Surgical Debulking of Large Ventricular Fibromas in Children.

OBJECTIVE: This study aims to provide an update on the clinical presentation, diagnostic work-up, operative strategies, and mid-term outcomes in children undergoing ventricular fibroma resection. METHODS: Single-center, retrospective cohort study of patients undergoing ventricular fibroma resection between 2000 and 2023. RESULTS: Among 52 patients, median age at surgery was 2.0 years (IQR 0.8-4.6) and median tumor volume index was 69 milliliters/m2 (IQR 49-169). Tumor distorted the atrioventricular (AV) valve/subvalvar apparatus in 30 (58%) patients and abutted major epicardial coronary arteries in 41 (79%) patients. Surgery was indicated for arrythmia (n=45, 86%), symptoms (n=14, 27%), and/or hemodynamic compromise (n=11, 21%). Tumor was debulked in 34 (65%) patients, including the last 21 patients. Concomitant AV valvuloplasty was performed in 18 patients and ventricular cavity closure in 15 (29%) patients. During a median follow-up of 2.4 years (IQR 0.8-6.2), there was no mortality, cardiac arrests, heart transplants, or single ventricle palliation. The 15-year risk of reoperation and clinical ventricular tachycardia/fibrillation was 6.7% (95% CI 0-14.3%) and 2.4% (95% CI 0-7.2%), respectively. On latest imaging, pre- and post-debulking LV ejection fraction did not significantly differ (P=.069), while no patients had signs of outflow tract obstruction, inflow tract obstruction, or > moderate AV valve regurgitation. CONCLUSIONS: Large ventricular fibromas can be resected safely with appropriate surgical planning and an emphasis on debulking. Most children maintain left ventricular function and remain free of recurrent ventricular arrhythmias at follow-up. Extended follow-up is warranted to understand whether patients remain at risk for scar-based ventricular arrhythmias in the future.

Rare cardiac inflammatory pseudotumor in a toddler: Complementary roles of cardiac magnetic resonance and positron emission tomography.

We present a rare pediatric case of cardiac inflammatory pseudotumor (IPT) with a unique presentation of fever of unknown origin with markedly elevated inflammatory markers. A right atrial mass was discovered incidentally by echocardiography. The cardiac magnetic resonance (CMR) signal characteristics and mass location were not consistent with any of the common benign cardiac tumors of childhood. The presence of high signal intensity on T2 imaging and late gadolinium enhancement, in conjunction with intense metabolic activity at the mass site on positron emission tomography (PET), raised the possibility of an inflammatory or malignant mass. The diagnosis of IPT was confirmed by biopsy. Our case highlights the utility of PET imaging to confirm the inflammatory nature and extent of an IPT.

The effects of pregnancy in subjects with repaired tetralogy of Fallot.

BACKGROUND: Previous reports reveal inconsistent findings of right ventricular (RV) changes following pregnancy in subjects with repaired tetralogy of Fallot (rTOF). METHODS: A two-center, retrospective cohort study which included women with rTOF who completed pregnancy that were matched to nulliparous women with rTOF by age at the time of baseline cardiac magnetic resonance (CMR), RV ejection fraction (RVEF), and indexed RV end-diastolic volume (RVEDVi). Pre-pregnancy and postpartum cardiac magnetic resonance (CMR) were analyzed and compared to sequential CMR of nulliparous subjects with rTOF. RESULTS: Thirty-six women with rTOF who completed pregnancy were matched to 72 nulliparous women with rTOF. Over a mean period of 3.1 years for the pregnancy group and 2.7 years for the comparison group, there was no significant change in the RVEDVi, RVEF, RV mass, pulmonary regurgitation severity, left ventricular (LV) volumes, LV ejection fraction (LVEF), or LV mass when comparing the baseline CMR and the follow-up CMR in either of the groups. There was a slight increase in RV indexed end-systolic volume (RVESVi) when comparing the baseline CMR and the follow-up CMR in the pregnancy group (68.93, SD 23.34 ml/m2 at baseline vs. 72.97, SD 25.24 mL/m2 at follow-up, P = .028). Using a mixed effects model for CMR parameters change over time; when adjusted for time between baseline and follow-up CMR there was no significant difference in rate of change between the pregnancy and comparison groups. CONCLUSIONS: Most ventricular remodeling parameters measured by CMR did not significantly change in subjects with rTOF who completed pregnancy or in nulliparous subjects with rTOF. In the pregnancy group, RVESVi is larger in those individuals who have undergone pregnancy without a significant change in ventricular function. These patients should be followed longitudinally to determine the long-term ventricular and clinical effects of pregnancy.

