Patent ID: 8406899

Claim:
A system for therapeutically stimulating a His bundle of a patient's heart, the system comprising: an implantable pulse generator configured for subcutaneous implantation in the patient and to generate an electrical pacing stimulus; and a multi-polar medical electrical lead operatively coupled to the pulse generator for delivering the pacing stimulus to cardiac tissue proximate the His bundle, the lead comprising: a proximal connector assembly configured to mechanically and electrically couple the lead to the pulse generator; a flexible tubular body dimensioned to extend at least partially intravascularly from the implantation site of the pulse generator through a superior vena cava of the patient to a location proximate the His bundle, the body including a proximal end coupled to the proximal connector, a distal end opposite the proximal end and a longitudinal conductor lumen extending from the proximal end of the body to the distal end of the body; a distal tip assembly fixedly coupled to the distal end of the body, the tip assembly comprising: a first electrode spaced from the distal end of the body; a fixation helix fixedly coupled to the body and extending distally of the first electrode, the fixation helix configured as a second electrode electrically isolated from the first electrode, the fixation helix further dimensioned to extend from a wall of a right atrial septum of the patient to a location proximate the His bundle and including a sharpened distal tip; and a shank portion extending proximally of the first electrode and the fixation helix within the conductor lumen of the body, the shank portion including a proximal face having a receptacle for receiving and engaging a stylet tip, wherein the distal tip assembly includes a tapered distal tip, wherein the fixation helix extends distally of the tapered distal tip, and wherein the first electrode is located on the tapered distal tip; a first coil conductor extending longitudinally through the conductor lumen of the body and electrically and mechanically coupled to the first electrode; and a second coil conductor extending longitudinally through the conductor lumen of the body and electrically and mechanically coupled to the fixation helix, wherein one or both of the first and second coil conductors defines a stylet lumen.