The evolving approach to paediatric myocarditis: a review of the current literature

Clinical Presentation, Diagnosis, Treatment, and Outcomes of Myocarditis in Children: A Tertiary Care Hospital Experience

Background Clinical presentation, diagnosis, and treatment of myocarditis in children can be highly challenging, and results can vary greatly. Research on the precise processes of myocardial injury, including the effects of viral infections and newly identified variables like COVID-19, is still underway. Though treatment approaches, such as immunosuppressive therapy, are still debatable, diagnostic methods such as cardiac MRI and biomarkers show promise in improving diagnostic accuracy. The purpose of this study is to describe the spectrum of pediatric acute myocarditis, assess existing therapy approaches, and develop regional guidelines based on the experience of a tertiary care institution.  Methods Children diagnosed with acute myocarditis over a six-month period were included in this retrospective and descriptive hospital-based study. Data on demographics, clinical presentations, diagnostic tests, treatments, and results were gathered and examined. Descriptive statistics, non-parametric tests for categorical variables, and Spearman's correlation tests for continuous data were used in the statistical analysis, with a significance level of p < 0.05.  Results Of the 99 patients included, the mean age was 2.37 years, with males making up the majority (n = 54, 54.55%). Clinical symptoms typically included shortness of breath (n = 998, 99.0%), vomiting (n = 63, 63.6%), and chest pain (n = 6, 6.1%). High levels of troponin I (n = 70, 70.7%), cardiomegaly on a chest X-ray (n = 97, 97.0%), and different degrees of ventricular dysfunction were found in the laboratory and in imaging studies. Methylprednisolone (n = 84, 84.8%) and IV immunoglobulin (n = 54, 54.5%) were the most often used treatment modalities, and there were no appreciable differences in the two treatment groups' outcomes. A weak negative association (Spearman's rho = -0.211, p = 0.036) was found in the correlation study between the administration of methylprednisolone and length of stay (LOS), indicating possible benefits in terms of shortening hospital stays.  Conclusion This research offers a significant understanding of the clinical manifestation, treatment, and complications of acute myocarditis in children. Methylprednisolone administration seems to be linked to a shorter length of stay (LOS), despite disagreements over treatment approaches. To confirm these results and provide guidance for evidence-based management guidelines for pediatric myocarditis in our setup, more studies are necessary.

Corticosteroid in anti-inflammatory treatment of pediatric acute myocarditis: a systematic review and meta-analysis

BACKGROUND

To evaluate the efficacy of corticosteroids in anti-inflammatory treatment of pediatric acute myocarditis.

METHODS

We searched PubMed, Embase and Cochrane library and included studies before October 2022 for clinical trials, observational studies and retrospective studies which reported on children with acute myocarditis treated with corticosteroid anti-inflammatory therapy. The quality of the clinical trials was assessed by Jadad score as an exclusion criterion.

RESULTS

This systematic review included 6 studies involving 604 pediatric patients with acute myocarditis. Corticosteroid therapy was not associated with reduced risk of mortality due to acute myocarditis (P = 0.53; RR = 0.87; 95% CI = 0.58 to 1.33) compared to anti-failure treatment. There was a significant improvement in pediatric patients' left ventricular function measured by left ventricular ejection fraction in the group on corticosteroid anti-inflammatory treatment (P = 0.0009; MD = 11.93%; 95% CI = 4.87% to 18.99%). No conclusion can be drawn due to the high heterogeneity in meta-analyses of risk of getting to a clinical endpoint (death or heart transplantation) and changes in left ventricular end-diastolic diameter (LVEDD).

CONCLUSIONS

Corticosteroid anti-inflammatory therapy in pediatric acute myocarditis patients showed no significant improvement in reducing the risk of mortality, but showed significant improvement in LVEF.

Spectrum of Viral Pathogens Identified in Children with Clinical Myocarditis (Pre-Coronavirus Disease-2019, 2000-2018): Etiologic Agent Versus Innocent Bystander

OBJECTIVE

To identify the etiologies of viral myocarditis in children in the pre-coronavirus disease 2019 era.

STUDY DESIGN

This was a retrospective review of all patients (age <18 years) diagnosed with myocarditis and hospitalized at Rady Children's Hospital San Diego between 2000 and 2018.