Pediatric ECG-Based Deep Learning to Predict Left Ventricular Dysfunction and Remodeling.

BACKGROUND: Artificial intelligence-enhanced ECG analysis shows promise to detect ventricular dysfunction and remodeling in adult populations. However, its application to pediatric populations remains underexplored. METHODS: A convolutional neural network was trained on paired ECG-echocardiograms (≤2 days apart) from patients ≤18 years of age without major congenital heart disease to detect human expert-classified greater than mild left ventricular (LV) dysfunction, hypertrophy, and dilation (individually and as a composite outcome). Model performance was evaluated on single ECG-echocardiogram pairs per patient at Boston Children's Hospital and externally at Mount Sinai Hospital using area under the receiver operating characteristic curve (AUROC) and area under the precision-recall curve (AUPRC). RESULTS: The training cohort comprised 92 377 ECG-echocardiogram pairs (46 261 patients; median age, 8.2 years). Test groups included internal testing (12 631 patients; median age, 8.8 years; 4.6% composite outcomes), emergency department (2830 patients; median age, 7.7 years; 10.0% composite outcomes), and external validation (5088 patients; median age, 4.3 years; 6.1% composite outcomes) cohorts. Model performance was similar on internal test and emergency department cohorts, with model predictions of LV hypertrophy outperforming the pediatric cardiologist expert benchmark. Adding age and sex to the model added no benefit to model performance. When using quantitative outcome cutoffs, model performance was similar between internal testing (composite outcome: AUROC, 0.88, AUPRC, 0.43; LV dysfunction: AUROC, 0.92, AUPRC, 0.23; LV hypertrophy: AUROC, 0.88, AUPRC, 0.28; LV dilation: AUROC, 0.91, AUPRC, 0.47) and external validation (composite outcome: AUROC, 0.86, AUPRC, 0.39; LV dysfunction: AUROC, 0.94, AUPRC, 0.32; LV hypertrophy: AUROC, 0.84, AUPRC, 0.25; LV dilation: AUROC, 0.87, AUPRC, 0.33), with composite outcome negative predictive values of 99.0% and 99.2%, respectively. Saliency mapping highlighted ECG components that influenced model predictions (precordial QRS complexes for all outcomes; T waves for LV dysfunction). High-risk ECG features include lateral T-wave inversion (LV dysfunction), deep S waves in V1 and V2 and tall R waves in V6 (LV hypertrophy), and tall R waves in V4 through V6 (LV dilation). CONCLUSIONS: This externally validated algorithm shows promise to inexpensively screen for LV dysfunction and remodeling in children, which may facilitate improved access to care by democratizing the expertise of pediatric cardiologists.

Right Heart Remodeling After Pulmonary Valve Replacement in Patients With Pulmonary Atresia or Critical Stenosis With Intact Ventricular Septum.

