A deflectable stylet system optimized for use in conjunction with a lead of the type having a fixation helix that is screwed into body tissue by rotation of the lead's connector pin is disclosed. The system includes an attachment that is rotatable and longitudinally slidable with respect to the handle of a deflectable stylet. A lead coupled to the attachment may be moved longitudinally with respect to a stylet to account for slight variances in the lead length. In one embodiment, the attachment couples to the lead via a pushbutton mechanism that can be locked to the lead using one hand. The attachment may be rotated to thereby rotate the lead connector. This allows for retraction and extension of a retractable fixation helix, and for further attachment or detachment of a fixation helix to adjacent tissue. In one embodiment, the attachment may be longitudinally rigidly positioned in predetermined locations with respect to the handle. According to another aspect of the system, a deflection device is coupled to the handle to facilitate deflection of the stylet. In one embodiment, this deflection device may be rotatably and/or slidably activated to accomplish the stylet deflection. The system allows a user to adjust lead length with respect to the stylet length, and to further perform stylet deflection and lead rotation all with one hand.