Intravascular implantable device having superior anchoring arrangement

1. An intravascular device comprising: an elongate device body with a proximal end and a proximal portion proximate the proximal end and a distal end that is adapted for chronic implantation within vasculature of a patient and that includes a distal portion of the intravascular device proximate the distal end of the elongate device body, wherein the intravascular device comprises an intravascular pulse generator device and further includes at least one lead having at least one electrode thereon extending from the proximal portion of the elongate device body with a free end of the lead adapted to be positioned proximate a chamber of the heart; and

an anchor that is radially expandable and is adapted to anchor only the distal portion of the intravascular device within a target vessel located superior to a heart of the patient, such that the proximal portion of the elongate device body is left mechanically unsecured within the vasculature of the patient.

2. The intravascular device of claim 1 wherein the distal portion of the intravascular device has an average cross-sectional diameter that is smaller than an average cross-sectional diameter of the elongate device body other than the distal portion.

3. The intravascular device of claim 1 wherein the distal portion of the intravascular device is a tether portion that extends beyond the distal end of the elongate device body, wherein the target vessel is located beyond a subclavian crush zone of the patient in a direction away from the heart and wherein the tether portion is adapted to be intervascularily positioned in the target vessel without the elongate device body being advanced into the subclavian crush zone.

4. The intravascular device of claim 1 wherein the distal portion includes a tether portion extending beyond the distal end of the device body, the tether portion including structure that interfaces with structure on the anchor to mechanically engage the tether portion with the anchor.

5. The intravascular device of claim 4 wherein the tether portion includes a cleat having a pair of laterally opposed structures on the tether portion, either of which are adapted to interface with structure on the anchor.

6. The intravascular device of claim 5 wherein the cleat includes a pair of laterally opposed clip structures and a corresponding pair of laterally opposed fin structures orthogonally offset from an orientation of the clip structures, wherein the anchor is a radially expandable stent having a plurality of struts that define vertices at intersections thereof, such that when the device body is rotated the fin structures orient one of the clip structures to interface with one of the vertices of the plurality of struts whereby the one of the clip structures engages with the one of the vertices of the plurality of struts when the device body is pulled back relative to the anchor.

7. The intravascular device of claim 1 wherein the device body has an aspect ratio of a cross-sectional diameter to a longitudinal length of less than 1:10.

8. The intravascular device of claim 1 wherein the device body comprises a plurality of generally rigid segments interconnected by a flexible zone, and wherein an aspect ratio of a cross-sectional diameter of a segment to a longitudinal length of a segment is less than 1.5:2.

9. A method of implanting an intravascular device, comprising:

providing an intravascular device having an elongate device body with a proximal end and a proximal portion proximate the proximal end and a distal end that is adapted for chronic implantation within vasculature of a patient and that includes a distal portion of the intravascular device proximate the distal end of the elongate device body the intravascular device including an intravascular pulse generator device having at least one lead having at least one electrode thereon extending from the proximal portion of the elongate device body

introducing the intravascular device into the vasculature of the patient;

advancing the intravascular device until the distal portion is positioned within a target vessel superior to a heart of the patient;

anchoring the distal portion of the intravascular device within the target vessel, such that the distal portion of the elongate device body is mechanically secured within the vasculature of the patient while the proximal portion of the elongate device body proximate the proximal end of the elongate device body is left mechanically unsecured within the vasculature of the patient,

advancing a free end of the lead to the heart until at least one electrode is positioned proximate a chamber of the heart; and

anchoring the lead proximate the free end of the lead.

10. The method of claim 9 wherein advancing the free end of the lead includes positioning the free end of the lead within one of a chamber of the heart or a cardiac vessel of the heart.

11. The method of claim 9 wherein providing the intravascular device provides an intravascular device in which the distal portion is a tether portion that extends beyond the distal end of the elongate device body, wherein the target vessel is located beyond a subclavian crush zone of the patient in a direction away from the heart and advancing the intravascular device further comprises advancing the tether portion to the target vessel without advancing the elongate device body into the subclavian crush zone.

12. The method of claim 9 wherein the target vessel is located superior to the heart and still generally within the torso of the patient, and wherein advancing the intravascular device further comprises advancing the distal portion of the intravascular device to one of the right or left cephalic veins, the right or left innominate (brachiocephalic) veins or the right or left subclavian veins.