The present disclosure is directed to an expandable energy delivery assembly adapted to deliver electrical energy to tissue. The assembly includes an elongate device including an irrigation shaft defining a irrigation lumen fluidly couplable to an irrigation source and a rapid exchange shaft defining a guidewire lumen configured for reception and passage of a guidewire. The assembly also includes an inflatable element that is secured to the elongate device. The inflatable element includes a double helical electrode disposed on the inflatable element that makes between about 0.5 to about 1.5 revolutions around the inflatable element.
