bubble_chart Overview

Endocardial fibroelastosis, also known as endocardial sclerosis, is characterized by thickening of the endocardium accompanied by elastic fiber proliferation and myocardial hypertrophy. It is often associated with other congenital malformations and is one of the main causes of heart failure-related deaths in infancy.

bubble_chart Etiology

The cause of the disease

is not yet fully understood and may be related to the following factors: (1) Intrauterine viral infection, primarily Coxsackie B group virus; (2) Congenital developmental defects and genetic factors; (3) Intrauterine hypoxia or nutritional deficiencies.

Pathology

The heart enlarges 2–4 times, with significant thickening of the left ventricle. Subendocardial elastic fiber proliferation can reach several millimeters; half of the cases involve the valve membranes. Myocardial hypertrophy exhibits degenerative changes or necrotic fibrosis. Due to the thickening and roughening of the endocardium, mural thrombosis is prone to form.

bubble_chart Clinical Manifestations

It is most commonly seen in children under 2 years old, with the main manifestation being heart failure. Clinically, it can be divided into three types: (1) Fulminant type: Sudden onset of heart failure, pulmonary edema, cyanosis, tachycardia, etc., in infants under 6 months old, which is one of the causes of sudden infant death. (2) Acute type: Primarily characterized by heart failure, often triggered by factors such as respiratory infections, with cough, dyspnea, cyanosis, and hepatomegaly. The heart failure is prone to recurrence and difficult to control, leading to death within 1–3 weeks. (3) Chronic type: Gradual onset in slightly older infants (over 6 months old), presenting with poor appetite, delayed growth and development, dyspnea after activity, and susceptibility to pneumonia, eventually leading to heart failure.

Other manifestations may include cerebral embolism due to detachment of mural thrombi, and a minority may have endocardial sclerosis with mitral valve insufficiency.
Signs: There may be precordial bulging, significantly enlarged cardiac borders, weak apical impulse, dull heart sounds, tachycardia, arrhythmia, and possibly a systolic murmur of grade II/6.

[Auxiliary examinations]

1. X-ray shows significant cardiac enlargement, primarily left ventricular enlargement, with weak pulsation.
2. Electrocardiogram mainly indicates left ventricular hypertrophy and strain, sometimes with hypertrophy of both left and right ventricles, S-T segment depression, flat or inverted T waves, and possible conduction block or extrasystoles.
3. Echocardiography reveals increased left ventricular diameter, thickened left ventricular wall, weakened movement, and sometimes enlarged ventricles; mural thrombi may also be observed if present.

bubble_chart Diagnosis

(1) The infant has significant cardiomegaly, weak heart sounds, and indistinct murmurs. (2) Recurrent episodes of heart failure occur. (3) X-ray shows predominant left ventricular enlargement. (4) Electrocardiogram indicates left ventricular hypertrophy with strain. (5) Changes are observed on echocardiography.

bubble_chart Treatment Measures

﹝Treatment﹞

(1) Prevent respiratory infections; (2) Control heart failure. After acute heart failure is controlled, long-term maintenance therapy with digoxin is administered for 1 to 2 years or longer, combined with prednisone at 1 to 2 mg/kg·d. The dosage is reduced after 6 to 8 weeks, and a maintenance dose of 2.5 to 5 mg/d is taken long-term for 1 to 3 years until the electrocardiogram returns to normal and X-ray examination shows no cardiac enlargement, after which the medication is gradually discontinued.

bubble_chart Differentiation

It should be differentiated from pericarditis, myocarditis, and cardiac glycogen storage disease. In areas where Keshan disease is prevalent, it should be distinguished from Keshan disease.