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Digital reality is an emerging platform for three-dimensional representation of medical imaging data. In this technical innovation paper, the authors evaluated the accuracy and utility of mixed-reality technology in the morphological evaluation of complex congenital heart disease. The authors converted CT datasets of 12 heart specimens with different subtypes of double-outlet right ventricle to stereoscopic images and interrogated them using a mixed-reality system. The morphological features identified on the stereoscopic models were compared with findings at macroscopic examination of the actual heart specimens. The results showed that the mixed-reality system provided highly accurate stereoscopic display of spatially complex congenital cardiac lesions, with interactive features that might enhance 3-D understanding of morphology. Additionally, the authors found that high-resolution digital reproduction of cardiac specimens using clinical CT scanners is feasible for preservation and educational purposes.

Purpose This study investigated the diagnostic utility of nontargeted genomic testing in patients with pediatric heart disease. Methods We analyzed genome sequencing data of 111 families with cardiac lesions for rare, disease-associated variation. Results In 14 families (12.6%), we identified causative variants: seven were de novo (ANKRD11, KMT2D, NR2F2, POGZ, PTPN11, PURA, SALL1) and six were inherited from parents with no or subclinical heart phenotypes (FLT4, DNAH9, MYH11, NEXMIF, NIPBL, PTPN11). Outcome of the testing was associated with the presence of extracardiac features (p = 0.02), but not a positive family history for cardiac lesions (p = 0.67). We also report novel plausible gene–disease associations for tetralogy of Fallot/pulmonary stenosis (CDC42BPA, FGD5), hypoplastic left or right heart (SMARCC1, TLN2, TRPM4, VASP), congenitally corrected transposition of the great arteries (UBXN10), and early-onset cardiomyopathy (TPCN1). The identified candidate genes have critical functions in heart development, such as angiogenesis, mechanotransduction, regulation of heart size, chromatin remodeling, or ciliogenesis. Conclusion This data set demonstrates the diagnostic and scientific value of genome sequencing in pediatric heart disease, anticipating its role as a first-tier diagnostic test. The genetic heterogeneity will necessitate large-scale genomic initiatives for delineating novel gene–disease associations.

Background Creation of a Potts shunt, a connection between the left pulmonary artery (LPA) and descending aorta (DAo), improves functional status and survival in drug-refractory suprasystemic pulmonary arterial hypertension. We investigated a new approach to transcatheter Potts shunt creation in pigs. Methods and results In six pigs, a steerable SureFlex sheath was used to optimize the trajectory of perforation from the DAo into LPA using a 0.035″ radiofrequency wire. The combination of a larger perforation, stiffer radiofrequency wire and smooth dilator-to-sheath transition allowed sheath entry into the LPA without requiring an arterio-venous wire circuit. The Occlutech Atrial Flow Regulator (AFR), a double-disc device with a central fenestration, was deployed through this sheath with apposition of the distal disc to the posterior LPA wall and the proximal disc to the anterior DAo wall. The AFR is compliant and crumpling of the central fenestration was resolved by balloon dilation. It was feasible to implant a stent within the fenestration (n = 3). Aortography confirmed a left-to-right shunt through the AFR without contrast extravasation. Autopsy demonstrated anchoring of both discs against the vessel walls, patency of the fenestration and secure placement of the stent with no intra-thoracic bleeding. Conclusions In an acute pig model, we have demonstrated the feasibility of creating a transcatheter Potts shunt with a simplified technique using a steerable sheath, a double-disc device with a central fenestration that acts as the shunt channel and optional stenting of the fenestration.

Background: Intrinsic myocardial stiffness (MS) is load-independent, unlike most parameters to assess LV systolic and diastolic function. Pre-clinical studies have found good correlation between 1) peak-systolic MS and contractility (or ESPVR); 2) end-diastolic MS and compliance (or EDPVR). Shear wave imaging (SWI) by ultrafast ultrasound imaging allows MS measurement throughout the cardiac cycle. Methods (Fig 1): Five children with LV pressure-overload (LV-PO; 2 aortic stenosis, 3 coarctation) were studied during cardiac catheterization and there were 5 age-matched controls. Interventricular septal MS was measured by SWI every 100ms during the cardiac cycle, pre- and post-balloon dilation. ESPVR and EDPVR were assessed by pressure-volume loops by a pressure catheter and real-time 3D-echo volumes. Results (Fig 2): Peak-systolic MS was higher in LV-PO (22.7±6.7 kPa) than controls (8.4±2.8 kPa; p Conclusions: Non-invasive MS is a load-independent measure of LV systolic contractility and diastolic compliance in children.

Background: Echocardiographic parameters to assess systolic and diastolic RV function are strongly dependent on loading conditions. Myocardial stiffness (MS) is an intrinsic myocardial property that influences both diastolic and systolic cardiac function. MS is independent of loading conditions and pre-clinical studies have demonstrated a correlation between 1) systolic MS and contractility (or ESPVR); 2) end-diastolic MS and compliance (or EDPVR). Shear wave imaging (SWI) by ultrafast ultrasound imaging allows quantitative MS assessment at any time of the cardiac cycle. This noninvasive technique could provide load-independent measure of RV function. Methods (figure 1): Ten children, 5 pulmonary arterial hypertension patients (PAH) undergoing diagnostic right heart catheterization (RHC) were prospectively enrolled as well as 5 age-matched heathy volunteers (HV). MS was assessed at baseline and during FiO2 70%+40ppm NO for the PAH group. MS in the RV free wall using SWI every 100ms during the cardiac cycle. RV-ESPVR and RV-EDPVR were assessed by pressure-volume loops using a pressure catheter and real-time 3D-echo volumes. Results (figure 2): MS increased significatively in systole compared to end-diastole in both groups (p Conclusions: Our preliminary data demonstrate that MS could be a quantitative measure of RV contractility and diastolic compliance of the RV.

