinical Research

BACKGROUND

There is no broadly accepted standard method for assessing the quality of echocardiographic measurements in clinical research reports, despite the recognized importance of this information in assessing the quality of study results.

METHODS

Twenty unique clinical studies were identified reporting echocardiographic data quality for determinations of left ventricular (LV) volumes (n = 13), ejection fraction (n = 12), mass (n = 9), outflow tract diameter (n = 3), and mitral Doppler peak early velocity (n = 4). To better understand the range of possible estimates of data quality and to compare their utility, reported reproducibility measures were tabulated, and de novo estimates were then calculated for missing measures, including intraclass correlation coefficient (ICC), 95% limits of agreement, coefficient of variation (CV), coverage probability, and total deviation index, for each variable for each study.

RESULTS

The studies varied in approaches to reproducibility testing, sample size, and metrics assessed and values reported. Reported metrics included mean difference and its SD (n = 7 studies), ICC (n = 5), CV (n = 4), and Bland-Altman limits of agreement (n = 4). Once de novo estimates of all missing indices were determined, reasonable reproducibility targets for each were identified as those achieved by the majority of studies. These included, for LV end-diastolic volume, ICC > 0.95, CV < 7%, and coverage probability > 0.93 within 30 mL; for LV ejection fraction, ICC > 0.85, CV < 8%, and coverage probability > 0.85 within 10%; and for LV mass, ICC > 0.85, CV < 10%, and coverage probability > 0.60 within 20 g.

CONCLUSIONS

Assessment of data quality in echocardiographic clinical research is infrequent, and methods vary substantially. A first step to standardizing echocardiographic quality reporting is to standardize assessments and reporting metrics. Potential benefits include clearer communication of data quality and the identification of achievable targets to benchmark quality improvement initiatives.

Speckle tracking echocardiography detects decreased cardiac longitudinal function in anthracycline-exposed survivors of childhood cancer

Longitudinal motion significantly contributes to the contraction of the ventricles. We studied the left (LV) and right ventricular (RV) longitudinal functions in 75 anthracycline-exposed, long-term childhood cancer survivors and 75 healthy controls with conventional echocardiography, tissue Doppler imaging (TDI), speckle tracking echocardiography (STE) of the mitral and tricuspid annular motion, and real-time three-dimensional echocardiography (RT-3DE). Cardiac magnetic resonance (CMR) imaging was performed on 61 of the survivors. The survivors had lower systolic myocardial velocities in the LV and lower diastolic velocities in both ventricles by TDI than did their healthy peers. The STE-based tissue motion annular displacement (TMAD) values describing the LV and RV systolic longitudinal function (MAD and TAD mid%, respectively) were also lower among the survivors (15.4 ± 2.4 vs. 16.1 ± 2.2 %, p = 0.049 and 22.5 ± 3.0 vs. 23.5 ± 3.0 %, p = 0.035). MAD and TAD mid in millimeters correlated with the respective ventricular volumes measured with RT-3DE or CMR.

CONCLUSION

Childhood cancer survivors exposed to low to moderate anthracycline doses had decreased longitudinal systolic and diastolic functions (TDI or STE) compared with healthy controls. The STE-based TMAD is a fast and reproducible method to assess cardiac longitudinal function. What is Known? • High anthracycline doses cause LV dysfunction as evidenced by a decreased ejection fraction. What is new? • Low to moderate anthracycline doses also have a negative impact on the LV and RV longitudinal systolic and diastolic function. • TMAD is a new and fast method to assess the cardiac longitudinal function after anthracycline exposure.

The Prevalence of Left Ventricular Hypertrophy in Obese Children Varies Depending on the Method Utilized to Determine Left Ventricular Mass

