Implantable intravascular device for defibrillation and/or pacing

1. A method of implanting a pacing and/or defibrillation device, comprising the steps of:

introducing a pulse generator into the vasculature of a patient and advancing the pulse generator to a target vessel;

anchoring the pulse generator within the target vessel; and

positioning a lead within the cardiovascular system, the lead attachable to the pulse generator.

2. The method of claim 1 wherein the target vessel is the superior vena cava.

3. The method of claim 1 wherein the target vessel is the inferior vena cava.

4. The method of claim 1 wherein the lead includes an electrode and the positioning step includes positioning the electrode within a vessel.

5. The method of claim 4 wherein the vessel is the left subclavian.

6. The method of claim 4 wherein the vessel is the superior vena cava.

7. The method of claim 1 wherein the lead includes an electrode and the positioning step includes positioning the electrode within a chamber of the heart.

8. The method of claim 7 wherein the chamber is the right ventricle.

9. The method of claim 7 wherein the chamber is the right atrium.

10. The method of claim 7 wherein the chamber is the left ventricle.

11. The method of claim 1 wherein the heart includes a coronary sinus, wherein the lead includes an electrode, and wherein the positioning step includes positioning the electrode within the coronary sinus.

12. The method of claim 1 wherein the lead is a first lead and wherein the method further includes positioning a second lead within the cardiovascular system, the second lead attachable to the pulse generator.

13. The method of claim 12 wherein each of the first and second leads includes an electrode, and wherein the positioning steps include positioning the electrode of the first lead within a vessel, and positioning the electrode of the second lead within a chamber of the heart.

14. The method of claim 12 wherein each of the first and second leads includes an electrode, and wherein the positioning steps include positioning the electrode of the first lead within a chamber of the heart, and positioning the electrode of the second lead within another chamber of the heart.

15. The method of claim 12 wherein each of the first and second leads includes an electrode, and wherein the positioning steps include positioning the electrode of the first lead within a vessel, and positioning the electrode of the second lead within a coronary sinus of the heart.

16. The method of claim 1 wherein the anchoring step includes positioning an anchor within the target vessel adjacent to the pulse generator, and expanding the anchor into contact with a wall of the target vessel such that expansion of the anchor engages the pulse generator between a portion of the anchor and the wall.

17. The method of claim 16 wherein the anchor substantially minimizes blood flow between the anchor and the device.

18. The method of claim 16 wherein the anchor includes a tubular member having end sections and an intermediate section between the end sections, and wherein the anchoring step includes positioning the intermediate section adjacent to the device, and radially expanding at least a portion of the end sections into contact with the vessel.

19. The method of claim 1 wherein the anchoring step includes expanding an anchor within the blood vessel, the anchor retaining the pulse generator within the blood vessel.

20. An intravascular pacing and/or defibrillation system, comprising:

a pulse generator implantable within a blood vessel, the pulse generator proportioned to allow blood flow through the blood vessel; and

at least one lead attachable to the pulse generator further including an anchor expandable into contact with the wall of the blood vessel to anchor the pulse generator within the blood vessel.

21. The system of claim 20 wherein the pulse generator has a diameter of approximately 10 mm or less.

22. The system of claim 20 wherein the pulse generator includes at least one flexible region, the region sufficiently flexible to permit bending of the pulse generator during positioning of the pulse generator through a blood vessel.

23. The system of claim 22 wherein the pulse generator includes an elongate array of rigid segments, and flexible regions between adjacent rigid segments.

24. The system of claim 20 wherein:

the pulse generator includes a plurality of components including a battery, a capacitor, and electronic components;

the pulse generator includes a housing containing at least a portion of the components, and

the pulse generator further includes a coil coupled to the housing, the coil including at least a portion of the components.

25. The system of claim 24 wherein the coil includes the capacitor.

26. The system of claim 24 wherein the coil includes the battery.

27. The system of claim 20 further including an anchor, the anchor positionable within a vessel at a location adjacent to the pulse generator, and moveable to an expanded position to engage the pulse generator against the vessel wall.

28. The system of claim 27 wherein the anchor is proportioned to allow blood flow through the vessel when used to engage the pulse generator against a vessel wall.

29. The system of claim 20 further including a lead anchor, the lead anchor positionable within a vessel at a location adjacent to the lead, and moveable to an expanded position to engage the lead against the vessel wall.

30. The system of claim 29 wherein the lead anchor is proportioned to allow blood flow through the vessel when used to engage the lead against a vessel wall.

31. The system of claim 20 wherein the pulse generator includes a non-thrombogenic surface.

32. The system of claim 20 wherein the lead includes a non-thrombogenic surface.