Patent ID: 7505810

Claim:
A method comprising: inserting a catheter into a heart cavity having an endocardium surface, the catheter comprising multiple, spatially distributed electrodes; prior to determining physiological information, generating a representation of the endocardium surface of a patient's heart cavity; registering the representation of the endocardium surface with a first coordinate system used to determine positions of the catheter electrodes relative to the endocardium surface after the catheter is inserted into the heart cavity; measuring signals at the catheter electrodes in response to electrical activity in the heart cavity with the catheter spaced from the endocardium surface; and determining the physiological information at multiple locations of the endocardium surface based on the measured signals, the positions of the catheter electrodes relative to the endocardium surface, and the registered representation of the endocardium surface; wherein generating the representation of the endocardium surface comprises segmenting a volumetric representation of the heart cavity.