System and method for multichamber cardiac stimulation with ventricular capture verification using far-field evoked response

• US 6,738,669 B1
• Filed: 10/24/2001
• Issued: 05/18/2004
• Est. Priority Date: 07/29/1998
• Status: Expired due to Term

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Bradley, Kerry, Sloman, Laurence S.
• Primary Examiner(s): Schaetzle, Kennedy
• Application Number:
  US10/011,127
• Time in Patent Office: 937 Days
• Field of Search: 607/28, 607/27, 607/13, 607/15, 607/9, 607/4, 607/5, 600/509, 600/521
• US Class Current: 607/28
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold
• CPC Class Codes: A61N 1/3714 Atrial capture

Abstract

An implantable cardiac stimulation device and method automatically verify capture of one or both ventricular chambers by sensing a far-field signal in both atrial chambers. A far-field interval window is set following the delivery of the ventricular stimulation, during which a far-field signal is detected and compared to a signal representing a predetermined far-field R-wave that represents successful capture of one or both ventricular chambers. If the far-field signal is approximately equal to the predetermined far-field R-wave signal, then capture is verified. If capture is not verified, a threshold search is performed in the ventricle in which capture was lost.

Claims

1. A method of verifying ventricular capture in a first ventricle, the method comprising:

delivering a ventricular stimulation pulse to the first ventricle;

monitoring far-field evoked responses on two atrial channels; and

verifying ventricular capture in the first ventricle by detecting the far-field evoked responses on the two atrial channels during a far-field interval window following the delivery of the ventricular stimulation pulse in the first ventricle.

2. The method of claim 1, further comprising verifying ventricular capture of a second ventricle by:

delivering a ventricular stimulation pulse to the second ventricle; and

verifying ventricular capture in the second ventricle by detecting the far-field evoked responses on the two atrial channels during the far-field interval window following the delivery of the ventricular stimulation pulse to the second ventricle.

3. The method of claim 1, wherein verifying ventricular capture in the first ventricle comprises comparing the far-field evoked responses to a ventricular far-field signal recognition template that is expected to follow successful ventricular capture.

4. The method of claim 3, wherein comparing the far-field evoked responses to the ventricular far-field signal recognition template comprises comparing the far-field evoked responses to a far-field R-wave template.

5. The method of claim 3, further comprising confirming ventricular capture when the far-field evoked responses correspond approximately to the ventricular far-field signal recognition template.

6. The method of claim 5, further comprising automatically generating the ventricular far-field signal recognition template by averaging a number of far-field R-wave signals that are sampled following the delivery of a plurality of ventricular stimulation pulses.

7. The method of claim 3, wherein comparing the far-field evoked responses to the ventricular far-field signal recognition template comprises comparing a characteristic of the far-field evoked responses to any one or more characteristics of the ventricular far-field signal recognition template:

a peak amplitude;

a maximum slope;

a minimum slope; and

an integral.

8. The method of claim 7, further comprising confirming ventricular capture if a characteristic of the far-field evoked responses approximately equals a characteristic of the ventricular far-field signal.

9. The method of claim 1, further comprising setting the far-field interval window during which a far-field R-wave is expected to occur following the delivery of a ventricular stimulation pulse.

10. The method of claim 9, wherein setting the far-field interval window comprises initiating the far-field interval window after a predetermined delay following the delivery of the ventricular stimulation pulse.

11. The method of claim 10, further comprising setting the predetermined delay equal to a ventricular-atrial (VA) conduction time.

12. The method of claim 10, further comprising setting the predetermined delay equal to the average time measured from a number of ventricular stimulation pulses to a plurality of far-field R-waves detected on the two atrial channels.

13. The method of claim 1, wherein verifying ventricular capture in the first ventricle comprises detecting an atrial signal during the far-field interval window.

14. The method of claim 1, wherein verifying ventricular capture in the first ventricle comprises detecting a right ventricular signal during the farfield interval window if a ventricular stimulation pulse has been delivered only in a left ventricle.

15. The method of claim 1, wherein verifying ventricular capture in the first ventricle comprises detecting a left ventricular signal during the far-field interval window if a ventricular stimulation pulse has been delivered only in a right ventricle.

16. The method of claim 1, further comprising triggering the delivery of a safety, backup stimulation pulse in the first ventricle if ventricular capture is not confirmed.

17. The method of claim 1, further comprising triggering a threshold test in the first ventricle if ventricular capture is not confirmed.

18. A method of verifying ventricular capture in a first ventricle, the method comprising:

delivering a bi-ventricular stimulation to the first ventricle and to a second ventricle;

monitoring a far-field evoked response on an atrial channel resulting from the bi-ventricular stimulation; and

verifying ventricular capture in the first ventricle by detecting the resulting far-field evoked response on the atrial channel during a far-field interval window following the delivery of the ventricular stimulation pulse in the first ventricle.

19. The method of claim 18, further comprising verifying ventricular capture of a second ventricle by detecting the resulting far-field evoked response on the atrial channel during a far-field interval window following the delivery of the ventricular stimulation pulse in the second ventricle.

20. The method of claim 19, wherein verifying capture in the first and second ventricles comprises detecting far-field evoked responses on two atrial channels during the far-field interval window following the delivery of the ventricular stimulation pulse in any one of the first or the second ventricle.

