A heart catheter visual support procedure displays (6, 13) electroanatomical 3D (Three Dimensional) mapping (15) from markers placed on the rib cage with segments (11) of a previously obtained tomographic image (14) in correct dimensional relationship (12) as a polygon network using a volume rendering technique with adjustable transparency and blending (7) factor. Independent claims are included for equipment using the procedure with images from X ray, or magnetic resonance tomography or ultrasonic imaging and for subsequent refinement stages using surface matching and calculation of the relative catheter tip position (16).
