Cardiac Abnormalities in Hypereosinophilic Syndromes

Abstract

Hypereosinophilia (HE) is defined as an eosinophil count exceeding 1500 cells/microL in peripheral blood in two tests, performed with an interval of at least one month and/or anatomopathological confirmation of HE, with eosinophils comprising more than 20% of all nucleated cells in the bone marrow. Hypereosinophilic syndrome (HES) indicates the presence of HE with organ involvement due to eosinophil action, which can be classified as primary (or neoplastic), secondary (or reactive), and idiopathic. Cardiac involvement occurs in up to 5% of cases in the acute phase and 20% of the chronic phase of the disease, ranging from oligosymptomatic cases to fulminant acute myocarditis or chronic restrictive cardiomyopathy (Loeffler endomyocarditis). However, the degree of cardiac dysfunction does not directly correlate with the degree of eosinophilia. The cardiac involvement of HES occurs in three phases: initial necrotic, thrombotic, and finally necrotic. It can manifest as heart failure, arrhythmias, and thromboembolic phenomena. The diagnosis of cardiopathy is based on multimodality imaging, with an emphasis on the importance of echocardiography (echo) as the primary examination. TTE with enhanced ultrasound agents can be used for better visualization, allowing greater accuracy in assessing ventricular apex, and myocardial deformation indices, such as longitudinal strain, may be reduced, especially in the ventricular apex (reverse apical sparing). Cardiac magnetic resonance imaging allows the characterization of subendocardial late gadolinium enhancement, and endomyocardial biopsy is considered the gold standard in diagnosing cardiopathy. Treatment is based on the etiology of HES.

Figura Central. : Anormalidades Cardíacas nas Síndromes Hipereosinofílicas

Figura 1. – Imagens de ecocardiograma transtorácico de um paciente diagnosticado com SHE e obliteração apical do ventrículo esquerdo no corte apical de 2 câmaras (A), corte apical de 4 câmaras (B) e do ventrículo direito no corte apical modificado para avaliação do VD (C). Observa-se insuficiência mitral de grau discreto ao Doppler colorido.

Figura 2. – Imagem de ressonância magnética cardíaca de um paciente com SHE e anormalidades cardíacas. Eixo longitudinal quatro câmaras com deposição de tecido fibroso endocárdico apical biventricular e microtrombos no átrio direito (A); Imagens para avaliação de fibrose pela técnica de realce tardio pelo gadolínio (RTG) (B). Eixo longitudinal da via de saída do ventrículo esquerdo com deposição de tecido fibroso endocárdico apical biventricular (C) ce avaliado pela técnica de RTG (D). Ao: aorta; AE: átrio esquerdo; VE: ventrículo esquerdo; AD: átrio direito; VD: ventrículo direito.

Central Illustration. : Cardiac Abnormalities in Hypereosinophilic Syndromes

Figure 1. – Transthoracic echocardiogram images of a patient diagnosed with HES and apical obliteration of the left ventricle in the apical 2-chamber view (A), apical 4-chamber view (B) and from the right ventricle to the apical 4-chamber view directed towards the RV (C). A mild degree of mitral regurgitation is observed on color Doppler echocardiography.

Figure 2. – Cardiac magnetic resonance imaging of a patient with HES and cardiac abnormalities. Four chamber view with biventricular apical endocardial fibrous tissue deposition and microthrombi in the right atrium (A) with late gadolinium enhancement (LGE) CMRI (B). Left ventricular outflow tract view with biventricular apical endocardial fibrous tissue deposition (C) with LGE (D). Ao,:aorta; LA: left atrium; LV: left ventricle; RA: right atrium; RV: right ventricle.