Patent ID: 8731685

Claim:
An implantable medical device, comprising: a lead having a proximal section adapted to be coupled to a pulse generator, a distal section adapted to be located within a heart of a patient, and a length, wherein the lead is configured to convey electrical signals between the heart and the pulse generator through an inner conductor; the inner conductor having a helix-like shape with a first inner conductor pitch, the inner conductor including a plurality of high impedance elements having a second inner conductor pitch different than the first inner conductor pitch along the length of the lead such that the inner conductor includes portions having the second inner conductor pitch interspersed with portions having the first conductor pitch, wherein a distance between each of the high impedance elements is less than ¼ of a wavelength of a highest frequency of one or more magnetic resonance imaging (MRI) frequencies such that, when the lead is exposed to the one or more MRI frequencies, incident and reflected waves inducted within the inner conductor subtract from each other to detune the inner conductor at the one or more MRI frequencies; and an outer conductor having a helix-like shape radially surrounding at least a portion of the inner conductor, wherein the outer conductor has an outer conductor pitch that varies at one or more locations along the length of the lead.