Giant Cell Myocarditis

Giant cell myocarditis (GCM) is a rare, rapidly progressive inflammatory cardiomyopathy characterized by diffuse myocardial necrosis with multinucleated giant cells, eosinophils, and lymphocytic infiltrates on endomyocardial biopsy. The pathophysiology involves an autoimmune T-cell-mediated attack against cardiac myocytes, often associated with other autoimmune conditions (inflammatory bowel disease, thymoma, myasthenia gravis). GCM presents with rapidly progressive heart failure, ventricular arrhythmias (often the presenting symptom), and hemodynamic collapse, with a median survival of 5.5 months without immunosuppressive treatment. Unlike lymphocytic myocarditis, which often resolves spontaneously, GCM requires aggressive combined immunosuppression (cyclosporine, corticosteroids, azathioprine). The nurse monitors hemodynamic status continuously, manages vasoactive infusions, monitors for and reports ventricular arrhythmias, assists with mechanical circulatory support (IABP, LVAD, ECMO) as a bridge to transplant, administers immunosuppressive medications while monitoring for adverse effects, and coordinates urgent cardiac transplant evaluation as definitive therapy.