Background Patients with pulmonary atresia or critical pulmonary stenosis with intact ventricular septum (PA/IVS) and biventricular circulation may require pulmonary valve replacement (PVR). Right ventricular (RV) remodeling after PVR is well described in tetralogy of Fallot (TOF); we sought to investigate RV changes in PA/IVS using cardiac magnetic resonance imaging. Methods and Results A retrospective cohort of patients with PA/IVS who underwent PVR at Boston Children's Hospital from 1995 to 2021 with cardiac magnetic resonance imaging before and after PVR was matched 1:3 with patients with TOF by age at PVR. Median regression modeling was performed with post-PVR indexed RV end-diastolic volume as the primary outcome. A total of 20 patients with PA/IVS (cases) were matched with 60 patients with TOF (controls), with median age at PVR of 14 years. Pre-PVR indexed RV end-diastolic volume was similar between groups; cases had higher RV ejection fraction (51.4% versus 48.6%; P=0.03). Pre-PVR RV free wall and left ventricular (LV) longitudinal strain were similar, although LV midcavity circumferential strain was decreased in cases (-15.6 versus -17.1; P=0.001). At a median of 2 years after PVR, indexed RV end-diastolic volume was similarly reduced; cases continued to have higher RV ejection fraction (52.3% versus 46.9%; P=0.007) with less reduction in RV mass (Δ4.5 versus 9.6 g/m2; P=0.004). Post-PVR, RV and LV longitudinal strain remained unchanged, and LV circumferential strain was similar, although lower in cases. Conclusions Compared with patients with TOF, patients with PA/IVS demonstrate similar RV remodeling after PVR, with lower reduction in RV mass and comparatively higher RV ejection fraction. Although no differences were detected in peak systolic RV or LV strain values, further investigation of diastolic parameters is needed.

Machine Learning for Prediction of Adverse Cardiovascular Events in Adults With Repaired Tetralogy of Fallot Using Clinical and Cardiovascular Magnetic Resonance Imaging Variables.

BACKGROUND: Existing models for prediction of major adverse cardiovascular events (MACE) after repair of tetralogy of Fallot have been limited by modest predictive capacity and limited applicability to routine clinical practice. We hypothesized that an artificial intelligence model using an array of parameters would enhance 5-year MACE prediction in adults with repaired tetralogy of Fallot. METHODS: A machine learning algorithm was applied to 2 nonoverlapping, institutional databases of adults with repaired tetralogy of Fallot: (1) for model development, a prospectively constructed clinical and cardiovascular magnetic resonance registry; (2) for model validation, a retrospective database comprised of variables extracted from the electronic health record. The MACE composite outcome included mortality, resuscitated sudden death, sustained ventricular tachycardia and heart failure. Analysis was restricted to individuals with MACE or followed ≥5 years. A random forest model was trained using machine learning (n=57 variables). Repeated random sub-sampling validation was sequentially applied to the development dataset followed by application to the validation dataset. RESULTS: We identified 804 individuals (n=312 for development and n=492 for validation). Model prediction (area under the curve [95% CI]) for MACE in the validation dataset was strong (0.82 [0.74-0.89]) with superior performance to a conventional Cox multivariable model (0.63 [0.51-0.75]; P=0.003). Model performance did not change significantly with input restricted to the 10 strongest features (decreasing order of strength: right ventricular end-systolic volume indexed, right ventricular ejection fraction, age at cardiovascular magnetic resonance imaging, age at repair, absolute ventilatory anaerobic threshold, right ventricular end-diastolic volume indexed, ventilatory anaerobic threshold % predicted, peak aerobic capacity, left ventricular ejection fraction, and pulmonary regurgitation fraction; 0.81 [0.72-0.89]; P=0.232). Removing exercise parameters resulted in inferior model performance (0.75 [0.65-0.84]; P=0.002). CONCLUSIONS: In this single-center study, a machine learning-based prediction model comprised of readily available clinical and cardiovascular magnetic resonance imaging variables performed well in an independent validation cohort. Further study will determine the value of this model for risk stratification in adults with repared tetralogy of Fallot.

Impact of Right Ventricular Surface Area-to-Volume Ratio on Ventricular Remodeling After Pulmonary Valve Replacement.

