Evaluation of right ventricular function using single-beat three-dimensional echocardiography in neonate

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.

Biventricular function in preterm infants with patent ductus arteriosus ligation: A three-dimensional echocardiographic study

BACKGROUND

The detailed hemodynamics after patent ductus arteriosus (PDA) ligation in preterm infants remain unknown. We aimed to clarify the effect of surgical ligation on left ventricular (LV) and right ventricular (RV) volume and function.

METHODS

Echocardiography was performed in 41 preterm infants (median gestational age: 25 weeks) before and after PDA ligation. Global longitudinal strain was determined using three-dimensional speckle-tracking echocardiography. These values were compared with those in 36 preterm infants without PDA (non-PDA).

RESULTS

Preoperatively, the PDA group had greater end-diastolic volume (EDV) and cardiac output (CO) in both ventricles, a higher LV ejection fraction (LVEF) (53% vs 44%) and LV global longitudinal strain, and a lower RVEF (47% vs 52%) than the non-PDA group. At 4-8 h postoperatively, the two groups had a similar LVEDV and RVEDV. However, the PDA group had a lower EF and CO in both ventricles than the non-PDA group. At 24-48 h postoperatively, the RVEF was increased, but the LVEF remained decreased, and LVCO was increased.

CONCLUSIONS

PDA induces biventricular loading and functional abnormalities in preterm infants, and they dramatically change after surgery. Three-dimensional echocardiography may be beneficial to understand the status of both ventricles.

IMPACT

Preterm infants are at high risk of hemodynamic compromise following a sudden change in loading conditions after PDA ligation. Three-dimensional echocardiography enables quantitative and serial evaluation of ventricular function and volume in preterm infants with PDA. PDA induces biventricular loading and functional abnormalities in preterm infants, and they dramatically change after surgery.

Right to left ventricular volume ratio is associated with mortality in congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is associated with high neonatal mortality. We performed this study to test the hypothesis that left ventricular (LV) and right ventricular (RV) volumes assessed by three-dimensional echocardiography may be associated with mortality in CDH.

METHODS

This study was a single-center retrospective cohort study involving 35 infants with CDH. RV and LV end-diastolic volume (RVEDV and LVEDV, respectively) were measured by three-dimensional echocardiography and were corrected by birth body weight (BBW) on day 1. RVEDV/BBW, LVEDV/BBW, and LVEDV/RVEDV were compared between CDH survivors and non-survivors. Receiver-operating characteristic curve analysis was performed to assess the predictive ability for mortality of the echocardiographic parameters.

RESULTS

Comparing CDH non-survivors (n = 6) with survivors (n = 29), respectively, RVEDV/BBW was significantly larger (2.54 ± 0.33 vs 1.86 ± 0.35 ml/kg; P < 0.01), LVEDV/BBW was significantly smaller (0.86 ± 0.21 vs 1.22 ± 0.33 ml/kg; P < 0.001), and LVEDV/RVEDV was significantly lower (0.34 ± 0.06 vs 0.66 ± 0.18; P < 0.001). The area under the curve for LVEDV/RVEDV was the largest (0.98).

CONCLUSIONS

Three-dimensional echocardiographic volume imbalance between the RV and LV was remarkable in CDH non-survivors. The LVEDV/RVEDV ratio may be associated with mortality in CDH.

IMPACT

Mortality with congenital diaphragmatic hernia (CDH) is high, and evaluating left and right ventricular structures and functions may be helpful in assessing the prognosis. Three-dimensional (3D) echocardiography indicated that the left ventricular end-diastolic volume/right ventricular end-diastolic volume ratio within 24 h after birth was associated with mortality in CDH infants. The usefulness of this ratio should be validated in prospective multicenter studies involving larger numbers of patients.

Comparison of 3D Echocardiogram-Derived 3D Printed Valve Models to Molded Models for Simulated Repair of Pediatric Atrioventricular Valves

Mastering the technical skills required to perform pediatric cardiac valve surgery is challenging in part due to limited opportunity for practice. Transformation of 3D echocardiographic (echo) images of congenitally abnormal heart valves to realistic physical models could allow patient-specific simulation of surgical valve repair. We compared materials, processes, and costs for 3D printing and molding of patient-specific models for visualization and surgical simulation of congenitally abnormal heart valves. Pediatric atrioventricular valves (mitral, tricuspid, and common atrioventricular valve) were modeled from transthoracic 3D echo images using semi-automated methods implemented as custom modules in 3D Slicer. Valve models were then both 3D printed in soft materials and molded in silicone using 3D printed "negative" molds. Using pre-defined assessment criteria, valve models were evaluated by congenital cardiac surgeons to determine suitability for simulation. Surgeon assessment indicated that the molded valves had superior material properties for the purposes of simulation compared to directly printed valves (p < 0.01). Patient-specific, 3D echo-derived molded valves are a step toward realistic simulation of complex valve repairs but require more time and labor to create than directly printed models. Patient-specific simulation of valve repair in children using such models may be useful for surgical training and simulation of complex congenital cases.

Three-Dimensional Mitral Valve Morphology and Age-Related Trends in Children and Young Adults with Structurally Normal Hearts Using Transthoracic Echocardiography

BACKGROUND

The mitral valve has a complex three-dimensional (3D) morphology that is incompletely described by two-dimensional echocardiography (echo). Three-dimensional echo provides a more robust tool to analyze the mitral valve. The shape of the mitral annulus and leaflets, and differences with age, have not been described by 3D echo in normal children. Our objective was to characterize and quantify the 3D mitral valve morphology in children with normal transthoracic echocardiograms over a broad spectrum of age and to identify differences in valve shape with age.

METHODS

Three-dimensional midsystolic mitral valve models were constructed in 100 children and young adults with normal echocardiograms using 3D transthoracic images. Annular and leaflet metrics were quantified and regression equations were prepared. Interuser and intrauser variability was measured.

RESULTS

Two hundred fifty patients, from neonate to young adult, were retrospectively reviewed to obtain 100 evaluable patients (40% evaluable). The annular height to commissural width ratio of the mitral valve ("saddle shape") was preserved across age (median 24.3, IQR 21.8-28.1). Three-dimensional mitral valve area, length, and volume parameters were linearly related to body surface area (P < .001). The ratio of anterior to posterior leaflet length and posterior leaflet angle increased with body surface area (P = .0004 and .002, respectively) suggesting posterior movement of the coaptation line. Two-dimensional lateral annular diameter underestimated 3D lateral annular metrics (P < .001, mean difference 20-22%) but was highly correlated (R > 0.87, P < .001). Interuser and intrauser variability were acceptable.

CONCLUSIONS

Assessment of 3D mitral valve morphology in children is possible in a modern clinical pediatric echocardiography laboratory using transthoracic images, although further optimization of imaging is needed. The saddle shape of the mitral annulus was preserved across age and size. Most mitral valve parameters increased linearly with patient size. Further investigation is warranted to explore changes in valve morphology in the pediatric population in health and with disease.