Obesity and left ventricular hypertrophy (LVH) have been identified as independent risk factors for cardiovascular events. The definition of LVH depends on the geometric algorithm used to calculate LV mass (LVM) by echocardiography and the method used to normalize LVM for body size. This study evaluates the effect of these methods on the prevalence of LVH in obese children. LVM for 109 obese and 109 age-matched non-obese children was calculated using M-mode or two-dimensional echocardiography (2DE). LVM was then normalized to height 2.7 as indexed LVM (LVMI), to body surface area (BSA), height, and lean body mass (LBM) as LVM Z-scores. LVH was defined as LVMI >95th ‰ using age-specific normal reference values or LVM Z-scores ≥2. The prevalence of LVH by LVMI and LVM Z-scores was compared. There was a correlation between LVM determined by M-mode and by 2DE (R (2) = 0.91), although M-mode LVM was greater than 2DE LVM. However, the difference between these values was greater in obese children than in non-obese children. Based on the method of normalization, the prevalence of LVH among obese children was 64 % using LVMI, 15 % using LVM Z-scores for height, 8 % using LVM Z-scores for BSA and 1 % using LVM Z-scores for LBM. Height-based normalization correlates with obesity and hypertension. The methods used to measure and normalize LVM have a profound influence on the diagnosis of LVH in obese children. Further study is needed to determine which method identifies children at risk for cardiovascular morbidity and mortality.

Left ventricular mass and systolic function in children with chronic kidney disease-comparing echocardiography with cardiac magnetic resonance imaging

BACKGROUND

Increased left ventricular mass (LVM) is an important risk marker of uremic cardiovascular disease. Calculation of LVM by echocardiography (Echo) relies on geometric assumptions and in adults on hemodialysis overestimates LVM compared to cardiac magnetic resonance (CMR). We compare both techniques in children with chronic kidney disease (CKD).

METHODS

Concurrent Echo and CMR was performed in 25 children with CKD (14 after kidney transplantation) aged 8-17 years.

RESULTS

Compared to normal children, CMR-LVM was increased (standard deviation score (SDS) 0.39 ± 0.8 (p = 0.03)), stroke volume and cardiac output decreased (SDS -1.76 ± 1.1, p = 0.002 and -1.11 ± 2.0, p = 0.001). CMR-LVM index but not Echo-LVMI correlated to future glomerular filtration rate (GFR) decline (r = -0.52, p = 0.01). Mean Echo-LVM was higher than CMR-LVM (117 ± 40 vs. 89 ± 29 g, p < 0.0001), with wide limits of agreement (-6.2 to 62.8 g). The Echo-CMR LVM difference increased with higher Echo-LVMI (r = 0.77, p < 0.0001). Agreement of classifying left ventricular hypertrophy was poor with Cohen's kappa of 0.08. Mean Echo and CMR-ejection fraction differed by 1.42% with wide limits of agreement (-12.6 to 15.4%).

CONCLUSIONS

Echo overestimates LVM compared to CMR, especially at higher LVM. Despite this, CMR confirms increased LVM in children with CKD. Only CMR-LVMI but not Echo-LVMI correlated to future GFR decline.

Intertwin cardiac status at 10-year follow-up after intrauterine laser coagulation therapy of severe twin-twin transfusion syndrome: comparison of donor, recipient and normal values

BACKGROUND

In twin-to-twin transfusion syndrome (TTTS), genetically identical twins are exposed to different haemodynamic conditions during fetal life, which are considered to be the cause of prenatal and postnatal cardiovascular differences between the donor and the recipient.

OBJECTIVE

To assess intertwin differences on childhood cardiac outcome after intrauterine laser coagulation therapy (LC) of severe TTTS.

DESIGN AND PATIENTS

Prospective, detailed, echocardiographic follow-up of 31 twin pairs aged 9.95±0.8 years (mean±SD) with severe TTTS treated by LC, and the comparison with reference values.

RESULTS

Cardiac function was normal and did not show intertwin differences in twins without structural heart disease. Discordant birth weight or birth weight <3rd centile for gestational age had no influence on blood pressure and cardiac indices. Pulmonary stenosis was more common (5/62; 8.1%) than in the general population (prevalence 0.066%, relative risk 134.4, 95% CI 42.1 to 428.8, p<0.0001) and affected both donor and recipient. Intertwin differences in late diastolic right ventricular filling (peak velocities: recipient 0.51±0.11 m/s vs donor 0.45±0.10 m/s, mean difference 0.74 m/s, 95% CI 0.23 to 1.24, p=0.009) and early septal relaxation (mean myocardial velocities: recipient -8.2±1.5 cm/s vs donor -8.9±1.2 cm/s, mean difference 0.7 cm/s, 95% CI 0.02 to 1.38, p=0.044) were found only when twins with right heart disease were included.

