An improved guidewire for assisting in implantation of a cardiac lead
includes three sections. The most distal zone is sufficiently floppy to
prevent trauma to the vessel walls through which the guidewire and lead
are inserted. An intermediate zone is generally stiffer and has a
cross-section less than or equal to the cross-section of the distal zone.
The third zone is stiffer yet and is joined to the intermediate zone by a
shoulder. The shoulder cooperates with protrusions on the lead to
transfer forces between the guidewire and lead. A finishing wire having
temporary locking means to lock the finishing wire to the lead is
employed to remove the guide catheter without moving the lead from its
desired location. Lubricious coatings are also provided to reduce
friction between the lead and guidewire.