Ablative treatment of atrial fibrillation via the coronary sinus

• US 20070208329A1
• Filed: 12/10/2004
• Published: 09/06/2007
• Est. Priority Date: 12/10/2004
• Status: Active Grant

• Current Assignee: Jim Ward, Mathew Williams
• Original Assignee: Jim Ward, Mathew Williams
• Inventors: Ward, Jim, Williams, Mathew
• Granted Patent: US 7,731,715 B2
• Time in Patent Office: Days
• US Class Current: 606/17
• CPC Class Codes: A61B 18/24 with a catheter A61B18/26, A61B18/28 take precedence
• CPC Class Codes: A61B 2017/00243 cardiac

Abstract

Ablation instruments and techniques are disclosed for accessing portions of the heart wall via the coronary sinus. While shielding the major portion of the sinus and/or the circumflex coronary artery from ablative energy, the present invention provides access to the heart wall to treat atrial fibrillation. In particular, the present invention provides instruments and methods for forming transmural lesions in the left atrium, such as the so-called “left isthmus block,” from within the coronary sinus.

Claims

1. A method for treating atrial fibrillation on a beating heart, the method comprising:

positioning a portion of an ablation instrument within the coronary sinus; and

activating the ablation instrument to form an ablative lesion in left atrial tissue, the lesion extending to the mitral valve annulus.

2. The method of claim 1, wherein the step of activating the ablation instrument further comprises directing ablative energy from within the coronary sinus into an epicardial region to form a lesion that extends from the pulmonary veins to the mitral valve annulus.

3. The method of claim 1, wherein the step of activating the ablation instrument further comprises preferentially directing ablative energy from within the coronary sinus towards the heart rather than other portions of the coronary sinus that are not proximate to the heart.

4. The method of claim 1, wherein the method further comprises forming a lesion encircling the pulmonary veins with a separate epicardial device and the step of activating the ablation instrument further comprises directing ablative energy to form a lesion that extends from the lesion encircling the pulmonary veins to the mitral valve annulus.

5. The method of claim 1, wherein the step of activating the ablation instrument further comprises directing at least one form of an ablative agent, selected from the group comprising radiation, electric current, ultrasound, ablative fluids and cryogenic contact, to a target region.

6. The method of claim 1, wherein the step of activating the ablation instrument further comprises delivering ablative energy as an elongate beam of energy substantially transverse to a longitudinal axis of the ablation instrument.

7. The method of claim 1, wherein the step of activating the ablation instrument further comprises delivering ablative radiant energy to a target region.

8. The method of claim 1, wherein the step of activating the ablation instrument further comprises delivering alternating electrical current energy to a target region via an electrode.

9. The method of claim 8, wherein the alternating electrical current energy is delivered to a target region as a radio frequency current.

10. The method of claim 1, wherein the step of activating the ablation instrument further comprises delivering focused ultrasound energy to a target region.

11. The method of claim 1, wherein the step of activating the ablation instrument further comprises delivering ablative energy to a target region via a cryogenic source. The method of claim 1, wherein the step of positioning the ablation instrument further comprises accessing the coronary sinus from the right atrium of the heart.

12. The method of claim 1, wherein the step of positioning the ablation instrument further comprises accessing the coronary sinus via an incision in the right atrium and passage of the instrument through the right atrium of the heart to the coronary sinus.

13. The method of claim 1, wherein the method further comprises fixing the position of the ablation instrument within the coronary sinus during at least a portion of the ablation.

14. The method of claim 13, wherein the step of fixing the position of the ablation instrument further comprises deploying an expandable element to secure the instrument within the coronary sinus.

15. The method of claim 14, wherein the expandable element comprises a balloon, and wherein the balloon is asymmetrical to deliver ablative energy in a controlled direction.

16. The method of claim 1, wherein the method further comprises rotating the ablation instrument within the coronary sinus during at least a portion of the ablation to form an elongated lesion.

17. A method for treating atrial fibrillation on a beating heart, the method comprising introducing a distal portion of an ablation instrument through the heart and into the coronary sinus, and delivering ablative energy through the distal portion to form a lesion in a target region of the heart near the mitral valve annulus, while protecting at least a portion of one of the coronary sinus and the circumflex artery from the ablative energy source.