Introduction: Diagnosing diastolic dysfunction (DD) non-invasively in children is challenging as no validated pediatric diagnostic algorithm is available. The aim of this study is to use machine learning (ML) to identify a model that integrates echocardiographic measurements to predict invasive hemodynamic markers of DD in children. Methods: We enrolled children with Kawasaki disease, heart transplant, aortic stenosis, and coarctation of the aorta undergoing left heart catheterization. We obtained simultaneous invasive and echo DD measurements. We applied random forest (RF) algorithms to develop separate models for each cath marker (time constant of isovolumic relaxation (Tau), LVEDP, and -dP/dt max) and used demographics, diagnosis, and echo features as inputs. Model approximation was done using a regression tree with the top ranked features of each RF model to improve model interpretability (Figure 1). Spearman correlations were also assessed. Results: 59 children were included. Spearman correlations were low. However, the RF models' adjusted R 2 values in predicting Tau, LVEDP, and -dP/dt max are 0.62, 0.51, and 0.83, respectively. A representative ML-generated tree for LVEDP is shown in Figure 2. The most important features were propagation velocity (Vp) for Tau; E/Vp ratio for LVEDP; and systolic global longitudinal strain rate for -dP/dt max. Model approximation showed that a Vp < 42 cm/s predicted a Tau > 39 ms, and an E/Vp > 2.4 predicted an LVEDP > 13 mmHg. Conclusions: Predicting invasively measured diastolic parameters with echo data may be improved using ML algorithms. Model approximation may help better interpret the complex interactions in ML models.

In hypoplastic left heart syndrome (HLHS), the mechanisms leading to left heart hypoplasia and their associated fetal abnormalities are largely unknown. Current animal models have limited utility in resolving these questions as they either do not fully reproduce the cardiac phenotype, do not survive to term and/or have very low disease penetrance. Here, we report the development of a surgically induced mouse model of HLHS that overcomes these limitations. Briefly, we microinjected the fetal left atrium of embryonic day (E)14.5 mice with an embolizing agent under high-frequency ultrasound guidance, which partially blocks blood flow into the left heart and induces hypoplasia. At term (E18.5), all positively embolized mice exhibit retrograde aortic arch flow, non-apex-forming left ventricles and hypoplastic ascending aortas. We thus report the development of the first mouse model of isolated HLHS with a fully penetrant cardiac phenotype and survival to term. Our method allows for the interrogation of previously intractable questions, such as determining the mechanisms of cardiac hypoplasia and fetal abnormalities observed in HLHS, as well as testing of mechanism-based therapies, which are urgently lacking., Summary: We report the first mouse model of isolated hypoplastic left heart syndrome (HLHS), allowing for the investigation of abnormal cardiac, brain and placental development that is implicated in HLHS.

Diagnosing left ventricular diastolic dysfunction (DD) noninvasively in children is difficult as no validated pediatric diagnostic algorithm is available. The aim of this study is to explore the use of machine learning to develop a model that uses echocardiographic measurements to explain patterns in invasively measured markers of DD in children.Children at risk for developing DD were enrolled, including patients with Kawasaki disease, heart transplantation, aortic stenosis, and coarctation of the aorta when undergoing clinical left heart catheterization. Simultaneous invasive pressure measurements were made using a high-fidelity catheter (time constant of isovolumic relaxation [Tau, τ], left ventricular end-diastolic pressure, and maximum negative rate of pressure change) and echocardiographic DD measurements. Spearman correlations were performed for each echocardiographic feature with invasive markers to understand pairwise relationships. Separate random forest (RF) models were implemented to assess all echocardiographic features, key demographic data, and clinical diagnosis in predicting invasive markers. A backward stepwise regression model was simultaneously implemented as a comparative conventional reference model. The relative importance of all parameters was ranked in terms of accuracy reduction. Model approximation was then performed using a regression tree with the top-ranked features of each RF model to improve model interpretability. Regression coefficients of the linear models were presented.Fifty-nine children were included. Spearman correlations were generally low. The RF models' performance measures were noninferior to those of the linear model. However, the linear model's regression coefficients were unintuitive. The highest ranked important features for the RF models were propagation velocity for Tau, E/propagation velocity ratio for left ventricular end-diastolic pressure, and systolic global longitudinal strain rate for maximum negative rate of pressure change.Estimating individual components of DD can potentially improve the noninvasive assessment of pediatric DD. Although pairwise correlations measured were weak and linear regression coefficients unintuitive, approximated machine learning models aided in understanding how echocardiographic and invasive parameters of DD are related. This machine learning approach could help in further development of pediatric-specific diagnostic algorithms.

