A biocompatible covering, soluble in body fluids, surrounds the fixation helix of an implantable cardiac electrode as the electrode, and its adjoining lead, are inserted intravenously to a selected cardiac chamber. The covering size and shape are selected for protection of blood vessels and other body tissues during insertion, and for exposure of the fixation element shortly after its proper positioning. The covering may be applied to the fixation element by a dip coating process, or formed separately by casting or injection molding, for later attachment to the lead distal end using an adhesive.