A system including: an implantable medical device; and an external apparatus, the external apparatus comprising: a display device (145; 202-602); a processor circuit; and a processor-readable medium including instructions that, when performed by the processor circuit, cause the processor circuit to: provide to a user an interactive representation of a first set of cardiac electrostimulation electrodes or vectors using the display device, wherein the interactive representation graphically represents relative locations of two or more cardiac electrostimulation electrodes with respect to each other; receive a first selection of an electrostimulation electrode or vector; provide a visual indication of the first selection using the interactive representation, wherein providing a visual indication includes superimposing one or more electrostimulation vectors over an image of a heart such as to provide visual context to the relative locations of the vectors; and interactively use the first selection, wherein the instructions to interactively use the first selection comprises instructions to display, using the interactive representation, information indicative of an electrostimulation parameter test result (470; 772-775) for an electrostimulation electrode combination or vector associated with the first selection, wherein the test result is a result of a test directed by the processor circuit of the external apparatus and performed by a processor circuit in the implantable medical device. an implantable medical device; and an external apparatus, the external apparatus comprising: a display device (145; 202-602); a processor circuit; and a processor-readable medium including instructions that, when performed by the processor circuit, cause the processor circuit to: provide to a user an interactive representation of a first set of cardiac electrostimulation electrodes or vectors using the display device, wherein the interactive representation graphically represents relative locations of two or more cardiac electrostimulation electrodes with respect to each other; receive a first selection of an electrostimulation electrode or vector; provide a visual indication of the first selection using the interactive representation, wherein providing a visual indication includes superimposing one or more electrostimulation vectors over an image of a heart such as to provide visual context to the relative locations of the vectors; and interactively use the first selection, wherein the instructions to interactively use the first selection comprises instructions to display, using the interactive representation, information indicative of an electrostimulation parameter test result (470; 772-775) for an electrostimulation electrode combination or vector associated with the first selection, wherein the test result is a result of a test directed by the processor circuit of the external apparatus and performed by a processor circuit in the implantable medical device. a display device (145; 202-602); a processor circuit; and a processor-readable medium including instructions that, when performed by the processor circuit, cause the processor circuit to: provide to a user an interactive representation of a first set of cardiac electrostimulation electrodes or vectors using the display device, wherein the interactive representation graphically represents relative locations of two or more cardiac electrostimulation electrodes with respect to each other; receive a first selection of an electrostimulation electrode or vector; provide a visual indication of the first selection using the interactive representation, wherein providing a visual indication includes superimposing one or more electrostimulation vectors over an image of a heart such as to provide visual context to the relative locations of the vectors; and interactively use the first selection, wherein the instructions to interactively use the first selection comprises instructions to display, using the interactive representation, information indicative of an electrostimulation parameter test result (470; 772-775) for an electrostimulation electrode combination or vector associated with the first selection, provide to a user an interactive representation of a first set of cardiac electrostimulation electrodes or vectors using the display device, wherein the interactive representation graphically represents relative locations of two or more cardiac electrostimulation electrodes with respect to each other; receive a first selection of an electrostimulation electrode or vector; provide a visual indication of the first selection using the interactive representation, wherein providing a visual indication includes superimposing one or more electrostimulation vectors over an image of a heart such as to provide visual context to the relative locations of the vectors; and interactively use the first selection, wherein the instructions to interactively use the first selection comprises instructions to display, using the interactive representation, information indicative of an electrostimulation parameter test result (470; 772-775) for an electrostimulation electrode combination or vector associated with the first selection, wherein the test result is a result of a test directed by the processor circuit of the external apparatus and performed by a processor circuit in the implantable medical device.