Patent ID: 7257435

Claim:
A method for mapping a tubular region of or near the heart comprising: introducing into the tubular region the distal end of a catheter comprising: an elongated catheter body having a proximal end, a distal end and at least one lumen extending longitudinally therethrough; a mapping assembly mounted at the distal end of the catheter body and comprising: a stem having proximal and distal ends, and at least two spines, each spine having a distal end fixedly mounted to the distal end of the stem and a free proximal end, wherein the spines are moveable between a collapsed position, where the distal end of each spine is fixedly attached to the stem and the free proximal end is positioned generally against the stem, and an expanded position, where the free proximal end of each spine extends outwardly from the stem, and wherein each spine carries at least one electrode, and at least one location sensor; positioning the mapping assembly so that at least one electrode from each spine is near or in contact with tissue within the tubular region, wherein the positioning comprises resistively heating a support member within each spine; and recording electrical data received from the at least one electrode in contact with the tissue.