Background: Little is known about serial changes in the physiology of single ventricle (SV) patients during staged palliation and if HLHS patients differ from the rest. Methods: We analyzed SV patients who had a combined cath with CMR at both the preBCPC and preFontan studies from 2016-2019. Flow contrast mapping used to calculate pulmonary arterial (Qpa) and venous (Qpv) flow. Systemic blood flow (Qs) calculated using [superior vena cava (SVC) flow + descending aortic flow at the level diaphragm]. Cerebral vascular resistance (CVRi) calculated using [ascending aortic pressure (AoP)-right atrial pressure (RAP)/SVC flow]. Systemic vascular resistance (SVR) calculated using [(AoP-RaP)/Qs]. Pulmonary vascular resistance (PVR) was calculated using [(mean PAP - LAP)/Qpv]. Results: 30 patients were found, 10 with HLHS. The BCPC unloaded the heart, EDVi fell from preBCPC to preFontan. From preBCPC to preFontan(Table1): PA flow fell, but was compensated by increased APC flow to keep QpQs~1, PApressure and PVRi fell. Compared to others, the HLHS patients had larger hearts (EDVi) and lower PA but higher APC flow at both preBCPC(Table2)and preFontan(Table3). By preFontan, HLHS patients had worse function: higher ESVi, lower EF. Conclusion: QpQs ~1 is maintained by increase in APC flow. HLHS hearts are larger and deteriorate progressively.

Introduction: Melody™ valve in the mitral position has been described for use in infants. Hypothesis: Melody™ valve (Medtronic) in the mitral position would improve survival compared to mechanical mitral valves for young children. Methods: Charts were retrospectively reviewed for children who had undergone a Melody™ valve insertion (MEL) between 2014 and 2020. MEL were case-matched by age and weight to those with a mechanical mitral valve (MECH). We compared transplant free survival and cumulative incidence of re-intervention. A sub-analysis was performed for children Results: Eleven children underwent Melody™ mitral valve replacement (MVR) over the study period. Age was 157 (104-402) days and weight 5.0 (4.2-7.4) kg. Indications for MVR were insufficiency in 6 (55%), stenosis in 3 (27%), and mixed disease in 2 (18%). MEL underwent a total of 13 repairs and 4 replacements (2 mechanical, 2 bioprosthetic) prior to Melody™ valve replacement. Final valve dilation size was 18 (15.5-18.5)mm. Two (18%) children salvaged from ECMO before MEL subsequently died. Three (33%) of the 9 survivors have required subsequent MVR at 9, 17, and 23 months; 1 for severe insufficiency, and 2 for severe mixed disease. The MECH cohort was not different in age, weight, valve size, bypass or cross-clamp times, indications for replacement, or number of prior repairs or replacements (p>0.10). At 1 and 3 years, transplant free survival (MEL: 80%, 80%; MECH: 82%, 64%; p=0.180) and re-intervention (MEL: 11%, 39%; MECH: 0%, 20% p=0.32) were equivalent between groups. For children Conclusions: Melody™ MVR represents a better surgical strategy for infants less than 1 year of age requiring mitral valve replacement.

Background: Balloon angioplasty for native coarctation of the aorta (CoA) is successful in children and adults but in neonates results in frequent restenosis. The efficacy of balloon angioplasty for native CoA during infancy beyond the neonatal period was examined in infants aged 3 to 12 months of age. Methods: A retrospective review of 68 infants who underwent balloon angioplasty for native CoA. 95% CI are in parentheses. Results: Procedural age was (mean±SD) 6±3.4 months and weight was 7±1.8 kg. Balloon angioplasty produced a large decrease in both the noninvasive arm-to-leg blood pressure gradient (41.2±18.7 to 5.6±9.6 mm Hg) and the invasive peak systolic pressure gradient (34±12 to 11±9 mm Hg). Balloon angioplasty increased the CoA diameter from 2.7±1 mm to 4.6±1.2 mm. One patient was lost to follow-up. A catheter reintervention was required in 11.8% and surgery in 10.3%. The hazard of reintervention was highest early. Median freedom from reintervention was 89% (95% CI, 80%–96%) at 1 year, 83% (95% CI, 73%–92%) at 5 years, and 81% (95% CI, 69%–90%) at 10 years. Femoral artery thrombosis was documented in 6 (9%) infants without any long-term consequence. One patient developed a small aortic aneurysm late and has not required treatment. A robust estimate of the frequency of aortic aneurysms remains to be determined as the majority of subjects have not had cross-sectional imaging. Conclusions: Balloon angioplasty of native CoA is effective and safe in infants aged 3 to 12 months with outcomes comparable to those in older children and adults. Catheter reinterventions can avoid the need for surgery in most patients.

Fetal cardiac interventions (FCI) offer the opportunity to rescue a fetus at risk of intrauterine death, or more ambitiously to alter disease progression. Most of these fetuses require multiple additional postnatal procedures, and it is difficult to disentangle the effect of the fetal procedure from that of the postnatal management sequence. The true clinical impact of FCI may only be discernible in large-volume institutions that can commit to a standardized postnatal approach and have sufficient case volume to overcome their FCI learning curve.

