A computer-implemented method for displaying a 3D model of an organ of a patient on a navigation system display device, the method comprising: a. Receiving a plurality of spatial coordinates (S XYZ), computed from data received from at least one sensor of a catheter inside a portion of said organ of the patient; the plurality of spatial coordinates defining a reference point cloud representing said portion of said organ of the patient; b. Receiving a plurality of points, said plurality of points defining a predefined 3D model of said organ of the patient, a sub-plurality of points being labelled to define a 3D model segmentation (R CS) corresponding to said portion of said organ of the patient; c. Computing a spatial transformation which, when applied to the 3D model, minimizes a predefined error metric between the result (T(R CS)) of this spatial transformation on the 3D model segmentation and the reference point cloud; d. Displaying on the navigation system display device a landmark at a current position of the catheter obtained from said plurality of spatial coordinates and, simultaneously, the result (IH') of the computed spatial transformation on the 3D model wherein the method comprises a step of identifying one or more areas in the 3D model segmentation (R CS) and in the reference point cloud having at least one geometrical feature matching a predetermined criteria, and the computed spatial transformation is the spatial transformation which, when applied to the 3D model, minimizes the predefined error metric between the result (T(R CS)) of this spatial transformation on the 3D model segmentation and the reference point cloud in at least said one or more areas; characterised in that the step of receiving a plurality of spatial coordinates (S XYZ) comprises the reception of at least a first and a second plurality of spatial coordinates, computed from data received from at least a first and a second sensors of the catheter; and wherein the step of identifying one or more areas in the reference point cloud comprises an estimation of the evolution of the curvature and/or the torsion of the reference point cloud from the first and the second plurality of spatial coordinates. a. Receiving a plurality of spatial coordinates (S XYZ), computed from data received from at least one sensor of a catheter inside a portion of said organ of the patient; the plurality of spatial coordinates defining a reference point cloud representing said portion of said organ of the patient; b. Receiving a plurality of points, said plurality of points defining a predefined 3D model of said organ of the patient, a sub-plurality of points being labelled to define a 3D model segmentation (R CS) corresponding to said portion of said organ of the patient; c. Computing a spatial transformation which, when applied to the 3D model, minimizes a predefined error metric between the result (T(R CS)) of this spatial transformation on the 3D model segmentation and the reference point cloud; d. Displaying on the navigation system display device a landmark at a current position of the catheter obtained from said plurality of spatial coordinates and, simultaneously, the result (IH') of the computed spatial transformation on the 3D model wherein the method comprises a step of identifying one or more areas in the 3D model segmentation (R CS) and in the reference point cloud having at least one geometrical feature matching a predetermined criteria, and the computed spatial transformation is the spatial transformation which, when applied to the 3D model, minimizes the predefined error metric between the result (T(R CS)) of this spatial transformation on the 3D model segmentation and the reference point cloud in at least said one or more areas; characterised in that the step of receiving a plurality of spatial coordinates (S XYZ) comprises the reception of at least a first and a second plurality of spatial coordinates, computed from data received from at least a first and a second sensors of the catheter; and wherein the step of identifying one or more areas in the reference point cloud comprises an estimation of the evolution of the curvature and/or the torsion of the reference point cloud from the first and the second plurality of spatial coordinates.