A catheter comprising: an elongated catheter body having proximal and distal ends and at least one lumen therethrough, the catheter body defining a longitudinal axis; an electrode assembly (18, 118) at the distal end of the catheter body, the electrode assembly having proximal and distal ends and comprising a plurality of spines (120, 20), each spine comprising a non-conductive covering on which at least two ring electrodes are mounted; a plurality of electrode lead wires configured to connect each ring electrode to a mapping system, each lead wire being attached to its corresponding ring electrode; an expander (22, 122) having proximal and distal ends (22P and 22D), the expander forming a longitudinal axis of the assembly, the spines attached at their proximal ends to the catheter body and at their distal ends to the expander; at least one puller wire (35, 37) that extends through the expander, the puller wire having a distal end anchored in the expander at a location distal of the distal end of the catheter body and proximal of the distal end of the assembly; and a control handle proximal of the catheter body, the control handle having an actuator adapted to move the at least one puller wire, wherein each electrode lead wire extends through the control handle, through the at least one lumen in the catheter body, and into the non-conductive covering of the corresponding spine, wherein the expander is adapted for longitudinal movement relative to the catheter body and for deflection relative to the longitudinal axis, and wherein the electrode assembly has an expanded arrangement when the expander is moved proximally along the longitudinal axis relative to the catheter body and the electrode assembly has a collapsed arrangement when the expander is moved distally along the longitudinal axis relative to the catheter body, and wherein the expander is adapted to deflect in at least one direction when the at least one puller wire is moved by the actuator. an elongated catheter body having proximal and distal ends and at least one lumen therethrough, the catheter body defining a longitudinal axis; an electrode assembly (18, 118) at the distal end of the catheter body, the electrode assembly having proximal and distal ends and comprising a plurality of spines (120, 20), each spine comprising a non-conductive covering on which at least two ring electrodes are mounted; a plurality of electrode lead wires configured to connect each ring electrode to a mapping system, each lead wire being attached to its corresponding ring electrode; an expander (22, 122) having proximal and distal ends (22P and 22D), the expander forming a longitudinal axis of the assembly, the spines attached at their proximal ends to the catheter body and at their distal ends to the expander; at least one puller wire (35, 37) that extends through the expander, the puller wire having a distal end anchored in the expander at a location distal of the distal end of the catheter body and proximal of the distal end of the assembly; and a control handle proximal of the catheter body, the control handle having an actuator adapted to move the at least one puller wire, wherein each electrode lead wire extends through the control handle, through the at least one lumen in the catheter body, and into the non-conductive covering of the corresponding spine, wherein the expander is adapted for longitudinal movement relative to the catheter body and for deflection relative to the longitudinal axis, and wherein the electrode assembly has an expanded arrangement when the expander is moved proximally along the longitudinal axis relative to the catheter body and the electrode assembly has a collapsed arrangement when the expander is moved distally along the longitudinal axis relative to the catheter body, and wherein the expander is adapted to deflect in at least one direction when the at least one puller wire is moved by the actuator.