Aortic valve function and aortic dimensions in obese and overweight patients with bicuspid aortic valve.

INTRODUCTION: Bicuspid aortic valve is the most common CHD and commonly associated with activity restrictions that may lead to a sedentary lifestyle known to increase obesity risk. It is unknown whether obesity is associated with changes in aortic dimensions or aortic valve function in young people with bicuspid aortic valve. This study investigates whether overweight and obese children with bicuspid aortic valve have worse aortic valve function or increased aortic dimensions compared to healthy weight children with bicuspid aortic valve. METHODS: This was a single centre retrospective cohort study comprised of patients 5 to 25 years old with a diagnosis of bicuspid aortic valve between 1 January, 2019 and 31 December, 2020. Patients were classified as healthy weight or overweight/obese. Values for aortic dimensions as well as peak and mean aortic valve gradients were obtained from echocardiogram reports. RESULTS: About 251 patients were analysed. Demographics were similar between groups. When indexed to height, the aortic valve annulus (1.28 ± 0.14 vs. 1.34 ± 0.15, p = 0.001) and sinotubular junctions (1.44 ± 0.21 vs. 1.49 ± 0.24, p = 0.038) were larger in the overweight/obese group, with no differences in aortic root or ascending aorta sizes. The obese/overweight group had a higher peak aortic valve gradient (23.03 ± 1.64 mmHg vs. 16.17 ± 1.55 mmHg, p = 0.003) compared to the healthy weight group. CONCLUSION: Healthy weight patients did not have larger aortic dimensions compared to the overweight/obese patients. There was evidence of worsening aortic valve stenosis in overweight/obese patients compared to those at a healthy weight.

Fontan-associated liver disease after heart transplant.

BACKGROUND: Fontan associated liver disease (FALD) potentially impacts Fontan patients undergoing heart transplant. This multi-center study sought to identify pre-transplant risk factors and characterize any post-transplant liver recovery in those patients undergoing heart-alone transplant. METHODS: Review of Fontan patients at 12 pediatric institutions who underwent heart transplant between 2001-2019. Radiologists reviewed pre and post-transplant liver imaging for fibrosis. Laboratory, pathology and endoscopy studies were reviewed. RESULTS: 156 patients underwent transplant due to decreased ventricular function (49%), protein losing enteropathy (31%) or plastic bronchitis (10%); median age at transplant was 13.6 years (interquartile range IQR 7.8, 17.2) with a median of 9.3 years (IQR 3.2, 13.4) between the Fontan operation and transplant. Few patients had pre-transplant endoscopy (18%), and liver biopsy (19%). There were 31 deaths (20%). The median time from transplant to death was 0.5 years (95% Confidence Interval CI 0.0, 3.6). The five-year survival was 73% (95% CI 64%, 83%). Deaths were related to cardiac causes in 68% (21/31) and infection in 6 (19%). A pre-transplant elevation in bilirubin was a predictor of death. Higher platelet levels were protective. Immediate post-transplant elevations in creatinine, AST, ALT, and INR were predictive of death. Advanced liver fibrosis identified on ultrasound, computed tomography, or magnetic resonance imaging was not predictive of death. Liver imaging suggested some improvement in liver congestion post-transplant. CONCLUSIONS: Elevated bilirubin, but not fibrosis on liver imaging, was associated with post-heart transplant mortality in Fontan patients in this multicenter retrospective study. Additionally, heart transplant may alter the progression of FALD.

Standard volume infusion unmasked diastolic dysfunction in pediatric heart transplant recipients during surveillance cardiac catheterization, but without echocardiographic correlates.

