A Rare Case of Isolated Right Ventricular Loeffler's Endocarditis in Primary Hypereosinophilic Syndrome

Abstract

Hypereosinophilic syndrome (HES) is a systemic disorder with various manifestations, characterized by hypereosinophilia and caused by primary or secondary conditions. Loeffler's endocarditis (LE) represents a frequent cardiac manifestation of HES, caused by infiltration of the myocardium by eosinophilic cells, which determines endocardial damage, with subsequent inflammation, thrombosis, and fibrosis of either one or both ventricles. The diagnosis of cardiac involvement is based on a multimodality approach (i.e., two-dimensional transthoracic echocardiography [2D-TTE], speckle-tracking echocardiography [STE], and cardiac magnetic resonance [CMR]), with different findings depending on the stage of disease. STE may be useful in the initial phase when traditional imaging techniques may result negative, whereas CMR allows myocardial tissue characterization along with a better definition of the right ventricle. We present a rare case of LE with isolated right ventricular involvement in a patient with HES caused by chronic eosinophilic leukemia with constitutively activated fusion tyrosine kinase on chromosome 4q12, successfully treated with imatinib mesylate.

Keywords: Cardiac magnetic resonance; Loeffler’s endocarditis; multimodality imaging; speckle-tracking echocardiography.

Figure 1

Resting electrocardiogram at admission which shows sinus tachycardia with negative T waves from V1 to V5

Figure 2

Two-dimensional transthoracic echocardiography views (four-chambers and parasternal long-axis view for the right ventricle) upon admission (a), at discharge (b), and after 3 months of therapy (c). Note the marked thickening of the right ventricle with the obliteration of the midportion and the apex in (a); in (b), there is a reduction of right ventricular thickness with an initial vacuolization; and in (c), a further improvement of right ventricular infiltration and a marked reduction wall thickness

Figure 3

Right ventricular free-wall longitudinal strain (RVFWLS) upon admission (a), at discharge (b), and after 3 months of therapy (c) with longitudinal strain curves. Of note, a global dyssynchrony and an early systolic lengthening of the basal segment were observed (arrow in a), with subsequent normalization (arrow in b and c) after treatment, together with an increase of RVFWLS value and a normalization of curve synchrony

Figure 4

Cardiac magnetic resonance at steady-state free precession sequences (left squares), T1-weighted sequence (middle squares), and perfusion sequence (right squares) at admission (a) and at 6 months after discharge (b). Note the obliteration of the right ventricular apex, the presence of diffuse endocardial late gadolinium enhancement (LGE) and thrombotic apposition at admission and the marked reduction of right ventricular obliteration and LGE signal intensity at 6-month follow-up