Mitral valve replacement is divided into mechanical and biological valves. Mechanical valves cost around$50,000-$100,000 for one valve and$100,000-$150,000 for two valves, while biological valves cost around$100,000 for one valve and over$150,000 for two valves. The difference between biological and mechanical valves is that mechanical valves work for a longer period of time, but require lifelong anticoagulant medication. Biologic valves have a shorter duration of action and need to be replaced periodically, but do not require anticoagulant medication, and can last up to 20 years. Once valve replacement is performed, postoperative infections, whether respiratory, digestive, or urinary, need to be strictly controlled, as once bacteria enter the bloodstream, endocarditis can easily develop and affect the prosthetic valve activity. Heart failure and arrhythmias should also be controlled, and cardiac stimulants and diuretics should be applied if necessary.