Pacing output configuration selection for cardiac resynchronization therapy patients

• US 20080177344A1
• Filed: 01/18/2007
• Published: 07/24/2008
• Est. Priority Date: 01/18/2007
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Maskara, Barun, Yu, Yinghong
• Granted Patent: US 7,890,172 B2
• Time in Patent Office: Days
• US Class Current: 607/25
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36842 Multi-site stimulation in the same chamber

Abstract

Cardiac therapy systems include multiple electrodes respectively positionable at multiple left ventricular electrode sites. A pulse generator is coupled to the electrodes and configured to deliver a cardiac resynchronization therapy (CRT). A processor is configured to measure, for each left ventricular electrode site, a timing interval between first and second cardiac signal features associated with left ventricular depolarization. The timing interval is associated with a degree of responsiveness of each left ventricular electrode site to CRT. The processor is configured to determine a pacing output configuration that provides improved patient responsiveness to CRT based on the timing interval measurements and to select at least one left ventricular electrode site from the plurality of left ventricular electrode sites based on the timing interval measurements. The processor may be configured to monitor for a change in hemodynamic status of the patient based on a change in the timing interval.

Claims

1. A method, implementable at least in part in a cardiac therapy device, for delivering cardiac resynchronization therapy to a patient, the method comprising:

sensing cardiac electrical signals from a plurality of left ventricular electrode sites;

measuring, for each left ventricular electrode site, a timing interval between first and second cardiac signal features associated with left ventricular depolarization, the timing interval associated with a degree of responsiveness of each left ventricular electrode site to cardiac resynchronization therapy (CRT); and

determining a pacing output configuration that provides improved patient responsiveness to CRT based on the timing interval measurements, wherein determining the pacing output configuration comprises selecting at least one left ventricular electrode site from the plurality of left ventricular electrode sites based on the timing interval measurements.

2. The method of claim 1, wherein the at least one left ventricular electrode site is associated with a relatively longer measured timing interval when compared to measured timing intervals associated with other left ventricular electrode sites.

3. The method of claim 1, further comprising delivering CRT to the patient using the determined pacing output configuration.

4. The method of claim 3, further comprising:

repeating time interval measuring over time; and

selecting an alternate pacing output configuration differing from a current pacing output configuration in response to the measured timing interval associated with the current pacing output configuration falling below a threshold.

5. The method of claim 3, further comprising:

repeating time interval measuring over time; and

generating a warning in response to the measured timing interval associated with a current pacing output configuration falling below a threshold.

6. The method of claim 1, wherein the pacing output configuration comprises an atrioventricular (AV) delay selected based on the measured timing intervals.

7. The method of claim 1, further comprising:

sensing a change in a patient hemodynamic parameter indicative of reduced patient responsiveness to CRT; and

selecting an alternate pacing output configuration differing from a current pacing output configuration in response the sensed change in the patient hemodynamic parameter.

8. The method of claim 1, further comprising identifying a pacing vector or pacing site associated with a longest timing interval duration, and selecting a left ventricular electrode site for electrode implantation based on the identified pacing vector or pacing site.

9. The method of claim 1, wherein the first feature comprises a signal deflection associated with a beginning of ventricular depolarization, and the second feature comprises a peak value of a cardiac electrical signal sensed from the left ventricular electrode site or a signal deflection associated with an end of ventricular depolarization.

10. A method, comprising:

sensing, from within a patient, one or more cardiac electrical signals, including a cardiac electrical signal from at least one left ventricular electrode site;

detecting a change in a timing interval between first and second cardiac electrical signal features associated with ventricular depolarization, the timing interval associated with a degree of responsiveness of the at least one left ventricular electrode site to cardiac resynchronization pacing therapy (CRT); and

monitoring for a change in hemodynamic status of the patient based on the detected timing interval change.

11. The method of claim 10, wherein monitoring the change in the patient'"'"'s hemodynamic status comprises tracking progression or regression of the patient'"'"'s heart failure status.

12. The method of claim 10, further comprising generating an alert signal responsive to the change in the patient'"'"'s hemodynamic status.

