Fulminant Myocarditis Following Gastric Bypass Surgery: A Case Report.

Fulminant myocarditis (FM) is a rare, life-threatening inflammatory disease of the myocardium characterized by sudden, severe cardiac dysfunction and hemodynamic instability. It often necessitates high-dose inotropic support and mechanical circulatory assistance, with a high risk of short-term mortality. We describe a 23-year-old woman who developed FM 18 months after undergoing Roux-en-Y gastric bypass. She presented with cardiogenic shock and ventricular arrhythmias precipitated by a period of clinical non-adherence and discontinued nutritional supplementation. Infectious and autoimmune workups were negative, but profound micronutrient and trace element deficiencies were identified. Emergency management included mechanical ventilation, inotropes, immunomodulatory therapy, and aggressive nutritional repletion. Cardiac magnetic resonance imaging confirmed myocarditis. Over two months, her left ventricular ejection fraction improved from approximately 25% to 56%, accompanied by full clinical recovery. This case illustrates the potential role of severe post-bariatric malnutrition in triggering myocardial inflammation and cardiovascular collapse. It underscores the importance of early recognition, multidisciplinary management, including immunomodulatory and nutritional therapy, and the necessity of vigilant long-term follow-up in patients after bariatric surgery to prevent such catastrophic outcomes.