BACKGROUND: Adult experience evaluating left ventricular diastolic function (LVDFx) includes volume administration during catheterization while obtaining pulmonary capillary wedge pressures (PCWP) or left ventricular end diastolic pressures (LVEDP). Catheterization is inherently challenging in pediatric patients, making echocardiographic assessment ideal. Pediatric echocardiographic studies predicting LVDFx have variable hemodynamic and hydration conditions and have produced inconsistent results. We evaluated the association between simultaneous echocardiographic and catheterization assessment of LVDFx, using a fluid bolus for optimal loading conditions. METHODS: Prospective cohort study of pediatric heart transplant recipients receiving echocardiogram simultaneous with routine cardiac catheterization. Mitral valve inflow velocities, septal and lateral wall tissue Doppler indices, and PCWP and/or LVEDP were obtained and repeated following a 10 ml/kg bolus. Echocardiographic parameters were evaluated for an association with changes in PCWP or LVEDP following the bolus. Abnormal LVDFx was defined as PCWP or LVEDP ≥12 mm Hg. RESULTS: Twenty-nine patients underwent catheterization. Median pre-bolus PCWP and LVEDP were 11.0 mm Hg and 10.0 mm Hg, respectively. After bolus, median PCWP and LVEDP increased to 14.0 mm Hg (p < .001) and 13 mm Hg (p < .001), respectively. Of 21 patients with normal pre-bolus catheterization hemodynamics, 14 (66.7%) increased to abnormal following fluid bolus. Using area under an ROC, no echocardiographic parameter of LVDFx, or their ratios, were associated with predetermined abnormal LVEDP and/or PCWP. CONCLUSION: After bolus, our cohort demonstrated significant increases in LVEDP and/or PCWP, unmasking diastolic dysfunction. Fluid challenges should be considered in pediatric patients undergoing cardiac catheterization with suspected diastolic dysfunction. Echocardiographic measurements were unable to discriminate between normal and abnormal LVEDP and/or PCWP.

Emergency department care of patients with Duchenne muscular dystrophy.

Patients with Duchenne muscular dystrophy are living longer and are increasingly seen in Emergency Departments. Though the most common cause of death remains progressive respiratory failure, increased life expectancies have unmasked the significance of progressive myocardial dysfunction, now associated with nearly 40% of mortalities in the DMD population. Cardiac complications such as arrhythmias and cardiomyopathy are becoming ever more widely recognized. Emergency physicians may encounter DMD patients with untreated, undiagnosed or worsening of known heart disease. This review will initially familiarize the emergency physician with the pathophysiology and lifetime trajectory of care for these patients before describing specific emergency department evaluation and treatment.

Diversity of Dystrophin Gene Mutations and Disease Progression in a Contemporary Cohort of Duchenne Muscular Dystrophy.

Abnormal dystrophin production due to mutations in the dystrophin gene causes Duchenne Muscular Dystrophy (DMD). Cases demonstrate considerable genetic and disease progression variability. It is unclear if specific gene mutations are prognostic of outcomes in this population. We conducted a retrospective cohort study of DMD patients followed at 17 centers across the USA and Canada from 2005 to 2015 with goal of understanding the genetic variability of DMD and its impact on clinical outcomes. Cumulative incidence of clinically relevant outcomes was stratified by genetic mutation type, exon mutation location, and extent of exon deletion. Of 436 males with DMD, 324 (74.3%) underwent genetic testing. Deletions were the most common mutation type (256, 79%), followed by point mutations (45, 13.9%) and duplications (23, 7.1%). There were 131 combinations of mutations with most mutations located along exons 45 to 52. The number of exons deleted varied between 1 and 52 with a median of 3 exons deleted (IQR 1-6). Subjects with mutations starting at exon positions 40-54 had a later onset of arrhythmias occurring at median age 25 years (95% CI 18-∞), p = 0.01. Loss of ambulation occurred later at median age of 13 years (95% CI 12-15) in subjects with mutations that started between exons 55-79, p = 0.01. There was no association between mutation type or location and onset of cardiac dysfunction. We report the genetic variability in DMD and its association with timing of clinical outcomes. Genetic modifiers may explain some phenotypic variability.

Effects of donor cause of death, ischemia time, inotrope exposure, troponin values, cardiopulmonary resuscitation, electrocardiographic and echocardiographic data on recipient outcomes: A review of the literature.

