Case presentation: We report on the case of a 5 year-old girl who developed fulminant myocarditis due to acute infection with influenza virus type B. Cardiac arrest occurred suddenly, resuscitation efforts were not successful, and the patient died of congestive heart failure 24 h after admission to the hospital.
Diagnosis: Lymphocytic infiltration of cardiac tissues and virologic studies confirmed the suspected diagnosis of acute viral myocarditis.
Conclusion: In conclusion, influenza virus type B is one of the infective agents that can cause rapid and fatal myocarditis in previously healthy children. Early cardiac support may be the only option to prevent fatal outcome.