The Ventak CHF/CONTAK CD Biventricular Pacing Study is a prospective randomized trial to examine the safety and efficacy of biventricular (BV) pacing in patients with standard indications for an ICD, symptomatic heart failure, a LVEF < or = 0.35, and a QRS > or = 120 ms. Patients underwent implantation of a BV pacing and sensing system with backup defibrillation capability, which includes a steroid-eluting coronary venous lead that is advanced into the coronary venous vasculature by over-the-wire techniques. LV pacing threshold, BV impedance, and BV R wave amplitude were measured in 58 consecutive patients. Using a percutaneous over-the-wire insertion technique, steroid-eluting coronary venous leads were associated with satisfactory mean LV pacing threshold, BV impedance, and BV R wave amplitude acutely up to 4 months after implantation. Pacing threshold stabilized 2 weeks after lead implantation and sensing threshold remained stable from the time of implant.