BACKGROUND: Heart transplantation has become standard of care for pediatric patients with either end-stage heart failure or inoperable congenital heart defects. Despite increasing surgical complexity and overall volume, however, annual transplant rates remain largely unchanged. Data demonstrating pediatric donor heart refusal rates of 50% suggest optimizing donor utilization is critical. This review evaluated the impact of donor characteristics surrounding the time of death on pediatric heart transplant recipient outcomes. METHODS: An extensive literature review was performed to identify articles focused on donor characteristics surrounding the time of death and their impact on pediatric heart transplant recipient outcomes. RESULTS: Potential pediatric heart transplant recipient institutions commonly receive data from seven different donor death-related categories with which to determine organ acceptance: cause of death, need for CPR, serum troponin, inotrope exposure, projected donor ischemia time, electrocardiographic, and echocardiographic results. Although DITs up to 8 hours have been reported with comparable recipient outcomes, most data support minimizing this period to <4 hours. CVA as a cause of death may be associated with decreased recipient survival but is rare in the pediatric population. Otherwise, however, in the setting of an acceptable donor heart with a normal echocardiogram, none of the other data categories surrounding donor death negatively impact pediatric heart transplant recipient survival. CONCLUSIONS: Echocardiographic evaluation is the most important donor clinical information following declaration of brain death provided to potential recipient institutions. Considering its relative importance, every effort should be made to allow direct image visualization.

Implantable Cardioverter Defibrillator Use in Males with Duchenne Muscular Dystrophy and Severe Left Ventricular Dysfunction.

Duchenne muscular dystrophy (DMD) is characterized by myocardial fibrosis and left ventricular (LV) dysfunction. Implantable cardioverter defibrillator (ICD) use has not been characterized in this population but is considered for symptomatic patients with severe LV dysfunction (SLVD) receiving guideline-directed medical therapy (GDMT). We evaluated ICD utilization and efficacy in patients with DMD. Retrospective cohort study of DMD patients from 17 centers across North America between January 2, 2005 and December 31, 2015. ICD use and its effect on survival were evaluated in patients with SLVD defined as ejection fraction (EF) < 35% and/ or shortening fraction (SF) < 16% on final echocardiogram. SLVD was present in 57/436 (13.1%) patients, of which 12 (21.1%) died during the study period. Of these 12, (mean EF 20.9 ± 6.2% and SF 13.7 ± 7.2%), 8 received GDMT, 5 received steroids, and none received an ICD. ICDs were placed in 9/57 (15.8%) patients with SLVD (mean EF 31.2 ± 8.5% and SF 10.3 ± 4.9%) at a mean age of 20.4 ± 6.3 years; 8/9 received GDMT, 7 received steroids, and all were alive at study end; mean ICD duration was 36.1 ± 26.2 months. Nine ICDs were implanted at six different institutions, associated with two appropriate shocks for ventricular tachycardia in two patients, no inappropriate shocks, and one lead fracture. ICD use may be associated with improved survival and minimal complications in DMD cardiomyopathy with SLVD. However, inconsistent GDMT utilization may be a significant confounder. Future studies should define optimal indications for ICD implantation in patients with DMD cardiomyopathy.

Risk Factors for Cardiac and Non-cardiac Causes of Death in Males with Duchenne Muscular Dystrophy.

As survival and neuromuscular function in Duchenne muscular dystrophy (DMD) have improved with glucocorticoid (GC) therapy and ventilatory support, cardiac deaths are increasing. Little is known about risk factors for cardiac and non-cardiac causes of death in DMD. A multi-center retrospective cohort study of 408 males with DMD, followed from January 1, 2005 to December 31, 2015, was conducted to identify risk factors for death. Those dying of cardiac causes were compared to those dying of non-cardiac causes and to those alive at study end. There were 29 (7.1%) deaths at a median age of 19.5 (IQR: 16.9-24.6) years; 8 (27.6%) cardiac, and 21 non-cardiac. Those living were younger [14.9 (IQR: 11.0-19.1) years] than those dying of cardiac [18 (IQR 15.5-24) years, p = 0.03] and non-cardiac [19 (IQR: 16.5-23) years, p = 0.002] causes. GC use was lower for those dying of cardiac causes compared to those living [2/8 (25%) vs. 304/378 (80.4%), p = 0.001]. Last ejection fraction prior to death/study end was lower for those dying of cardiac causes compared to those living (37.5% ± 12.8 vs. 54.5% ± 10.8, p = 0.01) but not compared to those dying of non-cardiac causes (37.5% ± 12.8 vs. 41.2% ± 19.3, p = 0.58). In a large DMD cohort, approximately 30% of deaths were cardiac. Lack of GC use was associated with cardiac causes of death, while systolic dysfunction was associated with death from any cause. Further work is needed to ensure guideline adherence and to define optimal management of systolic dysfunction in males with DMD with hopes of extending survival.

