Methods for providing diagnostic information using endocardial surface data for a patient's heart are described herein. In some embodiments, endocardial surface data for the left ventricle of a heart is received. The endocardial surface data represents the endocardial surface of the left ventricle at multiple times over a heartbeat and is obtained using a volumetric imaging application. A representation in prolate spheroidal coordinates of the endocardial surface of the left ventricle at least a portion of the multiple times is generated using the endocardial surface data. The prolate spheroidal coordinates include a longitudinal angular coordinate .mu., a circumferential angular coordinate .theta., and a coordinate .lamda. as a function of longitudinal angular coordinate .mu. and circumferential angular coordinate .theta.. A measure that provides diagnostic information related to the left ventricle is computed based at least on part on the value of coordinate .lamda..