Optimal reverse remodeling of the right ventricle (RV), a sentinel goal of pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot, is not fully predicted by volume-based pre-PVR parameters. Our objectives were to characterize novel geometric RV parameters in patients receiving PVR and in controls, and to identify associations between these parameters and chamber remodeling post-PVR. Secondary analysis was performed on cardiac magnetic resonance (CMR) data from 60 patients enrolled in a randomized trial of PVR with and without surgical RV remodeling. 20 healthy age-matched subjects served as controls. The primary outcome was optimal post-PVR RV remodeling (end-diastolic volume index (EDVi) ≤ 114 ml/m2 and ejection fraction (EF) ≥ 48%) vs. suboptimal remodeling (EDVi ≥ 120 ml/m2 and EF ≤ 45%). RV geometry was markedly different at baseline in PVR patients compared with controls, with lower systolic surface area-to-volume ratio (SAVR) (1.16 ± 0.26 vs.1.44 ± 0.21 cm2/mL, p < 0.001) and lower systolic circumferential curvature (0.87 ± 0.27 vs. 1.07 ± 0.30 cm- 1, p = 0.007) but similar longitudinal curvature. In the PVR cohort, higher systolic SAVR was associated with higher RVEF both pre- and post-PVR (p < 0.001). Among PVR patients, 15 had optimal and 19 had suboptimal remodeling post-PVR. Multivariable modeling showed that among the geometric parameters, higher systolic SAVR (OR 1.68 per 0.1 cm2/mL increase; p = 0.049) and shorter systolic RV long-axis length (OR 0.92 per 0.1 cm increase; p = 0.035) were independently associated with optimal remodeling. Compared with controls, PVR patients have lower SAVR and lower circumferential but not longitudinal curvature. Higher pre-PVR systolic SAVR is associated with optimal remodeling post-PVR.

Improved Outcomes After Pulmonary Valve Replacement in Repaired Tetralogy of Fallot.

BACKGROUND: The impact of pulmonary valve replacement (PVR) on major adverse clinical outcomes in patients with repaired tetralogy of Fallot (rTOF) is unknown. OBJECTIVES: The purpose of this study was to determine whether PVR is associated with improved survival and freedom from sustained ventricular tachycardia (VT) in rTOF. METHODS: A PVR propensity score was created to adjust for baseline differences between PVR and non-PVR patients enrolled in INDICATOR (International Multicenter TOF Registry). The primary outcome was time to the earliest occurrence of death or sustained VT. PVR and non-PVR patients were matched 1:1 on PVR propensity score (matched cohort) and in the full cohort, modeling was performed with propensity score as a covariate adjustment. RESULTS: Among 1,143 patients with rTOF (age 27 ± 14 years, 47% PVR, follow-up 8.3 ± 5.2 years), the primary outcome occurred in 82. The adjusted HR for the primary outcome for PVR vs no-PVR (matched cohort n = 524) was 0.41 (95% CI: 0.21-0.81; multivariable model P = 0.010). Full cohort analysis revealed similar results. Subgroup analysis suggested beneficial effects in patients with advanced right ventricular (RV) dilatation (interaction P = 0.046; full cohort). In patients with RV end-systolic volume index >80 mL/m2, PVR was associated with a lower primary outcome risk (HR: 0.32; 95% CI: 0.16-0.62; P < 0.001). There was no association between PVR and the primary outcome in patients with RV end-systolic volume index ≤80 mL/m2 (HR: 0.86; 95% CI: 0.38-1.92; P = 0.70). CONCLUSIONS: Compared with rTOF patients who did not receive PVR, propensity score-matched individuals receiving PVR had lower risk of a composite endpoint of death or sustained VT.

A comparison between the apical and subcostal view for three-dimensional echocardiographic assessment of right ventricular volumes in pediatric patients.

