The invention relates to a method and a device for visually supporting an electrophysiology catheter application in the heart, whereby electroanatomical 3D mapping data of an area of the heart to be treated which are provided during performance of the catheter application are visualized. Before the catheter application is carried out, 3D image data of the area to be treated are recorded by means of a tomographical 3D imaging method, a 3D surface profile of objects in the area to be treated is extracted from the 3D image data by segmentation and the electroanatomical 3D mapping data provided and the 3D images representing the 3D surface profile are associated with each other in the correct position and dimension relative each other and e.g. visualized in an superimposed manner during the catheter application. The present method and the corresponding device allow for an improved orientation of the user who carries out an electrophysiology catheter application in the heart.