Pulmonary hypertension diagnostic criteria WHO criteria: 1, in the resting state at sea level, the mean pulmonary artery pressure measured by right heart catheter ≥ 25 mmHg, or the mean pulmonary artery pressure in the exercise state ≥ 30 mmHg (National Institutes of Health criteria). 2.If there is no right heart catheter data, Doppler ultrasonography suggesting pulmonary artery systolic pressure ≥ 40 mmHg can also be tentatively diagnosed as pulmonary hypertension. 3, For arterial pulmonary hypertension, in addition to the above diagnostic criteria for pulmonary hypertension, it is also necessary to meet pulmonary capillary wedge pressure or left ventricular end-diastolic pressure or left atrial pressure ≤ 15 mmHg and pulmonary vascular resistance > 3wood units. The criteria proposed by Langevizy et al. in 1992: Echocardiographic Doppler or cardiac catheterization of the heart confirming resting pulmonary artery systolic pressure >3.3 kPa or a hyperactive second heart sound in the pulmonary valve area plus at least 1 of the following 4 items: 1. ECG showing right ventricular hypertrophy or right atrial enlargement; 2. Chest radiograph showing significant dilatation of the pulmonary arteries and large branches; 3. Carbon monoxide diffusion <43% of the expected value; 4. Right ventricular overload and right ventricular dilatation with tricuspid regurgitation.