When myocarditis is not what it seems: identifying Brugada syndrome through event ECG findings

Background. Myocarditis is frequently suspected in pediatric patients presenting with fever, elevated cardiac enzymes, and sudden cardiovascular collapse. However, inherited arrhythmia syndromes such as Brugada syndrome may mimic myocarditis and lead to misdiagnosis. Prompt differentiation is critical, as therapeutic strategies and outcomes differ significantly. Case Presentation. We report a previously healthy 5-year-old girl who suffered sudden cardiac arrest during a febrile illness and had markedly elevated troponin levels. Initial evaluation suggested myocarditis, but cardiac MRI revealed no abnormalities. Retrospective analysis of the event electrocardiogram (ECG) recorded during resuscitation demonstrated a diagnostic type 1 Brugada pattern that was absent on baseline ECGs. Ajmaline provocation testing confirmed Brugada syndrome, and an implantable cardioverter-defibrillator (ICD) was recommended for secondary prevention. Conclusion. This case underscores the diagnostic challenge of distinguishing Brugada syndrome from myocarditis in pediatric patients presenting with cardiac arrest. Event ECG recordings obtained during or immediately after cardiac arrest are crucial for accurate diagnosis. Clinicians should maintain a high index of suspicion for Brugada syndrome in pediatric patients experiencing cardiac arrest during a febrile illness to guide timely management. Reporting such cases contributes to clinical awareness and may prevent delays in life-saving interventions.