A pacing lead for a left cavity of the heart, implanted in the coronary system. The lead includes a lead body with a hollow sheath of deformable material, having a central lumen open at both ends, and at least one telescopic microcable of conductive material. The microcable slides along the length of the lead body and extends beyond the distal end thereof. The part emerging beyond the distal end is an active free part comprising a plurality of distinct bare areas, intended to come into contact with the wall of a target vein of the coronary system, so as to form a network of stimulation electrodes electrically connected together in parallel. The microcable further comprises, proximally, a connector to a generator of active implantable medical device such as a pacemaker or a resynchronizer.
