Patent ID: 7587239

Claim:
An implantable cardiac pacing and sensing system, the system being adapted to reject sensed far-field signals, the system comprising: a lead for transmitting electrical signals between an implantable medical device and selected body tissue in the heart, the lead comprising a lead body having a proximal end and a distal end, the proximal end of the lead body carrying a connector assembly connectable to the implantable medical device and the distal end of the lead body carrying a plurality of electrodes disposed in spaced-apart relationship along the distal end of the lead, the plurality of electrodes including a distal electrode, a proximal electrode and an intermediate electrode disposed between the distal and proximal electrodes; and an implantable medical device comprising a differential circuit having a plurality of inputs, the plurality of electrodes being electrically connected to respective inputs of said differential circuit, the differential circuit having an output providing a signal representing the difference between a first signal and a second signal, the first signal representing the difference between the magnitudes of the sensed signals generated by the distal and intermediate electrodes and the second signal representing the difference between the magnitudes of the sensed signals generated by the intermediate and proximal electrodes, the output signal being substantially devoid of far-field signals.