The Norwood procedure creates a reconstructed neo-aorta to provide unobstructed systemic cardiac output for hypoplastic left heart syndrome patients. We used patient-specific computational fluid dynamics (CFD) simulations incorporating physiologic boundary conditions to quantify hemodynamics for reconstructed aortic arch geometries versus native aortic arches from a control group of single ventricle patients. We hypothesized that reconstructed arches from Norwood patients (n = 5) would experience significant differences in time-averaged wall shear stress normalized to body surface area (TAWSSnBSA), oscillatory shear index (OSI), energy efficiency (Eeff), and energy loss (EL) versus controls (n = 3). CFD simulations were conducted using 3 T cardiac magnetic resonance imaging, blood flow, and pressure data. Simulations incorporated downstream vascular resistance and compliance to replicate patient physiology. TAWSSnBSA and OSI were quantified axially and circumferentially. Global differences in Eeff and EL were compared. Significance was assessed by Mann-Whitney U test. Norwood patients had higher TAWSSnBSA distal to the transverse arch at locations of residual narrowing presenting following coarctation correction, as well as higher OSI within ascending aorta and transverse arch regions (p < 0.05). EL correlated with patient features including cardiac output (r = 0.9) and BT-shunt resistance (r = -0.63) but did not correlate with arch measurements or morphology. These results indicate reconstructed arches from Norwood patients are exposed to altered wall shear stress and energy indices linked to cellular proliferation and inefficiency in prior studies. These results may help clinicians further understand what constitutes an optimally reconstructed arch after confirmation in larger studies.
Pediatric cardiac sonographers spend significant time teaching echocardiography. How prepared sonographers are for this crucial role remains unknown. We sought to understand current sonographer knowledge, attitudes, and confidence in teaching pediatric cardiology fellows. This cross-sectional study recruited sonographers and pediatric cardiology fellows at 4 centers by email from Jan-Feb 2025. All subjects provided demographic data and completed a 27-item Interprofessional Attitudes Scale (IPAS), validated to assess healthcare students’ cooperative learning beliefs (max score 135). Only sonographers completed a modified 15-item validated Maastricht Clinical Teaching Questionnaire (MCTQ), yielding average ratings (1–5) and teaching ratings (1–10). Open-ended responses were reviewed for recurrent themes. Response rate was 76/124 (61.3
Purpose of Review The current in silico study features a patient who underwent Norwood arch reconstruction to compare hemodynamic and energy-based indices between the image-based pre-operative reconstructed geometry (i.e., Pre-op) and a virtual post-operative reconstruction (i.e., Post-op). We hypothesized that the Post-op geometry would be associated with decreased afterload and increased stroke volume, consequently leading to a decrease in single ventricle workload as well as more favorable hemodynamic indices (i.e., decreased oscillatory shear index (OSI) and increased time-averaged wall shear stress (TAWSS)), particularly within the reconstructed region. Recent Findings Computational modeling can facilitate assessment of energy and hemodynamic alterations for difficult surgical procedures including the Norwood operation where outcomes remain suboptimal with high interstage mortality and frequent reoperations. Summary A patient-specific computational fluid dynamics (CFD) model was created from cardiac magnetic resonance imaging, blood flow, and blood pressure data. Virtual reconstruction was implemented based on surgeon and clinician input. Resulting simulations incorporated downstream vascular resistance and compliance to replicate patient physiology using 3-element Windkessel representations to quantify TAWSS and OSI locally. A closed-loop heart model was used to determine global differences in energy efficiency ( E eff ), energy loss (EL), and cardiac workload. WSS indices generally improved with virtual arch geometry reconstruction, which resulted in only modest changes in EL, E eff , and cardiac workload. A framework to implement and compare virtual arch reconstruction is presented. Results show that more drastic changes in geometry may need to be implemented if the virtual reconstruction is to yield a significant impact on indices of cardiac function.
Many factors affect patient outcome after congenital heart surgery, including the complexity of the heart disease, pre-operative status, patient specific factors (prematurity, nutritional status and/or presence of comorbid conditions or genetic syndromes), and post-operative residual lesions. The R esidual L esion S core is a novel tool for assessing whether specific residual cardiac lesions after surgery have a measurable impact on outcome. The goal is to understand which residual lesions can be tolerated and which should be addressed prior to leaving the operating room. The Residual Lesion Score study is a large multicentre prospective study designed to evaluate the association of Residual Lesion Score to outcomes in infants undergoing surgery for CHD. This Pediatric Heart Network and National Heart, Lung, and Blood Institute-funded study prospectively enrolled 1,149 infants undergoing 5 different congenital cardiac surgical repairs at 17 surgical centres. Given the contribution of echocardiographic measurements in assigning the Residual Lesion Score, the Residual Lesion Score study made use of a centralised core lab in addition to site review of all data. The data collection plan was designed with the added goal of collecting image quality information in a way that would permit us to improve our understanding of the reproducibility, variability, and feasibility of the echocardiographic measurements being made. There were significant challenges along the way, including the coordination, de-identification, storage, and interpretation of very large quantities of imaging data. This necessitated the development of new infrastructure and technology, as well as use of novel statistical methods. The study was successfully completed, but the size and complexity of the population being studied and the data being extracted required more technologic and human resources than expected which impacted the length and cost of conducting the study. This paper outlines the process of designing and executing this complex protocol, some of the barriers to implementation and lessons to be considered in the design of future studies.