RESULTS

Twenty-nine patients met inclusion criteria. Of 28 (97%) patients who underwent testing for viruses, polymerase chain reaction was used in 24 of 28 (86% of cases), and 16 of 24 (67%) detected a virus. Pathogens were rhinovirus (6), influenza A/B (4), respiratory syncytial virus (RSV) (3), coronavirus (3), parvovirus B19 (2), adenovirus (2), and coxsackie B5 virus, enterovirus, and parainfluenza virus type 2 in one case each. Six (21%) patients had no pathogen detected but imaging and other laboratory test results were compatible with myocarditis. Age 0-2 years was associated with RSV, influenza A/B, coronavirus, and enteroviruses (P < .001). Twenty-one patients (72%) experienced full clinical recovery. Three patients (10%) required venoarterial extracorporeal membrane oxygenation (VA-ECMO), and all 3 recovered. Three others (10%) required and underwent successful cardiac transplantation without complications. Two patients (7%) died 9-10 days after hospitalization (1 had RSV and 1 had influenza A/B). Two other patients presented with complete atrioventricular block; 1 case (rhinovirus) resolved spontaneously, and 1 (coronavirus) resolved after support with VA-ECMO. Age <2 years, female sex, lower ejection fraction at admission, and greater initial and peak levels of brain natriuretic peptide were significant predictors of critical outcomes (use of VA-ECMO, listing for cardiac transplantation, and death).

CONCLUSIONS

Viral nucleic acid-based testing revealed a wider spectrum of viruses that could be associated with myocarditis in children than previously reported and traditionally anticipated. A predilection of certain pathogens in the very young patients was observed. Whether the observed range of viral agents reflects an undercurrent of change in viral etiology or viral detection methods is unclear, but the wider spectrum of viral pathogens found underscores the usefulness of polymerase chain reaction testing to explore possible viral etiologies of myocarditis in children.

Acute Myocarditis in Children: An Overview of Treatment and Recent Patents

BACKGROUND

Pediatric myocarditis is rare but challenging. This overview summarized the current knowledge and recent patents on childhood myocarditis.

METHODS

Clinical queries and keywords of "myocarditis" and "childhood" were used as search engine.

RESULTS

Viral infections are the most common causes of acute myocarditis. Affected children often have a prodrome of fever, malaise, and myalgia. Clinical manifestations of acute myocarditis in children can be nonspecific. Some children may present with easy fatigability, poor appetite, vomiting, abdominal pain, exercise intolerance, respiratory distress/tachypnea, dyspnea at rest, orthopnea, chronic cough with wheezing, chest pain, unexplained tachycardia, hypotension, syncope, and hepatomegaly. Supraventricular arrhythmias, ventricular arrhythmias, and heart block may be present. A subset of patients have fulminant myocarditis and present with cardiovascular collapse, which may progress to severe cardiogenic shock, and even death. A high index of suspicion is crucial to its diagnosis and timely management. Cardiac magnetic resonance imaging is important in aiding clinical diagnosis while, endomyocardial biopsy remains the gold standard. The treatment consists of supportive therapy, ranging from supplemental oxygen and fluid restriction to mechanical circulatory support. Angiotensinconverting enzyme inhibitors, angio-tensin II receptor blockers, β-blockers, and aldosterone antagonists might be used for the treatment of heart failure while, immunosuppression treatments remain controversial. There are a few recent patents targeting prevention or treatment of viral myocarditis, including an immunogenic composition comprising a PCV-2 antigen, glutathione-S-transferase P1, neuregulins, NF-[kappa] B inhibitor, a pharmaceutical composition which contains 2-amino-2- (2- (4-octyl phenyl) - ethyl) propane 1,3-diol, a composition containing pycnojenol, Chinese herbal concoctions, and a Korean oral rapamycin. Evidence of their efficacy is still lacking.

CONCLUSION

This article reviews the current literature regarding etiology, clinical manifestations, diagnosis, and management of acute myocarditis in children.

