The present invention relates to a method for visually supporting an electrophysiological catheter application in the heart, in which, during the execution of the catheter application, 2D fluoroscopy images (13) of the area of the heart being treated are recorded with an x-ray image recording system (5) and displayed together with 3D mapping data (14) of the area being treated, said 3D mapping data having been prepared simultaneously. A feature of this method is that the 2D fluoroscopy images (13) are registered with the 3D mapping data (14), and said 3D mapping data (14) is displayed, from the same perspective as the 2D fluoroscopy images (13), alongside said 2D fluoroscopy images (13) or image content derived from these (14), or is superimposed over them in the display.