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; register and superimpose the two dimensional image data and the three dimensional image data to generate superimposed image data; position the prosthetic heart valve using the superimposed image data; opening the prosthetic heart valve to an expanded condition while in position in the patient's heart; and imaging the patient's heart using three dimensional imaging to determine a position of the prosthetic heart valve in the expanded condition in the patient's heart.