Echocardiographic two-dimensional speckle tracking identifies acute regional myocardial edema and sub-acute fibrosis in pediatric focal myocarditis with normal ejection fraction: comparison with cardiac magnetic resonance

The aim here was to describe the role of speckle tracking echocardiography (STE), in identifying impairment in systolic function in children and adolescents with focal myocarditis and without reduction in ejection fraction. We describe data from 33 pediatric patients (age 4–17 years) admitted for focal myocarditis, confirmed by cardiac magnetic resonance (CMR), and without impaired ejection fraction and/or wall motion abnormalities. All children underwent Doppler echocardiography examination with analysis of global (G) and segmental longitudinal strain (LS) and CMR for the quantification of edema and myocardial fibrosis. Reduction in LS was defined according to age-specific partition values. At baseline, impaired GLS was present in 58% of patients (n = 19), albeit normal ejection fraction. LS was also regionally impaired, according to the area of higher edema at CMR (i.e. most impaired at the level of the infero-lateral segments as compared to other segments (p < 0.05). GLS impairment was also moderately correlated with the percentage edema at CMR (r = − 0.712; p = 0.01). At follow-up, GLS improved in all patients (p < 0.001), and normal values were found in 13/19 patients with baseline reduction. Accordingly persistent global and regional impairment was still observed in 6 patients. Patients with persistent LS reduction demonstrated residual focal cardiac fibrosis at follow-up CMR. Both global and regional LS is able to identify abnormalities in systolic longitudinal mechanics in children and adolescents with focal myocarditis and normal ejection fraction. The reduction in LS is consistent with edema amount and localization at CMR. Furthermore, LS identifies regional recovery or persistent cardiac function impairment, possibly related to residual focal fibrosis.

A paediatric influenza update 100 years after the Skyros island Spanish flu outbreak

This year marks the 100th anniversary of the 1918 Spanish flu outbreak on the Greek Aegean Sea island of Skyros, which devastated its population in less than 30 days. According to Constantinos Faltaits's annals published in 1919, the influenza attack on the island of Skyros commenced acutely ‘like a thunderbolt’ on the 27th of October, 1918 and was exceptionally severe and fatal. At that time, the viral cause of the influenza had not been detected, while the total number of victims of the Spanish flu outbreak has been estimated to have surpassed 50 million, worldwide. Almost one century after this Aegean Sea island's tragedy, the ‘4th Workshop on Paediatric Virology’, organised on the 22nd of September, 2018 in Athens, Greece, was dedicated to the 100 years of the ‘Spanish’ flu pandemic. This review article highlights the plenary and key lectures presented at the workshop on the recent advances on the epidemiology, clinical management and prevention of influenza in childhood.

In-hospital and post-discharge outcomes of pediatric acute myocarditis underwent after high-dose steroid or intravenous immunoglobulin therapy

Background

High-dose steroids and intravenous immunoglobulin (IVIG) are controversial treatments for pediatric patients with acute myocarditis. This study aimed to investigate their efficacies in the Taiwanese pediatric population.

Methods

This study evaluated 5563 acute myocarditis patients from the Taiwan’s National Health Insurance Research Database and identified 1542 pediatric patients hospitalized for acute myocarditis between January 1, 2001 and December 31, 2011. The exclusion criteria were age of > 11 years, associated cardiovascular comorbidities, autoimmune disease, malignancy before the index hospitalization, extracorporeal membrane oxygenation, intra-aortic balloon pumping, and dual therapy using IVIG and high-dose steroids.

Results

After 2:1 propensity score matching, we identified 208 subjects without steroid therapy and 104 subjects who received high-dose steroids. The mean age in that cohort was 2.6 ± 2.9 years, and high-dose steroid therapy had no significant effects on major in-hospital complications and post-discharge outcomes. After 2:1 propensity score matching, we identified 178 subjects without IVIG therapy and 89 subjects who received IVIG. The mean age in that cohort was 2.0 ± 2.1 years, and IVIG had no significant effects on the major outcomes.

Conclusions

The present study revealed that high-dose steroid or IVIG therapy had no significant effects on major in-hospital complications, late heart failure hospitalization, and long-term mortality.

The Diagnostic and Clinical Approach to Pediatric Myocarditis: A Review of the Current Literature

