Bundle of His stimulation system

A system for therapeutically stimulating a His bundle includes an implantable pulse generator and a multi-polar medical electrical lead. The generator is configured for subcutaneous implantation and to generate a pacing stimulus. The lead includes a connector assembly, a flexible tubular body, a distal tip assembly and coil conductors. The body extends intravascularly from the generator to a location proximate the His bundle and includes a proximal end, a distal end, and a longitudinal lumen. The tip assembly includes an electrode, a fixation helix, and a shank portion. The helix extends to a location proximate the His bundle and is operable as an electrically isolated electrode. The shank portion extends within the lumen and includes a receptacle for receiving a stylet tip. The conductors extend longitudinally through the lumen and are coupled to the electrode and the helix. One or both of the conductors defines a stylet lumen.