The incidence of Fallot's trilogy accounts for approximately 2-3% of congenital heart diseases. Its pathological features include pulmonary valve stenosis accompanied by patent foramen ovale or secundum atrial septal defect and right ventricular hypertrophy. Due to obstructed right ventricular outflow, this condition leads to right ventricular hypertrophy and progressive obstruction of the right ventricular outflow tract, increasing pressure in the right ventricle and right atrium. This results in a right-to-left intracardiac shunt, causing symptoms such as palpitations, shortness of breath, easy fatigue, and cyanosis in patients.

bubble_chart Clinical Manifestations

1. Palpitation, shortness of breath, lack of strength, and poor development. In mild cases, cyanosis may not be obvious, while in severe cases, cyanosis or squatting and syncope are common. 2. Those with obvious cyanosis have clubbing of fingers and toes, weakened or absent second heart sound in the pulmonary valve area, a rough blowing systolic murmur heard in the second left intercostal space along the sternal border, and systolic tremor.

bubble_chart Diagnosis

1. Palpitation, shortness of breath, cyanosis, clubbing of fingers (toes), and a loud, rough systolic blowing murmur heard in the pulmonary valve area. 2. Severe cases show increased red blood cells and hemoglobin. 3. X-ray reveals decreased pulmonary blood flow, enlarged right ventricle and right atrium, and a prominent pulmonary segment. 4. Electrocardiogram indicates right ventricular hypertrophy, strain, and right axis deviation. 5. Color Doppler echocardiography shows enlargement of the right atrium and right ventricle, interruption of the atrial septum continuity, pulmonary valve stenosis, and right-to-left shunting at the atrial level. 6. Cardiac catheterization and selective right ventricular angiography demonstrate the catheter passing through the atrial septal defect from the right atrium to the left atrium, a pressure gradient between the pulmonary artery and right ventricle, and right ventricular angiography reveals pulmonary valve stenosis or hypertrophic muscle bundles in the right ventricular outflow tract. [Treatment Principles] 1. The primary pathology of Fallot's trilogy involves the right heart, so intraoperative protection of the hypertrophic right ventricle is essential. 2. Direct suturing or patching of the foramen ovale or atrial septal defect; incision of the stenotic pulmonary valve annulus; thorough resection of hypertrophic muscle bundles in the right ventricular outflow tract; sometimes patching of the right ventricular outflow tract incision is needed to ensure patency and achieve satisfactory postoperative reduction in right ventricular pressure.

The clinical symptoms of Fallot's trilogy or significant cyanosis, markedly increased right ventricular pressure, and right ventricular hypertrophy, even if the pulmonary valve stenosis is not severe but if the atrial septal defect is large with right-to-left shunting, all warrant aggressive surgical treatment. Currently, early surgery is advocated, and young age is not a contraindication for surgery, as a long medical history and older age lead to poorer treatment outcomes.

bubble_chart Cure Criteria

1. Cured: Symptoms and cyanosis disappear, with no limitations on general activities. 2. Improved: Postoperative symptoms are alleviated, but palpitations persist. 3. Not cured: Symptoms and signs show no improvement.