Pediatric heart transplantation from an influenza B-positive donor.

As heart transplantation demand is increasing without subsequent growth of the donor pool, need for expansion of acceptance criteria is paramount, particularly when considering critically ill, highly sensitized patients. We present a case report of a pediatric heart transplant recipient of an organ refused by 197 prior potential recipients due to the donor being infected with influenza virus. We perform a literature review of recent solid organ transplant cases from influenza-positive donors and conclude that the donor pool may be expandable by allowing donors with treatable infections to be included.

Screening Echocardiography and Brain Natriuretic Peptide Levels Predict Late Pulmonary Hypertension in Infants with Bronchopulmonary Dysplasia.

Through this study, we aimed to assess the ability of routine neonatal screening at time of bronchopulmonary dysplasia (BPD) diagnosis to predict the development of late pulmonary hypertension (PHTN). This is a retrospective longitudinal cohort study of 37 premature infants with BPD assessing the utility of screening serum brain natriuretic peptide (BNP) and echocardiograms performed at the time of BPD diagnosis ('early PHTN') to predict 'late PHTN' at the last follow-up. Screening evaluation demonstrated early PHTN in 9/37 patients. At an average follow-up interval of 52.7 ± 38.7 weeks, 4/9 had late PHTN; one patient without early PHT had late PHT. At initial screening, infants with late PHTN were significantly more likely to have demonstrated elevated BNP values (p = 0.003), and echocardiographic evidence of right atrial dilatation (p = 0.01), right ventricular hypertrophy (p = 0.01), lower right ventricular area change percentage (p = 0.03), and larger main pulmonary artery Z-scores (p = 0.02). Serum BNP and echocardiographic evaluation performed at the time of BPD diagnosis can detect patients at increased risk of late PHTN. Large, prospective studies are necessary to further address this question.

Use of advanced heart failure therapies in Duchenne muscular dystrophy.

BACKGROUND: As survival and neuromuscular function in Duchenne Muscular Dystrophy (DMD) improve with glucocorticoid therapy and respiratory advances, the proportion of cardiac deaths is increasing. Little is known about the use and outcomes of advanced heart failure (HF) therapies in this population. METHODS: A retrospective cohort study of 436 males with DMD was performed, from January 1, 2005-January 1, 2018, with the primary outcome being use of advanced HF therapies including: implantable cardioverter defibrillator (ICD), left ventricular assist device (LVAD), and heart transplantation (HTX). RESULTS: Nine subjects had an ICD placed, 2 of whom (22.2%) had appropriate shocks for ventricular tachycardia; 1 and 968 days after implant, and all of whom were alive at last follow-up; median 18 (IQR: 12.5-25.5) months from implant. Four subjects had a LVAD implanted with post-LVAD survival of 75% at 1 year; 2 remaining on support and 1 undergoing HTX. One subject was bridged to HTX with ICD and LVAD and was alive at last follow-up, 53 months after HTX. CONCLUSION: Advanced HF therapies may be used effectively in select subjects with DMD. Further studies are needed to better understand risk stratification for ICD use and optimal candidacy for LVAD implantation and HTX, with hopes of improving cardiac outcomes.

Magnetic resonance imaging measures of decreased aortic strain and distensibility are proportionate to insulin resistance in adolescents with type 1 diabetes mellitus.