18. A method for treating atrial fibrillation, the method comprising:

forming an incision in the right atrium;

introducing a distal end of an ablation instrument through the incision and into the coronary sinus; and

activating the ablation instrument to deliver ablative energy to form a lesion extending from the pulmonary veins to the mitral valve annulus.

19. The method of claim 18, wherein the incision is formed in the right atrial appendage of the right atrium.

20. The method of claim 18, wherein the method further comprises forming a lesion encircling the pulmonary veins with a separate epicardial device and wherein the lesion extending from the pulmonary veins to the mitral valve annulus extends to the lesion encircling the pulmonary veins.

21. The method of claim 18, wherein the step of activating the ablation instrument further comprises directing at least one form of an ablative agent, selected from the group comprising radiation, electric current, ultrasound, ablative fluids and cryogenic contact, to a target region.

22. The method of claim 18, wherein the step of activating the ablation instrument further comprises delivering ablative energy as an elongate beam of energy substantially transverse to a longitudinal axis of the distal end of the ablation instrument.

23. The method of claim 18, wherein the step of activating the ablation instrument further comprises delivering ablative radiant energy to a target region.

24. The method of claim 18, wherein the step of activating the ablation instrument further comprises delivering alternating electrical current energy to a target region via an electrode.

25. The method of claim 24, wherein the alternating electrical current energy is delivered to a target region as a radio frequency current.

26. The method of claim 18, wherein the step of activating the ablation instrument further comprises delivering focused ultrasound energy to a target region.

27. The method of claim 18, wherein the step of activating the ablation instrument further comprises delivering ablative energy to a target region via a cryogenic source.

28. The method of claim 18, wherein the step of positioning the ablation instrument further comprises accessing the coronary sinus from the right ventricle of the heart.

29. The method of claim 18, wherein the method further comprises fixing the position of the ablation instrument within the coronary sinus during at least a portion of the ablation.

30. The method of claim 29, wherein the step of fixing the position of the ablation instrument further comprises deploying an expandable element to secure the instrument within the coronary sinus.

31. The method of claim 30, wherein the expandable element comprises a balloon, and wherein the balloon is asymmetrical to deliver ablative energy in a controlled direction.

32. The method of claim 18, wherein the method further comprises rotating the ablation instrument within the coronary sinus during at least a portion of the ablation to form an elongated lesion.

33. An apparatus for treating atrial fibrillation by ablation on a beating heart, the method comprising:

a catheter body having a distal portion adapted for placement within a coronary sinus of a heart;

an expandable element coupled to the distal portion of the catheter body and adapted to secure the catheter in a position within the coronary sinus; and

an ablative element also coupled to the distal portion of the catheter body and adapted to selectively direct ablative energy into a target region of the heart to form an ablative lesion in left atrial tissue near the mitral valve annulus.

34. The apparatus of claim 33, wherein the ablative element is selected from the group consisting of a resistive electrical heating element, a cryogenic cooling element, an acoustic energy generating element, a microwave generating element, an ablative fluid releasing element, and a light emitting element.

35. The apparatus of claim 34, wherein the apparatus is further adapted to shield at least a portion of at least one of the coronary sinus and the circumflex artery from ablative energy delivered to form the ablative lesion.

36. The apparatus of claim 35, wherein at least a portion of the catheter body comprises energy absorbing or reflecting material adapted to prevent ablative energy from passing therethrough.

37. The apparatus of claim 34, wherein the expandable element comprises an asymmetric balloon adapted to deliver ablative energy in a controlled direction.

38. The apparatus of claim 34, wherein the ablative element is adapted to project ablative energy in a sideways direction that is substantially transverse to a longitudinal axis of the ablative element.

39. The apparatus of claim 34, wherein the ablative element comprises a light-directing tip structure that is adapted to project ablative light in a sideways direction that is substantially transverse to a longitudinal axis of the ablative element.

40. The apparatus of claim 39, wherein the light-directing tip structure is adapted to project ablative light in a small spot-shaped beam.

41. The apparatus of claim 39, wherein the light-directing tip structure is adapted to project ablative light in a substantially linear beam.

42. The apparatus of claim 39, wherein the light-directing tip structure is adapted to project ablative light in a substantially linear beam.