A medical treatment device is disclosed herein. In one example, the medical treatment device includes a core assembly which has a first conduct and a second conductor. An insulative material can surround the second conductor and define an electrode portion of the second conductor that is uncovered by the insulative material. The medical treatment device can include an interventional element that electrical couples to the first conductor. The electrode portion of the second conductor can be disposed radially adjacent to or distal of the interventional element.