CONCLUSIONS

Despite severe prenatal cardiac involvement, childhood cardiac function is normal in the majority of surviving donors and recipients after successful LC of severe TTTS. This underlines the favourable impact of intrauterine LC on postnatal cardiovascular performance.

Dynamic indices of mitral valve function using perioperative three-dimensional transesophageal echocardiography

OBJECTIVE

Perioperative transesophageal echocardiography is essential for decision-making for mitral valve surgery. While two-dimensional transesophageal echocardiography represents the standard of care, tracking of dynamic changes using three-dimensional imaging permits assessment of morphologic and functional characteristics of the mitral valve. The authors hypothesized that quantitative three-dimensional analysis would reveal distinct differences among diseased, repaired, and normal mitral valves.

DESIGN

Case-control observational clinical study.

SETTING

Tertiary care hospital.

PARTICIPANTS

Using novel mitral valve quantification software, the authors retrospectively analyzed 80 datasets of cardiac surgery patients who underwent intraoperative transesophageal echocardiographic imaging. Twenty patients with degenerative mitral regurgitation were evaluated before and after mitral valve repair. Twenty patients had functional mitral regurgitation, and 20 patients had no mitral valve disease.

MEASUREMENTS AND MAIN RESULTS

Primary outcome measures of dynamic mitral valve function were: 1) three-dimensional annulus area, 2) annular displacement distance, 3) annular displacement velocity, and 4) annular area fraction. Other mitral annular tracking indices, in addition to intraobserver reliability and interobserver agreement, also were reported. Annulus area was enlarged in degenerative and functional mitral regurgitation. Annular displacement distance was decreased in functional mitral regurgitation and repaired valves. Annular displacement velocity was decreased in functional mitral regurgitation. Annular area fraction was decreased in functional mitral regurgitation and repaired valves. Intraobserver reliability and interobserver agreement were high for all 4 analyzed indices.

CONCLUSIONS

Normal, functional regurgitant, degenerative, and repaired mitral valves have distinctly different dynamic signatures of anatomy and function as reliably determined by perioperative echocardiographic tracking.

Comparison of three-dimensional echocardiographic findings to those of magnetic resonance imaging for determination of left ventricular mass in patients with ischemic and non-ischemic cardiomyopathy

The standard echocardiographic evaluation of left ventricular (LV) mass, particularly in ischemic cardiomyopathy (IC) is challenging because it is based on geometric assumptions. The aim of this study was to assess the accuracy of LV mass calculation using echocardiographic modalities compared with cardiac magnetic resonance (CMR) in IC and in nonischemic cardiomyopathy (non-IC). Echocardiography was performed in 104 patients (mean age 55 ± 15 years) referred for CMR: 63 with IC and 41 with non-IC. CMR, M-mode echocardiography, 2-dimensional echocardiography, and 3-dimensional echocardiography (3DE) were analyzed using standard commercial tools to obtain LV mass. LV mass on 3DE showed a higher correlation with CMR than 2-dimensional echocardiography (r = 0.87 vs r = 0.70, p <0.001). M-mode echocardiography overestimated LV mass (bias +30%) and 2-dimensional echocardiography underestimated LV mass (bias -11%), whereas measurements on 3DE showed only minimal bias (-2%). LV mass on 3DE in non-IC showed a significantly higher correlation with CMR than in IC (r = 0.92 vs r = 0.84, z = 2.3, p <0.05). In non-IC, the mean difference was -2 g (-1% of the mean), with 95% limits of agreement of ±33 g (±19% of the mean). In IC, the mean difference was -7 g (-4% of the mean), with limits of agreement of ±56 g (±31% of the mean). There was a correlation between the absolute LV mass differences (3DE derived and CMR derived) and scar percentage (infarcted mass/total LV mass) using delayed-hyperenhancement images (r = 0.40, p <0.05). The net reclassification index with 3DE was +16% for concentric LV hypertrophy. In conclusion, the most accurate and reliable echocardiographic measurement of LV mass is 3DE, but underestimation and variability remain challenges in IC.

Left ventricular three-dimensional global systolic strain by real-time three-dimensional speckle-tracking in children: feasibility, reproducibility, maturational changes, and normal ranges

BACKGROUND

Three-dimensional (3D) strain analysis may help overcome the limitations of Doppler and two-dimensional strain analysis for the left ventricle and become the method of choice for left ventricular (LV) systolic function. The aims of this study were to evaluate the feasibility and reproducibility of LV global 3D systolic strain by real-time 3D speckle-tracking echocardiography (STE) in children and to establish their maturational growth patterns and normal values.

