An implantable medical system for delivering pacing pulses to HIS bundle of a heart of a patient when implanted in said patient includes a medical lead, which is adapted to be attached with a distal end to tissue of said heart, including a at least two electrodes arranged being electrically separated from each other. The implantable medical device connectable to the medical lead includes a pacing circuit adapted to deliver the pacing pulses to said heart via the medical lead, a selection device connected between the pacing circuit and the electrodes adapted to selectively activate at least one of said electrodes, and a processing device adapted to control the selection device to selectively activate at least one of the electrodes to direct the pacing pulses to the HIS bundle.