PMC7407015_01
Electrocardiography and thoracic radiography findings on admission. (a) Electrocardiogram shows a sinus rhythm with poor R progression in precordial leads; (b) postero-anterior thoracic radiogram shows no features of heart failure.
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The electrocardiogram showed sinus rhythm with low voltage in limb leads and poor R progression in precordial leads (Figure 1(a)). Thoracic radiography excluded cardiomegaly, pleural effusion, or pulmonary congestion (Figure 1(b)).
Right ventricular myocardial biopsy specimen. (a) Extensive inflammatory cell infiltration (consisting of lymphocytes and no giant cells) with little necrosis (hematoxylin-eosin (H&E) staining); (b) a few eosinophils (red arrow) with degranulation can be observed (H&E staining); (c, d) eosinophil degranulation (red arrowhead) confirmed by direct fast scarlet (DFS) staining and immunostaining for major basic protein (MBP).
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Myocardial specimens showed abundant lymphocytic infiltration with interstitial edema and slight perivascular fibrosis (Figure 2(a)). However, a close observation of the specimens revealed eosinophils with degranulation (Figure 2(b)). Eosinophil degranulation was also confirmed by direct fast scarlet stain (DFS) and immunostaining for major basic protein (MBP) (Figures 2(c) and 2(d)).
Changes in troponin I (TnI) level and left ventricular ejection fraction (LVEF) before and after steroid therapy. Rapid improvements in TnI and LVEF were found after the steroid administration.
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Echocardiography performed 12 hours after the first administration of methylprednisolone showed marked improvement of LVEF from 45% to 65% (Figure 3) and normalization of regional wall motion. On the following day, serum troponin I level decreased from 1.007 ng/muL to 0.152 ng/muL (Figure 3).