Adjustable lead systems for cardiac septal wall implantation

1. An implantable lead system comprising:

a fixation member comprising a proximal portion, a distal portion, a fixation element coupled to the distal portion, and an elongate body extending between the proximal portion and the distal portion, the fixation element configured to attach to a septal wall of a patient's heart, the elongate body configured to transfer torque from the proximal portion to the distal portion;

an implantable lead comprising a proximal portion, a distal portion, a lead body extending between the proximal portion and the distal portion, and an electrode coupled to the distal portion, the distal portion configured to be at least partially inserted into the septal wall, the electrode configured to be implanted at an implantation site in the septal wall, wherein the implantable lead is slidably coupled to and rotatable relative to the fixation member,

wherein the elongate body of the fixation member defines a lumen extending from the proximal portion to the distal portion of the fixation member, wherein the lumen is configured to receive the implantable lead such that the implantable lead is slidably and rotatably movable through the proximal portion and the distal portion of the fixation member during implantation of the implantable lead while the fixation member is attached to the septal wall; and

a securing member to couple the proximal portion of the fixation member and the proximal portion of the implantable lead after implantation of the implantable lead to mitigate migration of the implantable lead.

2. The system of claim 1 , wherein the fixation element comprises a helix to screw in or out of the septal wall in response to rotation of the fixation member.

3. The system of claim 1 , wherein the fixation element is electrically conductive and electrically coupled to the proximal portion of the fixation member.

4. The system of claim 1 , wherein the elongate body comprises a braided structure.

5. The system of claim 4 , wherein the braided structure comprises a conductor electrically coupled to the fixation element.

6. The system of claim 1 , wherein the elongate body comprises a porous region to allow fluid communication between an outside and an inside of the elongate body.

7. The system of claim 1 , wherein the implantable lead comprises multiple electrodes coupled to the lead body.

8. The system of claim 7 , wherein the implantable lead comprises one or more electrically insulated coil conductors electrically coupled to the multiple electrodes.

9. The system of claim 7 , wherein each of the multiple electrodes are independently electrically coupled to a therapy delivery circuit of an implantable medical device.

10. The system of claim 7 , wherein when the implantable lead is implanted, at least one of the electrodes is not implanted in the septal wall.

11. The system of claim 1 , wherein the implantable lead defines an inner lumen to receive a guide wire.

12. The system of claim 11 , wherein the electrode of the implantable lead defines at least part of the inner lumen.

13. The system of claim 12 , further comprising a sealing element coupled to the electrode of the implantable lead to form a fluid seal between the guide wire and an inner surface of the electrode.

14. The system of claim 1 , wherein the distal portion of the implantable lead comprises a tapered structure in a screw configuration, wherein the tapered structure comprises the electrode.

15. The system of claim 1 , further comprising telescoping delivery catheters defining catheter lumens to receive the fixation member and the implantable lead and to position the fixation member and the implantable lead proximate to the septal wall, wherein the telescoping delivery catheters comprise an outer catheter and an inner catheter slidably coupled to and rotatable relative to the outer catheter.

16. The system of claim 1 , wherein the electrode of the implantable lead comprises a segmented electrode including two or more segments angularly spaced from one another.