Abstract
Fulminant autoimmune myocarditis is a rare but life-threatening condition that can present as the initial manifestation of an underlying autoimmune disease. Early recognition and prompt initiation of mechanical circulatory support and immunosuppressive therapy are critical for survival. We report the case of a previously healthy young woman who presented with acute cardiogenic shock following a syncopal episode and rapidly progressive dyspnea. Initial investigations ruled out ischemic, infectious, and toxicologic causes. Coronary angiography revealed normal coronary arteries. She developed sustained ventricular arrhythmias and severe left ventricular dysfunction (ejection fraction 10–15%), requiring urgent Veno arterial extracorporeal membrane oxygenation (VA-ECMO) support. Immunologic testing revealed a positive antinuclear antibody (ANA) by ELISA (> 400 AU/mL), strongly positive anti-SSA (Ro) antibodies, and borderline anti-SSB antibodies, raising suspicion for Sjogren syndrome–associated myocarditis. High-dose intravenous methylprednisolone therapy was initiated, leading to rapid clinical improvement, with successful ECMO weaning after four days. Follow-up echocardiography showed normalization of left ventricular function. Cardiac MRI confirmed myocarditis according to the updated Lake Louise criteria. At one-year follow-up, the patient demonstrated full cardiac recovery and was diagnosed with Sjogren’s syndrome. This case highlights the importance of early recognition, aggressive immunosuppression, and mechanical circulatory support in fulminant autoimmune myocarditis. It also underscores the value of long-term follow-up for confirming underlying systemic autoimmune diseases, which may initially present with isolated cardiac involvement. Comprehensive autoimmune evaluation should be considered in young patients with unexplained fulminant myocarditis, especially females, to enable timely diagnosis and tailored immunosuppressive therapy.