Abstract: Lead body designs for forming a fluid tight seal between a multilumen tube and other portions of a lead body are provided. One lead body design has a multilumen tube having a first portion defining a first number of lumens and a second reduced dimension portion defining a second number of lumens, the second number of lumens being smaller than the first number of lumens. The reduced dimension portion is attached to a distal tip portion of the lead body, forming a fluid tight passageway through the multilumen tube to the distal tip portion. Also provided are methods for forming such multilumen tubes and incorporating such multilumen tubes into a lead body.

Abstract: Defibrillator lead designs and methods for manufacturing a lead having attachment between a fibrosis-limiting material covering, a shocking coil electrode, and an implantable lead body are disclosed herein. An electrode coil fitting is disposed within the shocking coil electrode. In an option, the fibrosis limiting material extends past the ends of the electrode coil, and is wrapped between the coil electrode and the electrode coil member.