Implantable cardiac device for restoring inter-chamber synchrony and method

• US 7,212,857 B2
• Filed: 05/01/2002
• Issued: 05/01/2007
• Est. Priority Date: 05/01/2002
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated), Affordable Building Systems
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Lu, Richard, Weinberg, Lisa P.
• Primary Examiner(s): Schaetzle; Kennedy
• Application Number:
  US10/136,916
• Publication Number:
  US 20030208238A1
• Time in Patent Office: 1,826 Days
• Field of Search: 607/9, 607/15, 607/14, 600/509
• US Class Current: 607/9
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions

Abstract

An implantable cardiac device returns activations of corresponding right and left chambers of a heart to inter-chamber synchrony. A sensing circuit senses intracardiac signals representing right and left chamber ventricular electrical activity. A detector determines if a predetermined characteristic of the electrogram signals indicates dissociation of the corresponding right and left chambers. If dissociation is indicated, a pulse generator stimulates at least one of the corresponding chambers to restore inter-chamber synchrony.

Claims

1. An implantable cardiac device that returns activations of corresponding right and left chambers of a heart to inter-chamber synchrony comprising:

a sensing circuit that senses intracardiac signals representing activations of the corresponding right and left chambers;

a timer that measures a right chamber activation to left chamber activation time during successive cardiac cycles; and

a pulse generator that stimulates at least one of the right and left chambers to restore inter-chamber synchrony of the right and left chambers responsive to a change in the right chamber to left chamber activation time.

2. The device of claim 1 wherein the corresponding right and left chambers are the right and left ventricles of the heart.

3. The device of claim 2 wherein the predetermined characteristic is a premature ventricular contraction and wherein the detector comprises a premature ventricular contraction detector.

4. The device of claim 3 wherein the pulse generator is configured to apply a stimulation pulse to one of the right ventricle and left ventricle responsive to the detector detecting a premature ventricular contraction in the other one of the right ventricle and left ventricle.

5. The device of claim 4 wherein the pulse generator is a pacing pulse generator.

6. The device of claim 5 wherein the pacing pulse generator delivers a pacing pulse to the one of the right ventricle and left ventricle an inter-ventricular delay time after the detector detects a premature ventricular contraction in the other one of the right ventricle and left ventricle.

7. The device of claim 2 wherein the pulse generator overdrive paces one of the right and left chambers with a shortened inter-ventricular delay to restore inter-chamber synchrony of the right and left chambers responsive to a change in the right chamber to left chamber activation time.

8. The device of claim 7 wherein the change in right ventricular activation to left ventricular activation time is an increase in right ventricular activation to left ventricular activation time.

9. The device of claim 8 wherein the increase is a sudden increase.

10. The device of claim 8 wherein the increase is a gradual increase to a threshold value.

11. The device of claim 7 wherein the change is instability in the right ventricular activation to left ventricular activation time over successive cardiac cycles.

12. The device of claim 2 wherein the predetermined characteristic is a change in order of right ventricular and left ventricular activation from a normal order of right ventricular and left ventricular activation.

13. The device of claim 12 wherein the pulse generator applies pacing pulses to at least one of the right ventricle and left ventricle to restore the order of ventricular activation to the normal order.

14. The device of claim 2 wherein the predetermined characteristic is a relative amplitude difference between a right ventricular activation and a left ventricular activation within at least one common cardiac cycle.

15. The device of claim 14 wherein the pulse generator is a pacing pulse generator that paces at least one of the right ventricle and left ventricle in response to the detector detecting a relative amplitude difference greater than a predetermined factor.

16. The device of claim 15 wherein the pacing pulse generator is an overdrive pacer.

17. The device of claim 15 wherein the pacing pulse generator paces both the right and left ventricle.

18. The device of claim 17 wherein the pacing pulse generator is an overdrive pacer.

19. The device of claim 1 wherein the pulse generator is configured to stimulate the left ventricle a predetermined delay time after a right ventricular activation in response to a change in the right ventricular activation to left ventricular activation time greater than a threshold to restore inter-ventricular synchrony.

