Eosinophilic myocarditis in a patient with biopsy proven systemic sarcoidosis who was referred for bradycardia

Background Eosinophilic myocarditis (EM) is an understudied and often missed diagnosis whose constellation of symptoms are frequently attributed to other morbidities. Case A 57-year-old woman with mediastinal lymphadenopathy (Figure 1A), uveitis, celiac lymph node biopsy in 2013 demonstrating noncaseating granulomas and a questionable prior diagnosis of hypereosinophilic syndrome presented to establish care for dizziness and bradycardia (Figure 1B). She had a stroke in 2004 with an echocardiographic diagnosis of left ventricular (LV) thrombus (Figure 1C-D) for which she was prescribed coumadin. She exhibited a pruritic maculopapular skin rash on several areas of her body (Figure 1E-F) and laboratory tests showed a history of peripheral eosinophilia. Decision-making There was concern for cardiac sarcoidosis or undiagnosed EM. A cardiac MRI demonstrated thickening of the LV apex (Figure G-H) with corresponding sub endocardial perfusion defect and late gadolinium enhancement, without LV thrombus. These findings were consistent with late stage myocardial fibrosis from EM. Reliance on the single imaging modality of echocardiogram resulted in past misdiagnosis of thrombus and delayed therapy of myocardial fibrosis in this patient. Conclusion This case highlights the need for awareness of EM and the importance of considering alternative or additional diagnoses in patients with complex past medical histories. An association of sarcoidosis and EM has not yet been reported in the literature