The symptoms of heart disease are basically panic attacks and shortness of breath, but in the case of simple mitral stenosis, the main symptom is a diastolic murmur heard in the apical region of the heart. At the same time, because of mitral stenosis, the flow of blood from the left atrium to the left ventricle is obstructed, and the obstruction causes an increase in pressure in the left atrium, and the blood from the left atrium flows out of the lungs. After the increase of pulmonary circulation pressure, the obstruction of pulmonary circulation will lead to the increase of pulmonary venous pressure, which in turn will lead to the increase of pulmonary artery pressure, resulting in pulmonary hypertension. The clinical sign of pulmonary hypertension is called pulmonary valve second sound hyperinflation or augmentation.