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Three Part Question

In [pediatric patients] presenting to the emergency department with [viral myocarditis], what are the [clinical features associated with acute infection]?

Clinical Scenario

A previously healthy 8-year-old boy, with a three-day history of flu-like symptoms presents to your emergency department. He was admitted with dehydration and hypothermia in the context of persistent vomiting. The following day he developed heart failure secondary to viral myocarditis.

Search Strategy

Medline 1946-10/14 using OVID interface, EMBASE, and PubMed clinical queries
[(clinical findings) OR (clinical characteristics) OR (clinical presentation)] AND [exp myocarditis)]. Limit to children (birth-18) and English language.

Search Outcome

118 papers were identified; five were relevant to the clinical question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Freedman SB, Haladyn JK, Floh A, et al. 2007	16 patients with definite myocarditis, 15 cases with probable myocarditis	Retrospective case series	Presenting symptoms and outcomes of pediatric patients with myocarditis	Most common symptoms in patients <10 years were respiratory (47%), hypoperfusion (20%), Kawasakie-associated (20%), and GI complaints (13%). In children >10, chest pain (56%), hypoperfusion (25%), and respiratory (19%). Most common physical exam findings were respiratory distress/abnormal respiratory exam/tachypnea (68%), tachycardia (58%), lethargy (39%), hepatomegaly (36%), abnormal heart sounds (32%) and fever (30%). CXR was abnormal in 55% of patients and EKG was abnormal in 93% of patients.	Retrospective study, small sample size, many patients were transferred so missing initial records in some cases, not definitive diagnosis in half the patients, symptoms broken up by category, not actual symptoms. Single institution.
Saji T, Matsuura H, Hasegawa K, et al. 2012	169 pediatric patients	Retrospective cohort analysis	Collected presentation, treatments, and outcomes of pediatric patients with myocarditis	Fever was observed in 47.9%, nausea or vomiting in 30.2%, abdominal pain in 9.4% and diarrhea in 7.7%, and cough was observed in 16.6%. Regarding cardiovascular manifestations, heart failure was observed in 36.1%, cardiomegaly on CXR in 29%, dyspnea in 25.4%, and cardiogenic shock in 13%. Overall, GI tract symptoms (nausea, vomiting abdominal pain and diarrhea) were more frequent than cardiopulmonary symptoms (45.3% vs 24.7%, P=0.01)	Retrospective survey. Different work-ups and treatments at different institutions.
Durani Y, Egan M, Baffa J, et al. 2009	62 pediatric patients with myocarditis or dialated cardiomyopathy	Retrospective cross-sectional study	Most common symptoms, physical exam findings, labs, and radiographic results, as well as initial incorrect diagnoses	Most common symptoms were shortness of breath (69%), vomiting (48%), poor feeding (40%), URI symptoms (39%), fever (36%), and lethargy (36%) Most common physical exam findings were tachypnea (60%), hepatomegaly (50%), respiratory distress (47%), and abnormal lug exam (34%). Also, 59/59 EKGs were abnormal, most commonly sinus tachycardia (46%) and ventricular hypertrophy (41%). 53/59 (90%) of CXR were abnormal with cardiomegaly (63%) the most common finding. Only 10 of 62 patients had the correct diagnosis on initial presentation	Retrospective chart review, most diagnoses were based on expert opinion, not biopsy-proven. Details of clinical history and physical exam not available for some prior evaluations. Only two institutions.
Abe T, Tsuda E, Miyazaki A, Ishibashi-Ueda H, Yamada O. 2013	24 pediatric patients	Retrospective case series	Identify clinical characteristics and long-term outcome of acute myocarditis in children	Gastrointestinal symptoms including abdominal pain, vomiting, and appetitie loss were the most frequesnt (58%), fever (46%), cardiovascular symptoms including chest pain, oppressive sensation in chest and edema (46%), respiratory symptoms including cough, wheezing, dyspnea (29%), neurological symptoms including convulsion and disturbed consciousness (29%) and general malaise (25%). All 24 patients had abnormal EKGs	Retrospective study. Small sample size. Long study time. Single institution.
Molina KM, Garcia X, Denfield SW, Fan Y, Morrow WR, Towbin JA, Frazier EA, Nelson DP. 2013	19 pediatric patients with PCR confirmed PVB19 myocarditis	Retrospective case series	Demographic information, presenting symptoms and exam findings, initial lab values (trop I, BNP, hemoglobin, creatinine), and diagnostic studies were collected. Patients were assessed for their need of support (inotropic, ventilator, and mechanical circulatory)	The common presenting symptoms were respiratory distress (n=17, 89%) and feeding intolerance or emesis (n=12, 66%) BNP were elevated in all patients tested (n=12), troponin elevated in 7	Retrospective study. Small group. Underpowered. Only in two institutions, local practice favored. Limited to one strain of myocarditis.

Comment(s)

Given the low number of patients who present to the emergency department with viral myocarditis as well as the variability in presentation, a prospective analysis of the clinical findings would be challenging. Heart failure seems to be the most common presenting picture in all ages. Although rare in young children, dyspnea and chest pain are the initial symptoms for many adolescents. Patients can present with any type of dysrhythmia; a resting tachycardia is the most common. Parents of young patients may refer to a recent, nonspecific, flulike illness, gastrointestinal (GI) symptoms, rapid breathing, or poor feeding. When clinical suspicion of myocarditis exists, chest radiography alone is an insufficient screening test. In patients with mild cardiac involvement, electrocardiographic (ECG) changes may be the only abnormal findings suggestive of myocarditis. Low-voltage QRS (< 5 mm throughout the limb leads) is the classic pattern. However, ECG abnormalities are widely variable, there is not one specific abnormality that occurs with enough frequency to be a specific marker. Durani et al found that 83% of children were not diagnosed at the first presentation to a clinician and required 2 or more visits to a medical provider before suspicion of myocarditis.

Editor Comment

KMJ

Clinical Bottom Line

There are no prospective studies that describe the clinical findings of viral myocarditis, although it is a significant cause of morbidity and mortality among children and young adults. Making the diagnosis of myocarditis can be challenging due to its subtle clinical signs and symptoms. The diagnosis should be suspected whenever a child presents with unexplained shortness of breath or chest pain, a new arrhythmia, or acute cardiac failure following a viral illness.

References

1. Freedman SB, Haladyn JK, Floh A, et al. Pediatric myocarditis: emergency department clinical findings and diagnostic evaluation. Pediatrics 2007;120:1278–1285.
2. Saji T, Matsuura H, Hasegawa K, et al. Comparison of the clinical presentation, treatment, and outcome of fulminant and acute myocarditis in children. Circ. J. 2012;76:1222–1228.
3. Durani Y, Egan M, Baffa J, et al. Pediatric myocarditis: presenting clinical characteristics. Am J Emerg Med. 2009;11:212–221
4. Abe T, Tsuda E, Miyazaki A, Ishibashi-Ueda H, Yamada O. Clinical characteristics and long-term outcome of acute myocarditis in children. Heart Vessels 2013 Sep;28(5):632-8.
5. Molina KM, Garcia X, Denfield SW, Fan Y, Morrow WR, Towbin JA, Frazier EA, Nelson DP. Parvovirus B19 myocarditis causes significant morbidity and mortality in children. Pediatric Cardiology. 2013 Feb;34(2):390-7.