Eosinophilic myocarditis is a myocarditis with a relative increase in eosinophils in the inflammatory infiltrate. A fulminant presentation may result in cardiac arrest or the need for circulatory support.
Causes:
(1) hypersensitivity reaction (drugs, other)
(2) eosinophilic granulomatosis with polyangiitis (EGPA, Churg-Strauss syndrome)
(3) hypereosinophilic syndrome
(4) infection (Toxocara canis, other parasites)
(5) cancer
(6) pregnancy-related
(7) toxic
(8) Omenn syndrome
(9) idiopathic
Spectrum:
(1) acute fulminant (acute necrotizing)
(2) chronic restrictive cardiomyopathy (Loeffler's eosinophilic endomyocarditis)
Clinical symptoms:
(1) dyspnea
(2) chest pain
(3) nausea
(4) myalgia
(5) fatigue
Laboratory finding:
(1) eosinophilia in the peripheral blood (may be absent in 25% at presentation)
(2) elevated C-reactive protein (CRP)
(3) elevated serum troponin
(4) elevated brain natriuretic peptide
The ECG may:
(1) be normal
(2) show ST segment elevation or abnormalities
(3) show bundle branch block
(4) ventricular flutter or fibrillation
Imaging studies may show a pericardial effusion, which can result in tamponade.
An endomyocardial biopsy can be diagnostic.
