Pulmonary valve stenosis (simple pulmonary stenosis) is a common congenital heart disease, which refers to a series of pathophysiological changes in the heart called pulmonary valve stenosis due to structural changes in the pulmonary valve caused by various reasons, resulting in the inability of the pulmonary valve to open completely when the right ventricle contracts. The pathogenesis of pulmonary valve stenosis The malformation has no significant effect on blood circulation during the fetal period. The heart is born with normal size and the lungs expand after birth, but due to the narrowing of the pulmonary artery opening, the right ventricular blood drainage is blocked, thus increasing the right ventricular pressure while the pulmonary artery pressure is low. The increased systolic load of the right ventricle over a long period of time causes hypertrophy of the right ventricle, and the cardiac output is usually still maintained. In right heart failure, the cardiac output decreases, the right ventricle enlarges, and the right atrial and peripheral venous pressure increases. The increased pressure in the right atrium may exceed the pressure in the left atrium. If there is an atrial septal defect or an unclosed foramen ovale, it may cause a right-to-left shunt and cyanosis. Clinical symptoms of pulmonary stenosis Patients with mild pulmonary stenosis are generally asymptomatic, but symptoms gradually appear with age, mainly manifesting as poor labor tolerance, fatigue, chest tightness, cough, occasional chest pain or syncope, palpitations and shortness of breath after exertion. In severe stenosis, dizziness or fainting episodes may occur. In advanced cases, symptoms of right heart failure such as jugular vein anger, hepatomegaly and swelling of the lower limbs may appear, and in case of coexisting atrial septal defect or oval fossa non-closure, cyanosis of the lips of the mouth or the ends of the terminal fingers (toes) and pestle-like fingers (toes) may be seen. Notably, patients with pulmonary stenosis are more susceptible to pulmonary infections, such as tuberculosis. Symptoms of right heart failure may be present in the later stages. Occasionally, it may be complicated by infective endocarditis. Physical examination of pulmonary stenosis, most patients are well developed. The main sign is a loud and rough systolic murmur of grade III-IV jet blowing wind-like sound can be heard at the 2nd rib at the left edge of the sternum, conduction to the left neck or left subclavian region, systolic tremor can be palpated at the loudest part of the murmur, the intensity of the murmur varies depending on the degree of stenosis, blood flow rate, blood flow and chest wall thickness. The 2nd heart sound in the pulmonary valve region is often diminished and split. In patients with funnel stenosis, the murmur and tremor are usually at the left 3rd or 4th intercostal space and are less intense. The 2nd heart sound in the pulmonary valve region may not be attenuated and sometimes even shows splitting. In severe stenosis there may be signs of right ventricular enlargement with marked elevated pulsations in the precordial region, and the patient may be less developed. Patients with right-to-left shunts in the presence of an atrial septal defect may present with cyanosis and pestle fingers. Auxiliary tests for pulmonary stenosis include X-ray, electrocardiogram, and echocardiography; echocardiography in cases of pulmonary stenosis may show restricted leaflet opening, a dome-shaped protruding leaflet with a narrow orifice, and may identify hypertrophy of the right ventricular outflow tract muscle and the degree of right ventricular and right atrial enlargement. It has important clinical value. Diagnosis of pulmonary stenosis The signs, X-rays, electrocardiograms, and echocardiograms of pulmonary orifice stenosis alone are characteristic and not difficult to confirm, while right heart catheterization can help determine the type and extent of stenosis. Selective cardiovascular angiography can further understand the anatomy of the pulmonary artery, pulmonary valve and funnel section. Treatment of pulmonary stenosis: Patients with mild pulmonary stenosis are clinically asymptomatic and can grow and develop normally and adapt to normal life skills without surgical treatment. Long-term results remain to be seen. Balloon catheter dilation is not effective in cases of combined funnel stenosis. In infants, right ventricular pressure as high as 20.0 to 26.7 kPa (150 to 200 mmHg) indicates severe obstruction, and urgent surgery should be performed to dissect the stenotic valve to avoid delaying the development of intractable right heart failure and losing the opportunity for treatment. Prognosis of pulmonary stenosis: Mild stenosis of the pulmonary valve has a good prognosis and can live into adulthood. Severe stenosis often results in early heart failure. Common complications are subacute bacterial endocarditis and heart failure. Successful surgery reduces or eliminates symptoms, allows participation in normal labor, reduces the shape of the heart, reduces right ventricular hypertrophy, and reduces the heart murmur, but rarely does it disappear completely.