A Case of Influenza Associated Fulminant Myocarditis Successfully Treated with Intravenous Peramivir

We report the case of a patient with fulminant myocarditis caused by influenza A virus, who presented with acute-onset heart failure and cardiogenic shock and was treated successfully with single dose of intravenous peramivir and with pharmacologic hemodynamic support. A 45-year-old Korean woman presented to our emergency department (ED) with shortness of breath and an episode of seizure that developed abruptly 5 hours before she arrived in the ED. She had a history of recurrent epileptic seizure 25 years ago, but denied other specific medical illnesses. In the ED, she was hypoxemic (arterial partial pressure of oxygen, 59.8 mmHg on room air) and chest radiography revealed bilateral alveolar infiltrates. A rapid antigen test for influenza A virus was positive, and she was administered a single dose of peramivir (300 mg) intravenously. Five hours later, the patient's dyspnea had worsened and she was hypotensive (blood pressure, 86/53 mmHg), requiring norepinephrine infusion. Further evaluation disclosed an increased cardiac troponin I level of 1.36 ng/mL and a depressed left ventricular ejection fraction of 30%. Under the diagnosis of influenza A-associated myocarditis and cardiogenic shock, she was managed with continuous critical care in the intensive care unit. On day 3, the patient's dyspnea began to resolve and her ventricular function returned to normal. Real-time polymerase chain reaction assays for influenza viruses in serial nasopharyngeal aspirates were positive for influenza A (hH3N2) with a threshold cycle value of 27.39 on day 2, but these became negative by day 4. The patient recovered and was discharged on day 9 after admission. In conclusion, this case indicates that intravenous peramivir might be an effective antiviral agent for the treatment of severe influenza A virus infection.