The present in invention relates to an apparatus for treating a defective heart valve in a patient, comprising a prosthetic valve comprising an expandable stent portion and a valvular structure supported within the stent portion； a balloon catheter comprising an elongated shaft and a balloon connected to a distal end portion of the shaft, the balloon catheter further comprising a wedge positioned adjacent the balloon； a guide catheter comprising an elongated shaft extending over the balloon catheter shaft, the shaft of the guide catheter comprising a steerable section, the guide catheter further comprising an adjustment mechanism operatively coupled to the steerable section, the adjustment mechanism being configured to adjust the curvature of the steerable section and the portion of the balloon catheter shaft extending through the steerable section； and a tapered nose piece positioned distal to the balloon for providing atraumatic tracking through tortuous vasculature； wherein the balloon catheter is advanceable relative to the prosthetic valve while the prosthetic valve is in a crimped state and wherein the wedge is configured to expand the prosthetic valve as the balloon is advanced into the prosthetic valve and wherein the balloon is inflatable for deploying the prosthetic valve at an implantation site in the patient's body.