Purpose To determine disease-associated single-gene variants in conotruncal defects, particularly tetralogy of Fallot (TOF). Methods We analyzed for rare loss-of-function and deleterious variants in FLT4 (VEGFR3) and other genes in the vascular endothelial growth factor (VEGF) pathway, as part of a genome sequencing study involving 175 adults with TOF from a single site. Results We identified nine (5.1%) probands with novel FLT4 variants: seven loss-of-function, including an 8-kb deletion, and two predicted damaging. In ten other probands we found likely disruptive variants in VEGF-related genes: KDR (VEGFR2; two stopgain and two nonsynonymous variants), VEGFA, FGD5, BCAR1, IQGAP1, FOXO1, and PRDM1. Detection of VEGF-related variants (19/175, 10.9%) was associated with an increased prevalence of absent pulmonary valve (26.3% vs. 3.4%, p

Background Novel quantification of stroke volume according to mitral inflow and aortic outflow using automated real-time 3-dimensional volume colour flow Doppler echocardiography (3D-RT-VCFDE) is more accurate than 2-dimensional echocardiography and has excellent correlation with cardiac magnetic resonance imaging-based flows in adults. This technology is applied for the first time to the right heart and in children. Methods 3D-RT-VCFDE was performed in 61 image sets of flow through the aortic (AV), mitral (MV), pulmonary (PV), and tricuspid (TV) valves of 34 children. These were compared with stroke volumes of the right (RV) and left (LV) ventricles and ratio of pulmonary to systemic blood flow determined using the Fick method in 31 children with atrial shunts. Results The mean age was 8.0 ± 3.3 years, and the mean weight was 27.8 ± 10.0 kg. The mean temporal resolution for flow analyses was ≥ 22 volumes per second. In conditions with no shunt, the correlations were: AV with MV flows ( r = 0.98), PV with TV flows ( r = 0.96), RV stroke volume with PV flow ( r = 0.95), and with TV flow ( r = 0.93), LV stroke volume with AV flow ( r = 0.87), and with MV flow ( r = 0.89). Fick ratio of pulmonary to systemic blood flow correlations were: PV/AV ratio ( r = 0.84), TV/MV ratio ( r = 0.87), and RV/LV ratio ( r = 0.70). Conclusions Stroke volume determined using automated 3D-RT-VCFDE is feasible in children and in the right side of the heart. This technique potentially provides a noninvasive alternative to historically invasively acquired hemodynamic data and to cardiac magnetic resonance imaging.

Purpose To estimate reference ranges for blood flow volume (BFV) in major splanchnic, thoracoabdominal, and neck vessels by using phase-contrast magnetic resonance (MR) imaging in children and young adults in fasting and postprandial states. Materials and Methods In this institutional research ethics board-approved prospective study, healthy volunteers underwent phase-contrast MR imaging in a fasting state and again after a standardized meal. BFV values were reported as medians and ranges, and postmeal to premeal BFV ratios were calculated. BFVs in volunteers divided into two groups according to age (≤18 years old and18 years old) were compared by using the Mann-Whitney test adjusted for multiple comparisons. Linear regression for internal validation of BFV and Pearson correlation and Bland-Altman analysis for interobserver agreement were used. Results Reference ranges for BFVs were estimated in 39 volunteers (23 male and 16 female; mean age, 21.2 years ± 8.5; range, 9-40 years) and were indexed according to body surface area, with internal validation (R

Neoaortic root dilation is a common phenomenon after the Norwood procedure, but the real incidence and its natural history are unclear. Regular surveillance in these patients after the operation is necessary. Herein, we present an 11-year-old boy born with tricuspid atresia, a discordant ventriculo-arterial connection and a hypoplastic aortic arch, who was palliated initially with a hybrid stage I procedure involving a reversed Blalock–Taussig shunt, followed by comprehensive stage II and then, an extra-cardiac fenestrated Fontan operation. The patient developed an aortic root aneurysm and severe aortic regurgitation. He was electively taken into the operating room, where cardiopulmonary bypass was established through a peripheral cannulation of the femoral vessels due to the high risk nature of the reoperation. A mechanical Bentall procedure was performed without residual lesions and the native ascending aorta was anastomosed as a single coronary button to the anterior wall of the graft.

OBJECTIVE To investigate the regional flow distribution in patients with Fontan circulation by using magnetic resonance imaging (MRI). MATERIALS AND METHODS We identified 39 children (18 females and 21 males; mean age, 9.3 years; age range, 3.3-17.0 years) with Fontan circulation in whom flow volumes across the thoracic and abdominal arteries and veins were measured by using MRI. The patients were divided into three groups: fenestrated Fontan circulation group with MRI performed under general anesthesia (GA) (Group 1, 15 patients; average age, 5.9 years), completed Fontan circulation group with MRI performed under GA (Group 2, 6 patients; average age, 8.7 years), and completed Fontan circulation group with MRI performed without GA (Group 3, 18 patients; average age, 12.5 years). The patient data were compared with the reference ranges in healthy controls. RESULTS In comparison with the controls, Group 1 showed normal cardiac output (3.92 ± 0.40 vs. 3.72 ± 0.69 L/min/m², p = 0.30), while Group 3 showed decreased cardiac output (3.24 ± 0.71 vs. 3.96 ± 0.64 L/min/m², p = 0.003). Groups 1 and 3 showed reduced abdominal flow (1.21 ± 0.28 vs. 2.37 ± 0.45 L/min/m², p < 0.001 and 1.89 ± 0.39 vs. 2.64 ± 0.38 L/min/m², p < 0.001, respectively), which was mainly due to the diversion of the cardiac output to the aortopulmonary collaterals in Group 1 and the reduced cardiac output in Group 3. Superior mesenteric and portal venous flows were more severely reduced in Group 3 than in Group 1 (ratios between the flow volumes of the patients and healthy controls was 0.26 and 0.37 in Group 3 and 0.63 and 0.53 in Group 1, respectively). Hepatic arterial flow was decreased in Group 1 (0.11 ± 0.22 vs. 0.34 ± 0.38 L/min/m², p = 0.04) and markedly increased in Group 3 (0.38 ± 0.22 vs. -0.08 ± 0.29 L/min/m², p < 0.0001). Group 2 showed a mixture of the patterns seen in Groups 1 and 3. CONCLUSION Fontan circulation is associated with reduced abdominal flow, which can be attributed to reduced cardiac output and portal venous return in completed Fontan circulation, and diversion of the cardiac output to the aortopulmonary collaterals in fenestrated Fontan circulation.