METHODS

A prospective study was conducted in 256 consecutive healthy subjects using real-time 3D echocardiography. Full-volume 3D data were acquired using a 3D matrix-array transducer. Three-dimensional LV peak systolic global strain (GS), global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) values were determined using real-time 3D STE.

RESULTS

A total of 228 patients (89%) met the criteria for analysis; 28 (11%) were excluded. The correlations between age and strain variables by real-time 3D STE were poor (R(2) = 0.01-0.05, P < .05). The differences in GLS and GCS among the five age groups were statistically significant but clinically irrelevant. There were no statistical differences in GRS and GS values among the age groups, nor were there statistical differences between the genders for all 3D strain parameters. Intraobserver and interobserver variability ranged from 5.0 ± 4.3% to 10.1 ± 8.5% versus 6.9 ± 6.1% to 17.0 ± 16.2% for coefficients of variation, respectively. Interclass correlation coefficients ranged from 0.78 to 0.87 and from 0.75 to 0.79 for intraobserver and interobserver measurements for GS, GLS, GCS, and GRS, respectively.

CONCLUSIONS

LV global 3D systolic strain analysis using the new 3D STE is feasible and reproducible in the pediatric population. There are small maturational changes in GLS and GCS, but not in GRS and GS, that are statistically significant but probably clinically irrelevant. Further investigation is warranted for potential clinical application of this new technology in a pediatric population.

Real-time 3-dimensional echocardiographic assessment of ventricular volume, mass, and function in human fetuses

Objectives

We sought to determine the feasibility and reproducibility of real-time 3-dimensional echocardiography (RT3DE) for evaluation of cardiac volume, mass, and function and to characterize maturational changes of these measurements in human fetuses.

Methods

Eighty pregnant women in the 2^nd and 3^rd trimesters (59 with normal fetuses and 21 with fetuses with congenital heart disease [CHD]) were enrolled. We acquired RT3DE images using a matrix-array transducer. RT3DE measurements of volume, mass, stroke volume (SV), combined cardiac output (CCO), and ejection fraction (EF) were obtained. Images were scored and analyzed by two blinded independent observers. Inter- and intraobserver variabilities and correlations between fetal cardiac indices and gestational age were determined.

Results

Fifty-two of 59 normal data sets (88%) and 9 of 21 CHD data sets (43%) were feasible for analysis. In normal fetuses, the right ventricle (RV) is larger than the left ventricle (LV) (P<0.05), but no difference exists between the LV and RV in mass, SV, CO, and CO/CCO. The EFs for the LV and RV were diminished; the RVSV/LVSV was reduced in CHD fetuses compared with normal fetuses (P<0.05). Fetal ventricular volumes, mass, SV, and CCO fit best into exponential curves with gestational age, but LVEF, RVEF, and RVSV/LVSV remain relatively constant.

Conclusions

RT3DE is feasible and reproducible for assessment of LV and RV volume, mass, and function, especially in normal fetuses. Gestational growth of these measures, except for EF, is exponential in normal and CHD fetuses. CHD fetuses exhibit diminished LV and RV EFs.

Three-dimensional echocardiography in evaluation of left ventricular indices

Accurate determination of left ventricular mass, volume, ejection fraction, and wall motion is important for clinical decision making. Currently, M-mode and two-dimensional echocardiography (2DE) have been routinely used for this purpose. Although these 1D or 2D modalities provide excellent diagnostic and prognostic information, they have a number of technical limitations including the time required to perform the procedure and operator-dependent image acquisitions. In addition, they are inherently limited by geometric assumption of three-dimensional (3D) left ventricular structures based on 2D slices. With the improvement in transducer technology and software development, 3D echocardiography (3DE) has become widely available. Left ventricular quantitation by 3DE has been demonstrated to be accurate by multiple studies that compared 3DE with reference techniques. In addition, 3DE measurements were found to be more reproducible and less variable than 2DE. Real time 3DE imaging has potential advantages in stress echocardiography including rapid acquisition, unlimited number of planes, avoidance of foreshortening, and precise segment matching. This is a major step forward in our diagnostic armamentarium for the evaluation of ischemia. In this review, we summarized the current evidence of 3DE for left ventricular evaluation.

