A medical device used to percutaneously gain access to a targeted site within a living body, for example the left ventricle of the heart. The device is comprised of an inner tubular member, outer tubular member, and an adjustable control handle. The control handle can precisely control the relative position of the inner tubular member relative to the outer member by providing feedback to the operator. This feedback provided by the control handle allows the operator to precisely maneuver the catheter within a body and change the shape of the catheter system without taking his/her eyes off the task that he/she is performing. The control handle is designed to precisely change the catheter system from one tip shape to another tip shape and back. Described herein are methods to use such devices.