Real Time Three-Dimensional Echocardiography for Quantification of Ventricular Volumes, Mass, and Function in Children with Congenital and Acquired Heart Diseases

Guidelines for Performing a Comprehensive Pediatric Transthoracic Echocardiogram: Recommendations From the American Society of Echocardiography

Echocardiography is a fundamental component of pediatric cardiology, and appropriate indications have been established for its use in the setting of suspected, congenital, or acquired heart disease in children. Since the publication of guidelines for pediatric transthoracic echocardiography in 2006 and 2010, advances in knowledge and technology have expanded the scope of practice beyond the use of traditional modalities such as two-dimensional, M-mode, and Doppler echocardiography to evaluate the cardiac segmental structures and their function. Adjunct modalities such as contrast, three-dimensional, and speckle-tracking echocardiography are now used routinely at many pediatric centers. Guidelines and recommendations for the use of traditional and newer adjunct modalities in children are described in detail in this document. In addition, suggested protocols related to standard operations, infection control, sedation, and quality assurance and improvement are included to provide an organizational structure for centers performing pediatric transthoracic echocardiograms.

The value of myocardial strain imaging in the evaluation of patients with repaired Tetralogy of Fallot: a review of the literature

Tetralogy of Fallot (ToF) is considered to be the most common, complex, cyanotic congenital heart disease (CHD) representing 7-10% of all congenital heart defects, whereas the patients with ToF are the most frequently operated in their early infancy or childhood. Cardiac magnetic resonance (CMR) consists a valuable imaging technique for the diagnosis and serial follow-up of CHD patients. Furthermore, in recent years, advanced echocardiography imaging techniques have come to the fore, aiming to achieve a complete and more accurate evaluation of cardiac function using speckle tracking imaging modalities. We conducted a review of the literature in order to assess the myocardial deformation of patients with repaired ToF (rToF) using echocardiographic and CMR parameters. Patients with rToF have impaired myocardial strain parameters, that are well standardized either with the use of speckle tracking echocardiography or with the use of CMR imaging. Subclinical left ventricular dysfunction (low GLS) and myocardial dyssynchrony are commonly identified in rToF patients. Impaired left atrium (LA) and right atrium (RA) mechanics are, also, a common finding in this study population, but the studies using atrial strain are a lot fewer than those with LV and RV strain. No studies using myocardial work were identified in the literature, as far as rToF patients are concerned, which makes it an ideal field for further investigation.

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.

Evaluating Left Ventricular Systolic Synchronicity with Real-Time 3D Echocardiography in Newborns

Knowing the normal values of left ventricular (LV) systolic synchronicity in the early neonatal period is very important for understanding myocardial function. This retrospective study analyzed data of 105 newborns who were examined using real-time 3-dimensional echocardiography (RT3DE). The time to the point of minimal regional systolic volume (Tmsv) was measured from volume-time curves in each segment. Standard deviation (SD) and maximal difference (Dif) of Tmsv were calculated from 16 (6 basal/6 mid/4 apical), 12 (6 basal/6 mid), and 6 (basal) LV segments with the corresponding parameters adjusted for the R-R interval. Influences of age, sex, gestational age, birth weight, and heart rate on parameters were explored. Data showed no significant difference among Tmsv-16-SD, Tmsv-12-SD, and Tmsv-6-SD. A strong correlation was found between Tmsv-6-SD and Tmsv-6-Dif (r = 0.83, P < 0.001), Tmsv-12-SD and Tmsv-6-SD (r = 0.77, P < 0.001), and Tmsv-12-Dif and Tmsv-6-Dif (r = 0.76, P < 0.001) and a moderate correlation was found between Tmsv-16-SD and Tmsv-16-Dif (r = 0.66, P < 0.001), Tmsv-6-SD and Tmsv-12-Dif (r = 0.62, P < 0.001), and Tmsv-12-SD and Tmsv-6-Dif (r = 0.61, P < 0.001). Heart rate correlated negatively with Tmsv (r = - 0.03 to - 0.11, P < 0.004-0.000), but had no effect on parameters adjusted for %R-R. Age, sex, gestational age, and birth weight did not affect any of these parameters. Tmsv-Dif and Tmsv-SD measured from 16 segments using RT3DE are useful as possible parameters for evaluating LV systolic synchronicity in normal newborns.

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.

