Methods and apparatus for determining cardiac stimulation sites using hemodynamic data

• US 20070060961A1
• Filed: 02/10/2006
• Published: 03/15/2007
• Est. Priority Date: 09/12/2005
• Status: Active Grant

• Current Assignee: EBR Systems, Inc.
• Original Assignee: EBR Systems, Inc.
• Inventors: Brisken, Axel, Cowan, Mark, Echt, Debra, Riley, Richard
• Granted Patent: US 7,702,392 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36564 controlled by blood pressure

Abstract

Methods and apparatus for determining an endocardial implantation site for implanting an electrode, such as a leadless stimulation electrode. An embodiment of one method in accordance with the invention includes delivering sufficient electrical energy for initiation of cardiac activation to a plurality of different test locations at the heart of a patient, and determining hemodynamic responses in reaction to that the stimulus delivered to the different test locations. This method further includes identifying an implantation site for implanting the electrode by selecting at least one of the test locations corresponding to a favorable hemodynamic response.

Claims

1. A method of determining an implantation site for attaching a leadless stimulation electrode to the heart of a patient, wherein the leadless electrode is configured to convert acoustic energy to electrical energy and deliver the electrical energy to the implantation site, the method comprising:

delivering electrical energy to a plurality of different test locations on the heart of the patient;

determining cardiac performance responses in reaction to the electrical energy delivered to the different test locations; and

identifying an implantation site for implanting the electrode by selecting at least one test location corresponding to a favorable cardiac performance response.

2. The method of claim 1, further comprising implanting the leadless stimulation electrode at the identified implantation site.

3. The method of claim 1, further comprising:

implanting the leadless stimulation electrode at the identified implantation site; and

pacing the heart by wirelessly transmitting acoustic energy from an acoustic generator located remotely from the heart to the implanted stimulation electrode, wherein the implanted leadless electrode converts the acoustic energy to electrical energy and applies the electrical energy to the identified implantation site.

4. The method of claim 1 wherein delivering the electrical energy to the test locations comprises:

positioning an electrode at endocardial locations in the heart, wherein the electrode has a lead wire configured to extend through the vasculature of the patient and an electrical contact at a distal end of the lead wire; and

transmitting the electrical energy through the lead wire to the contact.

5. The method of claim 1 wherein delivering the electrical energy to the test locations comprises:

positioning the leadless stimulation electrode that is to be implanted in the patient at endocardial test locations in the heart, wherein the leadless stimulation electrode comprises a transducer that coverts acoustic energy to electrical energy and an electrical contact electrically coupled to the transducer; and

wirelessly transmitting acoustic energy through the patient from an acoustic generator located remotely from the heart to the leadless stimulation electrode, wherein the transducer coverts the acoustic energy to electrical energy and the contact delivers the electrical energy to the test locations.

6. The method of claim 5, further comprising implanting the leadless stimulation electrode at the identified implantation site.

7. The method of claim 5, further comprising:

implanting the leadless stimulation electrode at the identified stimulation site; and

pacing the heart by wirelessly transmitting acoustic energy from the acoustic generator.

8. The method of claim 1 wherein determining the cardiac performance responses comprises measuring pressure within a chamber of the heart.

9. The method of claim 1 wherein determining the cardiac performance responses comprises measuring pressure from a first location within the left ventricle chamber of the heart and a second location within the ascending aorta.

10. The method of claim 1 wherein determining the cardiac performance responses comprises measuring (a) pressure from a first location within the left ventricle of the heart and a second location within the ascending aorta, and (b) blood volume in the left ventricle.

11. The method of claim 1, further comprising determining a baseline hemodynamic value during a period while electrical energy is not delivered to the test locations.

12. The method of claim 1 wherein identifying the implantation site comprises:

ascertaining at least one hemodynamic parameter selected from at least one of a pressure-volume loop, rate of pressure change, ejection fraction, stroke volume, end systolic pressure, blood motion velocity, cardiac wall motion velocity, cardiac wall motion force, and cardiac wall motion timing for the test locations based on the determined hemodynamic responses; and

selecting a test location corresponding to a value of the selected hemodynamic parameter.

13. The method of claim 12, further comprising referencing the ascertained hemodynamic parameter to test locations corresponding to locations on a representation of the heart.

