Fig. 2.

Example of a piecewise cubic, three-dimensional spline, solid line, approximating the 16 marker coordinates in space, top view (left) and lateral view (right). We implant markers, black spheres, at the anterior and posterior trigones, at the mid anterior portion, at the mid posterior portion and at each commissure. Additionally, we place ten markers to subdivide the annulus into 16 segments of approximately equal length. The figure also illustrates mitral annular area (MAA), septal-lateral distance (SL), commissure-commissure distance (CC), and saddle height (SH).