OBJECTIVES: To determine whether children with type 1 diabetes mellitus (T1DM) have evidence of increased aortic stiffness or early atherosclerosis as measured by magnetic resonance imaging (MRI). BACKGROUND: T1DM increases risk for cardiovascular disease in adults but whether this process starts in childhood is unknown. SUBJECTS: A total of 54 T1DM patients (15.4 ± 2.6 yr) and 30 age-matched controls (14.8 ± 2.7 yr) participated. METHODS: MRI was performed to assess aortic arch pulse wave velocity (PWV), strain, and distensibility of the ascending and descending thoracic aorta and measures of atherosclerosis. RESULTS: Groups were well-matched for age, pulse pressure, and gender. Low-density lipoprotein-cholesterol (LDL-C) was higher in T1DM (119.3 ± 50 vs. 76.1 ± 13.5 mg/dL, p < 0.0001). There was a trend toward decreased strain and distensibility in T1DM vs. controls in the ascending (distensibility: T1DM 62.2 ± 19.9 kPa⁻¹ × 10⁻³, control 71.6 ± 26.4 kPa⁻¹ × 10⁻³, p = 0.08) and descending aorta (strain: T1DM 25.8 ± 6.2% vs. control 28.3 ± 6.8%, p = 0.09). There was no difference in arch PWV. Advancing age and male gender was negatively associated with aortic stiffness. Hemoglobin A1c (HbA1c) was inversely related to descending aorta strain and distensibility (p < 0.05). Children with diabetes in the lowest two tertiles of insulin sensitivity demonstrated thoracic descending aortas with significantly lower strain (p = 0.027) and distensibility (p = 0.039) and increased measures of wall irregularity (p = 0.005). There were no differences in measurements of atherosclerosis between the two groups. CONCLUSIONS: Adolescents with T1DM, especially those with lower insulin sensitivity, demonstrated a trend toward stiffer, less compliant thoracic aortas, which was inversely associated with diabetes control. These data suggest large vessel aortopathy starts early in T1DM.

Patients with single ventricle anatomy may respond better to octreotide therapy for chylothorax after congenital heart surgery.

BACKGROUND AND AIMS: Chylothorax (CTX) occurs in 3% to 6% of children after surgery for congenital heart disease with significant morbidity and mortality. Octreotide has been proposed as therapy, but there are no predictors of response. The objective of this study was to identify possible predictors of response to octreotide. METHODS: Single-center retrospective review of patients who developed CTX after cardiac surgery. Data collected included demographics, cardiac lesion, surgical data, hospital course, CTX volume and duration, and interventions for CTX. Patients who received octreotide as part of their therapy were compared to those who did not. RESULTS: A total of 1150 patients underwent 1455 cardiac surgeries with 67 (4.6%) episodes of CTX. Patients with CTX were younger, lower weight, more likely to undergo cardiopulmonary bypass, and had higher RACHS-1 scores and mortality. Nineteen patients with CTX received octreotide as part of their treatment and six (32%) had at least 50% reduction in CTX volume. Patients who responded to octreotide had lower CTX volume (18 mL/kg/day vs. 55 mL/kg/day, p=0.023) and a higher proportion of patients with single ventricle anatomy (67% vs. 18%, p=0.046). CONCLUSIONS: There is a subset of patients who seem to respond to octreotide, but they have lower CTX volume and may have already been improving before octreotide therapy. Patients with single ventricle anatomy seemed to respond to octreotide and may benefit from its use.

Hypoxemia in infants with trisomy 21 in the neonatal intensive care unit.

OBJECTIVE: Newborns with trisomy 21 (T21) often require NICU hospitalization. Oxygen desaturations are frequently observed in these infants, even in the absence of congenital heart defects (CHD). We hypothesized that NICU patients with T21 have more hypoxemia than those without T21. DESIGN: All infants with T21 without significant CHD discharged home from the NICU between 2009 and 2018 were included (n = 23). Controls were matched 20:1 for gestational age and length of stay. We compared daily severe hypoxemia events (SpO2 < 80% for ≥10 s) for the whole NICU stay and the pre-discharge week. RESULTS: Infants with T21 showed significantly more daily hypoxemia events during their entire NICU stay (median 10 versus 7, p = 0.0064), and more so in their final week (13 versus 7, p = 0.0008). CONCLUSION: NICU patients with T21 without CHD experience more severe hypoxemia events than controls, particularly in the week before discharge. Whether this hypoxemia predicts or contributes to adverse outcomes is unknown.

