Abstract: A disposable percutaneous lead is provided which is suitable for caring out a variety of functions, including endocardial functions of mapping, ablation and/or pacing. The percutaneous lead maintains a substantially isodiametric profile for insertion through a body cavity such as a vein or artery. By manipulation of a proximal end portion of the device, elongated peripheral segments of the distal end portion of the device move generally radially outwardly in order to provide a plurality of radially adjustable electrodes for forming a mapping array. An elongated shaft structure is also provided for ablation purposes, while electrodes for pacing are also available on the device.