A catheter includes an articulation assembly that enables the distal end of the catheter to bend away from the longitudinal axis of a proximal portion of the catheter. The catheter may include a dilation catheter or a guide catheter. The articulation assembly may provide bending in response to changes in electrical current and/or in response to changes in temperature. In addition, or in the alternative, the articulation assembly may provide bending in response to translation of a wire member.