The right ventricular outflow tract is one of the most common congenital cardiac malformations, with 3.6 cases per 10,000 deliveries found in infants with this condition, accounting for 12% to 14% of congenital organs, and the first among cyanotic cardiac malformations, accounting for 50% to 90%. The most common major clinical signs are cyanosis and blood hypoxia. So, what are the right ventricular outflow tract examinations? Common examinations are as follows: Chest X-ray: typical cases of tetralogy of Fallot show no enlargement of the heart, abnormally clear lung fields, and sparse vascular shadow patterns. If the common pulmonary artery trunk is small, the left edge of the heart is flat or depressed. If the 3rd ventricle is large, the pulmonary artery segment at the left edge of the heart is prominent. The apex of the heart is elevated due to right ventricular hypertrophy. On posteroanterior radiographs, the heart image is boot-shaped. In about 1/4 cases, the aortic arch is located on the right side. Electrocardiography: shows right ventricular hypertrophy and strain with a right-sided electrical axis. The R waves in the right precordial leads are significantly elevated, and the T waves are inverted. A subset of patients showed hypertrophied right atrial hypertrophy in leads I and II with hyperacute P waves. The left precordial leads do not show Q waves and have low R-wave voltage. Right heart catheterization: Right heart catheterization shows increased right ventricular pressure that can reach left ventricular pressure levels. The cardiac catheter can go directly from the right ventricle into the aorta indicating the presence of a ventricular septal defect and aortic riding. The right ventricular outflow tract and/or pulmonary artery stenosis shows a systolic pressure step difference between the right ventricle and the pulmonary artery. Analysis of the pressure curve pattern can determine the site and type of stenosis and the presence or absence of a 3rd ventricle. Arterial oxygen saturation is reduced; typically below 89%, with further reduction after exercise. The indicator dilution curves recorded in the peripheral arteries show an early appearance of the right ventricular injected indicator and a bimodal right-to-left shunt curve in the descending branch of the curve. A normal curve was recorded when the indicator was injected in the pulmonary artery. Echocardiography: Cross-sectional echocardiography is valuable for the diagnosis of tetralogy of Fallot. It directly shows significant thickening of the right ventricular wall; tubular stenosis of the right ventricular outflow tract or formation of a third ventricle; narrowing of the pulmonary artery orifice; smaller caliber of the pulmonary artery than the aorta; interruption of the ventricular septal echo and rightward shift of the anterior aortic wall that rides over the ventricular septum. Selective right ventriculography: Selective right ventriculography is required before deciding on surgical treatment in cases of tetralogy of Fallot. A cardiac catheter is inserted into the right ventricular cavity to inject contrast. Serial radiographs show simultaneous visualization of the pulmonary artery and aorta and the degree of aortic span while the contrast enters the left ventricle from the right ventricle through the ventricular septal defect. It also shows the location and extent of right ventricular outflow tract and/or pulmonary artery stenosis, the development of the pulmonary artery, and measures the diameter of the common pulmonary artery trunk and ascending aorta to calculate the ratio of the two. Retrograde aortography: It can show the development of arterial duct failure, bronchial artery collateral circulation and aortic valve opening and closing function. McGoon measures the diameters of the left and right pulmonary arteries and the descending aorta in the diaphragm plane, and if the ratio of the sum of the diameters of the left and right pulmonary arteries to the diameter of the descending aorta is greater than 2.0, then there is no obstruction of pulmonary artery blood flow. Blood tests: erythrocyte count, hemoglobin and erythrocyte pressure volume are significantly elevated. In severe cyanosis, the red blood cell count can reach 10 million, hemoglobin 258%, and erythrocyte pressure volume is usually 50-70%, but can be as high as 90%.