Value of echocardiography for mini-invasive per-atrial closure of perimembranous ventricular septal defect

The purpose of this study was to assess the value of echocardiography for intraoperative guidance during closure of perimembranous ventricular septal defects (pmVSD) and to assess outcomes of these patients. We identified and assessed 78 patients who underwent 2- and 3-dimensional echocardiography-guided mini-invasive per-atrial closure of pmVSD in the cardiac surgery department of our institution, from February 2016 to August 2018, and 76 patients who underwent transcatheter closure of VSD guided by fluoroscopy at the pediatric department (percutaneous control group). All the patients underwent echocardiography. Their clinical data were retrospectively reviewed and analyzed. All patients were followed up using transthoracic echocardiography (TTE) for a maximum of 24 months after the closure. All patients underwent successful device implantation. Echocardiography showed that the major immediate complications included residual shunt, pericardial effusion, and tricuspid regurgitation in the per-atrial group. During the mid-term follow-up period, TTE revealed that the most common complication was tricuspid regurgitation (non-preexisting). There were no cases of VSD recurrence, device displacement, valvular injury, malignant arrhythmias, hemolysis, or death. Moreover, according to the TTE data, the intracardiac structure of the patients were improved. Compared to the control group, the intracardiac manipulation time was shorter and the number of patients with residual shunts, redeployment of devices, or immediate new tricuspid regurgitations was fewer when using 2- and 3-dimensional echocardiography. However, the procedure time in the per-atrial group was slightly longer than that in the control group. Two- and 3-dimensional echocardiography are feasible monitoring tools during mini-invasive per-atrial VSD closure. The short- and mid-term follow-up showed satisfactory results compared to fluoroscopy.

Accuracy and Trending Ability of Cardiac Index Measured by the CNAP System in Patients Undergoing Abdominal Aortic Aneurysm Surgery

OBJECTIVES

The CNAP system is a noninvasive monitor that provides a continuous arterial pressure waveform using an inflatable finger cuff. The authors hypothesized that dramatic changes in systemic vascular resistance index during abdominal aortic aneurysm (AAA) surgery might affect the accuracy of noninvasive pulse contour monitors. The aim of this study was to evaluate the accuracy and trending ability of cardiac index derived by the CNAP system (CI_CN) in patients undergoing AAA surgery.

DESIGN

Prospective clinical study.

SETTING

Cardiac surgery operating room in a single cardiovascular center.

PARTICIPANTS

Twenty patients who underwent elective AAA surgery.

INTERVENTIONS

CI_CN and cardiac index measured using 3-dimensional images (CI_3D) were determined simultaneously at 8 points during the surgery. At aortic clamping and unclamping, the authors tested the trending ability of CI_CN using 4-quadrant plot analysis and polar plot analysis.

MEASUREMENTS AND MAIN RESULTS

The authors found a wide limit of agreement between CI_CN and CI_3D (percentage error: 85.0%). The cubic splines, which show the relationship between systemic vascular resistance index and percentage CI discrepancy [(CI_CN-CI_3D)/CI_3D], were sloped positively. Four-quadrant plot analysis showed poor trending ability for CI_CN at both aortic clamping and unclamping (concordance rate: 29.4% and 57.9%, respectively). In the polar plot analysis, the concordance rates at aortic clamping and unclamping were 15.0% and 35.0%, respectively.

CONCLUSIONS

CI_CN is not interchangeable with CI_3D in patients undergoing AAA surgery. The trending ability for CI_CN at aortic clamping and unclamping was below the acceptable limit. These inaccuracies might be secondary to the high systemic vascular resistance index during AAA surgery.

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.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Three-dimensional echocardiography in congenital heart disease

Three-dimensional echocardiography is a valuable tool for the assessment of cardiac function where it permits calculation of chamber volume and function. The anatomy of valvar and septal structures can be presented in unique and intuitive ways to enhance surgical planning. Guidance of interventional procedures using the technique has now become established in many clinical settings. Enhancements of image processing to include intracavity flow, image fusion and true 3D displays look set to further improve the contribution of this modality to care of the patient with congenital heart disease.

Usefulness of three-dimensional echocardiography for the assessment of ventricular function in children: Comparison with cardiac magnetic resonance, with a focus on patients with arrhythmia

BACKGROUND

Focusing on patients with arrhythmia, the aims of this study was to assess ventricular function in children using three-dimensional echocardiography (3D-ECHO) and to compare the results to those obtained with cardiac magnetic resonance (CMR).