14. A method of determining an implantation site for implanting an electrode in a heart of a patient, comprising:

delivering electrical energy to a plurality of endocardial test locations within the heart of the patient;

determining cardiac performance responses in reaction to the electrical energy delivered to the different test locations; and

identifying an implantation site for implanting the electrode by selecting at least one of the test locations corresponding to a favorable cardiac performance response.

15. The method of claim 14 wherein the test locations are in the endocardial aspect of the left ventricle of the heart.

16. The method of claim 15, further comprising implanting a leadless stimulation electrode at the identified implantation site, wherein the leadless stimulation electrode is configured to convert acoustic energy to electrical energy and deliver the electrical energy to the implantation site.

17. The method of claim 16, further comprising pacing the heart by wirelessly transmitting acoustic energy from an acoustic generator located remotely from the heart to the implanted stimulation electrode, wherein the implanted leadless stimulation electrode converts the acoustic energy to electrical energy and applies the electrical energy to the identified stimulation site in the left ventricle of the heart.

18. The method of claim 14 wherein determining the cardiac performance responses comprises measuring pressure within a chamber of the heart.

19. The method of claim 14 wherein determining the cardiac performance responses comprises measuring pressure from a first location within the left ventricle chamber of the heart and a second location within the ascending aorta.

20. The method of claim 14 wherein determining the cardiac performance responses comprises measuring (a) pressure from a first location within the left ventricle of the heart and a second location within the ascending aorta, and (b) blood volume in the left ventricle.

21. The method of claim 14 wherein determining the cardiac performance responses comprises measuring electrical activation timing within the left ventricle of the heart.

22. The method of claim 15 wherein determining the cardiac performance responses comprises measuring electrical activation timing within the left ventricle of the heart.

23. The method of claim 16 wherein determining the cardiac performance responses comprises measuring electrical activation timing within the left ventricle of the heart.

24. The method of claim 17 wherein determining the cardiac performance responses comprises measuring electrical activation timing within the left ventricle of the heart.

25. A method of implanting a stimulation electrode within the heart of a patent, comprising:

locating a leadless electrode at a first test location in the heart of the patient, wherein the leadless electrode is configured to convert acoustic energy to electrical energy;

delivering electrical energy to the first test location via the leadless electrode by wirelessly transmitting acoustic energy to the leadless electrode;

determining a first hemodynamic response in reaction to the electrical energy delivered to the first test location;

delivering electrical energy to a second test location in the heart via the leadless electrode by wirelessly transmitting acoustic energy to the leadless electrode;

determining a second hemodynamic response in reaction to the electrical energy delivered to the second test location;

identifying an implantation site by selecting one of the first and second test locations; and

implanting the leadless electrode at the identified implantation site.

26. The method of claim 25 wherein the first and second test locations are in the endocardial aspect of the left ventricle of the heart.

27. The method of claim 25, further comprising pacing the heart by wirelessly transmitting acoustic energy from an acoustic generator located remotely from the heart to the implanted leadless electrode, wherein the implanted leadless electrode converts the acoustic energy to electrical energy and applies the electrical energy to the identified stimulation site in the left ventricle of the heart.

28. The method of claim 25 wherein determining the first and second hemodynamic responses comprises measuring pressure within a chamber of the heart.

29. The method of claim 25 wherein determining the first and second hemodynamic responses comprises measuring pressure from a first location within the left ventricle chamber of the heart and a second location within the ascending aorta.

30. The method of claim 25 wherein determining the first and second hemodynamic responses comprises measuring (a) pressure from a first location within the left ventricle of the heart and a second location within the ascending aorta, and (b) blood volume in the left ventricle.

31. A method of automatically determining an implantation site for attaching a leadless stimulation electrode to the heart of a patient, wherein the leadless electrode is configured to convert acoustic energy to electrical energy and deliver the electrical energy to the stimulation site, the method comprising:

delivering electrical energy to a plurality of different test locations at the heart of the patient;

determining acute intrinsic hemodynamic responses in reaction to the electrical energy delivered to the different test locations; and

identifying an implantation site for implanting the electrode by operating a computer to select at least one of the test locations at the heart corresponding to a favorable hemodynamic response.