Background: Accurate measurement of ventricular volumes is an important clinical imaging goal. Three-dimensional echocardiography (3DEcho) is used increasingly as it is more available and less costly than cardiac magnetic resonance (CMR). For the right ventricle (RV), the current practice is to acquire 3DEcho volumes from the apical view. However, in some patients the RV may be better seen from the subcostal view. Therefore, this study compared RV volume measurements from the apical vs. the subcostal view, using CMR as a reference standard. Methods: Patients <18 years old undergoing a clinical CMR examination were prospectively enrolled. 3DEcho was performed on the day of the CMR. 3DEcho images were acquired with Philips Epic 7 ultrasound system from apical and subcostal views. Offline analysis was performed with TomTec 4DRV Function for 3DEcho images and cvi42 for CMR ones. RV end-diastolic volume and end-systolic volume were collected. Agreement between 3DEcho and CMR was assessed with Bland-Altman analysis and the intraclass correlation coefficient (ICC). Percentage (%) error was calculated using CMR as the reference standard. Results: Forty-seven patients were included in the analysis (age range 10 months to 16 years). The ICC was moderate to excellent for all volume comparisons to CMR (subcostal vs. CMR: end-diastolic volume 0.93, end-systolic volume 0.81; apical vs. CMR: end-diastolic volume 0.94, end-systolic volume 0.74).The 3DEcho mean % error vs. CMR for end-systolic volume was 25% for subcostal and 31% for apical; for end-diastolic volume it was 15% for subcostal and 16% for apical. The % error was not significantly different between apical vs. subcostal views for end-systolic and end-diastolic volume measurements. Conclusions: For apical and subcostal views, 3DEcho-derived ventricular volumes agree well with CMR. Neither echo view has a consistently smaller error when compared to CMR volumes. Accordingly, the subcostal view can be used as an alternative to the apical view when acquiring 3DEcho volumes in pediatric patients, particularly when the image quality from this window is superior.

Exercise in patients with repaired tetralogy of Fallot: a systematic review and meta-analysis.

OBJECTIVE: Children and adults with repaired tetralogy of Fallot (rTOF) have an impaired exercise capacity, a less active lifestyle and an increased long-term risk of adverse outcomes compared with healthy peers. This study aimed to summarise the current evidence for the effectiveness and safety of exercise training interventions in patients with rTOF. METHODS: PubMed/MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Scopus and reference lists of relevant articles were searched for prospective studies published by November 2021. Random-effects meta-analysis and descriptive synthesis were performed to assess the effectiveness and safety of exercise training in patients with rTOF. RESULTS: Of the 9677 citations identified, 12 articles were included that reported on 10 unique studies and covered 208 patients with rTOF (range of mean/median age: 7.4-43.3 years). All studies implemented 2 to 7 aerobic or respiratory training sessions per week with durations ranging from 6 to 26 weeks. Meta-analysis of the included randomised controlled trials showed that exercise training was associated with a significant improvement in peak VO2 (pooled mean difference: +3.1 mL/min/kg; 95% CI: 0.76 to 5.36 mL/min/kg, p=0.019). Cardiac imaging studies revealed no subclinical adverse remodelling after the exercise interventions. No serious adverse events including arrhythmias were reported in these studies. CONCLUSION: Current evidence suggests that exercise training can improve exercise capacity in patients with rTOF with a low risk for adverse events. Exercise prescription may be a safe and effective tool to help improving outcomes in patients with rTOF. PROSPERO REGISTRATION NUMBER: CRD42021292809.

Preterm Birth Is Associated With Adverse Cardiac Remodeling and Worse Outcomes in Patients With a Functional Single Right Ventricle.

OBJECTIVE: To assess the effects of preterm birth on cardiac structure and function and transplant-free survival in patients with hypoplastic left heart syndrome and associated anomalies throughout the staged palliation process. STUDY DESIGN: Data from the Single Ventricle Reconstruction trial were used to assess the impact of prematurity on echocardiographic measures at birth, Norwood, Stage II, and 14 months in 549 patients with a single functional right ventricle. Medical history was recorded once a year using medical records or telephone interviews. Cox regression models were applied to analyze transplant-free survival to age 6 years. Causal mediation analysis was performed to estimate the mediating effect of birth weight within this relationship. RESULTS: Of the 549 participants, 64 (11.7%) were born preterm. Preterm-born participants had lower indexed right ventricle end-diastolic volumes at birth but higher volumes than term-born participants by age 14 months. Preterm-born participants had an increased risk of death or heart transplantation from birth to age 6 years, with an almost linear increase in the observed risk as gestational age decreased below 37 weeks. Of the total effect of preterm birth on transplant-free survival, 27.3% (95% CI 2.5-59.0%) was mediated through birth weight. CONCLUSIONS: Preterm birth is associated with adverse right ventricle remodeling and worse transplant-free survival throughout the palliation process, in part independently of low birth weight. Further investigation into this vulnerable group may allow development of strategies that mitigate the impact of prematurity on outcomes in patients with hypoplastic left heart syndrome.

