Pulmonary stenosis is a common congenital heart disease. Simple pulmonary stenosis accounts for about 10% of congenital heart disease, and about 20% of congenital heart disease combined with pulmonary stenosis. I. Diagnosis (a) Symptoms: The severity of symptoms depends on the severity of obstruction, the functional status of the right ventricle, the degree of myocardial fibrosis, the function of the papillary muscle and the presence of tricuspid valve insufficiency. 1.Mild cases are mostly asymptomatic and are only detected during physical examination. 2.Moderate stenosis is asymptomatic in the second or third year of life, but shortness of breath is easily detected by fatigue during strenuous activity when older. In severe cases, symptoms may appear in infancy, with bruising and heart failure occurring. In children, respiratory distress, palpitations, weakness and occasionally syncope or sudden death may occur due to reduced cardiac output. (B) Signs: The sternum is seen to be raised forward, and there is a characteristic loud and rough jet systolic murmur in the pulmonary valve area, accompanied by tremor and early pulmonary artery jet sounds. In severe cases, there may be a relative systolic murmur and fourth heart sound in the tricuspid region, and the second pulmonary artery sound may be diminished or even absent. In severe cases with heart failure, the murmur may tend to soften and the tremor may disappear. (c) X-ray examination: in mild to moderate cases, the heart is generally not large and the pulmonary blood is generally normal; in heavy cases, the heart is often enlarged, with the right ventricle being the most important, the heart is mitral valve type, the pulmonary blood is small, and the pulmonary artery segment is dilated (post-stenosis expansion). The left pulmonary hilar pulsation is enhanced under fluoroscopy, while the right pulmonary hilar artery is relatively quiescent, resulting in asymmetry between the two hilum (left>right), which has important reference value for the diagnosis of this disease. (d) Electrocardiogram: mild cases are generally normal or show right bundle branch conduction block; medium-sized cases often have right-sided electrical axis and some degree of right ventricular hypertrophy; heavy cases have obvious right ventricular hypertrophy with extensive inversion of t waves in the thoracic leads and 75% p-wave hyperacusis indicating hypertrophy of the right atrium. (E) Echocardiography: 2D ultrasound aortic short-axis views showed enhanced pulmonary valve reflection, small annulus, thickened internal diameter of the main pulmonary artery and left pulmonary artery, and enlarged right heart system signs in apical four-chamber views. Systolic turbulent flow spectrum can be detected in the main pulmonary artery by pulsed Doppler. The degree of stenosis can be determined by ultrasound, and it is generally considered that pulmonary valve stenosis exists when the transvalvular pressure difference is >15 mmHg, mild when it is <40 mmHg, moderate when it is 40-70 mmHg, and severe when it is >70 mmHg. (F) Cardiac catheterization and angiography 1. Right heart catheterization to measure the right ventricular and pulmonary artery pressure and record the continuous pulmonary artery-right ventricular pressure curve. A pressure step difference between the two >2kpa (15mmhg) indicates the presence of stenosis. Selective right ventriculography shows the site and degree of right ventricular outflow tract stenosis and post-stenosis dilation, and can estimate right ventricular function. Treatment 1.Interventional treatment Currently, the use of balloon dilatation pulmonary stenosis shaping intervention has been listed as the preferred treatment option for simple pulmonary valve stenosis. This method has the advantages of less trauma, faster recovery, and higher success rate, and the cost of treatment is close to or even lower than that of surgical procedures. It is generally accepted that any dilated valve with a differential pressure greater than 50 mmHg requires treatment. The optimal age is 2 to 4 years. Any other age can be performed. Those greater than 35 mmHg can also be treated, and those less than 35 mmHg generally do not require treatment. Our experience is that the treatment is slightly less effective in mild cases and more effective in severe stenosis as long as the catheter can pass through the narrowed pulmonary artery. 2.Surgical treatment Some pulmonary stenoses that are not suitable for interventional treatment, such as severe dysplastic pulmonary stenosis, must be solved by surgical means.