SHM Converge Scientific Abstract ePoster Gallery-Diagnostic Utility of Cardiac Mri in Dermatomyositis-Associated Myocarditis

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A 24-year-old man with a history of major depressive disorder, generalized anxiety disorder, and obesity presented with 3 months of progressive fatigue, weight gain, diaphoresis, dyspnea, proximal muscle weakness, and a widespread pruritic erythematous rash. Exam showed classic dermatomyositis findings, including heliotrope rash, Gottron’s papules, periungual erythema/edema, and proximal weakness. Laboratory testing revealed elevated troponins and inflammatory markers, while autoimmune and infectious workups were negative. Thigh MRI showed inflammatory myositis, and muscle biopsy demonstrated perifascicular atrophy with regenerating and necrotic fibers, consistent with dermatomyositis.<br /><br />He was initially treated with azathioprine but returned two weeks later with worsening weakness and persistent troponin elevation, prompting cardiac evaluation. Transthoracic echocardiogram showed preserved systolic and diastolic function, but cardiac MRI demonstrated subepicardial enhancement of the mid-anterolateral wall plus pericardial thickening and trace effusion, consistent with myopericarditis due to dermatomyositis-associated myocarditis (DAM). This case highlights that clinically significant cardiac involvement can occur even when echocardiography is normal.<br /><br />The patient was started on high-dose prednisone and IVIG, later transitioned to a regimen of low-dose prednisone, monthly IVIG, and rituximab after intolerance to azathioprine (elevated liver enzymes) and mycophenolate (diarrhea). Over time, his symptoms improved and troponin levels normalized.<br /><br />The report emphasizes that dermatomyositis can have under-recognized cardiac involvement, affecting up to 40% of patients. Cardiac MRI is the most sensitive noninvasive tool for detecting myocarditis, edema, fibrosis, and pericardial inflammation, and is especially useful when troponin rises during DM flares. Early recognition and immunosuppressive treatment are important for improving outcomes.

Asset Subtitle

Sahithi Reddi

Meta Tag

Author List Rachel Suen, Sahithi Reddi

Category Clinical Vignettes

Concept Dermatomyositis

Concept Proximal Muscle Weakness

Concept Myocarditis

Concept Cardiac MRI

Concept Corticosteroid

Distinguished Non-Finalist

Presenter Organization Stony Brook University Hospital

Presenting Author Sahithi Reddi

Track Adult

Keywords

dermatomyositis

myopericarditis

myocarditis

cardiac MRI

troponin elevation

heliotrope rash

Gottron papules

proximal muscle weakness

IVIG

rituximab

Dermatomyositis

Proximal Muscle Weakness

Myocarditis

Cardiac MRI

Corticosteroid