Objective The aim of this systematic review and meta-analysis is to evaluate whether duct stenting is associated with better survival and other clinical outcomes compared with the modified Blalock–Taussig shunt in infants with duct-dependent pulmonary flow. Methods A systematic search of the Medline, Embase, and Cochrane databases was performed by 4 independent reviewers from inception to March 2019. Meta-analysis was performed using the DerSimonian and Laird method with inverse-variance weighting. The quality of evidence was summarized using the Grading of Recommendations, Assessment, Development, and Evaluation framework. Results Six comparative observational studies were included, of which 3 were rated low risk of bias. There was no difference in 30-day mortality between the Blalock–Taussig shunt and duct stenting groups (risk ratio, 1.02; 95% confidence interval, 0.46-2.27; P = .96; I2 = 0%). However, there was benefit in favor of duct stenting for medium-term mortality (risk ratio, 0.63; 95% confidence interval, 0.40-0.99; P = .05; I2 = 0%). Duct stenting demonstrated a reduced risk for procedural complications compared with the Blalock–Taussig shunt (risk ratio, 0.50; 95% confidence interval, 0.31-0.81; P = .005; I2 = 0%). However, there was an increased risk for unplanned reintervention for duct stenting (risk ratio, 1.77; 95% confidence interval, 1.39-2.26; P Conclusions Duct stenting demonstrated comparable early mortality, lower medium-term mortality, lower risk of procedural complications, and higher risk of reintervention compared with the Blalock–Taussig shunt.

Percutaneous, ultrasound-guided fetal cardiac intervention (FCI) is increasingly used to alter the prognosis of specific forms of congenital heart disease. Careful patient selection and postnatal management strategy are essential for optimal outcomes. This article discusses the rationale, patient selection criteria, procedural techniques, and contemporary results of FCI. Sources of information included published patient series, the International Fetal Cardiac Intervention Registry, and the Toronto experience as the Canadian referral center.

ObjectiveThe relationship between right ventricular (RV) fibrosis and right heart reverse remodelling following pulmonary valve replacement (PVR) has not been well studied in adults with repaired tetralogy of Fallot (rTOF). Our aims were to histologically quantify RV fibrosis and to explore the relationship between fibrosis severity and cardiac remodelling post-PVR.MethodsAdults with rTOF and pre-PVR cardiovascular (CMR) imaging were consented to procurement of RV muscle during PVR. Samples were stained with picrosirius red to quantify collagen volume fraction. Clinical data at baseline and at last follow-up were reviewed. Adverse cardiovascular outcomes included death, sustained arrhythmia and heart failure.ResultsFifty-three patients (male 58%, 38±11 years) were studied. Those with severe fibrosis (collagen volume fraction >11.0%, n=13) had longer aortic cross-clamp times at initial repair compared with the remainder of the population (50 vs 33 min, p=0.018) and increased RV mass:volume ratio pre-PVR (0.20 vs 0.18 g/mL, p=0.028). Post-PVR, the severe fibrosis group had increased indexed RV end-systolic volume index (RVESVi) (74 vs 66 mL/m2, p=0.044), decreased RVESVi change (Δ29 vs Δ45 mL/m2, p=0.005), increased RV mass (34 vs 25 g/m2, p=0.023) and larger right atrial (RA) area (21 vs 17 cm2, p=0.021). A trend towards increased heart failure events was observed in the severe fibrosis group (15% vs 0%, p=0.057).ConclusionsSevere RV fibrosis was associated with increased RVESVi, RV mass and RA area post-PVR in rTOF. Further study is required to define the impact of fibrosis and persistent right heart enlargement on clinical outcomes.

Objectives To assess the effectiveness of radiation-reduction measures implemented during pediatric catheterization, and provide data on the radiation doses for common interventional and diagnostic procedures, indexed to body weight. Background Ionizing radiation exposure must be minimized to “as low as reasonably achievable,” by instituting radiation-limiting techniques and knowledge of expected radiation exposure. Methods Radiation-reduction measures included pulsed-fluoroscopy at 7.5 pulses/second (0.032–0.045 µGy/pulse), an air-gap magnification technique for children 30 kg, P

Radiofrequency (RF) assisted perforation of the atrial septum was performed successfully in three infants using a 0.035΂ RF wire deployed through a Williams right posterior catheter. Balloon atrial septoplasty was performed over the 0.035΂ RF wire in two of them, shortening the procedural time.

We report the first ultrasonographically guided percutaneous balloon atrial septoplasty (BAS), to our knowledge, in a fetus with transposition of the great arteries and an intact ventricular and atrial septum (37 + 2 weeks). After vaginal delivery at 38 weeks, the infant had an elective septostomy (day 1) and an arterial switch procedure (day 7), with an uneventful postoperative course. For centres with experience in fetal cardiac interventions, fetal BAS is a superior management option compared with the alternatives for this high-risk physiology.

