First, what is a heart valve The human heart has four sets of valves, namely, the aortic valve, pulmonary valve, mitral valve, tricuspid valve, each set of valves consists of two to three valve leaflets, which have the role of one-way valves to ensure that the heart to the normal direction of blood discharge. Second, why replace the artificial heart valve heart valve if suffered rheumatic activity, bacterial infection, trauma or congenital malformation, such as breakage or adhesion or deformation, the formation of valve stenosis or closure of incomplete, lose its one-way valve function, thus affecting the heart’s normal blood, and thus affect the function of the heart, or even lead to cardiac insufficiency, therefore, when you find the heart valve lesions, you should go to the hospital in time to seek medical treatment, according to the degree of valve lesions to perform a one-way valve. According to the degree of valve lesions heart valve surgery, if the valve can not be repaired, it is necessary to replace the artificial heart valve, in order to protect and improve heart function. Types and selection of prosthetic valves Biological valves: do not require lifelong anticoagulation (generally anticoagulated for 3-6 months), but the durability is poor, the general working life of about 10 years. Mechanical valves: lifelong anticoagulation. Choice: young anticoagulation conditions choose mechanical flap, the elderly (generally greater than 60 years old) need to give birth to children of women, remote and unconditional laboratory monitoring anticoagulation indicators, there are contraindications to anticoagulation (eg, gastric ulcer or its bleeding tendency of the patient) can choose biological flap. Fourth, why anticoagulation after valve replacement surgery prosthetic heart valve can correct valve lesions, restore heart function, but it is after all a foreign body, the blood is easy to coagulate in the prosthetic valve and around the formation of thrombus, thus affecting the valve leaflet opening and closing, so that the valve dysfunction, if the thrombus off and can cause embolism, affecting the surrounding organs and pipe function, such as cerebral infarction, arterial embolism in the lower limbs, so the valve replacement surgery must be Therefore, anticoagulation is necessary after valve replacement to prevent thrombosis and to ensure the normal function of the prosthetic valve. Commonly used anticoagulants: Warfarin is a kind of anticoagulant, i.e., it prevents blood from coagulating.