Myocarditis is an inflammatory disease of the myocardium with a broad spectrum of clinical presentations, ranging from mild symptoms to severe heart failure. The course of patients with myocarditis is heterogeneous, varying from partial or full clinical recovery in a few days to advanced low cardiac output syndrome requiring mechanical circulatory support or heart transplantation. Myocarditis is a very heterogeneous disease, especially in the pediatric age group as worldwide disease myocarditis has been defined by the World Health Organization/International Society and Federation of Cardiology as an inflammatory disease of the heart muscle diagnosed by established histological, immunologic, and immunohistological criteria. Pediatric myocarditis remains challenging from the perspectives of diagnosis and management. Multiple etiologies exist, and the majority of cases appear to be related to viral illnesses. Enteroviruses are believed to be the most common cause, although cases related to adenovirus may be more frequent than suspected. The clinical presentation is extremely varied, ranging from asymptomatic to sudden unexpected death. A high index of suspicion is crucial. There is emerging evidence to support investigations such as serum N-terminal B-type natriuretic peptide levels, as well as cardiac magnetic resonance imaging as adjuncts to the clinical diagnosis. In the future, these may reduce the necessity for invasive methods, such as endomyocardial biopsy, which remain the gold standard. Management generally includes supportive care, consisting of cardiac failure medical management, with the potential for mechanical support and cardiac transplantation. Treatments aimed at immunosuppression remain controversial. The paediatrics literature is extremely limited with no conclusive evidence to support or refute these strategies. All these summarised in this article and the listed current literature showed that there is no consensus regarding aetiology, clinical presentation, diagnosis, and management of myocarditis in pediatric patients.

Identification of targeting peptides for the diagnosis of myocarditis

Aim: Current diagnostic tests for myocarditis are invasive and have low diagnostic value. Our aim was to identify potential targeting peptides to detect early myocarditis following intravenous delivery. Materials & methods: We used an animal model of experimental autoimmune myocarditis and a phage display library to identify potential targeting peptides. After several steps, we selected two peptides, MyH-PhD-05 and MyH-PhD-120, for in vivo screening using fluorescent imaging. Immunofluorescence and proteonomic analysis was used to identify potential cellular and molecular targets of MyH-PhD-05. Echocardiography was used to assess functional changes. Results: Peptide MyH-PhD-05 was able to detect animals with severe myocarditis even in the absence of functional changes. Immunofluorescence demonstrated that MyH-PhD-05 colocalizes with CD4+ T cells and monocytes (CD11b+) in cardiac infiltrates. Conclusion: We identified potential targeting peptides for the diagnosis of myocarditis. Future studies will focus on better identification of potential targets and translating this technology to clinically relevant imaging modalities.

Histoplasmosis Myocarditis in an Immunocompetent Host After a Recreational Mud Run

Mud runs are an increasingly popular recreational fitness activity across the United States, combining a running race through an obstacle course with submersion in mud. Recent reports estimate 4 million people have participated in these types of events over the last 5 years. We describe an atypical case of myocarditis and multiorgan failure from disseminated histoplasmosis in a previously healthy pediatric patient, likely acquired during participation in a mud run. Although cases of histoplasmosis-associated endocarditis and pericarditis have been reported in the literature, cases of histoplasmosis myocarditis are rare.

Toward evidence-based diagnosis of myocarditis in children and adolescents: Rationale, design, and first baseline data of MYKKE, a multicenter registry and study platform

The aim of this registry is to provide data on age-related clinical features of suspected myocarditis and to create a study platform allowing for deriving diagnostic criteria and, at a later stage, testing therapeutic interventions in patients with myocarditis.

STUDY DESIGN AND RESULTS

After an initial 6-month pilot phase, MYKKE was opened in June 2014 as a prospective multicenter registry for patients from pediatric heart centers, university hospitals, and community hospitals with pediatric cardiology wards in Germany. Inclusion criteria consisted of age<18 years and hospitalization for suspected myocarditis as leading diagnosis at the discretion of the treating physician. By December 31, 2015, fifteen centers across Germany were actively participating and had enrolled 149 patients. Baseline data reveal 2 age peaks (<2 years, >12 years), show higher proportions of males, and document a high prevalence of severe disease courses in pediatric patients with suspected myocarditis. Severe clinical courses and early adverse events were more prevalent in younger patients and were related to severely impaired leftventricular ejection fraction at initial presentation.

SUMMARY

MYKKE represents a multicenter registry and research platform for children and adolescents with suspected myocarditis that achieve steady recruitment and generate a wide range of real-world data on clinical course, diagnostic workup, and treatment of this group of patients. The baseline data reveal the presence of 2 age peaks and provide important insights into the severity of disease in children with suspected myocarditis. In the future, MYKKE might facilitate interventional substudies by providing an established collaborating network using common diagnostic approaches.

Fatal Varicella Myocarditis in a Child with Down Syndrome-A Case Report

A 12-year-old male child with Down syndrome, who had recovered from congenital heart disease, succumbed to severe varicella myocarditis. His clinical presentation at admission mimicked acute coronary syndrome. Analysis of this case throws insight into several aspects of varicella myocarditis.

