The invention provides a deflectable tip guiding device, such as a catheter, that enables the operator to vary the radius of curvature of the tip of the catheter. This is a novel variation on the classic "fixed fulcrum" tip deflectors used in minimally invasive procedures in open surgical treatments. The described device permits a more comprehensive ability to navigate complex geometric pathways in patient's body and enables better access to target structures (e.g., to all endomyocardial walls from a transaortic approach). The guiding device can be made compatible with imaging methods like MRI. The described technology can be used as a platform for a variety of interventional devices for delivery of drugs, cells, energy, or sutures through complex trajectories of the body.