Secure and efficacious therapy delivery for an extra-systolic stimulation pacing engine

• US 20050101998A1
• Filed: 11/07/2003
• Published: 05/12/2005
• Est. Priority Date: 10/07/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gillberg, Jeffrey M., Kleckner, Karen J., Deno, D. Curtis, Zillmer, Glenn C., Zhou, Ren, Anderson, Kenneth M., Splett, Vincent E., Prieve, Kathleen A., Klepfer, Ruth N.
• Granted Patent: US 7,233,824 B2
• Time in Patent Office: Days
• US Class Current: 607/4
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• 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 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36564 controlled by blood pressure
• CPC Class Codes: A61N 1/36578 controlled by mechanical motion of the heart wall, e.g. measured by an accelerometer or microphone
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• 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
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation

Abstract

An extra-systolic stimulation (ESS) therapy addresses cardiac dysfunction including heart failure. ESS therapy employs atrial and/or ventricular extra-systoles via pacing-level stimulation to a heart. These extra-systoles must be timed correctly to achieve beneficial effects on myocardial mechanics (efficacy) while maintaining an extremely low level of risk of arrhythmia induction and excellent ICD-like arrhythmia sensing and detection (security). The present invention relates to therapy delivery guidance and options for improved ESS therapy delivery. These methods may be employed individually or in combinations in an external or implantable ESS therapy delivery device.

Claims

1. A method for managing an extra-systolic stimulation cardiac pacing therapy on a beat-by-beat basis, comprising:

sensing electrical activity of a heart on a beat-by-beat basis to provide output signals related to at least one of;

a sensed atrial depolarization, a first atrial pacing event, a second atrial pacing event, a sensed right ventricular depolarization, a first right ventricular pacing event, a second right ventricular pacing event, a sensed left ventricular depolarization, a first left ventricular pacing event, a second left ventricular pacing event;

examining the output signals for an occurrence of at least one unscheduled depolarization in a single cardiac chamber; and

if at least one unscheduled depolarization occurred, operating in one of mode of ceasing delivery and delivering an extra-systolic stimulation therapy to at least one chamber of the heart.

2. A method according to claim 1, wherein said at least one unscheduled depolarization comprises a premature atrial contraction or a premature ventricular contraction.

3. A method according to claim 1, wherein the ceasing step further comprises one of:

withholding delivery and not initiating delivery of the extra-systolic stimulation therapy for at least one subsequent cardiac cycle.

4. A method according to claim 1, wherein the ceasing step further comprises one of:

withholding delivery and not initiating delivery of the extra-systolic stimulation therapy in the event that the unscheduled cardiac activity comprises a tachycardia episode.

5. A method according to claim 1, wherein the ceasing step further comprises one of:

withholding delivery and not initiating delivery of the extra-systolic stimulation therapy in the event that the unscheduled cardiac activity begins an accumulating tachycardia evidence counter of an on-going tachycardia episode or until such time as either the evidence counter reaches a preset threshold and a tachycardia episode is declared or the evidence counter is reset to a nominal or null value.

6. A method according to claim 5, wherein the accumulating tachycardia evidence counter collects evidence based only on ventricular events.

7. A method according to claim 6, wherein said ventricular events comprise right ventricular chamber events.

8. A method according to claim 5, wherein the accumulating tachycardia evidence counter collects evidence based only on atrial events.

9. A method according to claim 6, wherein said ventricular events comprise right atrial chamber events.

10. A method according to claim 1, wherein the at least one unscheduled depolarization comprises two unscheduled depolarizations.

11. A method according to claim 10, further comprising:

searching to detect a fibrillation condition;

in the event that the fibrillation condition is detected either;

withholding delivery of the extra-systolic stimulation therapy, or

not initiating delivery of the extra-systolic stimulation therapy;

attempting to re-detect the fibrillation condition; and

in the event that the fibrillation condition is re-detected performing at least one of;

applying a cardioversion therapy to at least one chamber of the heart, and

applying a defibrillation therapy to at least one chamber of the heart.

12. A method according to claim 11, wherein the at least one chamber of the heart comprises a ventricular chamber.

13. A method according to claim 11, further comprising:

discontinuing delivery of the extra-systolic therapy following the application of one of the cardioversion therapy and the defibrillation therapy.

14. A method according to claim 11, wherein the attempting to detect step further comprises:

deriving a parameter related to mechanical function of the heart; and

comparing the parameter to a known or a derived confirmatory fibrillation condition parameter.

