Tricuspid valve malformation is a rare congenital heart malformation. Ebstein first reported a case in 1866, so it is also called Ebstein malformation. Its incidence rate accounts for 0.5-1% of congenital heart diseases. Tricuspid valve malformation refers to tricuspid valve malformation, in which the posterior valve and septal valve are located lower than normal, not at the level of the atrioventricular ring but moved downward to the right ventricular wall near the apex, and the anterior valve is in a normal position, resulting in a larger right atrium than normal and a smaller right ventricle than normal, with tricuspid valve regurgitation. This type of malformation is often combined with open foramen ovale or atrial septal defect and pulmonary artery stenosis. Because there is more blood in the right atrium and the pressure is increased, part of the blood it contains flows into the left atrium through the atrial septal defect or the foramen ovale, and part of it still flows into the right ventricle through the tricuspid valve. Due to pulmonary artery stenosis, the amount of blood entering the pulmonary circulation is reduced, so the amount of arterial blood returning to the left atrium is also less. At this time, it is mixed with the venous blood shunted from the right atrium and enters the left ventricle and systemic circulation through the mitral valve.