Patent ID: 7207989

Claim:
A method for ablating tissue in or around the heart comprising: introducing into the heart a distal end of a catheter comprising a catheter body and, a needle electrode assembly at the distal end of the catheter body, the needle electrode assembly comprising a proximal tubing and distal tubing, wherein the proximal tubing is more flexible than the distal tubing, the distal tubing of the needle electrode assembly being in a retracted position within the distal end of the catheter; introducing a distal end of the distal tubing of the needle electrode assembly into the tissue, including moving the distal tubing of the needle electrode assembly from its retracted position within the distal end of the catheter to an extended position outside the distal end of the catheter; infusing into the tissue an electrically-conductive fluid through the distal tubing of the needle electrode assembly while in the extended position; and ablating the tissue after and/or during introduction of the fluid into the tissue, whereby the fluid conducts ablation energy within the tissue to create a larger lesion than would be created without the introduction of the fluid.