Overview.
Leffler endocarditis is also known as eosinophilic endocarditis or eosinophilic endocardial disease. The patients are mostly middle-aged people in poor tropical and subtropical areas, with insidious onset and relatively slow progression of the disease. The clinical manifestations depend on the severity of the affected heart and lesions. According to the clinical manifestations of this disease combined with relevant laboratory tests, most cases can be diagnosed. Adrenal glucocorticoids and immunosuppressive drugs may be used in early cases.
Etiology
The cause is unknown. It is thought to be related to excessive intake of 5-hydroxytryptamine (local people eat a lot of bananas, and plantains and bananas are rich in 5-hydroxytryptamine), malnutrition, vitamin E and tryptophan deficiency. While filariasis, malaria, and schistosomiasis mansoni are widely spread in tropical and subtropical areas, it has also been suggested that the disease is related to the above parasitic diseases, but all lack specificity, so the etiology of the disease has not been clarified so far and needs to be further studied.
Symptoms
The patients are mostly middle-aged people in poor tropical and subtropical areas, with insidious onset and relatively slow progression. Its clinical manifestations depend on the affected heart and the severity of the lesion. The right heart is mainly involved in the person, cool narrowing pericarditis and tricuspid valve closure signs, can be found in the tricuspid valve auscultation area of systolic regurgitant murmur and the signs of body circulation stasis, while the lower extremity edema is relatively mild. In the predominantly left heart involvement, mitral valve insufficiency and signs of pulmonary bruising may occur. Simultaneous involvement of both ventricles may produce signs of total heart failure, but right heart failure is the predominant clinical condition. In addition, dislodgment of epiphyseal thrombus may produce signs of arterial embolism. Systemic symptoms such as splenomegaly, enlarged lymph nodes and gastrointestinal involvement, anemia, and eosinophilia in the blood and bone marrow may also occur.
Tests
Peripheral blood eosinophilia and leukocyte count are increased, eosinophils >15×108/L, bone marrow granulopoiesis is active, in which the proportion of eosinophils is increased.
1. X-ray examination
The predominant right ventricular involvement may be manifested as obvious enlargement of the right atrium, dilatation of the right ventricular outflow tract leading to mild expansion of the upper left cardiac margin below the pulmonary artery, spherical or flask-shaped cardiac shadows, and reduction of pulmonary blood, which may resemble the manifestation of pericardial effusion or Ebstein’s anomaly. Because endocardial fibrous thickening and/or calcification of the attached thrombus are common in this disease, calcified shadows can be seen in some cases in the apical direction toward the outflow tract. Right ventriculography and cardiac function measurements often show apical occlusion and hypodiastolic function of the right ventricle, diastolic dysfunction of the inflow tract, and essentially normal function of the outflow tract, which are the characteristic changes of this disease. The left ventricular involvement of the main type of X-ray performance can be very similar to the mitral valve closure of wind heart disease, but the heart is generally only mildly enlarged, there may be the left atrium, the left ventricle is mildly enlarged, as well as pulmonary stasis and pulmonary hypertension changes. Left ventricular angiography may reveal filling defects caused by attached wall thrombus, the endocardial surface is not smooth and uneven, and cardiac function measurements mostly show left ventricular diastolic dysfunction. In the case of biventricular involvement, the X-ray performance is a combination of the above two types, but the right ventricular damage is often more serious.
2. Echocardiography
Echocardiography can be enhanced by endocardial thickening and subendocardial myocardial fibrosis, and sometimes it can find attached thrombus, and it can show apical occlusion in systole, and the inner diameter of ventricular cavity can be normal, enlarged or narrowed, and the atria are often enlarged to different degrees. In addition, there may be ultrasound signs of tricuspid and/or mitral valve insufficiency. Cardiac function tests often show diastolic dysfunction. Pericardial effusion may be present in some cases.
3. Electrocardiogram
Electrocardiographic changes are not specific and may include atrial enlargement and non-specific ST-T changes. In addition, there may be various types of arrhythmias.
4. Endomyocardial biopsy
It is of great value in the diagnosis of this disease, and can find pathological changes such as endocardial eosinophilic infiltration, endocardial fibroplasia, and subendocardial myocardial necrosis.
Diagnosis
According to the clinical manifestations of this disease combined with relevant laboratory tests, the diagnosis can be made in most cases. Clinically, this disease should be considered in the following cases: ① Unexplained progressive heart failure with murmur of tricuspid and tricuspid insufficiency and third heart sound, enlarged heart, but the hemodynamic changes are similar to constrictive pericarditis. Increased blood leukocyte count, eosinophils＞15×108/L, active proliferation of bone marrow granulopoiesis, in which the proportion of eosinophils is increased. (iii) Accompanied by involvement of organs other than the cardiovascular system, e.g. hepatosplenomegaly, gastrointestinal symptoms, superficial lymph node enlargement, anemia, etc., disproportionate to the degree of heart failure. ④ X-rays and ULGs show apical occlusion, inflow tract involvement, outflow tract dilatation, endocardial and subendocardial thickening and appendage thrombosis, and diastolic dysfunction predominates in cardiac function tests. ⑤ Subendocardial myocardial biopsy showed pathological changes such as endocardial collagen fiber proliferation, myocardial necrosis and eosinophil infiltration.
Differential diagnosis
This disease needs to be distinguished from Ebstein’s malformation, mitral valve insufficiency and constrictive pericarditis.
Treatment
There is a lack of effective treatment for this disease. Adrenal glucocorticoids and immunosuppressive drugs may be used in early cases. Hydroxyurea is effective in treating this disease, with 4 to 6 weeks as a course of treatment, supplemented with vincristine if necessary. If heart failure, arrhythmia and other complications occur, should be treated accordingly, severe valvular insufficiency can be performed valve replacement, while removing excessive fibrous tissue and attached wall thrombus. Anticoagulant drugs are helpful in the prevention and treatment of arterial embolism.