An ablation catheter adapted for use with a guide wire has a 3-D shapedportion thatcarries ring electrodes for ablating a vessel or tubular region, including therenal artery. The 3-Dshaped portion, for example, a helical portion, enables the ring electrodes tocontact an innersurface of the vessel at a plurality of locations at different depths alongthe vessel to form aconduction block without forming a closed conduction loop which wouldotherwise increasethe risk of stenosis of the vessel. In one embodiment, the catheter has alumen with entry andexit ports to allow the guide wire to pass through the lumen but bypass the 3-D shaped portion.In another embodiment, the catheter has outer bands providing side tunnelsthrough which theguide wire can pass through.
