An apparatus for creating linear lesions in body tissue within a body vessel includes a catheter adapted for insertion into the body vessel, the catheter having a proximal end and a distal end, a loop of a non-conducting material at the distal end being deformable such that when the loop is pressed against a wall of the body vessel, a section of the loop conforms to the internal contours of the wall of the body vessel by changing the circumferential shape of the loop, a linear ablating conductor disposed on the loop, preferably along at least a part of the circumferential length of the loop, such that when the loop is pressed against the wall of the body vessel a portion of the linear ablating conductor is in contact with the body tissue in a smaller area than the total area of the section of the loop conformed to the internal contours of the wall of the body vessel.