15. A method according to claim 14, wherein the parameter related to mechanical function comprises at least one of:

a cardiac fluid pressure parameter, a rate of change of a cardiac fluid parameter, a mathematical integral of a cardiac fluid pressure parameter, a cardiac wall acceleration parameter, an apical acceleration parameter, a septal wall acceleration signal, a mid-basal left ventricular acceleration signal, an acoustic cardiac parameter, an impedance-based cardiac parameter.

16. A method according to claim 1, wherein in lieu of examining the output signals for any unscheduled cardiac activity, performing the following steps:

examining the output signals to measure a heart rate; and

withholding delivery of the extra-systolic stimulation therapy in the event that the heart rate exceeds a programmed threshold value.

17. A method according to claim 16, further comprising:

initiating a non-extra-systolic stimulation pacing modality.

18. A method according to claim 17, wherein the non-extra-systolic stimulation pacing modality includes at least one of the following pacing modalities:

a cardiac resynchronization pacing therapy, a single-chamber pacing therapy, a double-chamber pacing therapy, and a quadruple-chamber pacing therapy.

19. A method according to claim 16, wherein said heart rate comprises at least a one of:

an R-R interval, an P-P interval, an interval between a first ventricular pacing event and an immediately subsequent ventricular pacing event delivered following an atrial depolarization, an interval between a first right ventricular pacing event and an immediately subsequent right ventricular pacing event delivered following an atrial depolarization, an interval between a first left ventricular pacing event and an immediately subsequent left ventricular pacing event delivered following an atrial depolarization, an interval between a second left ventricular pacing event and an immediately subsequent left ventricular pacing event delivered following an atrial depolarization.

20. A method according to claim 8, further comprising:

in the event that an atrial tachycardia is detected, switching from a currently applied pacing therapy mode to a ventricular coupled pacing therapy mode.

65. A method according to claim 19, further comprising at least two maximum heart rate thresholds, a first maximum heart rate threshold and a second maximum heart rate threshold.

66. A method according to claim 65, wherein the first maximum heart rate threshold applies during delivery of the extra-systolic stimulation therapy and the second maximum heart rate threshold applies during delivery of a non-extra-systolic stimulation therapy.

67. A medium according to claim 1, wherein the beat-by-beat basis comprises an extra-systolic interval and a post-extra-systolic interval and said post-extra-systolic interval exceeds said extra-systolic interval.

68. A medium according to claim 67, wherein any cardiac activity occurring during the extra-systolic interval qualifies as the at least one unscheduled depolarization.

21. An apparatus for one of commencing, continuing or ceasing delivery of an extra-systolic stimulation cardiac pacing therapy on a beat-by-beat basis, comprising:

means for sensing electrical activity of a heart on a beat-by-beat basis to provide output signals related to at least one of;

a sensed atrial depolarization, a first atrial pacing event, a second atrial pacing event, a sensed right ventricular depolarization, a first right ventricular pacing event, a second right ventricular pacing event, a sensed left ventricular depolarization, a first left ventricular pacing event, a second left ventricular pacing event; and

means for examining the output signals for any unscheduled cardiac activity and in the event that at least one unscheduled depolarization occurs in a single chamber;

means for substantially immediately ceasing delivery, and for not initiating delivery, of an extra-systolic stimulation therapy to at least one chamber of the heart.

22. An apparatus according to claim 21, wherein said at least one unscheduled depolarization comprises a premature atrial contraction or a premature ventricular contraction.

23. An apparatus according to claim 21, wherein the means for substantially immediately ceasing comprises:

means for withholding delivery and for not initiating delivery of the extra-systolic stimulation therapy for at least one subsequent cardiac cycle.

24. An apparatus according to claim 21, wherein the means for substantially immediately ceasing further comprises:

means for withholding delivery and for not initiating delivery of the extra-systolic stimulation therapy in the event that the unscheduled cardiac activity comprises a tachycardia episode.

25. An apparatus according to claim 21, wherein the means for substantially immediately ceasing further comprises:

means for withholding one delivery and for not initiating delivery of the extra-systolic stimulation therapy in the event that the unscheduled cardiac activity begins an accumulating tachycardia evidence counter of an on-going tachycardia episode or until such time as either the evidence counter reaches a preset threshold and a tachycardia episode is declared or the evidence counter is reset to a nominal value.