Acute myopericarditis in an adolescent mimicking acute myocardial infarction

Acute myopericarditis is primarily a pericarditic syndrome with variable myocardial involvement, as evidenced by elevated cardiac enzymes. It is a rare entity, exclusively seen in male adolescents and accounts for less than 2% of the cases of inpatient admissions for chest pain/pericarditis in the pediatric age group. The electrocardiographic changes of pericarditis include J point/ST segment elevation, which needs to be differentiated from the benign early repolarization pattern that is common in young adolescents and the subtle anterior ST segment elevation myocardial infarction. Differentiating acute myopericarditis from acute coronary syndromes can be challenging because they share the presenting triad of acute chest pain, ST segment changes, and elevated cardiac enzymes. The accurate distinction of myopericarditis from acute myocarditis or acute coronary syndrome is important because of their differences in risk for specific complications, prognosis, and treatment implications. We present a case of acute myopericarditis in an adolescent who presented with atypical precordial chest pain, accompanied by inferolateral focal electrocardiographic changes and significant elevation of cardiac enzymes. The differential diagnosis and management of myopericarditis is reviewed with a focus on electrocardiographic changes and troponin assays.

Diagnostic evaluation of pediatric myocarditis in the emergency department: a 10-year case series in the Asian population

OBJECTIVES

Pediatric myocarditis is a known cause of dilated cardiomyopathy and is associated with significant mortality. Our primary objective was to describe the frequency of presenting symptoms, signs, and investigation results among children diagnosed with acute myocarditis. Our secondary objective was to review these patients' initial diagnoses by the emergency physicians.

METHODS

This was a retrospective chart review of all patients younger than 16 years who were diagnosed with acute myocarditis in our hospital over a 10-year period (January 2001 to December 2010). The symptoms and signs were stratified according to age (infants, 1-5 years, 6 years or older).

RESULTS

Thirty-nine children met the search criteria, of whom 10 patients (25.6%) were definite cases proven by myocardial biopsy. The average age was 5.4 years (SD, 4.3 years). The most common symptom complex was that of hypoperfusion (61.5%), which consisted of lethargy (53.8%), syncope (23.1%), and seizure (23.1%). Only 4 patients had cardiac symptoms, and all were older than 6 years old. Hepatomegaly was present in 16 patients (41.0%), whereas gallop rhythm or cardiac murmur was heard only in 5 patients (12.8%), Chest radiographs showed abnormalities in only 21 cases (53.8%), whereas all had abnormal electrocardiogram findings. Fifteen cases (38.5%) were diagnosed correctly at initial presentation, whereas the most common misdiagnosis was that of respiratory tract infections (20.5%).

CONCLUSIONS

Pediatric myocarditis rarely presents with specific cardiac symptoms in the younger population. Any child with symptoms and signs of hypoperfusion, especially unexplained seizure or syncope, should have an electrocardiogram performed.

Acute myocardial infarction induced by concurrent use of adderall and alcohol in an adolescent

Adderall (amphetamine, dextroamphetamine mixed salts), a widely prescribed stimulant for the treatment of attention-deficit/hyperactivity disorder in children and adolescents, is considered safe with due precautions. Nonmedical use of Adderall is prevalent and rising in high school and college students. Use of prescribed Adderall without intention to overdose as a cause of myocardial infarction is extremely rare, and to our knowledge, only 3 cases have been reported in the pediatric literature. We report a case of acute myocardial infarction in an adolescent without cardiovascular risk factors who took the total prescribed daily dose of Adderall one time while consuming alcohol. The sporadic use of Adderall with alcohol creates a potentially dangerous situation with serious cardiovascular adverse effects. We should have a high degree of suspicion for children and adolescents on stimulant therapy who present with chest pain and an abnormal electrocardiogram in the pediatric emergency department, and there is a need to evaluate them for myocardial ischemia and infarction.