13. The method of claim 10, further comprising modifying selection of one or more pacing sites responsive to the change in the patient'"'"'s hemodynamic status.

14. The method of claim 10, further comprising modifying one or more pacing delays responsive to the change in the patient'"'"'s hemodynamic status.

15. The method of claim 14, wherein the pacing delay comprises an AV delay.

16. The method of claim 10, further comprising modifying delivery of CRT in response to the change in the patient'"'"'s hemodynamic status.

17. A cardiac therapy system, comprising:

multiple electrodes respectively positionable at multiple locations within at least a left ventricle for sensing cardiac electrical signals from a plurality of left ventricular electrode sites;

a pulse generator coupled to the multiple electrodes and configured to deliver at least a cardiac resynchronization therapy (CRT); and

a processor coupled to the multiple electrodes and the pulse generator, the processor configured to measure, for each left ventricular electrode site, a timing interval between first and second cardiac signal features associated with left ventricular depolarization, the timing interval associated with a degree of responsiveness of each left ventricular electrode site to CRT, the processor configured to determine a pacing output configuration that provides improved patient responsiveness to CRT based on the timing interval measurements and to select at least one left ventricular electrode site from the plurality of left ventricular electrode sites based on the timing interval measurements.

18. The system of claim 17, wherein the at least one left ventricular electrode site is associated with a relatively longer measured timing interval when compared to measured timing intervals associated with other left ventricular electrode sites.

19. The system of claim 17, wherein the processor is configured to cooperate with the pulse generator to deliver CRT to the patient using the determined pacing output configuration.

20. The system of claim 17, wherein the processor is configured to select an alternate pacing output configuration differing from a current pacing output configuration in response to the measured timing interval associated with the current pacing output configuration falling below a threshold.

21. The system of claim 17, wherein the processor is configured to generate a warning in response to the measured timing interval associated with the pacing output configuration falling below a threshold.

22. The system of claim 17, wherein the processor computes an atrioventricular (AV) delay based on the measured timing interval measurements.

23. The system of claim 17, further comprising one or more sensors configured to sense a change in a patient hemodynamic parameter indicative of reduced patient responsiveness to CRT, wherein the processor is configured to select an alternate pacing output configuration differing from a current pacing output configuration in response the sensed change in the patient hemodynamic parameter.

24. The system of claim 17, wherein the processor is configured to identify a pacing vector or pacing site associated with a longest timing interval duration, and to select a left ventricular electrode site for electrode implantation based on the identified pacing vector or pacing site.

25. The system of claim 17, wherein the first feature comprises a signal deflection associated with a beginning of ventricular depolarization, and the second feature comprises a peak value of a cardiac electrical signal sensed from the left ventricular electrode site or a signal deflection associated with an end of ventricular depolarization.

26. A cardiac therapy system, comprising:

multiple electrodes respectively positionable at multiple locations within at least a left ventricle for sensing cardiac electrical signals from at least one left ventricular electrode site;

a pulse generator coupled to the multiple electrodes and configured to deliver at least a cardiac resynchronization therapy (CRT); and

a processor coupled to the multiple electrodes and the pulse generator, the processor configured to detect a change in a timing interval between first and second cardiac signal features associated with ventricular depolarization, the timing interval associated with a degree of responsiveness of the at least one left ventricular electrode site to CRT, the processor configured to monitor for a change in hemodynamic status of the patient based on the detected timing interval change.

27. The system of claim 26, wherein the processor is configured to track progression or regression of the patient'"'"'s heart failure status.

28. The system of claim 26, wherein the processor is configured to generate an alert signal responsive to the change in the patient'"'"'s hemodynamic status.

29. The system of claim 26, wherein the processor is configured to modify selection of one or more pacing sites responsive to the change in the patient'"'"'s hemodynamic status.

30. The system of claim 26, wherein the processor is configured to modify one or more pacing delays responsive to the change in the patient'"'"'s hemodynamic status.

31. The system of claim 26, wherein the processor is configured to modify delivery of CRT in response to the change in the patient'"'"'s hemodynamic status.