Tricuspid valve anomaly (Ebstein's anomaly): symptoms, diagnosis, treatment

Ebstein's anomaly (tricuspid valve anomaly) is a congenital pathology of the tricuspid valve characterized by the displacement of the cusps (usually both the septal and posterior) into the cavity of the right ventricle, which leads to the formation of an atrialized part of the right ventricle. As a result of the displacement of the tricuspid valve cusps, the cavity of the right ventricle is divided into two parts. Only the lower part, located under the valve, functions as the right ventricle and consists of the trabecular and outflow sections. With moderate displacement of the cusps and regurgitation, circulatory disorders are minimal, the defect can be asymptomatic for a long time. Blood discharge through an atrial septal defect or through an open oval window is possible. In this case, symptoms of arterial hypoxemia occur. Volume overload of the right sections leads to bulging of the interventricular septum to the left, which limits filling of the left ventricle, and congestive heart failure may develop. In the natural course of the defect, the prognosis depends on the degree of dysfunction of the tricuspid valve, as well as on the degree of hypoplasia of the right ventricle. About a quarter of children die during the first month of life; in non-operated patients, the cause of death is progressive heart failure. The frequency of the defect is 0.4% of all congenital cardiac anomalies. Familial cases of Ebstein's anomaly are possible.

Symptoms of tricuspid valve anomaly (Ebstein's anomaly) depend on the degree of hemodynamic impairment. In the presence of an atrial septal defect, the leading symptom is cyanosis, the severity of which depends on the pressure in the right atrium and the volume of blood discharged through the interatrial communication. Over time, signs of heart failure increase, and tolerance to physical activity decreases. A cardiac hump may form due to the large size of the right atrium and right ventricle. Auscultatory changes are mild. With tricuspid insufficiency, a soft systolic murmur is heard; in the presence of stenosis of the right atrioventricular orifice, a presystolic or mesodiastolic murmur appears at the right edge of the sternum. The intensity of the murmurs increases during the inhalation phase, which indicates their connection with damage to the tricuspid valve. With significant dilation of the right atrium and ventricle, cardiac arrhythmias occur. Paroxysmal supraventricular tachycardia is detected in 25-50% of patients, Wolff-Parkinson-White syndrome - in 14%.

Electrocardiographic examination is often helpful in diagnosing Ebstein's anomaly. Typically, the electrical axis of the heart is sharply deviated to the right, signs of incomplete or complete right bundle branch block are found with low amplitude of the R and S waves.

On chest X-ray, the heart has a spherical configuration, enlarged mainly due to the right atrium and the "atrialized" part of the right ventricle. The pulmonary pattern is normal or depleted.

EchoCG in the projection of four chambers attracts attention to the displacement of the septal valve into the cavity of the right ventricle. An open oval window or an atrial septal defect is detected in 85% of cases. Doppler echocardiography reveals the magnitude of tricuspid insufficiency.

Cardiac catheterization is performed to assess the condition of the pulmonary bed and electrophysiological examination in case of cardiac arrhythmia.

Treatment of tricuspid valve anomaly (Ebstein's anomaly)

Patients with moderate or minor tricuspid regurgitation require constant monitoring by a cardiologist and electrocardiographic control. Surgical treatment is indicated for heart failure, arterial hypoxemia, and cardiac arrhythmias refractory to therapy.

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