Application of Routine Echocardiography Combined with Contrast-Enhanced Echocardiography in the Diagnosis of Endomyocardial Fibrosis

Background: In China, endomyocardial fibrosis (EMF) is a type of restrictive cardiomyopathy that is rare and easy to be misdiagnosed. Our aim was to examine the value of routine echocardiography (RE) combined with contrast-enhanced echocardiographyMethods: We studied 16 EMF patients retrospectively, from 2012 to 2022. All patients underwent RE, from which 11 underwent CEE. We divided the patients into three groups: biventricular EMF (Bi-EMF), right ventricular EMF (RV-EMF), and left ventricular EMF (LV-EMF) based on different lesion locations. We also analyzed the clinical and conventional ultrasound characteristics of the three groups of patients and examined the ventricle opacification (VO) and myocardial contrast echocardiography (MCE) characteristics of patients who underwent CEE.Results: All patients with EMF subtypes had the following ultrasound findings: apical occlusion on one or both sides, corresponding atrial dilatation, atrioventricular valve regurgitation in varying degrees, and cardiac diastolic dysfunction. Of the subjects, 69% had apical thrombus calcification and 81% had mild pericardial effusion. RV-EMF patients had statistically significant right atrial enlargement compared with the other two groups (p < 0.05), moderate or severe tricuspid regurgitation, and inferior vena cava (IVC) dilation. LV-EMF patients had statistically significant left atrial enlargement compared with the other two groups (p < 0.05), elevated pulmonary artery systolic pressure (PASP), and 60% of LV-EMF patients had moderate or severe mitral regurgitation. Bi-EMF patients had bilateral atrial enlargement, an IVC collapsibility index <50%, and elevated PASP. CEE was performed in 11 patients, whose ventricle opacification showed no contrast filling in the apical occluded area and the heart chambers presented the "mushroom sign" during diastole. Their myocardial contrast echocardiography (MCE) showed delayed perfusion in the thickened fibrotic endomyocardium (TFE) of the apical and subvalvular regions and perfusion defect in the apical thrombus. The number and location of thrombus determined by the MCE combined with RE were the same as those detected by cardiac magnetic resonance imaging (CMR). MCE shows that the position and range of TFE are similar to CMR.Conclusions: EMF has characteristic RE presentation, and different EMF subtypes have unique characteristics. CEE can better display heart structure, ventricular wall motion, and tissue perfusion compared to RE. A combination of RE and CEE can make the EMF diagnosis more accurate, thereby allowing early treatment for EMF patients.