[Current value of 3D echocardiography in international guidelines]

Real-time 3D echocardiography is one of the most important developments in the field of non-invasive cardiac imaging within the last years. To investigate whether this new technology can be considered as a standard method the current guidelines and recommendations were reviewed. In the field of left ventricular function assessment, evaluation of mitral valve pathologies and peri-interventional monitoring of percutaneous valve repair procedures 3D echocardiography plays a major role. For other clinical applications, such as right heart assessment, congenital heart disease and stress echocardiography, a high potential is seen but evidence is currently too weak for general recommendations. However, in the near future no echo laboratory will be working without 3D modalities.

Limitations of expressing left ventricular mass relative to height and to body surface area in children

BACKGROUND

Left ventricular (LV) mass varies in proportion to lean body mass (LBM) but is usually expressed relative to height or body surface area (BSA), each of which functions as a surrogate for LBM. The aims of this study were to characterize the adiposity-related biases associated with each of these scaling variables and to determine the impact of these biases on the diagnosis of LV hypertrophy (LVH) in a group of children at risk for LVH.

METHODS

In a retrospective study, LV mass was estimated using M-mode echocardiography in 222 healthy nonoverweight reference children and 112 children "at risk" for LVH (48 healthy overweight children and 64 children with hypertension). LBM was estimated for all children using validated predictive equations and was considered the criterion scaling variable. Z scores for LV mass for LBM, LV mass for height, and LV mass for BSA were calculated for each child relative to the reference group. The performance of height-based and BSA-based Z scores were compared with that of LBM-based Z scores at different levels of adiposity (estimated by the Z score for body mass index for age [BMIz]).

RESULTS

Among healthy normotensive children, LV mass-for-height Z scores were greater than LV mass-for-LBM Z scores at higher values of BMIz and lower than LV mass-for-LBM Z scores at lower values of BMIz (R(2) = 0.52, P < .0001). LV mass-for-BSA Z scores for agreed well with LBM-based Z scores at BMIz < 0.7 but were lower than LV mass-for-LBM Z scores for at BMIz > 0.7 (R(2) = 0.31, P < .0001). Compared with 13% of at-risk children classified as having LVH on the basis of LV mass for LBM > 95th percentile, 30% and 11% had LVH when LV mass was scaled to height and BSA, respectively.

CONCLUSIONS

Scaling LV mass to BSA in children results in less misclassification with respect to LVH than does scaling to height.

Meta-analysis of accuracy of left ventricular mass measurement by three-dimensional echocardiography

Left ventricular (LV) hypertrophy is a fundamental prognostic factor in a variety of cardiac diseases. Three-dimensional echocardiography (3DE) has achieved better estimation of LV mass than 2-dimensional echocardiography. However, significant underestimation has often been reported, and no previous study has synthesized these data. The aim of this meta-analysis was to investigate if there has been improvement in the accuracy in LV mass measurement by 3DE over time. Studies comparing LV mass between 3DE and magnetic resonance imaging were eligible. A cumulative meta-analysis was performed to investigate improvement in accuracy, followed by subgroup and meta-regression analysis to reveal factors affecting the bias. A total of 25 studies including 671 comparisons were analyzed. Studies published in or before 2004 showed high heterogeneity (I(2) = 69%) and significant underestimation of LV mass by 3DE (-5.7 g, 95% confidence interval -11.3 to -0.2, p = 0.04). Studies published from 2005 to 2007 were still heterogenous (I(2) = 60%) but showed less systematic bias (-0.5 g, 95% confidence interval -2.5 to 1.5, p = 0.63). In contrast, studies published in or after 2008 were highly homogenous (I(2) = 3%) and showed excellent accuracy (-0.1 g, 95% confidence interval -2.2 to 1.9, p = 0.90). Investigation of factors affecting the bias revealed that evaluation of cardiac patients compared to healthy volunteers led to larger bias (p <0.05). In conclusion, this meta-analysis elucidates the underestimation of LV mass by 3DE, its improvement over the past decade, and factors affecting the bias. These data provide a more detailed basis for improving the accuracy of 3DE, an indispensable step toward further clinical application.

