The present invention relates to a device for treating a human heart, comprising: a prosthetic valve (16); a tubular delivery sleeve (24) having a proximal end; a lead screw nut (514) coupled to the proximal end of the tubular delivery sleeve; a valve catheter (23) having a distal end configured for releasable attachment to the prosthetic valve, wherein the valve catheter and the prosthetic valve are slidably advanceable through the delivery sleeve; and a lead screw (506) coupled to the valve catheter; wherein the lead screw engages the lead screw nut and wherein rotation of the lead screw causes the valve catheter and the prosthetic valve to advance relative to the delivery sleeve.