Respiratory failure secondary to congenital pulmonary arterial thrombus with lung dysplasia.

Respiratory failure requiring extracorporeal membranous oxygenation in the newborn is commonly seen secondary to severe pathology such as congenital diaphragmatic hernia, meconium aspiration syndrome, pulmonary hypertension and pulmonary hypoplasia. However, atypical causes of respiratory failure, such as pulmonary arterial thrombi, are often refractory to traditional management and require careful multidisciplinary evaluation. We report a case of respiratory failure secondary to congenital pulmonary arterial thrombosis of unknown aetiology in an otherwise healthy neonate. We discuss the abnormal anatomy and pathophysiology that presented in our patient secondary to this condition and discuss our diagnostic process, management and outcomes. Additionally, we review the literature for reported cases and discuss current hypotheses on the development of congenital pulmonary arterial thrombi. Given the rare occurrence of this event, we hope to contribute to the understanding of future similar cases and emphasise the importance of keeping pulmonary arterial thrombi in the clinical differential.

Care of the acutely ill pediatric heart transplant recipient.

Young children may present to the emergency department after undergoing orthotopic heart transplantation. Emergency department care of pediatric heart transplant recipients with an acute illness is not clearly defined. To assist the emergency physician with treating these children, 2 cases are detailed to demonstrate the variation in outcome of young children presenting to the emergency department with acute illness months after their transplant. The cases typify the varied outcomes possible after emergency department presentation. After the cases, a review of the medical conditions common in transplant recipients precedes a description of management suggestions.

Urgent listing exceptions and outcomes in pediatric heart transplantation: Comparison to standard criteria patients.

BACKGROUND: United Network for Organ Sharing (UNOS) policy enables listing exceptions to avoid penalizing patients with waitlist mortality not captured by standard criteria. Outcomes among patients listed by exception have not been analyzed. METHODS: We performed a retrospective analysis of pediatric (≤17 years of age, n = 4,706) listings (2006 to 2015) for primary, isolated heart transplantation within the UNOS data set, assessing Status 1A exception (n = 211, 4.5%) use across regions and patient characteristics and evaluating waitlist outcomes compared with candidates listed using standard criteria. RESULTS: Death or removal for reason other than transplant did not differ between exception and standard criteria patients at 1 month (11.7% vs 16.2%, p = not statistically significant [NS]), 2 months (18.2% vs 29.0%, p = 0.11) or overall (16.1% vs 22.0%, p = NS) on the waitlist. Rates were higher than among Status 1B patients (1 month: 2.8%; 2 months: 5.6%; overall: 14.9%; p < 0.0001). The cumulative incidence of competing risks (transplantation, death/removal for reasons other than transplant and removal) did not differ when comparing Status 1A exception patients with Status 1A standard criteria patients. Use of 1A exceptions varied across UNOS regions (1.9% to 22.3%, p < 0.0001). Risk-adjusted modeling identified patients more (hypertrophic cardiomyopathy: odds ratio [OR] = 2.8, 95% confidence interval [CI] 1.5 to 5.0; restrictive cardiomyopathy: OR = 2.7, 95% CI 1.7 to 4.3) and less (low socioeconomic status: OR = 0.7, 95% CI 0.5 to 1.0) likely to use an exception. Use of exceptions was uncorrelated with regional outcomes. CONCLUSIONS: Waitlist mortality among Status 1A exception patients is similar to that among those listed by standard criteria. However, variation in exception use across geography and demography may contribute to inequities in access to transplantation, particularly for those with low socioeconomic status. Standardization of practices may decrease regional variation and minimize inequities.

Computational design and experimental performance testing of an axial-flow pediatric ventricular assist device.

