Abstract: A guiding catheter and method of its use are presented wherein the catheter includes an elongate catheter shaft having a proximal region and a distal region and a length. The shaft defines a distal region and includes a distal tip. The distal region defines an arc of approximately 180 degrees and having a radius of 0.3 inches to 0.6 inches. The distal tip forms a half turn of a left-hand helix having a pitch of 0 inches to 0.4 inches. The unique shape of the distal region allows the distal tip be perpendicularly aligned with the septal wall of the right atrium at the His bundle location when the catheter is advanced therein.