Assessment of global left ventricular function with dual-source computed tomography in patients with valvular heart disease

BACKGROUND

Left ventricular (LV) function is a vital parameter for prognosis, therapy guidance, and follow-up of cardiovascular disease. Dual-source computed tomography (DSCT) provides an accurate analysis of global LV function.

PURPOSE

To assess the performance of DSCT in the determination of global LV functional parameters in comparison with cardiovascular magnetic resonance (CMR) and two-dimensional transthoracic echocardiography (2D-TTE) in patients with valvular heart disease (VHD).

MATERIAL AND METHODS

A total of 111 patients (58 men, mean age 49.9 years) with known VHD and who underwent DSCT, 2D-TTE, and CMR a period of 2 weeks before undergoing valve surgery were included in this study. LV end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF) were calculated by DSCT using the threshold-based technique, by 2D-TTE using a modified Simpson's method, and by CMR using Simpson's method. Agreement for parameters of LV global function was determined with the Pearson's correlation coefficient (r) and Bland-Altman analysis. All the DSCT and CMR data-sets were assessed independently by two readers.

RESULTS

Fifty of the total 111 patients had aortic VHD, 29 patients had mitral VHD, and 32 patients had mixed aortic and mitral VHD. An excellent inter-observer agreement was seen for the assessment of global LV function using DSCT (r = 0.910-0.983) and CMR (r = 0.854-0.965). An excellent or good correlation (r = 0.93, 0.95, 0.87, and 0.71, respectively, P < 0.001) was noted between the DSCT and 2D-TTE values for EDV, ESV, SV, and EF. EDV (33.7 mL, P < 0.001), ESV (12.1 mL, P < 0.001), SV (21.2 mL, P < 0.001), and EF (1.6%, P = 0.019) were significantly overestimated by DSCT when compared with 2D-TTE. An excellent correlation (r = 0.96, 0.97, 0.91, and 0.94, respectively, P < 0.001) between DSCT and CMR was seen in the evaluation of EDV, ESV, SV, and EF. EDV (15.9 mL, P < 0.001), ESV (7.3 mL, P < 0.001), and SV (8.5 mL, P < 0.001) were significantly underestimated, but EF (1.1%, P = 0.002) was significantly overestimated by DSCT when compared with CMR.

CONCLUSION

Our study showed that DSCT measurements of global LV function using the threshold-based technique were highly reproducible and compared more favorably with CMR measurements using Simpson's method than those of 2D-TTE using the modified Simpson's method. DSCT enables accurate quantification of global LV function in patients with VHD.

Variables influencing the accuracy of 2-dimensional and real-time 3-dimensional echocardiography for assessment of small volumes, areas, and distances: an in vitro study using static tissue-mimicking phantoms

OBJECTIVES

The aim of this study was to assess the validity, accuracy, and reproducibility of real-time 3-dimensional (3D) echocardiography for small distances, areas, and volumes.

METHODS

Real-time 3D echocardiography using matrix technology was performed in small calibrated tissue-mimicking phantoms and compared with 2-dimensional (2D) echocardiography. In a systematic variation of variables on data acquisition and analysis including different 3D workstations (manual disk summation versus semiautomatic border detection), the relative contributions of sources of errors were determined. The clinical relevance of the in vitro findings was assessed in 5 neonates and infants.

RESULTS

Distance calculation was valid (mean relative error ± SD, -0.15% ± 1.2%). Underestimation of areas and volumes was significant for both 2D and 3D echocardiography (area: 2D, -7.0% ± 2.9%; 3D, -6.0% ± 2.8%; volume: 2D, -13.1% ± 4.5%; 3D, -6.7% ± 2.5%; P < .05). Adjustment of compression and gain on data acquisition (difference of the means: 2D, 11.6%; 3D, 17.9%), gain on postprocessing (3D, 3.4%), and the border detection algorithm on analysis (2D, 4.8%; 3D, 16.6%) had a highly significant effect on volume and area calculations (P < .001). In vivo, compression and gain on acquisition (3D, 19.1%) and the 3D workstation on analysis (3D, 22.2%) had a highly significant impact on left ventricular volumetry (P < .001).

CONCLUSIONS

Real-time 3D echocardiography is a reliable method for calculation of small distances, areas, and volumes comparable with the size of the neonatal and infant heart. Variables influencing boundary identification during image acquisition and analysis have a significant impact on 2D and 3D area and volume calculations. Standardized protocols are mandatory to avoid these sources of error in both clinical practice and research.