26. An apparatus according to claim 25, wherein the accumulating tachycardia evidence counter collects evidence based only on ventricular events.

27. An apparatus according to claim 26, wherein said ventricular events comprise right ventricular chamber events.

28. An apparatus according to claim 25, wherein the accumulating tachycardia evidence counter collects evidence based only on atrial events.

29. An apparatus according to claim 26, wherein said ventricular events comprise right atrial chamber events.

30. An apparatus according to claim 21, wherein the at least one unscheduled depolarization comprises two unscheduled depolarizations.

31. An apparatus according to claim 30, further comprising:

means for searching to detect a fibrillation condition;

means for withholding delivery or not initiating delivery of the extra-systolic stimulation therapy in the event that the fibrillation condition is detected;

means for again attempting to re-detect the fibrillation condition; and

means for applying a cardioversion therapy or a defibrillation therapy to at least one chamber of the heart in the event that the fibrillation condition is re-detected.

32. An apparatus according to claim 31, wherein the at least one chamber of the heart comprises a ventricular chamber.

33. An apparatus according to claim 32, wherein the at least one chamber of the heart comprises a right ventricular chamber.

34. An apparatus according to claim 31, wherein the means for searching to detect further comprises:

means for deriving a parameter related to mechanical function of the heart; and

means for comparing the parameter to a known or derived fibrillation condition parameter.

35. An apparatus according to claim 34, wherein the parameter related to mechanical function comprises at least one of:

a cardiac fluid pressure parameter, a rate of change of a cardiac fluid parameter, a mathematical integral of a cardiac fluid pressure parameter, a cardiac wall acceleration parameter, an apical acceleration parameter, a septal wall acceleration signal, a mid-basal left ventricular acceleration signal, an acoustic cardiac parameter, an impedance-based cardiac parameter.

36. An apparatus according to claim 31, further comprising:

means for examining the output signals to measure a heart rate; and

means for withholding delivery of the extra-systolic stimulation therapy in the event that the heart rate exceeds a programmed threshold value.

37. An apparatus according to claim 36, further comprising:

means for initiating a non-extra-systolic stimulation pacing modality.

38. An apparatus according to claim 37, wherein the non-extra-systolic stimulation pacing modality includes at least one of the following pacing modalities:

a cardiac resynchronization pacing therapy, a single-chamber pacing therapy, a double-chamber pacing therapy, a quadruple-chamber pacing therapy.

39. An apparatus according to claim 36, wherein said heart rate comprises at least a one of:

an R-R interval, an A-A event, an interval between a first ventricular pacing event and an immediately subsequent ventricular pacing event delivered following an atrial depolarization, an interval between a first right ventricular pacing event and an immediately subsequent right ventricular pacing event delivered following an atrial depolarization, an interval between a first left ventricular pacing event and an immediately subsequent left ventricular pacing event delivered following an atrial depolarization, an interval between a second left ventricular pacing event and an immediately subsequent left ventricular pacing event delivered following an atrial depolarization.

40. An apparatus according to claim 38, further comprising:

means for changing an applied pacing mode to a ventricular coupled pacing mode in the event that an atrial tachycardia is detected.

41. A computer readable medium storing executable instructions for managing delivery of an extra-systolic stimulation cardiac pacing therapy on a beat-by-beat basis, comprising:

instructions for sensing electrical activity of a heart on a beat-by-beat basis to provide output signals related to at least one of;

a sensed atrial depolarization, a first atrial pacing event, a second atrial pacing event, a sensed right ventricular depolarization, a first right ventricular pacing event, a second right ventricular pacing event, a sensed left ventricular depolarization, a first left ventricular pacing event, a second left ventricular pacing event;

instructions for examining the output signals for any unscheduled cardiac activity and in the event that at least one unscheduled depolarization occurs in a single chamber; and

means for substantially immediately ceasing delivery, and for not initiating delivery, of an extra-systolic stimulation therapy to at least one chamber of the heart.

42. A medium according to claim 41, wherein said at least one unscheduled depolarization comprises a premature atrial contraction and a premature ventricular contraction.

43. A medium according to claim 41, wherein the instructions for substantially immediately ceasing further comprises:

instructions for withholding delivery and for not initiating delivery of the extra-systolic stimulation therapy for at least one subsequent cardiac cycle.

44. A medium according to claim 41, wherein the instructions for substantially immediately ceasing further comprises:

instructions for withholding delivery or not initiating delivery of the extra-systolic stimulation therapy in the event that the unscheduled cardiac activity comprises a tachycardia episode.