Profile of circulating levels of IL-1Ra, CXCL10/IP-10, CCL4/MIP-1β and CCL2/MCP-1 in dengue fever and parvovirosis

Dengue virus (DENV) and parvovirus B19 (B19V) infections are acute exanthematic febrile illnesses that are not easily differentiated on clinical grounds and affect the paediatric population. Patients with these acute exanthematic diseases were studied. Fever was more frequent in DENV than in B19V-infected patients. Arthritis/arthralgias with DENV infection were shown to be significantly more frequent in adults than in children. The circulating levels of interleukin (IL)-1 receptor antagonist (Ra), CXCL10/inducible protein-10 (IP-10), CCL4/macrophage inflammatory protein-1 beta and CCL2/monocyte chemotactic protein-1 (MCP-1) were determined by multiplex immunoassay in serum samples obtained from B19V (37) and DENV-infected (36) patients and from healthy individuals (7). Forward stepwise logistic regression analysis revealed that circulating CXCL10/IP-10 tends to be associated with DENV infection and that IL-1Ra was significantly associated with DENV infection. Similar analysis showed that circulating CCL2/MCP-1 tends to be associated with B19V infection. In dengue fever, increased circulating IL-1Ra may exert antipyretic actions in an effort to counteract the already increased concentrations of IL-1β, while CXCL10/IP-10 was confirmed as a strong pro-inflammatory marker. Recruitment of monocytes/macrophages and upregulation of the humoral immune response by CCL2/MCP-1 by B19V may be involved in the persistence of the infection. Children with B19V or DENV infections had levels of these cytokines similar to those of adult patients.

Changes in cardiac output and stroke volume as measured by non-invasive CO monitoring in infants with RSV bronchiolitis

OBJECTIVES

The primary aim of the study was to determine the changes, if any, in cardiac output (CO) and stroke volume (SV) in normal infants with RSV bronchiolitis. The secondary aim was to determine whether changes in CO (ΔCO) and SV (ΔSV) are associated with changes in respiratory rate (ΔRR).

METHODS

Non-invasive CO recordings were obtained within 24 h of admission and discharge. Changes in CO, SV, and HR measurements were compared using paired t-tests. The effect of fluid boluses during the first 24 h (<60 or ≥60 cc/kg) on CO was assessed by 2 way ANOVA with time and group as main effect. The relationship between ΔRR and ΔCO or ΔSV was assessed by linear regression. Data is presented as Mean ± SEM and mean differences with 95 % confidence interval (p < 0.05 considered significant).

RESULTS

15 infants with RSV bronchiolitis were studied. CO (1.31 ± 0.13 to 1.11 ± 0.11 l/min (0.21 [0.04-0.37]) and SV (9.42 ± 1.10 to 7.75 ± 0.83 ml/beat (1.67 [0.21-3.12]) decreased significantly while HR (142.1 ± 4.0 to 145.2 ± 3.1 beats/min 3.0 [-5.3 to 11.3]) was unchanged. SV (p = 0.02) and CO (p = 0.04) significantly decreased only in the 7 infants that received ≥60 cc/kg. ΔRR correlated significantly with ΔCO (r (2) = 0.28, p = 0.04); but not with ΔSV (r (2) = 0.20, p = 0.09).

CONCLUSIONS

∆CO was related to ΔSV and not Δ HR. The ∆CO and ΔSV were affected by fluid boluses. ΔRR correlated with ΔCO. Non-invasive CO monitoring can trend CO and SV in infants with bronchiolitis during hospitalization.

Use of troponin as a screen for chest pain in the pediatric emergency department

Troponin levels are commonly employed in the assessment of adults presenting with chest pain or concern for coronary ischemia. However, the utility of troponin measurements in children is not well defined. The purpose of this study was to review the use and clinical yield of serum troponin assay in a large pediatric emergency department (ED). We identified all patients <22 years of age, not previously known to have cardiac disease, who presented with chest pain and whose troponin levels were evaluated in our pediatric ED during a 7-year period. Test results were correlated to patient factors, such as chief complaint, cardiac history, diagnostic workup, and discharge diagnoses. Of the 212 study patients who presented with chest pain, troponin levels were increased (≥ 0.1 ng/ml) in 37 (17%) subjects. The disposition for these 37 subjects included transfer to adult facility (n = 6), admission to our pediatric inpatient service (n = 27), and discharge to home from the ED (n = 10). Only one subject had an acute myocardial infarction. For those with increased troponin level, 18 of 37 (48%) cases were attributed to a primary cardiac diagnosis with the most common discharge diagnosis of myocarditis or pericarditis. In the pediatric ED setting, selective use of troponin assay may be a useful test in the management of patients with chest pain. Most cases of increased troponin level related to chest pain represent myocarditis, often mild and self-resolving. Given the low likelihood that acute coronary syndrome is the etiology of chest pain, immediate transfer to an adult facility for the majority of patients with increase of troponin does not appear warranted.