An electrophysiology catheter, e.g., a coronary sinus catheter, for insertion into a cardiac vessel, such as the coronary sinus, includes a handle and a catheter shaft coupled at one end to the handle. The catheter shaft has a distal end and an anchor is associated with the catheter shaft and is movable between a deployed position and a collapsed position. In the deployed position, the anchor extends radially outward from an outer surface of the catheter shaft for contacting a wall and temporarily anchoring the catheter shaft within the coronary sinus. The catheter also includes an actuator for causing deployment and collapsing of the anchor upon manipulation of the actuator.