Ventricular arrhythmias after fibroma resection: Are patients still at risk?

BACKGROUND: Ventricular fibromas frequently present with life-threatening ventricular tachycardia (VT) or ventricular fibrillation (VF) in children. The long-term risk of sustained ventricular arrhythmias after surgical resection is unknown. OBJECTIVES: The aims of this study were to quantify the VT/VF risk after surgical resection and to examine the results of early (during index surgical hospitalization) and late (≥3 months after surgery) postoperative ventricular stimulation (V-stim) studies. METHODS: We performed a retrospective cohort study of all patients with ventricular fibromas who underwent surgical resection at our institution (2000-2020). The primary outcome was defined as recurrent VT/VF ≥3 months after index surgical resection. RESULTS: Forty-six patients with a median age at surgery of 2 years (range 0.3-18.9 years) formed our study cohort. Indications for surgery included cardiac arrest in 11 (24%), sustained VT in 16 (35%), premature ventricular contractions/nonsustained VT in 10 (22%), and hemodynamic abnormalities in 9 (20%). Of the 11 patients who presented with cardiac arrest, 4 underwent pre-resection implantable cardioverter-defibrillator (ICD) implantation, all of which were explanted at the time of surgery. An early postoperative V-stim study was performed in 26 (57%) patients, and all were negative for inducible VT/VF. Of the 13 late postoperative V-stim studies, 3 were positive: 2 underwent ICD implantation and 1 was initiated on amiodarone and underwent loop recorder implantation. At the time of last follow-up (median 1.5 years; range 0.3-16.5 years), 45 (98%) were free of clinical VT/VF and no patient with an ICD has received an appropriate shock. CONCLUSION: Surgical resection of ventricular fibromas significantly reduces the risk of life-threatening arrhythmias in children; however, a small number of patients remain vulnerable.

Managing uncertainty in decision-making of common congenital cardiac defects.

Decision-making in congenital cardiac care, although sometimes appearing simple, may prove challenging due to lack of data, uncertainty about outcomes, underlying heuristics, and potential biases in how we reach decisions. We report on the decision-making complexities and uncertainty in management of five commonly encountered congenital cardiac problems: indications for and timing of treatment of subaortic stenosis, closure or observation of small ventricular septal defects, management of new-onset aortic regurgitation in ventricular septal defect, management of anomalous aortic origin of a coronary artery in an asymptomatic patient, and indications for operating on a single anomalously draining pulmonary vein. The strategy underpinning each lesion and the indications for and against intervention are outlined. Areas of uncertainty are clearly delineated. Even in the presence of "simple" congenital cardiac lesions, uncertainty exists in decision-making. Awareness and acceptance of uncertainty is first required to facilitate efforts at mitigation. Strategies to circumvent uncertainty in these scenarios include greater availability of evidence-based medicine, larger datasets, standardised clinical assessment and management protocols, and potentially the incorporation of artificial intelligence into the decision-making process.

Outcomes of Repair of Congenital Aortic Valve Lesions Using Autologous Pericardium vs Porcine Intestinal Submucosa.

