This invention is a multipolar or multi-conductor guidewire which can be navigated or steered through the vasculature from outside a patient's body to perform a medical procedure within the patient's vasculature. In one embodiment, a guidewire of this invention has at least 4, preferably at least 6, to as many as 10 or more distal-to-proximal conductive pathways, which are substantially longitudinally parallel to each other running linearly along substantially the majority if not the entire length of the guidewire body, preferably in a printed circuit format. In a further practice, the conductive pathways helically wound around the guidewire body.