Fulminant pH1N1-09 influenza-associated myocarditis in pediatric patients

OBJECTIVE: To report an atypical presentation of pH1N1-09 influenza infection in children as fulminant myocarditis and tamponade and the successful treatment with extracorporeal membrane oxygenation. DESIGN: Case report. SETTING: Pediatric cardiac intensive care unit in a quarternary care children's hospital. PATIENTS: Two girls, 5 and 7 yrs of age, infected with pH1N1-09 influenza virus who presented in cardiogenic shock with a pericardial effusion and echocardiographic evidence of tamponade from fulminant myocarditis. INTERVENTIONS: Both patients received a pericardiocentesis. One was managed with multiple, high-dose inotropic agents, whereas the other required institution of extracorporeal membrane oxygenation. MEASUREMENTS AND MAIN RESULTS: Acute respiratory distress syndrome is the major reported clinical manifestation of pH1N1-09 influenza virus infection in hospitalized pediatric patients. In this report we describe two children with confirmed pH1N1-09 influenza infection that required intensive care for fulminant myocarditis. Neither patient had the typical symptoms of influenza-like illness, respiratory compromise, or evidence of pulmonary involvement. One child required extracorporeal membrane oxygenation. Both children survived to hospital discharge. CONCLUSIONS: pH1N1-09 influenza infection can cause fulminant myocarditis in the healthy pediatric population. The clinical presentation may be nonspecific, and the lack of pulmonary symptoms may make diagnosis difficult. Extracorporeal membrane oxygenation support may offer an effective bridge to the recovery of heart function.