A numerical code for analyzing the dynamic behaviour of heart valve prostheses is presented. The study is conducted with the valve in a simplified cardiovascular system, represented schematically by a circuit with a pump, the valve under test, a rugged elastic tube and a capacity. The pump represents the left ventricle, while the tube and the capacity represent the arterial system. The tube, unlike the other components, presents propagative effects. Input includes the physiological data and valve type, geometry and masses, while time-dependent output include fluid pressure and velocity in the circuit and downstream of the valve, valve opening time and the angular speed and acceleration of moving parts.