Multicenter studies in pediatric cardiovascular magnetic resonance (CMR) improve statistical power and generalizability. However, a structured process for identifying important research topics has not been developed. We aimed to (1) develop a list of high priority knowledge gaps, and (2) pilot the use of a wiki survey to collect a large group of responses. Knowledge gaps were defined as areas that have been either unexplored or under-explored in the research literature. High priority goals were: (1) feasible and answerable from a multicenter research study, and (2) had potential for high impact on the field of pediatric CMR. Seed ideas were contributed by a working group and imported into a pairwise wiki survey format which allows for new ideas to be uploaded and voted upon ( https://allourideas.org ). Knowledge gaps were classified into 2 categories: ‘Clinical CMR Practice’ (16 ideas) and ‘Disease Specific Research’ (22 ideas). Over a 2-month period, 3,658 votes were cast by 96 users, and 2 new ideas were introduced. The 3 highest scoring sub-topics were myocardial disorders (9 ideas), translating new technology & techniques into clinical practice (7 ideas), and normal reference values (5 ideas). The highest priority gaps reflected strengths of CMR (e.g., myocardial tissue characterization; implementation of technologic advances into clinical practice), and deficiencies in pediatrics (e.g., data on normal reference values). The wiki survey format was effective and easy to implement, and could be used for future surveys.
BACKGROUND Many factors affect outcomes after congenital cardiac surgery. OBJECTIVES The RLS (Residual Lesion Score) study explored the impact of severity of residual lesions on postoperative outcomes across operations of varying complexity. METHODS In a prospective, multicenter, observational study, 17 sites enrolled 1,149 infants undergoing 5 common operations: tetralogy of Fallot repair (n = 250), complete atrioventricular septal defect repair (n = 249), arterial switch operation (n = 251), coarctation or interrupted arch with ventricular septal defect (VSD) repair (n = 150), and Norwood operation (n = 249). The RLS was assigned based on post-operative echocardiography and clinical events: RLS 1 (trivial or no residual lesions), RLS 2 (minor residual lesions), or RLS 3 (reintervention for or major residual lesions before discharge). The primary outcome was days alive and out of hospital within 30 post-operative days (60 for Norwood). Secondary outcomes assessed post-operative course, including major medical events and days in hospital. RESULTS RLS 3 (vs. RLS 1) was an independent risk factor for fewer days alive and out of hospital (p <-0.008) and longer post-operative hospital stay (p <-0.02) for all 5 operations, and for all secondary outcomes after coarctation or interrupted arch with VSD repair and Norwood (p <-0.03). Outcomes for RLS 1 versus 2 did not differ consistently. RLS alone explained 5% (tetralogy of Fallot repair) to 20% (Norwood) of variation in the primary outcome. CONCLUSIONS Adjusting for pre-operative factors, residual lesions after congenital cardiac surgery impacted in hospital outcomes across operative complexity with greatest impact following complex operations. Minor residual lesions had minimal impact. These findings may provide guidance for surgeons when considering short-term risks and benefits of returning to bypass to repair residual lesions. (J Am Coll Cardiol 2021;77:2382-94) (c) 2021 the American College of Cardiology Foundation. Published by Elsevier. All rights reserved.
Background: The FUEL trial (Fontan Udenafil Exercise Longitudinal) demonstrated statistical improvements in exercise capacity following 6 months of treatment with udenafil (87.5 mg po BID). The effect of udenafil on echocardiographic measures of single ventricle function in this cohort has not been studied. Methods: The 400 enrolled participants were randomized 1:1 to udenafil or placebo. Protocol echocardiograms were obtained at baseline and 26 weeks after initiation of udenafil/placebo. Linear regression compared change from baseline indices of single ventricle systolic, diastolic and global function, atrioventricular valve regurgitation, and mean Fontan fenestration gradient in the udenafil cohort versus placebo, controlling for ventricular morphology (left ventricle versus right ventricle/other) and baseline value. Results: The udenafil participants (n=191) had significantly improved between baseline and 26 weeks visits compared to placebo participants (n=195) in myocardial performance index ( P =0.03, adjusted mean difference [SE] of changes between groups −0.03[0.01]), atrioventricular valve inflow peak E ( P =0.009, 3.95 [1.50]), and A velocities ( P =0.034, 3.46 [1.62]), and annular Doppler tissue imaging-derived peak e′ velocity ( P =0.008, 0.60[0.23]). There were no significant differences in change in single ventricle size, systolic function, atrioventricular valve regurgitation severity, or mean fenestration gradient. Participants with a dominant left ventricle had significantly more favorable baseline values of indices of single ventricle size and function (lower volumes and areas, E/e′ ratio, systolic:diastolic time and atrioventricular valve regurgitation, and higher annular s′ and e′ velocity). Conclusions: FUEL participants who received udenafil demonstrated a statistically significant improvement in some global and diastolic echo indices. Although small, the changes in diastolic function suggest improvement in pulmonary venous return and/or augmented ventricular compliance, which may help explain improved exercise performance in that cohort. Registration: URL: https://clinicaltrials.gov ; Unique Identifier: NCT02741115.