Acute cellular rejection (ACR) compromises graft function after heart transplantation (HTX). The purpose of this study was to describe systolic myocardial deformation in pediatric HTX and to determine whether it is impaired during ACR. Eighteen combined cardiac magnetic resonance imaging (CMR)/endomyocardial biopsy (EMBx) examinations were performed in 14 HTX patients (11 male, age 13.9 ± 4.7 years; 1.2 ± 1.3 years after HTX). Biventricular function and left ventricular (LV) circumferential strain, rotation, and torsion by myocardial tagging CMR were compared to 11 controls as well as between patients with and without clinically significant ACR. HTX patients showed mildly reduced biventricular systolic function when compared to controls [LV ejection fraction (EF): 55 ± 8% vs. 61 ± 3, p = 0.02; right ventricular (RV) EF: 48 ± 7% vs. 53 ± 6, p = 0.04]. Indexed LV mass was mildly increased in HTX patients (67 ± 14 g/m2 vs. 55 ± 13, p = 0.03). LV myocardial deformation indices were all significantly reduced, expressed by global circumferential strain (−13.5 ± 2.3% vs. −19.1 ± 1.1%, p

Objectives Mortality associated with the modified Blalock–Taussig shunt (MBTS) remains high despite advanced perioperative management. This study was formulated to provide data on (1) current indications, (2) outcomes, and (3) factors affecting mortality and morbidity. Design A retrospective single center chart review identified 95 children (excluding hypoplastic left heart lesions) requiring a MBTS. Mortality and major morbidity were analyzed using the Kaplan Meier method and risk factor analysis using Cox's proportional hazard regression. Results Median age was 8 (0–126) days, weight 3.1(1.7–5.4) kg. Seventy-three percent were neonates, 58% duct dependent and 73% had single ventricle physiology. Ninety-seven percent had a sternotomy approach for shunt placement with 70% receiving a 3.5 mm graft. Mean graft index (shunt cross sectional area [mm2]/BSA [m2]) was 44.39 ± 8.04 and shunt size (mm) to body weight (kg) ratio 1.1 ± 0.2. Hospital mortality was 12%, with an interval mortality of 6%. Shunt thrombosis/stenosis occurred in 23% and pulmonary over circulation in 30%, while shunt reoperation was required in 12% and catheter intervention in 8% of the cohort. At 1-year, survival was 82.0% (95% CI [72.7%, 88.4%]), and survival free of major morbidity 61.4% (95% CI [50.7%, 70.5%]). Duct dependency predisposed to mortality (P = .01, HR 6.74 [1.54, 29.53]) and composite outcome (mortality and major morbidity) (P = .04, HR 2.15, CI [1.036, 4.466]) and higher graft index to mortality (P = .005, HR 1.07 [1.02, 1.12]). Conclusions The commonest indication for a MBTS in the current era was single ventricle palliation. Morbidity and mortality was considerable, partly explained by the higher at risk population. Alternative methods to maintain pulmonary blood flow in place of a MBTS requires further investigation.

Objectives We sought to review our single center experience with secundum atrial septal defect (ASD) device closure, evaluating the incidence and morphological characteristics where percutaneous closure was thought inappropriate. Material and methods All children assessed as unsuitable for transcatheter device closure were reviewed. Data collected included: demographics, defect morphology by echocardiogrphy or at cardiac catheterization and defect size focusing on the reasons for procedural deferral. Results Between January 2002 and December 2010, 639 children underwent closure of an isolated secundum ASD: 82 children (13%) where referred directly to surgery, 43 (6%) were thought unsuitable for device closure at the time of catheterization and underwent subsequent surgery and the remaining 514 (81%) underwent successful device closure including 2 on a second attempt. The reasons for pursuing a surgical closure (n = 124, mean age = 5.7 years; range: 0.6–17.4 years; defect diameter/body weight = 1.39) included: the need for a device thought too large for implantation versus the child's size (n = 51), defects with deficient rim(s) (n = 48), multiple defects (n = 7), defects sized >36 mm (n = 2), malposition (n = 2), ECG changes (n = 3), aneurysmal IAS (n = 2), sinus venosus (n = 2), or others (n = 7). Conclusion The reasons for deferring transcatheter device closure of a secundum ASD are diverse, not only isolated rim deficiencies but the requirements of large implants, malposition, arrhythmias, and lack of hemodynamic need are influential components in clinical decision making. © 2014 Wiley Periodicals, Inc.

Objective Large solid sacrococcygeal teratomas (SCT) can cause high-output cardiac failure and fetal or neonatal death. The aim of this study was to describe the outcomes of minimally invasive antenatal procedures for the treatment of fetal SCT. Methods A case review was performed of five fetuses with a large SCT treated antenatally using minimally invasive techniques, and a systematic literature review on fetal therapy for solid SCTs was carried out. Results Five women were referred between 17 + 5 and 26 + 4 weeks' gestation for a large fetal SCT with evidence of fetal cardiac failure. Vascular flow to the tumors was interrupted by fetoscopic laser ablation (n = 1), radiofrequency ablation (RFA; n = 2) or interstitial laser ablation ± vascular coiling (n = 2). There were two intrauterine fetal deaths. The other three cases resulted in preterm labor within 10 days of surgery. One neonate died. Two survived without procedure-related complications but had long-term morbidity related to prematurity. The systematic literature review revealed 16 SCTs treated minimally invasively for (early) hydrops. Including our cases, six of 20 hydropic fetuses survived after minimally invasive therapy (30%). Survival after RFA or interstitial laser ablation was 45% (5/11). Of 12 fetuses treated for SCT without obvious hydrops and for which perinatal survival data were available, eight (67%) survived. Mean gestational age at delivery after minimally invasive therapy was 29.7 ± 4.0 weeks. Survival after open fetal surgery in hydropic fetuses was 6/11 (55%), with a mean gestational age at delivery of 29.8 ± 2.9 weeks. Conclusions Fetal therapy can potentially improve perinatal outcomes for hydropic fetuses with a solid SCT, but is often complicated by intrauterine death and preterm birth. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

