Disclosed herein is a left ventricular lead for tracking over a guide wire into a coronary sinus and providing active fixation in, or adjacent to, the coronary sinus. The guide wire is configured for coronary sinus lead implantation and has an outer diameter. In one embodiment, the lead includes a tubular body including a proximal end, a distal end and a central lumen through which the guide wire is extendable. The lead also includes a lead connector end proximally projecting from the proximal end and comprising at least one electrical contact. The lead also includes a fixed helical anchor comprising a wire member having a diameter of between approximately 0.22 mm and approximately 0.27 mm. The wire member distally extends away from the distal end in a helical arrangement including an inner helical coil diameter that is sufficient to allow the guide wire to extend through the fixed helical anchor.
