Cardiac Magnetic Resonance Imaging Used to Determine a Rare Etiology of a Layered Left Ventricular Apical Thrombus

Eosinophilic myocarditis (EM) is a rare disease, often associated with hypereosinophilic syndrome (HES). Historically, the diagnostic gold standard was endomyocardial biopsy (EMB). We present a unique case of a 58-year-old female who presents after a syncopal episode and was found to have a layered left ventricular (LV) thrombus. Using laboratory studies and cardiac magnetic resonance imaging (MRI), we were able to delineate the etiology, avoiding any invasive testing.