METHODS

The study group consisted of 43 children in whom 3D-ECHO and CMR were performed. Twenty-five patients had a ventricular arrhythmia, 7 left ventricular cardiomyopathies, 9 proved to be healthy. In all children, 3D-ECHO (offline analysis) was used to assess ventricular ejection fraction (EF). The results were compared to CMR using the Bland-Altman analysis and linear regression. The Student paired T-test was used to compare of means between both modalities.

RESULTS

The relation between the results derived from both methods is linear (for left ventricle: estimated slope = 1.031, p < 0.0001, R-squared = 0.998; for right ventricle: estimated slope = 0.993, p < 0.0001, R-squared = 0.998). In spite of minimal mean differences between results for both ventricles and narrow 95% confidence intervals, the paired t-test proved those differences not to be significant (p > 0.05) for the right ventricle but statistically significant (p < 0.05) for the left ventricle, for which the left ventricular EF calculated in 3D-ECHO was systematically underestimated with a mean difference of -1.8% ± 2.6% (p < 0.0001).

CONCLUSIONS

Three-dimensional echocardiography assessment of both left and right ventricular EF in children showed high significant correlation and agreement with CMR. 3D-ECHO could be a valuable tool in follow-up of children with arrhythmic disorders requiring regular assessment of ventricular function.

Normal Values and Growth-Related Changes of Left Ventricular Volumes, Stress, and Strain in Healthy Children Measured by 3-Dimensional Echocardiography

Normal pediatric values of three-dimensional (3D) left ventricular (LV) volumes and strain are not well established; moreover, no reports exist of the stress-strain relation and the heart rate-corrected velocity of circumferential fiber shortening (VCFc) based upon 3D imaging in children. Three-dimensional LV datasets were obtained in pediatric patients (≤18 years of age) with structurally normal hearts. Ventricular volumes and strain components (longitudinal, GLS; circumferential, GCS; and 3D strain, 3DS) were analyzed using a commercial 3D speckle-tracking analysis package. LV mid-wall global average end-systolic fiber stress was calculated from 3D LV volumes. A total of 238 patients were included in the analysis with a median age of 13.1 years (range 0.4 to 17.9 years). Regression equations were derived for 3D volume parameters, permitting body surface area-based Z score calculation. Overall, 3DS values were more negative than GLS and GCS (mean ± SD = -33.8 ± 2.8; -27.8 ± 2.9; and -21.7 ± 3.1, respectively); only GLS varied significantly with age (r = 0.22; p <0.001). Both global average end-systolic fiber stress and 3D VCFc increased significantly with age (p <0.001 for both). Stress-adjusted 3DS and VCFc both varied with age (p <0.001 for both), consistent with increased contractility. In conclusion, 3D echocardiography may be used to calculate LV stress, strain, and volumes in pediatric patients with strong reproducibility. Among strain parameters, significant age-related changes were seen only in GLS. Both indexes of contractility investigated (3DS and VCFc indexed to wall stress) improved with age. Future studies of the 3D echocardiography stress-strain relation may yield new insights into maturational changes in myocardial contractility.

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.

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.

Cardiac Function After the Immediate Transitional Period in Very Preterm Infants Using Speckle Tracking Analysis

BACKGROUND

The postnatal period in preterm infants involves multiple physiologic changes starting directly after birth and continuing for days or weeks. To recognize and treat compromise, it is important to measure cardiovascular function. We used a novel technique (speckle tracking echocardiography, STE) to measure cardiac function in this period.

METHODS

We obtained cardiac ultrasound images at day 3, 7, 14, 21 and 28 in preterm infants <30-week gestation. Conventional measures included cardiac size, left ventricular stroke volume, atrial volume and the patent ductus arteriosus (PDA). Four chamber images were analyzed with STE, which provided parameters of left ventricular volume, longitudinal deformation and myocardial velocities.

RESULTS

Images of 54 infants (gestational age 23-29 weeks) were analyzed. STE-derived stroke volume correlated well with conventional echocardiography-derived stroke volume, but agreement was suboptimal. Most STE parameters showed good reliability. All volume parameters and systolic and atrial velocities increased over time. Cardiac deformation and early diastolic velocity did not change. A PDA was associated with 33 % increased stroke volume at day 3 up to 98 % at day 28 with a spherically enlarged heart and increased filling pressure.

