Avian influenza A (H5N6) virus combined with hypertrophic obstructive cardiomyopathy treated with veno-venous extracorporeal membrane oxygenation: a case report

Background: Avian influenza A H5N6 is considered to be extremely lethal, and when combined with hypertrophic obstructive cardiomyopathy （HOCM）, difficulty of treatment and risk of death are highly increased. In case report described the treatment of a patient with H5N6 combined with HOCM, in which lessons learned regarding treatment failure were discussed. The information provided by this report may provide a reference for treatment. Thus far, no cases of H5N6 combined with hypertrophic obstructive cardiomyopathy have been reported in literature. Case Presentation: A 56-year-old male diagnosed with Avian influenza A H5N6 combined with HOCM who was treated with veno‑venous extracorporeal membrane oxygenation（VV-ECMO ）for thirty-two days presented to hospital. Oseltamivir, immunoglobulin, methylprednisolone and continuous renal replacement therapy were also given; however, the patient unfortunately died given H5N6’s high pathogenicity. Conclusions: : Avian influenza A (H5N6) has a high fatality rate. Multiple organ failure can lead to the death of patients in a short period of time, and HOCM is prone to diastolic dysfunction and arrhythmia. According to its pathophysiological characteristics, an appropriate preload should be maintained, though it is not conducive in reducing pulmonary exudation. Therefore, H5N6 combined with HOCM can increase the difficulty of volume management. Accordingly, prompt treatment, early antiviral therapy, strong organ support, and enhanced infection control may improve patient outcomes. In particular, attention should be given to the possibility of secondary bacterial and fungal infections after influenza.