45. A medium according to claim 41, wherein the instructions for substantially immediately ceasing further comprises:

instructions for withholding delivery and for not initiating delivery of the extra-systolic stimulation therapy in the event that the unscheduled cardiac activity starts an accumulating tachycardia evidence counter of an on-going tachycardia episode or until such time as either the evidence counter reaches a preset threshold and a tachycardia episode is declared or the evidence counter is reset to a nominal or null value.

46. A medium according to claim 45, wherein the accumulating tachycardia evidence counter collects evidence based on ventricular events.

47. A medium according to claim 46, wherein said ventricular events comprise right ventricular chamber events.

48. A medium according to claim 45, wherein the accumulating tachycardia evidence counter collects evidence based only on atrial events.

49. A medium according to claim 46, wherein said ventricular events comprise right atrial chamber events.

50. A medium according to claim 41, wherein the at least one unscheduled depolarization comprises two unscheduled depolarizations.

51. A medium according to claim 50, further comprising:

instructions for attempting to detect a fibrillation condition;

instructions for withholding delivery and for not initiating delivery of the extra-systolic stimulation therapy in the event that the fibrillation condition is detected;

instructions for attempting to re-detect the fibrillation condition; and

instructions for applying a cardioversion therapy or a defibrillation therapy to at least one chamber of the heart in the event that the fibrillation condition is re-detected.

52. A medium according to claim 51, wherein the at least one chamber of the heart comprises a ventricular chamber.

53. A medium according to claim 52, further comprising instructions for a one of ceasing delivery of the extra-systolic stimulation therapy and withholding the extra-systolic stimulation therapy following an application of either the cardioversion therapy or the defibrillation therapy.

54. A medium according to claim 51, wherein the instructions for attempting to detect further comprises:

instructions for deriving a parameter related to mechanical function of the heart; and

instructions for comparing the parameter to a known or derived confirmatory fibrillation condition parameter.

55. A medium according to claim 54, wherein the parameter related to mechanical function comprises at least one of:

a cardiac fluid pressure parameter, a rate of change of a cardiac fluid parameter, a mathematical integral of a cardiac fluid pressure parameter, a cardiac wall acceleration parameter, an apical acceleration parameter, a septal wall acceleration signal, a mid-basal left ventricular acceleration signal, an acoustic cardiac parameter, an impedance-based cardiac parameter.

56. A medium according to claim 51, further comprising:

instructions for examining the output signals to measure a heart rate; and

instructions for withholding delivery of the extra-systolic stimulation therapy in the event that the heart rate exceeds a programmed threshold value.

57. A medium according to claim 56, further comprising:

instructions for initiating a non-extra-systolic stimulation pacing modality.

58. A medium according to claim 57, wherein the non-extra-systolic stimulation pacing modality includes at least one of the following pacing modalities:

a cardiac resynchronization pacing therapy, a single-chamber pacing therapy, a double-chamber pacing therapy, and a quadruple-chamber pacing therapy.

59. A medium according to claim 56, wherein said heart rate comprises at least a one of:

an R-R interval, an A-A event, an interval between a first ventricular pacing event and an immediately subsequent ventricular pacing event delivered following an atrial depolarization, an interval between a first right ventricular pacing event and an immediately subsequent right ventricular pacing event delivered following an atrial depolarization, an interval between a first left ventricular pacing event and an immediately subsequent left ventricular pacing event delivered following an atrial depolarization, an interval between a second left ventricular pacing event and an immediately subsequent left ventricular pacing event delivered following an atrial depolarization.

60. A medium according to claim 58, further comprising:

instructions for changing an applied pacing mode to a ventricular coupled pacing mode in the event that an atrial tachycardia is detected.

61. A medium according to 59, further comprising at least two maximum heart rate thresholds, a first maximum heart rate threshold and a second maximum heart rate threshold.

62. A medium according to claim 61, wherein the first maximum heart rate threshold applies during delivery of the extra-systolic stimulation therapy and the second maximum heart rate threshold applies during delivery of a non-extra-systolic stimulation therapy.

63. A medium according to claim 41, wherein the beat-by-beat basis comprises an extra-systolic interval and a post-extra-systolic interval and said post-extra-systolic interval exceeds said extra-systolic interval.

64. A medium according to claim 63, wherein any cardiac activity occurring during the extra-systolic interval qualifies as the at least one unscheduled depolarization.