An ablation catheter system including a radio frequency generator and an elongate catheter having an ablation element at the distal portion thereof The ablation element has at least one electrode electrically connected to the radio frequency generator and a shape memory component formed from a shape memory material. The shape memory component transforms the ablation element between a first straightened delivery configuration and a second deployed configuration. Thermal energy transfer between the electrode and the shape memory component transforms the shape memory component into the deployed configuration and places the electrode of the ablation element into contact with tissue at a treatment site. The transformation temperature of the shape memory material is a temperature above body temperature such that the transformation of the shape memory component is not activated by mere placement within the body but rather is activated by heat transfer from the electrodes.