The Virginia Artificial Heart Institute continues to design and develop an axial-flow pediatric ventricular assist device (PVAD) for infants and children in the United States. Our research team has created a database to track potential PVAD candidates at the University of Virginia Children's Hospital. The findings of this database aided with need assessment and design optimization of the PVAD. A numerical analysis of the optimized PVAD1 design (PVAD2 model) was also completed using computational fluid dynamics (CFD) to predict pressure-flow performance, fluid force estimations, and blood damage levels in the flow domain. Based on the PVAD2 model and after alterations to accommodate manufacturing, a plastic prototype for experimental flow testing was constructed via rapid prototyping techniques or stereolithography. CFD predictions demonstrated a pressure rise range of 36-118 mm Hg and axial fluid forces of 0.8-1.7 N for flows of 0.5-3 l/min over 7000-9000 rpm. Blood damage indices per CFD ranged from 0.24% to 0.35% for 200 massless and inert particles analyzed. Approximately 187 (93.5%) of the particles took less than 0.14 seconds to travel completely through the PVAD. The mean residence time was 0.105 seconds with a maximum time of 0.224 seconds. Additionally, in a water/glycerin blood analog solution, the plastic prototype produced pressure rises of 20-160 mm Hg for rotational speeds of 5960 +/- 18 rpm to 9975 +/- 31 rpm over flows from 0.5 to 4.5 l/min. The numerical results for the PVAD2 and the prototype hydraulic testing indicate an acceptable design for the pump, represent a significant step in the development phase of this device, and encourage manufacturing of a magnetically levitated prototype for animal experiments.

Cardiovascular emergencies in the pediatric patient.

Children who have heart disease may present to the emergency department (ED) in many stages of life with a range of cardiovascular manifestions, from minimally irritating palpitations to the life-threatening derangements of shock or lethal dysrhythmia. They can present with congenital heart disease, after a temporizing procedure has been performed or after their definitive repair. Children can also present with fever, weakness, dyspnea, syncope, or chest pain; alternatively, children may present to the ED with active dysrhythmia, pulmonary edema, or cardiogenic shock . These symptoms and presentations may result from Kawasaki disease,hypertrophic cardiomyopathy, or arrhythmia; therefore, emergency physicians must also be comfortable with the most common types of heart disease associated with these symptoms and presentations. The purpose of this article is to describe the physiology and presentation of undiagnosed congenital heart disease, to describe the complications that can occur after a staged or definitive repair,and to discuss acquired heart disease in children.

Low body mass index is associated with increased waitlist mortality among children listed for heart transplant.

BACKGROUND: In adults, low body mass index (BMI) and high BMI have been associated with increased mortality after heart transplantation. Studies of BMI in children with heart failure have had inconsistent results. METHODS: The United Network for Organ Sharing database has 4,035 listings for primary, isolated heart transplant in patients 3 to 18 years old (1995-2012). BMI percentile-for-age (BMI%) was calculated, and patients were stratified based on BMI% into 4 groups: underweight (BMI% <5, n = 701 [17.4%]), normal weight (BMI% 5-84, n = 2,321 [57.5%]), overweight (BMI% 85-94, n = 440 [10.9%]), or obese (BMI% ≥95, n = 573 [14.2%]). Outcomes of patients on the waitlist and after transplantation were assessed. RESULTS: Unadjusted early waitlist mortality was highest in underweight patients (16.7%) compared with normal-weight (11.4%), overweight (10.9%), and obese (12.9%) patients (p = 0.04). In multivariable analysis, underweight patients had elevated risk-adjusted waitlist mortality (odds ratio = 1.4, 95% confidence interval = 1.0-2.2). Unadjusted post-transplant mortality did not differ across BMI% groups (underweight, 5.7%; normal weight, 5.4%; overweight, 5.5%; obese, 5.8%), but obese patients had borderline higher risk-adjusted post-transplant mortality (odds ratio = 1.7, 95% confidence interval = 1.0-3.0). Change in BMI% while waiting did not affect post-transplant mortality. CONCLUSIONS: Children listed for heart transplant are commonly either underweight or obese. Underweight patients have high risk-adjusted mortality before transplantation, whereas obese patients have borderline higher adjusted post-transplant mortality.