The Fontan operation allows for longer survival of those born with functionally single ventricle physiology. Although it effectively eliminates cyanosis, increased systemic venous pressure is an unavoidable consequence and low cardiac output is frequent. The abdomen is particularly vulnerable to these alterations in hemodynamics because the hepatic blood flow consists predominantly of portal venous flow, which relies on a low pressure gradient between the portal and hepatic veins. Therefore, any subtle increase in systemic venous pressure will adversely affect the hemodynamic balance of the liver as well as the intestine. As the clinical manifestations and routine laboratory findings of abdominal complications can lag behind the hemodynamic and pathologic changes in the abdominal organs, regular imaging surveillance is critical. Magnetic resonance (MR) provides excellent visualization of both cardiovascular and abdominal systems. It provides robust anatomic and hemodynamic data which can be used for timely implementation of treatment options. In this review paper, we discuss the pathogenesis and MR findings of abdominal complications following the Fontan operation. Specifically we explore the utility of phase-contrast MR for assessment of the abdominal circulation in children following the Fontan palliation.

The aim of this study was to explore the clinical impact of transverse aortic arch hypoplasia (TAH) after stent implementation for isthmal coarctation of the aorta (CoA). From a retrospective chart review, 51 children (median age 11.1 years) were identified who had TAH and a CoA stent implanted between 10/1995 and 4/2015. Arm–leg cuff blood pressure measurements, echocardiographic arch imaging, and 24-h ambulatory blood pressure monitoring, prior to and after stent implantation, were reviewed. At catheterization, peak systolic gradients across the CoA’s were 25 mmHg before and 4 mmHg after stent implantation. At a median 37-month follow-up, echocardiographic imaging showed no significant catch-up growth in the transverse arch (median z-score; proximal and distal arch −1.54 and −1.99 vs. −1.78 and −1.63, p = 0.13 and 0.90). A trend to increasing systolic blood pressure (SBP) differentials between the right and left arms was noted (11 mmHg [prior to]; 16 mmHg [follow-up], p = 0.09). Age-adjusted percentiles for right arm SBP decreased from 99.7% prior to, and 87.6% in follow-up (p

Background Hypoplastic left heart syndrome with a highly restrictive or intact atrial septum (HLHS-RAS) has a very high mortality. Fetal left atrial (LA) hypertension results in abnormal lung development with lymphangiectasia and pulmonary vein muscularization. We report our initial experience with percutaneous ultrasound-guided stenting of the fetal atrial septum to decompress the LA. Methods Retrospective review of fetuses with HLHS-RAS or a variant that underwent active perinatal management from 2000 to 2012. Results Ten fetuses were identified. Two died in utero (33, 29weeks). Four required the urgent creation of an atrial communication immediately after birth but died subsequently (5–54days). Four fetuses (28–36weeks) underwent percutaneous stenting of the atrial septum, with ultrasound guidance and intravenous maternal sedation. Elevated LA pressure, pulmonary vein dilation and MRI estimated pulmonary perfusion all improved after stenting. Three of four stented fetuses were delivered vaginally. Atrial septectomy was performed within 48h of delivery to ensure complete LA decompression, rather than for hypoxemia. Intraoperative lung biopsy demonstrated muscularized pulmonary veins and lymphangiectasia in all four. Two fetuses developed stent stenosis in utero and died after birth, from pulmonary hypertension and sepsis respectively. Two are alive, representing an improved outcome over our previous experience (p=0.03). Conclusion Fetal atrial septal stenting is feasible without maternal complications and allows vaginal delivery of a more stable neonate. Fetal LA decompression ameliorates rather than reverses lung injury, and is one component of an approach that may improve survival in HLHS-RAS.

Introduction We sought to assess the efficacy, safety and clinical outcomes of the Advanta V12™ covered stent in management of coarctation of the aorta (CoA). Materials and Methods Stent functionality was assessed by review of angiographic imaging, clinical data at admission, discharge and at the last clinic visit, stent configuration on chest roentgenogram, radiation exposure, and complications. Results Between October 2009 and February 2012, 17 patients underwent stent implantation. There were 9–12, 2–14, and 6–16 mm diameter stents deployed. Balloon angioplasty after implantation was required in 2 patients. Mean percent recoil in the middle of the stent for the 12, 14, and 16 mm implants was 14%, 24%, and 24%, respectively. There was improvement in CoA diameter from 6.6 ± 3.2 to 11.5 ± 1.7 mm (P

