Endovascular lead design and delivery systems are described herein. One variation of an endovascular lead apparatus may generally comprise an elongate body having a proximal portion and a distal portion, one or more electrodes positioned along a first side of the distal portion, a tray positioned along a second side of the distal portion opposite to the first side, and one or more frame members positioned along the tray and which are reconfigurable from a low-profile delivery configuration to an expanded deployed configuration, wherein expansion of the one or more frame members to the expanded deployed configuration reconfigures the distal portion into contact against a tissue wall for energy delivery via the one or more electrodes.