An implantable lead for placement by means of a guide wire passing therethrough. The lead has an elongated insulative lead body with an axially extending lumen through at least a distal portion of the lead body. A conductor is mounted within and extends to an electrode assembly mounted to a distal portion of the lead body. A seal housing with a seal located therein located at a distal end of the lead body. The seal is located generally perpendicular to the axis of the lead body and is concave on both its proximal and distal sides. The housing is provided with a cavity adjacent each of the seals proximal and distal sides, into which the seal may be deflected. The electrode assembly may be mounted to the seal housing.