Background Adverse fibrotic remodeling is detrimental to myocardial health and a reliable method for monitoring the development of fibrotic remodeling may be desirable during the follow-up of patients after heart transplantation (HTx). Quantification of diffuse myocardial fibrosis with cardiovascular magnetic resonance (CMR) has been increasingly applied and validated histologically in adult patients with heart disease. However, comparisons of CMR findings with histological fibrosis burden in children are lacking. This study aimed to compare native T1 times and extracellular volume fraction (ECV) derived from CMR with the degree of collagen on endomyocardial biopsy (EmBx), and to investigate the association between myocardial fibrosis and clinical as well as functional markers in children after HTx. Methods EmBx and CMR were performed on the same day. All specimens were stained with picrosirius red. The collagen volume fraction (CVF) was calculated as ratio of stained collagen area to total myocardial area on EmBx. Native T1 values and ECV were measured by CMR on a mid-ventricular short axis slice, using a modified look-locker inversion recovery approach. Results Twenty patients (9.9 ± 6.2 years of age; 9 girls) after HTx were prospectively enrolled, at a median of 1.3 years (0.02–12.6 years) post HTx, and compared to 24 controls (13.9 ± 2.6 years of age; 12 girls). The mean histological CVF was 10.0 ± 3.4%. Septal native T1 times and ECV were higher in HTx patients compared to controls (1008 ± 32 ms vs 979 ± 24 ms, p

Background— Tetralogy of Fallot with cyanosis requiring surgical repair in early infancy reflects poor anatomy and is associated with more clinical instability and longer hospitalization than those who can be electively repaired later. We bridged symptomatic infants with risk factors for early primary repair by right ventricular outflow tract stenting (stent). Methods and Results— Four groups of tetralogy of Fallot with confluent central pulmonary arteries were studied: stent group (n=42), primary repair (aged 3mo group; n=45). Stent patients had the smallest pulmonary arteries with a median (95% credible intervals) Nakata index (mm 2 /m 2 ) of 79 (66–85) compared with the early-PA 139 (129–154), early-PS 136 (121–153), and surg>3mo 167 (153–200) groups. Only stent infants required unifocalization of aortopulmonary collaterals (17%). Stent and early-PA infants had younger age and lower weight than early-PS infants. Stent infants had the most multiple comorbidities. Stenting allowed deferral of complete surgical repair to an age (6 months), weight (6.3 [5.8–7.0] kg), and Nakata index (147 [132–165]) similar to the low-risk surg>3mo group. The 3 early treatment groups had similar intensive care unit/hospital stays and high reintervention rates in the first 12 months after repair, compared with the surg>3mo group. Conclusions— Right ventricular outflow tract stenting of symptomatic tetralogy of Fallot with poor anatomy (small pulmonary arteries) and adverse factors (multiple comorbidities, low weight) relieves cyanosis and defers surgical repair. This allowed pulmonary arterial and somatic growth with clinical results comparable to early surgical repair in more favorable patients.

A 33-day-old infant with obstructed cor triatriatum sinister and partial anomalous pulmonary venous drainage presented with respiratory distress and fever. Her suprasystemic pulmonary hypertension was relieved by opening the connection to the right atrium using balloon atrial septoplasty and septostomy, and to the inferior chamber using balloon dilation of a fenestration in the dividing membrane. This enabled extubation and discharge, with elective surgical repair at 2 months. To our knowledge, this is the youngest patient to receive a catheter intervention for obstructed cor triatriatum sinister, providing relief of pulmonary hypertension and postponement of surgical repair.

This chapter provides an overview of the normal atrial septum and the main lesions that are associated with prenatal septal restriction, proposes selection criteria of patients and procedures for possible in utero interventions, and illustrates the fetal and postnatal outcome after intrauterine intervention.

Background: Femoral venous and arterial approaches are the commonly used to obtain vascular access for pediatric cardiac catheterization. Hemostasis after catheter removal is usually obtained by manual compression. However, this technique is time consuming and at times painful. Although several closure devices are available for adults, they are not widely applicable in children. Objectives: To evaluate the safety and efficacy of a microporous polysaccharide hemospheres hemostasis (MPH) bandage compared to manual compression. Methods: Prospective randomized study, involving 112 children after cardiac catheterization. One group received the MPH bandage, another manual compression. Compression time was predetermined by the size of sheath plus one minute. Success was defined as no bleeding or hematoma formation. If bleeding continued, compression was continued as needed and time to hemostasis recorded. Informed consent was obtained prior to randomization. Group comparisons were performed with a Student's t, Pearson's Chi Square, and Fisher's exact test as appropriate. Results: Fewer children required a compression time of >15 min (P = 0.006) and more had a shorter time to hemostasis (P = 0.003) in the MPH group for venous access control. Time to hemostasis was also shorter in the MPH (P = 0.048) in arterial access cases, but the number of children requiring a compression time >15 min was the same. Complications including hematoma formation in each group were similar. Conclusions: The MPH bandage allows a shorter time to achieve hemostasis compared to manual compression. This improves turnaround time and laboratory efficiency. © 2011 Wiley-Liss, Inc.

Introduction. Pre-operative recognition of significant abnormalities of the coronary arteries is important in a variety of congenital cardiac conditions. Failure to diagnose anomalous origin of the coronary artery from the pulmonary artery during repair of other anomalies is important because reduction in pulmonary artery pressure will reduce myocardial perfusion pressure. Patients. We report two cases of the rare association of anomalous origin of the left coronary artery from the right pulmonary artery, aortic coarctation, and mitral stenosis. Conclusions. Definitive imaging of coronary artery anatomy by echocardiography or other modalities should form a routine part of diagnostic assessment in all congenital heart disease patients but particularly those with left heart obstruction.