CONCLUSION

Speckle tracking echocardiography analysis is a feasible and reliable technique that can simultaneously obtain systolic and diastolic volumes, longitudinal deformation and myocardial velocities from one ultrasound window. Preterm hearts maintain cardiac function well during the first weeks of life, even with increased preload as a consequence of a PDA.

Utility of Real Time 3D Echocardiography for the Assessment of Left Ventricular Mass in Patients with Hypertrophic Cardiomyopathy: Comparison with Cardiac Magnetic Resonance

INTRODUCTION AND OBJECTIVES

Patients with hypertrophic cardiomyopathy (HCM) have irregular ventricular shapes with small and sometimes obliterated cavities at end-systole that affect the quantification of left ventricular mass (LVM) by conventional methods, such as M-mode or two-dimensional echocardiography. The goal of this study was to validate the use of real time three-dimensional echocardiography (RT3DE) to quantify LVM using cardiac magnetic resonance imaging (CMR) as a reference, in a large population of patients with different types of HCM.

METHODS

Forty-eight consecutive patients with HCM had a complete transthoracic examination and CMR performed within 7 days. LVM was calculated by M-mode and RT3DE and compared to CMR that served as gold standard.

RESULTS

Left ventricular mass calculated by RT3DE was 195 ± 41 g and 187 ± 49 g by CMR. The correlation between the two methods was moderate, with a Lin index of 0.63 and good linear correlation (r = 0.63, P < 0.0001). The correlation was high when RT3DE was of high or adequate image quality. The correlation between LVM by M-mode and CMR was poor.

CONCLUSION

Three-dimensional echocardiography is an accurate method for the quantification of LVM in patients with different subtypes of HCM that is in better agreement with CMR reference values than M-mode measurements.

Real Time Three-Dimensional Echocardiographic Evaluations of Fetal Left Ventricular Stroke Volume, Mass, and Myocardial Strain: In Vitro and In Vivo Experimental Study

BACKGROUND

Left ventricular stroke volume, mass, and myocardial strain are valuable indicators of fetal heart function. This study investigated the feasibility of nongated real time three-dimensional echocardiography (RT3DE) to determine fetal stroke volume (SV), left ventricular mass (LVM), and myocardial strain under different conditions.

METHODS

To evaluate fetal hearts, fetal-sized rabbit hearts were used in this study. The in vitro portion of this study was carried out using a balloon inserted into the LV of eight fresh rabbit hearts and driven by a calibrated pulsatile pump. RT3DE volumes were obtained at various pump-set SVs. The in vivo experiments in this study were performed on open-chest rabbits. RT3DE volumes were acquired at the following conditions: baseline, simulated hypervolemia, inferior vena cava (IVC) ligation, and ascending aorta (AAO) ligation. Displacement values and sonomicrometry data were used as references for RT3DE-derived SV, LVM, longitudinal strain (LS), and circumferential strain (CS).

RESULTS

Excellent correlations between RT3DE-derived values and reference values were demonstrated and accompanied by high coefficients of determination (R(2) ) for both in vitro and in vivo studies for SV, LVM, LS, and CS (in vitro: SV: R(2)  = 0.98; LVM: R(2)  = 0.97; LS: R(2)  = 0.87, CS: R(2)  = 0.80; in vivo: SV: R(2)  = 0.92; LVM: R(2)  = 0.98; LS: in vivo: R(2)  = 0.84; CS: in vivo: R(2)  = 0.76; all P < 0.05).

CONCLUSIONS

RT3DE is capable of quantifying the SV, LVM, and myocardial strain of fetal-sized hearts under different conditions. This nongated RT3DE may aid the evaluation of fetal cardiac function, providing a superior understanding of the progress of fetal heart disorders.

Pediatric echocardiography: new developments and applications

In this Special Issue of the Journal, 6 review articles that represent the new developments and applications of echocardiography for diagnosis and assessment of congenital heart disease from fetus to adult are included. The goal is to provide an updated review of the evidence for the current and potential use of some of the new methodologies, i.e. fetal echocardiography, tissue Doppler imaging, strain imaging by speckle tracking imaging, ventricular synchrony, quantification using real time three-dimensional (3D) echocardiography, and 3D echocardiography for adults with congenital heart disease. We hope this effort will provide an impetus for more investigation and ultimately clinical application of these new methodologies to improve the care of those with congenital and acquired heart diseases in the pediatric population and beyond.