1. A method for emplacement of a heart valve prosthesis in a patient's heart, comprising the steps of: positioning a patient on a table; accessing the patient's heart; penetrating a wall of the patient's heart to form an opening; inserting a catheter having a prosthetic heart valve mounted in a compact state on the catheter into the opening including inserting the prosthetic heart valve into the patient's heart; imaging the patient's heart using two dimensional imaging during insertion of the prosthetic heart valve to produce two dimensional image data; imaging the patient's heart using three dimensional imaging to produce three dimensional image data; registering and superimposing the two dimensional image data and the three dimensional image data to generate superimposed image data; imaging the patient's heart using two dimensional imaging during a positioning imaging step; positioning the prosthetic heart valve by positioning an image of the heart valve within the superimposed image data while imaging the patient's heart in said positioning imaging step; imaging the patient's heart using two dimensional imaging during an opening imaging step; opening the prosthetic heart valve to an expanded condition while in position in the patient's heart within the superimposed image data while imaging the patient's heart in said opening imaging step; imaging the patient's heart using three dimensional imaging to obtain a soft tissue image to determine a position of the prosthetic heart valve in the expanded condition in the patient's heart, said imaging step using three dimensional imaging to obtain a soft tissue image being performed without use of a contrast agent; imaging the patient's heart using a contrast agent to obtain high contrast image data of the expanded prosthetic heart valve in the patient's heart; and comparing the soft tissue image of the prosthetic heart valve in position with the high contrast image data to determine at least one of attachment and functioning of the expanded prosthetic heart valve.