Published online Mar 6, 2019. doi: 10.12998/wjcc.v7.i5.548
Peer-review started: November 23, 2018
First decision: December 15, 2018
Revised: December 29, 2018
Accepted: January 30, 2019
Article in press: January 30, 2019
Published online: March 6, 2019
Pediatric myocarditis constitutes an important cause of morbidity and mortality in the form of death, heart transplant, and dilated cardiomyopathy. Pediatric myocarditis diagnosis is usually challenging. It is mainly due to its heterogeneous and unspecific clinical presentation, and the low accuracy of the currently available non-invasive diagnostic tests. Also, the gold standard for diagnosis, the endomyocardial biopsy has inherent risks and is not widely available. Of note, a diagnostic delay can lead to a subsequent elevated morbimortality.
We aimed to investigate the clinical presentation and the results of the non-invasive tests utilized in the diagnostic work-up of pediatric myocarditis at presentation.
Our main purpose was to provide clinical, biochemical, or echocardiographic clues in order to improve the early recognition of pediatric myocarditis at presentation in the emergency department. Also, we sought to identify predictors for poor outcome in pediatric myocarditis in order to identify high-risk patients that will need a more intensive therapy and close follow-up.
We carried out a retrospective cross-sectional single-center study. A total of 42 patients between 2008 and 2017 were enrolled. Patients were divided into two groups: poor outcome and no poor outcome. We delineated the clinical presentation of our patients with myocarditis. Also, different clinical and diagnostic test variables were analyzed in order to find possible poor outcome predictors.
The clinical presentation of pediatric myocarditis was heterogeneous, ranging from asymptomatic to cardiogenic shock cases. Of note, pediatric myocarditis clinical presentation can mimic benign viral infections in children, usually in those younger patients that are not able to verbalize symptoms and debut as fulminant myocarditis. Conversely older patients presented with acute coronary syndrome-like myocarditis. There was no single non-invasive diagnostic test that led to rule out or rule in the diagnosis of pediatric myocarditis. Cardiac magnetic resonance imaging presented a high diagnostic accuracy, but was mostly useful only for older children with acute coronary syndrome-like presentation. Severe depressed left ventricle systolic function on echocardiography was the only independent predictor for poor outcome (death, transplant, or dilated cardiomyopathy). The presence of age < 2-years-old, a clinical course of more than 7 d from initial symptoms, or N-terminal pro-brain natriuretic peptide levels > 5000 pg/mL was associated with a severe depressed LV systolic function.
A high grade of clinical suspicion is needed to make an early diagnosis of pediatric myocarditis, especially in infants who cannot verbalize their symptoms. This clinical suspicion must be used in combination with several findings of different non-invasive diagnostic tests in order to improve the prompt recognition of pediatric myocarditis. This study provided some clinical pictures that can help clinicians in this context. Echocardiography is a reliable diagnostic tool for pediatric myocarditis. Patients that present with a severe depressed LV systolic function have a poor outcome. Age younger than 2 years, prolonged course of disease, and higher N-terminal pro-brain natriuretic peptide levels are predictors of poor outcome that could be useful even in centers where echocardiography is not available. The combined use of these predictors can lead to an early detection of high-risk patients in order to initiate adequate treatment and monitoring.
This article reflects the challenge to diagnose pediatric myocarditis. Future studies should prospectively collect multicenter data on epidemiology, clinical presentation, and diagnostic value of currently available diagnostic tools in children with myocarditis to establish clinically meaningful criteria for the diagnosis of myocarditis. This will enhance the early recognition and subsequently the prognosis of these patients.