Delivery device having a deflectable and peelable mapping guide sheath for his bundle pacing

A delivery device for delivering a lead to a patient's heart, the delivery device comprising:

• a sheath that is elongated and defines a lumen configured to receive the lead therethrough, wherein a distal portion of the sheath includes a plurality of flexible sections spaced apart from one another along a length of the sheath, the sheath comprising:
• an inner layer having a longitudinal rib that protrudes radially outward from an outer surface of the inner layer, the longitudinal rib extending along the length of the sheath;
• a first split line aligned with the longitudinal rib to facilitate splitting of the sheath;
• an outer layer composed of at least one polymer material;
• and
• a middle layer radially disposed between the outer surface of the inner layer and the outer layer, wherein the longitudinal rib extends through the middle layer so that C-shaped sections of the middle layer are circumferentially positioned on both sides of the longitudinal rib.