Hypoplastic Right Heart Syndrome

At a glance

Congenital heart disease characterized by underdevelopment of the right-sided structures of the heart, which causes inadequate blood flow to the lungs, severe cyanosis, and abnormal coronary supply, causing damage to the heart muscle. It can be associated with aortic stenosis.

Synonyms

Congenital Isolated Hypoplasia of the Right Ventricle; Hypoplasia of the Right Heart Ventricle; Hypoplastic Right Ventricle.

Incidence

Hypoplastic right heart syndrome is less common than hypoplastic left heart syndrome and occurs in 4 out of every 10,000 births.

Genetic inheritance

Autosomal recessive.

Pathophysiology

In its usual form, there is attenuation of the apical trabecular zone of the right ventricle with a normal and nonobstructed pulmonary outflow tract. The tricuspid valve may be hypoplastic or frankly obstructive.

Diagnosis

Electrocardiography demonstrates sinus rhythm with right atrial enlargement. Chest radiography shows mild cardiac enlargement with an enlarged right heart border, decreased pulmonary segment, and reduced vascularity.

Clinical aspects

Significant cyanosis at birth. Signs of venous congestion with hepatomegaly may occur within the first week. Death from progressive hypoxemia is common if appropriate therapy is not commenced.

Precautions before anesthesia

Adequate treatment of hypoxemia and heart failure. Echocardiography and cardiac catheterization are recommended to assess cardiac function and degree of right ventricular inflow obstruction. Need to exclude tetralogy of Fallot, Ebstein anomaly of the tricuspid valve, pulmonary atresia with intact septum, and tricuspid atresia with pulmonary stenosis.

Anesthetic considerations

Right ventricular filling is restricted because of the small tricuspid valve and hypoplastic right ventricle. This situation necessitates unimpeded blood flow from the right atrium to the left atrium, which is commonly achieved with balloon atrioseptostomy at birth. Anesthesia may be required later for aortopulmonary shunt, Glenn anastomosis (superior vena cava to right pulmonary artery), or Fontan operation (right atrium to right ventricle anastomosis).

Pharmacological implications

Determined by cardiac function.

References