A system for stimulating a left phrenic nerve and a right phrenic nerve of a patient includes a signal generator to produce stimulation signals a lead structure configured for insertion into a venous system of the patient, the lead structure having a plurality of leads to receive stimulation signals from the signal generator a plurality of second pairs of electrodes on the lead structure proximate a distal portion of the lead structure and configured to receive stimulation signals from at least one of the plurality of leads a plurality of first pairs of electrodes on the lead structure proximal of the plurality of second pairs of electrodes and configured to receive stimulation signals from at least one of the plurality of leads and a control system programmed to (a) select a first stimulation pair of electrodes from the plurality of first pairs of electrodes to stimulate the left phrenic nerve, and (b) select a second stimulation pair of electrodes from the plurality of second pairs of electrodes to stimulate the right phrenic nerve.
