bubble_chart Overview

Pulmonary stenosis is morphologically classified into two types. The more common type involves the fusion of three valve membranes at the commissures, forming a septal membrane that protrudes dome-like or nipple-like into the pulmonary artery, with a narrow central orifice (typically 2–3 mm in diameter). The less common type features significantly thickened and shortened valve membranes with irregular edges, resulting in milder stenosis (orifice diameter approximately 5–10 mm).

bubble_chart Auxiliary Examination

1. X-ray examination: In mild to grade II cases, the heart is generally not enlarged, and pulmonary blood flow is roughly normal; in severe cases, there is often cardiac enlargement, predominantly in the right ventricle, with the heart appearing mitral-shaped. Pulmonary blood flow is reduced, and the pulmonary artery segment is bulging (post-stenotic dilation). Under fluoroscopy, the left hilar pulsation is enhanced, while the right hilar pulsation remains relatively static, resulting in asymmetry between the two hila (left > right), which is of significant diagnostic value for this condition.
2. Electrocardiogram: Mild cases are generally normal or show right bundle branch block; moderate cases often exhibit right axis deviation and a certain degree of right ventricular hypertrophy; severe cases show marked right ventricular hypertrophy, with widespread T-wave inversion in the chest leads, and 75% of cases have tall, peaked P waves indicating right atrial hypertrophy as well.
3. Echocardiography: In the two-dimensional ultrasound short-axis view of the main pulmonary artery, the pulmonary valve appears hyperechoic, the valve ring is small, and the diameters of the main pulmonary artery and left pulmonary artery are increased. The apical four-chamber view reveals signs of enlargement in the right heart system. Pulsed Doppler can detect a systolic turbulent flow spectrum within the main pulmonary artery.
4. Cardiac catheterization and angiography:
   1. Right heart catheterization measures the pressure in the right ventricle and pulmonary artery and records the pulmonary artery-right ventricular continuous pressure curve. A pressure gradient >2 kPa (15 mmHg) between the two indicates the presence of stenosis.
   2. Selective right ventricular angiography reveals the location and degree of right ventricular outflow tract stenosis, post-stenotic dilation, and can also assess right ventricular function.

bubble_chart Diagnosis

(1) Symptoms The severity of symptoms depends on the degree of obstruction, the functional status of the right ventricle, the extent of myocardial fibrosis, papillary muscle function, and the presence or absence of tricuspid regurgitation, among other factors.

1. Mild cases are often asymptomatic and are only discovered during physical examinations.
2. Severe cases may present with symptoms such as cyanosis and heart failure as early as infancy. Children may experience dyspnea, palpitation, lack of strength, and occasionally syncope due to reduced cardiac output.

(2) Signs A forward bulge of the sternum may be observed, along with a characteristic loud and harsh ejection systolic murmur in the pulmonary valve area, accompanied by a thrill and an early ejection click of the pulmonary valve. In grade III cases, a relative systolic murmur in the tricuspid area and a fourth heart sound may be present, with weakening or even disappearance of the pulmonary second sound. In grade III cases complicated by heart failure, the murmur may become softer, and the thrill may also disappear.

bubble_chart Treatment Measures

1. Surgical Indications: A systolic pressure gradient >50mmHg between the right ventricle and the pulmonary stirred pulse or a right ventricular systolic pressure >100mmHg requires surgical treatment. If the pressure gradient < 50mmHg或右心室收縮壓<50mmHg而臨床無症狀，心電圖及X線無明顯變化者，一般暫不需手術治療，而應定期隨訪。
2. Surgical Method: Perform an open pulmonary stirred pulse valvotomy under direct vision. For cases complicated by fistula disease with infundibular stenosis, corrective surgery should be performed under extracorporeal circulation.
3. Balloon Pulmonary stirred pulse Valvuloplasty: Currently, this non-surgical method is widely used both domestically and internationally to treat pulmonary stirred pulse stenosis, replacing traditional surgical approaches. It demonstrates significant efficacy with fewer complications. The procedure involves inserting a balloon-tipped catheter into the femoral vein, advancing the balloon to the level of the stenotic valve membrane orifice, and rapidly injecting a 60% meglumine diatrizoate contrast agent to inflate and expand the balloon, thereby enlarging the valve membrane orifice. This method is highly effective for moderate to grade III pulmonary stirred pulse valve stenosis, significantly reducing postoperative right ventricular pressure and the right ventricle-pulmonary stirred pulse pressure gradient. However, it is less effective for cases of pulmonary stirred pulse valve dysplasia. Currently, balloon pulmonary stirred pulse valvuloplasty is considered the first-line treatment for congenital pulmonary stirred pulse valve stenosis. It also significantly improves hemodynamics in cases of pulmonary stirred pulse stenosis and branch stenosis.