32. The method of claim 31 wherein:

determining acute hemodynamic responses comprises ascertaining at least one hemodynamic parameter selected from at least one of a pressure-volume loop, rate of pressure change, ejection fraction, stroke volume, end systolic pressure, blood motion velocity, cardiac wall motion velocity, cardiac wall motion force, and cardiac wall motion timing for the test locations based on the determined hemodynamic responses; and

identifying the implantation site by operating the computer comprises selecting a test location corresponding to a value of the selected hemodynamic parameter.

33. An apparatus for determining an implantation site for attaching a stimulation electrode to the heart of a patent, comprising:

an elongated body having a proximal portion and a distal portion, wherein the distal portion is configured to be inserted into the heart of the patient;

a hemodynamic sensor at the distal portion of the body; and

a stimulation electrode at the distal portion of the body, wherein the stimulation electrode comprises (a) a transducer configured to convert acoustic energy to electrical energy and (b) an electrical contact electrically coupled to the transducer to deliver electrical energy from the transducer to the implantation site.

34. The apparatus of claim 33 wherein the hemodynamic sensor comprises a pressure sensor.

35. The apparatus of claim 33 wherein the hemodynamic sensor comprises an electrical sensor.

36. The apparatus of claim 33 wherein the hemodynamic sensor comprises a first pressure sensor located at the distal portion of the body to be inserted into the left ventricle of the heart, and wherein the apparatus further comprises a second pressure sensor located proximally of the first pressure sensor to be positioned in the ascending aorta.

37. The apparatus of claim 33 wherein the hemodynamic sensor comprises a pressure sensor, and wherein the apparatus further comprises an electrical sensor proximate to the pressure sensor.

38. A system for determining an implantation site for attaching a stimulation electrode to the heart of a patient, comprising:

a generator configured to wirelessly transmit acoustic energy;

a stimulation electrode configured to be placed against the heart of the patient, wherein the stimulation electrode comprises (a) a case, (b) a transducer at least partially in the case and configured to convert the wirelessly transmitted acoustic energy from the generator to electrical energy, and (c) an electrical contact electrically coupled to the transducer and configured to deliver the electrical energy from the transducer to the heart of the patient; and

a hemodynamic sensor configured to detect acute intrinsic hemodynamic responses in reaction to the electrical energy delivered to the heart from the stimulation electrode.

39. The system of claim 38 wherein the hemodynamic sensor comprises a pressure sensor.

40. The system of claim 38 wherein the hemodynamic sensor comprises an electrical sensor.

41. The apparatus of claim 38 wherein the hemodynamic sensor comprises a first pressure sensor located at the distal portion of the body to be inserted into the left ventricle of the heart, and wherein the apparatus further comprises a second pressure sensor located proximally of the first pressure sensor to be positioned in the ascending aorta.

42. The apparatus of claim 38 wherein the hemodynamic sensor comprises a pressure sensor, and wherein the apparatus further comprises an electrical sensor proximate to the pressure sensor.

43. A system for determining an implantation site for attaching a stimulation electrode to the heart of a patient, comprising:

a generator configured to wirelessly transmit a source energy;

a stimulation electrode configured to be placed against the heart of the patient, wherein the stimulation electrode comprises a transducer configured to convert the source energy to electrical energy and an electrical contact configured deliver the electrical energy to the heart of the patient;

a hemodynamic sensor configured to detect acute intrinsic hemodynamic responses in reaction to electrical energy applied to the heart by the stimulation electrode; and

a computer operatively coupled to the hemodynamic sensor and the stimulation electrode, wherein the computer includes a computer operable medium containing instructions that provide an output indicative of stimulation performance of the stimulation electrode at test sites of the heart of the patient.

44. The system of claim 43 wherein the hemodynamic sensor comprises a pressure sensor.

45. The system of claim 43 wherein the hemodynamic sensor comprises an electrical sensor.

46. The apparatus of claim 43 wherein the hemodynamic sensor comprises a first pressure sensor located at the distal portion of the body to be inserted into the left ventricle of the heart, and wherein the apparatus further comprises a second pressure sensor located proximally of the first pressure sensor to be positioned in the ascending aorta.

47. The apparatus of claim 43 wherein the hemodynamic sensor comprises a pressure sensor, and wherein the apparatus further comprises an electrical sensor proximate to the pressure sensor.

48. The system of claim 43 wherein the computer operable medium provides an output in which the stimulation performance of the stimulation electrode is mapped onto an image representative of the heart of the patient.