BACKGROUND: Outcomes following congenital aortic valve (AoV) repair are plagued by progressive dysfunction of currently available leaflet substitute materials. OBJECTIVES: We compared the long-term outcomes of congenital AoV repair using porcine intestinal submucosa vs autologous pericardium (AP). METHODS: This was a single-center retrospective review of all patients who underwent congenital AoV repair with either porcine intestinal submucosa or AP from October 2009 to March 2013. The primary outcome was postdischarge (late) unplanned AoV reintervention. Secondary outcomes included number of late AoV reinterventions and a composite of at least moderate aortic regurgitation or stenosis at latest follow-up or before the first reintervention. Associations between leaflet repair material and outcomes were assessed using multivariable regression models, adjusting for prespecified patient-related and operative variables. RESULTS: Of 26 porcine intestinal submucosa and 49 AP patients who met entry criteria, the median age was 11.0 years (IQR: 4.7-16.6 years). At a median follow-up of 8.5 years (IQR: 4.4-9.6 years), 17 (65.4%) porcine intestinal submucosa and 22 (44.9%) AP patients underwent at least 1 AoV reintervention. On multivariable analysis, porcine intestinal submucosa use was significantly associated with unplanned AoV reintervention (HR: 4.6; 95% CI: 2.2-9.8; P < 0.001), number of postdischarge AoV reinterventions (incidence rate ratio: 1.7; 95% CI: 1.0-2.9; P = 0.037), and at least moderate aortic regurgitation or stenosis at latest follow-up or before the first reintervention (OR: 5.0; 95% CI: 1.2-21.0; P = 0.027). CONCLUSIONS: Aortic valvuloplasty with porcine intestinal submucosa is associated with earlier time to reintervention compared with autologous pericardium. The search for the ideal AoV leaflet repair material continues.

SCMR expert consensus statement for cardiovascular magnetic resonance of acquired and non-structural pediatric heart disease.

Cardiovascular magnetic resonance (CMR) is widely used for diagnostic imaging in the pediatric population. In addition to structural congenital heart disease (CHD), for which published guidelines are available, CMR is also performed for non-structural pediatric heart disease, for which guidelines are not available. This article provides guidelines for the performance and reporting of CMR in the pediatric population for non-structural ("non-congenital") heart disease, including cardiomyopathies, myocarditis, Kawasaki disease and systemic vasculitides, cardiac tumors, pericardial disease, pulmonary hypertension, heart transplant, and aortopathies. Given important differences in disease pathophysiology and clinical manifestations as well as unique technical challenges related to body size, heart rate, and sedation needs, these guidelines focus on optimization of the CMR examination in infants and children compared to adults. Disease states are discussed, including the goals of CMR examination, disease-specific protocols, and limitations and pitfalls, as well as newer techniques that remain under development.

Learned iterative segmentation of highly variable anatomy from limited data: Applications to whole heart segmentation for congenital heart disease.

Training deep learning models that segment an image in one step typically requires a large collection of manually annotated images that captures the anatomical variability in a cohort. This poses challenges when anatomical variability is extreme but training data is limited, as when segmenting cardiac structures in patients with congenital heart disease (CHD). In this paper, we propose an iterative segmentation model and show that it can be accurately learned from a small dataset. Implemented as a recurrent neural network, the model evolves a segmentation over multiple steps, from a single user click until reaching an automatically determined stopping point. We develop a novel loss function that evaluates the entire sequence of output segmentations, and use it to learn model parameters. Segmentations evolve predictably according to growth dynamics encapsulated by training data, which consists of images, partially completed segmentations, and the recommended next step. The user can easily refine the final segmentation by examining those that are earlier or later in the output sequence. Using a dataset of 3D cardiac MR scans from patients with a wide range of CHD types, we show that our iterative model offers better generalization to patients with the most severe heart malformations.

Atrial septal defect in adulthood: a new paradigm for congenital heart disease.

Atrial septal defects (ASDs) represent the most common congenital heart defect diagnosed in adulthood. Although considered a simple defect, challenges in optimal diagnostic and treatment options still exist due to great heterogeneity in terms of anatomy and time-related complications primarily arrhythmias, thromboembolism, right heart failure and, in a subset of patients, pulmonary arterial hypertension (PAH). Atrial septal defects call for tertiary expertise where all options may be considered, namely catheter vs. surgical closure, consideration of pre-closure ablation for patients with atrial tachycardia and suitability for closure or/and targeted therapy for patients with PAH. This review serves to update the clinician on the latest evidence, the nuances of optimal diagnostics, treatment options, and long-term follow-up care for patients with an ASD.