20. The device of claim 19 wherein the predetermined delay time is less than a normal right ventricular activation to left ventricular activation time.

21. The device of claim 1 wherein the corresponding right and left chambers are the right and left atria of the heart.

22. The device of claim 21 wherein the predetermined characteristic is a change in right atrial activation to left atrial activation time and wherein the detector comprises a timer that times the right atrial activation to left atrial activation time during successive cardiac cycles.

23. The device of claim 22 wherein the change in right atrial activation to left atrial activation time is an increase in right atrial activation to left atrial activation time.

24. The device of claim 23 wherein the increase is a sudden increase.

25. The device of claim 23 wherein the increase is a gradual increase to a threshold value.

26. The device of claim 22 wherein the change is instability in the right atrial activation to left atrial activation time over successive cardiac cycles.

27. The device of claim 22 wherein the pulse generator is configured to stimulate the left atrium a predetermined delay time after a right atrial activation when the detector detects the change in the right atrial activation to left atrial activation time to restore inter-atrial synchrony.

28. The device of claim 27 wherein the predetermined delay time is less than a normal right atrial activation to left atrial activation time.

29. The device of claim 21 wherein the predetermined characteristic is a change in order of right atrial and left atrial activation from a normal order of right atrial and left atrial activation.

30. The device of claim 29 wherein the pulse generator applies pacing pulses to at least one of the right atrium and left atrium to restore the order of atrial activation to the normal order.

31. The device of claim 21 wherein the predetermined characteristic is a relative amplitude difference between a right atrial activation and a left atrial activation within at least one common cardiac cycle.

32. The device of claim 31 wherein the pulse generator is a pacing pulse generator that paces at least one of the right atrium and left atrium in response to the detector detecting a relative amplitude difference greater than a predetermined factor.

33. The device of claim 32 wherein the pacing pulse generator is an overdrive pacer.

34. The device of claim 32 wherein the pacing pulse generator paces both the right and left atrium.

35. The device of claim 34 wherein the pacing pulse generator is an overdrive pacer.

36. An implantable cardiac device that detects inter-chamber dissociation of a heart and restores inter-chamber synchrony comprising:

sensing means for sensing electrical activity of corresponding right and left chambers of the heart and generating electrical signals representing activations of the corresponding right and left chambers;

timing means for measuring a right chamber to left chamber activation time during successive cardiac cycles; and

stimulating means for applying stimulating pulses to at least one of the corresponding right and left chambers to restore inter-chamber synchrony responsive to a change in the right chamber to left chamber activation time.

37. The device of claim 36 wherein the corresponding right and left chambers are the right and left ventricles.

38. The device of claim 37 wherein the predetermined characteristic is a premature ventricular contraction and wherein the detector means comprises means for detecting premature ventricular contractions responsive to the electrical signals.

39. The device of claim 38 wherein the stimulating means comprises means for applying a stimulation pulse to one of the right ventricle and left ventricle responsive to the detecting means detecting a premature ventricular contraction in the other one of the right ventricle and left ventricle.

40. The device of claim 39 wherein the stimulating means comprises means for providing pacing pulses.

41. The device of claim 40 wherein the stimulating means delivers a pacing pulse to the one of the right ventricle and left ventricle an inter-ventricular delay time after the detecting means detects a premature ventricular contraction in the other one of the right ventricle and left ventricle.

42. The device of claim 37 wherein the stimulating means overdrive paces one of the right and left chambers with a shortened inter-ventricular delay to restore inter-chamber synchrony of the right and left chambers responsive to a change in the right chamber to left chamber activation time.

43. The device of claim 42 wherein the change in the right chamber to left chamber activation time is an increase in the inter-ventricular activation time.

44. The device of claim 43 wherein the increase is a sudden increase.

45. The device of claim 43 wherein the increase is a gradual increase to a threshold value.

46. The device of claim 42 wherein the change in the right chamber to left chamber activation time is instability in the the right chamber to left chamber activation time.

