Referring to FIG. 26, a releasable lasso member 142 may be manufactured from electrical conductors such as platinum/iridium, gold, stainless steel, or other metallic coils or rings and may be attached through electrically conductive wires 141 traversing the catheter lumen 140 to a radiofrequency generator, such as the EPT-1000, which transmits current at 500 kHz to the lasso member 142 to resistiv