Modified guidewire for left ventricular access lead
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.
1. An intravenous lead insertion assembly, comprising
a catheter having a proximal end and a distal end;
an intravenous lead at least partially located within the catheter and having at least one electrode and a lumen extending from a proximal end of the lead to a distal end of the lead, the lumen having a first opening through the proximal end of the lead, a second opening through the distal end of the lead, and a helical coil portion;
a guidewire for facilitating advancement of the intravenous lead into the coronary sinus, said guidewire sized to extend through the first and second openings in said lumen and past the distal end of the lead during implantation of the lead, and being removable from the lead after placement of the lead in the coronary sinus; and
a removal wire sized to extend through the first opening and into the lumen of the intravenous lead, the removal wire having a distal end portion including a spherical tip and a lead contacting portion for contacting the lead to facilitate securing the lead during a removal of the catheter from around the lead, the lead contacting portion including a braided mesh material that expands radially under compressive loads.
2. The intravenous lead insertion assembly according to claim 1 , wherein the lumen of the intravenous lead is of a size to separately receive the guidewire and the removal wire, but is not of a size to receive the guidewire and the removal wire simultaneously.
3. The intravenous lead insertion assembly according to claim 1 , wherein the distal end of the intravenous lead extends distal of the distal end of the catheter prior to removal of the catheter.
4. The intravenous lead insertion assembly according to claim 1 , wherein the contacting portion of the removal wire abuts a portion of the intravenous lead.
5. The intravenous lead insertion assembly according to claim 1 , wherein the contacting portion of the removal wire provides a frictional engagement with the lumen of the intravenous lead.
6. The intravenous lead insertion assembly according to claim 1 , wherein the contacting portion engages the helical coil portion of the lead.