47. The device of claim 37 wherein the predetermined characteristic is a change in ventricular activation order from a normal ventricular activation order.

48. The device of claim 47 wherein the stimulating means comprises means for applying pacing pulses to at least one of the right ventricle and left ventricle to restore the ventricular activation order to the normal order.

49. The device of claim 37 wherein the predetermined characteristic is a relative amplitude difference between a right ventricular activation and a left ventricular activation within at least one common cardiac cycle.

50. The device of claim 49 wherein the stimulating means comprises pacing means for applying pacing pulses to at least one of the right ventricle and left ventricle in response to the detecting means detecting a relative amplitude difference greater than a predetermined factor.

51. The device of claim 50 wherein the pacing means comprises an overdrive pacer.

52. The device of claim 50 wherein the pacing means paces both the right and left ventricle.

53. The device of claim 52 wherein the pacing means is an overdrive pacer.

54. The device of claim 36 wherein the stimulating means comprises means for stimulating the left ventricle a predetermined delay time after a right ventricular activation responsive to the change in the right chamber to left chamber activation time greater than a threshold to restore inter-ventricular synchrony.

55. The device of claim 54 wherein the predetermined delay time is less than a normal right ventricular activation to left ventricular activation time.

56. The device of claim 36 wherein the corresponding right and left chambers are the right and left atria.

57. The device of claim 56 wherein the predetermined characteristic is a change in inter-atrial activation time and wherein the detecting means comprises timing means for timing the time between right atrial activation and left atrial activation during successive cardiac cycles.

58. The device of claim 57 wherein the change in inter-atrial activation time is an increase in the inter-atrial activation time.

59. The device of claim 58 wherein the increase is a sudden increase.

60. The device of claim 58 wherein the increase is a gradual increase to a threshold value.

61. The device of claim 57 wherein the change in inter-atrial activation time is instability in the inter-atrial activation time.

62. The device of claim 57 wherein the stimulating means comprises means for stimulating the left atrium a predetermined delay time after a right atrial activation responsive to the detecting means detecting the change in the inter-atrial activation time to restore inter-atrial synchrony.

63. The device of claim 62 wherein the predetermined delay time is less than a normal right atrial activation to left atrial activation time.

64. The device of claim 56 wherein the predetermined characteristic is a change in atrial activation order from a normal atrial activation order.

65. The device of claim 64 wherein the stimulating means comprises means for applying pacing pulses to at least one of the right atrium and left atrium to restore the atrial activation order to the normal order.

66. The device of claim 56 wherein the predetermined characteristic is a relative amplitude difference between a right atrial activation and a left atrial activation within at least one common cardiac cycle.

67. The device of claim 66 wherein the stimulating means comprises pacing means for applying pacing pulses to at least one of the right atrium and left atrium in response to the detecting means detecting a relative amplitude difference greater than a predetermined factor.

68. The device of claim 67 wherein the pacing means comprises an overdrive pacer.

69. The device of claim 67 wherein the pacing means paces both the right and left atria.

70. The device of claim 69 wherein the pacing means is an overdrive pacer.

71. A method of detecting inter-chamber dissociation of a heart and restoring inter-chamber synchrony to the heart, the method comprising:

sensing electrical activity of corresponding right and left chambers of the heart and generating electrical signals representing activations of the corresponding right and left chambers;

measuring a right chamber to left chamber activation time during successive cardiac cycles; and

applying one or more stimulating pulses to at least one of the corresponding right and left chambers of the heart to restore inter-chamber synchrony responsive to detecting a change in the right chamber to left chamber activation time.

72. The method of claim 71 wherein the corresponding right and left chambers are the right and left ventricles.

73. The method of claim 72 wherein the predetermined characteristic is a premature ventricular contraction and wherein detecting comprises detecting premature ventricular contractions responsive to the electrical signals.

74. The method of claim 73 wherein applying comprises applying a stimulation pulse to one of the right ventricle and left ventricle responsive to detecting a premature ventricular contraction in the other one of the right ventricle and left ventricle.

