Giant cell myocarditis is a life threatening form of dilated cardiomyopathy which presents as sudden onset acute systolic heart failure commonly with refractory ventricular tachycardia in young previously healthy individuals. Giant cell myocarditis is quite rare as only approximately 100 cases have been reported in the published literature.
The etiology remains unclear, however is likely viral or autoimmune. Diagnosis is made on heart biopsy which shows multinucleate giant cells. Heart transplantation is frequently required, however the disease can recur in the transplanted heart. Immunosuppressive therapy with cyclosporine or azathioprine can be helpful, however corticosteroids alone are not recommended.