Introduction: Tricuspid regurgitation (TR) is common in single right ventricle (RV) and affects outcomes of staged palliation. However, longitudinal studies are limited, and the impact of tricuspid...
Background: Ventricular dysfunction is associated with increased morbidity and mortality in children with hypoplastic left heart syndrome. The aim of this study was to assess the diagnostic performance of conventional and speckle-tracking echocardiographic measures of right ventricular (RV) function before bidirectional cavopulmonary anastomosis palliation in predicting death or need for heart transplantation (HTx). Methods: RV fractional area change (RVFAC) and longitudinal and circumferential strain and strain rate (SR) were measured in 64 prospectively recruited patients with hypoplastic left heart syndrome from echocardiograms obtained before bidirectional cavopulmonary anastomosis surgery. The composite end point of death or HTx was examined. Receiver operating characteristic analysis was performed, and cutoff values optimizing sensitivity and specificity were derived. Results: At a median follow-up of 5.0 years (interquartile range, 2.8-6.4 years), 13 patients meeting the composite end point had lower longitudinal strain and SR, circumferential SR, and RVFAC compared with survivors (n = 51). The conventional cutoff of RVFAC < 35% was specific for death or HTx (86%) but had poor sensitivity (46%), with an area under the curve of 0.73. Speckle-tracking echocardiographic variables showed similar areas under the curve (range, 0.69-0.79), with negative predictive values >90%. Addition of speckle-tracking echocardiographic variables to RVFAC < 35% showed no added benefit. However, in a subpopulation of patients with RVFAC >= 35% (n = 44), those meeting the composite end point (n = 7) had lower longitudinal SR (median, -1.0 1/sec [interquartile range, -0.8 to -1.1 1/sec] vs -1.21/sec [interquartile range, -1.0 to -1.3 1/sec], P = .03). Interobserver reproducibility was superior for longitudinal strain and SR (intraclass correlation coefficient > 0.92) compared with RVFAC (intraclass correlation coefficient = 0.75). Conclusions: Children with hypoplastic left heart syndrome with normal RVFAC and ventricular deformation before bidirectional cavopulmonary anastomosis have a low likelihood of death or HTx in the medium term. In the presence of reduced RVFAC, speckle-tracking echocardiography does not provide additional prognostic value. However, in patients with "normal" RVFAC, it may have a role in improving outcome prediction and warrants further investigation.
Introduction: Pulmonary regurgitation or stenosis after repaired tetralogy of Fallot (TOF) impacts the long-term ventricular mechanics. Our objective was to measure RV myocardial deformation using novel CMR software in repaired TOF. We postulate that RV strain will correlate with cardiac MRI (CMR) volumetric data. Methods: Retrospective study of 55 patients s/p TOF repair compared to 40 normal controls. RV longitudinal strain was measured from the standard 4-chamber view and circumferential strain from the short axis slice apical to the RV outflow tract. Using CMR software developed in-house that utilizes a semi-automatic segmentation program, peak strain was identified. Unpaired t test assessed differences between groups and correlation was performed between strain and volumetric data. Results: The predominant lesion was regurgitation in 48 (regurgitant fraction (RF) 43±2%), stenosis in 10 (peak gradient 32±2 mmHg), and mixed in 4. Longitudinal strain was reduced in TOF compared to controls while circumferential strain was preserved (Table 1). Correlations found reduced strain with increasing volumes and decreasing right ventricular ejection fraction (RVEF) (Table 2). Longitudinal:circumferential ratio (L/C) increased with increasing volumes and decreasing RVEF. No relationship was found between RV strain and RF. Conclusions: The relationships between longitudinal and circumferential strain, and the L/C ratio with RV volumes and RVEF suggest that preservation of circumferential strain is important in maintaining RV systolic function. Measurement of RV deformation may provide insight into the RV’s response to volume or pressure overload in TOF, suggesting we should focus on RV mechanical changes rather than RF when managing these patients.
Pediatric heart transplant recipients undergo frequent invasive cardiac catheterization with endomyocardial biopsy for routine allograft surveillance. Risks associated with catheterization and sampling error call into question this accepted “gold standard.” Cardiac magnetic resonance imaging (CMR), with parametric imaging, may advance myocardial surveillance in this population. Fifty-two pediatric patients (transplanted at ≤18 years old) underwent CMR (September 2016 to June 2019) at 3T to evaluate myocardial health using MOLLI sequence. Healthy transplant recipients had normal global biventricular function, native T1 higher than published values for healthy children at 3T with similar extracellular volume (ECV) despite history of treated rejection.