75. The method of claim 74 wherein applying comprises providing at least one pacing pulse.

76. The method of claim 75 wherein applying comprises delivering a pacing pulse to the one of the right ventricle and left ventricle an inter-ventricular delay time after detecting a premature ventricular contraction in the other one of the right ventricle and left ventricle.

77. The method of claim 72 wherein applying one or more stimulating pulses to at least one of the corresponding right and left chambers of the heart to restore inter-chamber synchrony comprises overdrive pacing one of the right and left chambers with a shortened inter-ventricular delay to restore inter-chamber synchrony of the right and left chambers responsive to a change in the right chamber to left chamber activation time.

78. The method of claim 77 wherein the change in the right chamber to left chamber activation time is an increase in the the right chamber to left chamber activation time.

79. The method of claim 78 wherein the increase is a sudden increase.

80. The method of claim 78 wherein the increase is a gradual increase to a threshold value.

81. The method of claim 77 wherein the change in the right chamber to left chamber activation time is instability in the the right chamber to left chamber activation time.

82. The method of claim 72 wherein the predetermined characteristic is a change in ventricular activation order from a normal ventricular activation order.

83. The method of claim 82 wherein applying comprises applying pacing pulses to at least one of the right ventricle and left ventricle to restore the ventricular activation order to the normal order.

84. The method of claim 72 wherein the predetermined characteristic is a relative amplitude difference between a right ventricular activation and a left ventricular activation within at least one common cardiac cycle.

85. The method of claim 84 wherein applying comprises applying pacing pulses to at least one of the right ventricle and left ventricle in response to detecting a relative amplitude difference greater than a predetermined factor.

86. The method of claim 85 wherein applying comprises overdrive pacing.

87. The method of claim 85 wherein applying comprises applying pacing pulses to both the right and left ventricle.

88. The method of claim 87 wherein applying further comprises overdrive pacing.

89. The method of claim 71 wherein applying comprises stimulating the left ventricle a predetermined delay time after a right ventricular activation responsive to detecting the change in the inter-ventricular activation time to restore inter-ventricular synchrony.

90. The method of claim 89 wherein the predetermined delay time is less than a normal right ventricular activation to left ventricular activation time.

91. The method of claim 71 wherein the corresponding right and left chambers are the right and left atria.

92. The method of claim 91 wherein the predetermined characteristic is a change in inter-atrial activation time and wherein detecting comprises timing the time between right atrial activation and left atrial activation during successive cardiac cycles.

93. The method of claim 92 wherein the change in inter-atrial activation time is an increase in the inter-atrial activation time.

94. The method of claim 93 wherein the increase is a sudden increase.

95. The method of claim 93 wherein the increase is a gradual increase to a threshold value.

96. The method of claim 92 wherein the change in inter-atrial activation time is instability in the inter-atrial activation time.

97. The method of claim 92 wherein applying comprises stimulating the left atrium a predetermined delay time after a right atrial activation responsive to detecting the change in the inter-atrial activation time to restore inter-atrial synchrony.

98. The method of claim 97 wherein the predetermined delay time is less than a normal right atrial activation to left atrial activation time.

99. The method of claim 91 wherein the predetermined characteristic is a change in atrial activation order from a normal atrial activation order.

100. The method of claim 99 wherein applying comprises applying pacing pulses to at least one of the right atrium and left atrium to restore the atrial activation order to the normal order.

101. The method of claim 91 wherein the predetermined characteristic is a relative amplitude difference between a right atrial activation and a left atrial activation within at least one common cardiac cycle.

102. The method of claim 101 wherein applying comprises applying pacing pulses to at least one of the right atrium and left atrium in response to detecting a relative amplitude difference greater than a predetermined factor.

103. The method of claim 102 wherein applying comprises overdrive pacing.

104. The method of claim 102 wherein applying comprises applying pacing pulses to both the right and left atrium.

105. The method of claim 104 wherein applying further comprises overdrive pacing.