Types of Prosthetic Heart Valves and Their Characteristics Mechanical Valves:The main clinical application at present is the bileaflet valve. As the newest generation of mechanical valves, the bilobed valve should reflect decades of mechanical valve research in its design to achieve the best clinical results. At present, there are more clinical applications of imported ST-JADEMEDICAL flap, CARBOMEDICS flap, ATS flap, SORIN flap, and domestic bilobed flap have also been used in clinical practice. In general, its mechanical durability can reach 30 to 100 years; fatigue resistance test is conducted, the valve closing activity can reach 4 billion times, and its strain is in the safe range, equivalent to 140 years of life, but the mechanical valve replacement requires a lifetime of anticoagulant drugs. During its normal opening and closing activity, it produces a higher-than-normal heart sound, called the artificial valve sound, which can be clearly heard by the patient in a quiet state, but the currently used mechanical valves have a slight sound. Biologic valves: Biologic valves are central flow type, have good hemodynamic performance, and most patients do not require lifelong anticoagulation; the incidence of thromboembolism is low, and valve-related comorbidities are significantly lower than those of mechanical valves. Most biologic valves calcify and decay in about 20 years after implantation, but in recent years, as the quality of biologic valves has improved, the use of biologic valves has been on the rise again. Biologic valves can be divided into two main categories, homogeneous and heterogeneous valves. The current clinical application of heterogeneous biologic valves mainly includes porcine aortic valve and bovine pericardial valve, so it is suitable for elderly patients over 65 years old, women of childbearing age with fertility aspirations and right heart system valve (such as tricuspid valve) replacement. Homogeneous biologic valves have a longer service life than heterogeneous biologic valves and are currently used to correct malformations in complex congenital heart disease and to replace valves in valvular endocarditis. Thrombosis caused by implantation of an artificial heart valve is one of the most serious comorbidities and a problem that has not yet been solved, as it is inevitable that thrombosis may occur after implantation of any artificial heart valve, only to varying degrees, which is the greatest difference between artificial and natural valves.