Fulminant Myocarditis with COVID-19 Infection Having Normal C-Reactive Protein and Serial Magnetic Resonance Follow-Up

Figures

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  Figure 1. Electrocardiogram. Electrocardiography revealed sinus tachycardia, low voltages in limb leads, ST‐segment elevations in V5,6, poor R progression in V2,3, and QT prolongation.

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  Figure 2. Hospital course in an acute phase. ECMO, extracorporeal membrane oxygenation; LVEF, left ventricular ejection fraction; mPSL, methylprednisolone; PSL, prednisolone.

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  Figure 3. Serial cardiac magnetic resonance imaging. LVEF and LV mass, measured using cine imaging, recovered over time. Oedematous wall thickening with high signal intensity on T2‐weighted images was observed on Day 64 and subsequently recovered. Native T1 values in the anteroseptal and inferolateral walls were high on Day 64 and decreased over time. LGE was observed in the basal‐to‐apical inferolateral mid‐myocardial wall (red arrowheads), corresponding to the regions with the highest native T1 value. The ECV was high in the anteroseptal and inferolateral walls. AS, anteroseptal wall; ECV, extracellular volume; IL, inferolateral wall; LGE, late gadolinium enhancement; IVSd, interventricular septal thickness in diastole; LVEF, left ventricular ejection fraction; LVPWd, left ventricular posterior wall thickness in diastole.

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  Figure 4. Histopathological findings of endomyocardial biopsy samples. An endomyocardial biopsy showing mild inflammation on haematoxylin and eosin staining (A). Moderate endomyocardial thickening and mild interstitial fibrosis on Masson's trichrome staining (B). High‐power view of Masson's trichrome staining showing a microthrombus with fibrin and platelets within the arteriole (C, arrow). Immunohistochemical features of myocarditis: CD61 (C, inset), CD68 (D), CD3 (E), and tenascin‐C (F). CD61‐positive platelets were observed in obstructive microthrombi in the microvessels. CD68‐positive macrophages and a few CD3‐positive T‐cells infiltrated sparsely in the interstitium without necrosis of the adjacent cardiomyocytes. Tenascin‐C was distributed in the endocardium and partially located in the interstitium. Scale bars: 50 μm.