Patent ID: 6845257

Claim:
A method for mapping electrical activity within a tubular region of or near the heart having an inner circumference, the method comprising: inserting into the heart a distal end of a catheter comprising: an elongated tubular catheter body having an outer wall, proximal and distal ends, and at least one lumen extending therethrough, and a mapping assembly comprising: a tubular structure having a generally straight proximal region attached to the catheter body, a generally circular main region generally transverse and distal to the proximal region and having an outer circumference, a transition region connecting the proximal region and the main region, and a generally straight distal region distal the main region and extending substantially tangentially relative to the main region, wherein the tubular structure comprises a non-conductive cover over at least the main region of the mapping assembly, and a plurality of spaced-apart electrodes carried by the generally circular main region of the mapping assembly; contacting the inner circumference of the tubular region with the outer circumference of the generally circular main region of the mapping assembly; and mapping the electrical activity within the tubular region with the plurality of electrodes carried by the generally circular main region.