Fulminant Lupus Myocarditis as the Initial Manifestation of Systemic Lupus Erythematosus Successfully Treated with High-Dose Steroid Therapy: A Case Report.

Lupus myocarditis (LM) is a rare but potentially life-threatening manifestation of systemic lupus erythematosus. We report the case of a 36-year-old woman who presented with fulminant heart failure refractory to standard therapy. Concomitant nephrotic syndrome, hypocomplementemia, and positive anti-double-stranded DNA antibodies supported the diagnosis of LM. Given her rapid hemodynamic deterioration, high-dose intravenous steroid therapy was promptly initiated, leading to a rapid recovery of her cardiac function without mechanical circulatory support. An endomyocardial biopsy demonstrated mononuclear inflammatory cell infiltration and mild fibrosis, consistent with LM, with prominent tenascin-C deposition.