Cureus. 2026 Sep 11;18(9):e116094. doi: 10.7759/cureus.116094. eCollection 2026 Sep.
ABSTRACT
Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with heterogeneous cardiovascular involvement, while clinically overt lupus myocarditis remains uncommon. We report the case of a 50-year-old woman with no previous cardiovascular or autoimmune disease who presented with acute decompensated heart failure after a two-year history of progressive exertional dyspnea. Transthoracic echocardiography revealed severe biventricular dilated cardiomyopathy with a left ventricular ejection fraction of 21% and profoundly reduced global longitudinal strain (-5.0%). Cardiac biomarkers were markedly elevated, whereas coronary angiography showed normal epicardial coronary arteries. Autoimmune testing revealed high-titer antinuclear antibodies, elevated anti-double-stranded DNA and anti-Smith antibodies, and complement consumption, despite the absence of typical cutaneous, articular, renal, or neurological manifestations of SLE. Cardiac magnetic resonance demonstrated subepicardial late gadolinium enhancement involving the anterolateral wall in a non-ischemic distribution. The integration of clinical, immunological, coronary, and multimodality imaging findings supported clinically suspected lupus myocarditis as the inaugural manifestation of previously unrecognized SLE. Guideline-directed heart failure therapy and immunosuppressive treatment were initiated, with early clinical improvement and a decrease in cardiac biomarkers. In the absence of endomyocardial biopsy, the diagnosis remained clinically and imaging-supported rather than histologically confirmed. This case highlights an unusual presentation of SLE revealed by severe biventricular dilated cardiomyopathy and emphasizes the pivotal role of multimodality imaging and targeted autoimmune testing in identifying an inflammatory etiology of otherwise unexplained non-ischemic cardiomyopathy.
PMID:42861242 | PMC:PMC13654238 | DOI:10.7759/cureus.116094