accomplished by conventional painting or sputter coating techniques for example gold can be sputtered onto the exterior surface of the body 16 alternatively a two phase sputter coating process may be employed in which an initial layer of titanium is applied followed by an outer coating of gold the coating process may also use an ion beam assisted deposition ibad process this process implants the conductive material into the polymer of the body 16 the wires 12 conduct ablating energy to the coating on the body 16 the body 16 shown in fig2 and 5 is operated in a unipolar ablation mode the energy transmitted by the body 16 flows through myocardial tissue to an external indifferent electrode 52 on the patient see fig5 which is typically an epidermal patch in the illustrated and preferred embodiment the conductive coating covers the entire exposed area of the body 16 in this case the body 16 when inflated functions as a single ablation electrode alternatively the conductive coating can be applied in a defined portion 54 such as one third or one half of the circumference of the body 16 as shown in fig6 or any variety of patterns that may enhance the ablation performance and or optimize the ablation procedure additionally the coated inflatable body 16 can serve to carry electrical signals from the heart tissue along wires 12 through cable 28 and plugs 29 for recording of electrogram potentials by recording equipment the inflatable body 16 can be attached to.