Echocardiography as a hemodynamic monitor in critically ill children

Echocardiography is a widely used modality to assess myocardial structure and function in pediatric intensive care settings. While the use of echocardiography for diagnostic purposes remains important, its use as a hemodynamic monitoring tool has not been well established. The benefits of echocardiography are in its widespread availability, relative ease of use, and importance in diagnosing structural disease and simple changes in myocardial function. However, echocardiography in pediatric critical care is limited in its use because it requires the acquisition of quality images and the accurate interpretation of the study. To date, the literature on echocardiography in pediatric critical care is limited. The purpose of this review is to examine the scientific evidence for the usefulness of echocardiography as a hemodynamic monitoring tool in pediatric critical care.

Assessment of left ventricular volumes and function by real time three-dimensional echocardiography in a pediatric population: a TomTec versus QLAB comparison

BACKGROUND

Three-dimensional echocardiography (3DE) allows accurate calculation of ventricular volumes despite a remaining geometric assumption on the ventricular shape. Few studies involving full volume reconstruction software have been performed on children. Our aim was to compare the left ventricular (LV) volume measurements obtained with the most used 3D analysis software in a pediatric population.

METHODS

Fifty patients (median age: 9.5 years) without cardiac disease were included in the study. 3DE was performed with the X4-2 or X7-2 matrix probe (ie33, Philips). The LV volume analysis was performed with QLAB 6.0 (semiautomated border detection) and TomTec 4D LV (primary manual tracking with semiautomated border detection).

RESULTS

TomTec analysis feasibility amounted to 94% whereas QLAB analysis feasibility only reached 80% (P = 0.037). The analysis time was shorter with QLAB than TomTec (5 ± 2 versus 6 ± 3 minutes, P < 0.05). The stroke volume, end diastolic and end systolic LV volume measurements performed on the 40 patients were strongly correlated (r > 0.97; P < 0.0001) with minimal bias. The LV ejection fraction was well correlated (r = 0.79; P < 0.0001).

CONCLUSION

3D LV volume quantification is feasible either by using manual or automated reconstruction software in a normal pediatric population. LV Measurements are well correlated. Differences in volume reconstruction algorithms provide specific software performance characteristics. TomTec is a more feasible method but requires a longer analysis time. Further studies are needed to validate the accuracy of the method to calculate enlarged LV volumes in patients with congenital heart diseases.

Validation of 3D echocardiographic assessment of left ventricular volumes, mass, and ejection fraction in neonates and infants with congenital heart disease: a comparison study with cardiac MRI

BACKGROUND

quantitative assessment and validation of left ventricular (LV) volumes and mass in neonates and infants with complex congenital heart disease (CHD) is important for clinical management but has not been undertaken. We compared matrix-array 3D echocardiography (3D echo) measurements of volumes, mass, and ejection fraction (EF) with those measured by cardiac MRI in young patients with CHD and small LVs because of either young age or LV hypoplasia.

METHODS AND RESULTS

thirty-five patients aged <4 years (median, 0.8 years) undergoing MRI were prospectively enrolled. Three-dimensional echo was acquired immediately after MRI, and volume, mass, and EF measurements, using summation of discs methodology, were compared with MRI. Three-dimensional echo end-diastolic volume (24.4±15.7 versus 24.8±46.4 mL; P=0.01; intraclass correlation coefficient [ICC], 0.96) and end-systolic volume (12.3±8.6 versus 9.6±6.8 mL; P<0.001; ICC, 0.90) correlated with MRI with small mean differences (-0.49 mL [P=0.6] and 2.7 mL [P=0.001], respectively). Three-dimensional echo EF was smaller than MRI by 9.3% (P<0.001), and 3D echo LV mass measurements were comparable to MRI (17.3±10.3 versus 17.6±12 g; P<0.77; ICC, 0.93), with a small mean difference (1.1 g; P=0.28). There was good intra- and interobserver reliability for all measurements.

CONCLUSIONS

in neonates and infants with CHD and small LVs (age appropriate or hypoplastic), matrix-array 3D echo measurements of mass and volumes compare well with MRI, providing an important modality for ventricular size and performance analysis in these patients, particularly in those with left-side heart obstructive lesions.