Catheter systems and methods for making and using catheters systems are disclosed. An example catheter system may include a catheter having a proximal end, and a distal end, an electrode for tissue modulation disposed on a distal portion of the catheter. An expandable basket structure may be placed over a distal section of the catheter. The expandable basket structure may have a basket having a fixed end and a movable end. The movable end may be slidably coupled to the catheter. An actuating structure may be connected to the movable end for moving the expandable basket between a collapsed state and an expanded state.
