The authors have executed an investigation on the functional evaluation of the valvular prosthesis, availing themselves of the use of the Echocardiography complete of Doppler effect and executing echocardiography tracings not according to the standard position, but putting the sound in correspondence with the cardiac apex. This method has been considered valid to obtain olways images of the movable element for all the types of the prosthesis and for amy situation of theirs. Furthermore the classic position of the sound can't be respected either for the eventual cardiomegaly, either for the manipulations that the heart undergoes inevitable during the operation, either for the pleurapericardic adhesions, alla factors that induce a change of the anatomic focuses.