A medical apparatus, comprising: a catheter, adapted for insertion into a heart, the catheter comprising an elongated body having a distal end, and a plurality of spines mounted at the distal end, each of the spines having a proximal end attached at the distal end of the body, a free end, and a plurality of electrodes (39, 41); a memory having programs stored therein; a display; and a processor linked to the display and being coupled to access the memory to execute the programs, the processor being connected to the catheter and configured to receive an input provided by the catheter from the heart, wherein the programs cause the processor to perform the steps of: obtaining intracardiac electrical signal data via the electrodes; determining respective intracardiac locations and orientations of the spines; deriving an electroanatomic map of the heart from the signal data, wherein the electroanatomic map comprises a graphic representation of the respective intracardiac locations and orientations of the spines, and further comprises distinctive graphical indicia of at least portions of the spines; and displaying the electroanatomic map on the display wherein the graphic representation comprises a circle having a center and a plurality of radii (89, 91, 93, 95, 97), the center representing a location of the distal end of the body of the catheter, and the radii (89, 91, 93, 95, 97) representing the locations and orientations of the spines and bearing the graphical indicia of the spines, respectively. a catheter, adapted for insertion into a heart, the catheter comprising an elongated body having a distal end, and a plurality of spines mounted at the distal end, each of the spines having a proximal end attached at the distal end of the body, a free end, and a plurality of electrodes (39, 41); a memory having programs stored therein; a display; and a processor linked to the display and being coupled to access the memory to execute the programs, the processor being connected to the catheter and configured to receive an input provided by the catheter from the heart, wherein the programs cause the processor to perform the steps of: obtaining intracardiac electrical signal data via the electrodes; determining respective intracardiac locations and orientations of the spines; deriving an electroanatomic map of the heart from the signal data, wherein the electroanatomic map comprises a graphic representation of the respective intracardiac locations and orientations of the spines, and further comprises distinctive graphical indicia of at least portions of the spines; and displaying the electroanatomic map on the display obtaining intracardiac electrical signal data via the electrodes; determining respective intracardiac locations and orientations of the spines; deriving an electroanatomic map of the heart from the signal data, wherein the electroanatomic map comprises a graphic representation of the respective intracardiac locations and orientations of the spines, and further comprises distinctive graphical indicia of at least portions of the spines; and displaying the electroanatomic map on the display wherein the graphic representation comprises a circle having a center and a plurality of radii (89, 91, 93, 95, 97), the center representing a location of the distal end of the body of the catheter, and the radii (89, 91, 93, 95, 97) representing the locations and orientations of the spines and bearing the graphical indicia of the spines, respectively.