Written by Kimiko Dunbar
Spoon Feed
This narrative review of pediatric myocarditis covers common presentations, diagnostics and treatment of myocarditis.
Don’t go breaking my heart
Myocarditis is a rare condition with an in-hospital mortality of 6.1%. Given the rare but serious nature of this condition and range of clinical presentations, this narrative review updates diagnostic strategies and treatment approaches for pediatric myocarditis. Highlights are summarized below:
- Presentation: Most commonly heart failure, chest pain, new arrhythmia in the setting of viral illness within the last 10-14 days. Consider in infants with poor weight gain, irritability, periodic pallor/diaphoresis, or in older children with weakness, exercise intolerance, respiratory symptoms and even fever.
- Diagnostics: Usually troponin and NT pro-BNP are elevated. Viral testing may also be positive, although this does not necessarily confirm causality. ECG may also be abnormal, with repolarization anomalies or arrhythmia. ECHO typically shows biventricular dilation with reduced contractility but may be normal. Cardiac magnetic resonance (CMR) is recommended for diagnosis, if available, due to higher sensitivity and specificity. Biopsy remains the gold standard and is recommended for severe cases.
- Treatment: Bed rest for all! Refrain from competitive sports for 3-6 months; full cardiac evaluation is needed prior to resuming activity. Give antiviral treatment if applicable. Start an ACE-I to prevent fibrosis. Heart failure should be managed in accordance with current guidelines. Evidence supports immunomodulators (IVIG, corticosteroids, anakinra) despite mixed results.
- Causes: Myocarditis is most often secondary to a virus; however, it can also be a manifestation of non-infectious causes, especially rheumatologic disease or Kawasaki. Myocarditis has been seen post COVID vaccine, especially in adolescent males, though cases are typically mild and self-limited, and vaccination significantly reduces the overall risk of myocarditis.
How does this change my practice?
Myocarditis is quite rare, but it’s a can’t-miss diagnosis given potentially life-threatening implications. This is a good review of the symptoms and initial work-up and treatment. ECG is an obvious first screen in pediatric patients with chest pain. Troponin and NT pro-BNP may be a good addition if suspicion is high, although not in line with the AHA recommendations for pediatric myocarditis given lack of sensitivity and specificity.
Sources
Diagnosis and Management of Pediatric Myocarditis. Pediatr Infect Dis J. 2025 Mar 1;44(3):e95-e98. doi: 10.1097/INF.0000000000004678. Epub 2024 Dec 17. PMID: 39705605
