A catheter comprising an elongated catheter body, and an electrode assembly distal of the catheter body, the assembly comprising a plurality of spines, wherein each spine has a distal end that is connected to the distal end of at least one other spine, wherein each spine has an electrode-carrying portion, the electrode-carrying portions of all spines of the assembly being in a single common plane, and wherein all spines of the assembly have a uniform exposed total length.