21. A multi-chamber stimulation device that verifies ventricular capture in a first ventricle, the device comprising:

a pulse generator that generates stimulation pulses;

a lead connected to the pulse generator that delivers a ventricular stimulation pulse to the first ventricle;

an atrial sensor assembly that monitors far-field evoked responses on two atrial channels; and

a controller that is in communication with the sensor assembly and that is operative to verify ventricular capture in the first ventricle by detecting the far-field evoked responses on the two atrial channels during a far-field interval window following the delivery of the ventricular stimulation pulse in the first ventricle.

22. The stimulation device of claim 21, wherein the controller verifies ventricular capture of a second ventricle by detecting the far-field evoked responses on the two atrial channels during the far-field interval window following the delivery of a ventricular stimulation pulse to the second ventricle.

23. The stimulation device of claim 21, wherein the controller verifies ventricular capture in the first ventricle by comparing the far-field evoked responses to a biventricular far-field signal recognition template that is expected to follow successful ventricular capture.

24. The stimulation device of claim 23, wherein the biventricular farfield signal recognition template comprises a far-field R-wave template.

25. The stimulation device of claim 23, wherein the controller verifies ventricular capture if the far-field evoked responses correspond approximately to the biventricular far-field signal recognition template.

26. The stimulation device of claim 25, wherein the biventricular far-field signal recognition template results from the average of a plurality of far-field R-wave signals that are sampled following the delivery of a plurality of ventricular stimulation pulses.

27. The stimulation device of claim 23, wherein the controller confirms ventricular capture if a characteristic of the far-field evoked responses corresponds to any one or more characteristics of the biventricular farfield signal recognition template:

a peak amplitude;

a maximum slope;

a minimum slope; and

an integral.

28. The stimulation device of claim 21, wherein the far-field interval window is initiated during a period in which a far-field R-wave is expected to occur following the delivery of a ventricular stimulation pulse.

29. The stimulation device of claim 28, wherein the far-field interval window is initiated after a predetermined delay following the delivery of the ventricular stimulation pulse.

30. The stimulation device of claim 29, wherein the predetermined delay is substantially equal to a ventricular-atrial (VA) conduction time.

31. The stimulation device of claim 29, wherein the predetermined delay is substantially equal to the average time measured from a number of ventricular stimulation pulses to a plurality of far-field R-waves detected on the two atrial channels.

32. A multi-chamber stimulation device that verifies ventricular capture in a first ventricle, the device comprising:

a pulse generator that generates stimulation pulses;

a lead connected to the pulse generator that delivers a bi-ventricular stimulation to the first ventricle and to a second ventricle;

an atrial sensor that monitors a far-field evoked response on an atrial channel resulting from the bi-ventricular stimulation; and

a controller in communication with the sensor and that is operative to verify ventricular capture in the first ventricle by detecting the resulting far-field evoked response on the atrial channel during a far-field interval window following the delivery of the ventricular stimulation pulse in the first ventricle.

33. The stimulation device of claim 32, wherein the controller verifies ventricular capture of a second ventricle by detecting the far-field evoked response on the atrial channel during a far-field interval window following the delivery of the ventricular stimulation pulse in the second ventricle.

34. The stimulation device of claim 33, wherein the controller verifies ventricular capture in the first and second ventricles by detecting far-field evoked responses on two atrial channels during the far-field interval window following the delivery of the ventricular stimulation pulse in any one of the first or the second ventricle.

35. A multi-chamber stimulation device that verifies ventricular capture in a first ventricle, comprising:

means for delivering a stimulation pulse to the first ventricle;

means for monitoring a far-field evoked response on a pair of atrial channels corresponding to the two atria; and

means for verifying capture in the first ventricle by detecting the far-field evoked response on the atrial channels during a farfield interval window following the delivery of the ventricular stimulation pulse in the first ventricle.

36. The stimulation device of claim 35, further comprising means for verifying ventricular capture of a second ventricle.

37. The stimulation device of claim 36, wherein the means for verifying ventricular capture of the second ventricle comprises:

means for delivering a ventricular stimulation pulse to the second ventricle; and

means for verifying ventricular capture in the second ventricle by detecting the far-field evoked responses on the one or more atrial channels during the far-field interval window following the delivery of the ventricular stimulation pulse to the second ventricle.

38. The stimulation device of claim 35, wherein the means for verifying ventricular capture in the first ventricle compares the far-field evoked responses to a biventricular far-field signal recognition template that is expected to follow successful ventricular capture.

39. The stimulation device of claim 35, wherein the biventricular far-field signal recognition template comprises a far-field R-wave template.

40. A multi-chamber stimulation device that verifies capture in a first ventricle, comprising:

means for delivering a bi-ventricular stimulation to the first ventricle and to a second ventricle;

means for monitoring a far-field evoked response on an atrial channel resulting from the bi-ventricular stimulation; and

means for verifying capture in the first ventricle by detecting the resulting far-field evoked response on the atrial channel during a far-field interval window following the delivery of the ventricular stimulation pulse in the first ventricle.

41. The stimulation device of claim 40, further comprising means for verifying capture of a second ventricle.

42. The stimulation device of claim 41, wherein the means for verifying capture of the second ventricle comprises means for detecting the far-field evoked response on the atrial channel during a far-field interval window following the delivery of the ventricular stimulation pulse in the second ventricle.

43. The stimulation device of claim 42, wherein the means for verifying capture of the first and second ventricles comprises means for detecting far-field evoked responses on two atrial channels during the far-field interval window following the delivery of the ventricular stimulation pulse in any one of the first or the second ventricle.