Fulminant myocarditis associated with the H1N1 influenza virus: case report and literature review

A case of fulminant myocarditis associated with the H1N1 influenza virus. This case report describes the patient's clinical course and emphasizes the importance of bedside echocardiography as an aid in the early diagnosis and management of children with severe myocardial dysfunction. It also discusses aspects relevant to the treatment and prognosis of fulminant myocarditis. The patient was a female, 4 years and 8 months old, previously healthy and with a history of flu symptoms in the past two weeks. The patient was admitted to the emergency room with signs of hemodynamic instability, requiring ventilatory support and vasoactive drugs. The laboratory tests, chest X-ray and echocardiogram suggested the presence of myocarditis. The test for H1N1 in nasopharyngeal secretions was positive. The patient evolved to refractory cardiogenic shock despite the clinical measures applied and died 48 hours after admission to the intensive care unit. The H1N1 influenza virus is an etiological agent associated with acute myocarditis, but there are few reported cases of fulminant myocarditis caused by the H1N1 virus. The identification of signs and symptoms suggestive of fulminant progression should be immediate, and bedside echocardiography is a useful tool for the early detection of myocardial dysfunction and for therapeutic guidance. The use of immunosuppressive therapy and antiviral therapy in acute myocarditis of viral etiology is controversial; hence, the treatment is based on hemodynamic and ventilatory support. The use of hemodynamic support by extracorporeal membrane oxygenation emerges as a promising treatment.