Method and apparatus for stimulation of baroreceptors in pulmonary artery

• US 20070038259A1
• Filed: 07/07/2006
• Published: 02/15/2007
• Est. Priority Date: 09/27/2000
• Status: Active Grant

• Current Assignee: CVRx, Inc.
• Original Assignee: CVRx, Inc.
• Inventors: Kieval, Robert, Rossing, Martin, Keith, Peter, Serdar, David, Burns, Matthew
• Granted Patent: US 8,290,595 B2
• Time in Patent Office: Days
• US Class Current: 607/44
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36117 for treating hypertension

Abstract

Devices and methods for controlling the low-pressure baroreflex system for the treatment and/or management of cardiovascular, renal, and neurological disorders.

Claims

1. A method for treating hypertension, comprising:

accessing a circadian rhythm template;

setting a baroreflex stimulation level based on the circadian rhythm template; and

applying baroreflex stimulation at the baroreflex stimulation level to a baroreceptor site in a pulmonary artery.

2. The method of claim 1, wherein accessing a circadian rhythm template includes accessing a pre-programmed circadian rhythm template.

3. The method of claim 1, wherein accessing a circadian rhythm template includes:

sensing and recording parameters related to hypertension; and

generating a patient-specific circadian rhythm template based on the recorded parameters; and

setting a baroreflex stimulation level based on the circadian rhythm template includes setting a baroreflex stimulation level based on the patient-specific circadian rhythm template.

4. A baroreflex stimulator, comprising:

a pulse generator to provide a baroreflex stimulation signal through an electrode; and

a modulator to modulate the baroreflex stimulation signal based on a circadian rhythm template,

wherein the stimulator is implantable, the stimulator further comprising a lead adapted to be electrically connected to the pulse generator and to be fed through a right ventricle and into a pulmonary artery, the lead including the electrode to be positioned in the pulmonary artery and to deliver the baroreflex stimulation signal to a baroreceptor site in the pulmonary artery.

5. A method for operating an implantable medical device, comprising:

applying a baroreflex stimulation therapy using a baroreflex stimulator in the implantable medical device;

modulating the baroreflex stimulation therapy based on a circadian rhythm template; and

delivering baroreflex stimulation through a lead adapted to be fed through a right ventricle and pulmonary valve into a pulmonary artery.

6. A method for treating hypertension, comprising:

accessing an algorithm;

setting a baroreflex stimulation level based on the algorithm; and

periodically applying a desired baroreflex stimulation therapy to an intravascular baroreceptor site in the pulmonary artery.

7. An implantable medical system, comprising:

means for detecting a myocardial infarction; and

means for applying baroreflex therapy to a pressoreceptive region to decrease coronary vascular resistance and increase blood flow in response to detecting the myocardial infarction,

wherein the means for applying baroreflex therapy includes means for applying baroreflex stimulation signals to a baroreceptor site in a pulmonary artery.

8. A method, comprising:

inserting a lead through a right ventricle and a pulmonary valve into a pulmonary artery to position an electrode proximate to a baroreceptor site; and

applying a baroreflex therapy through the electrode to the baroreceptor site.

9. The method of claim 8, further comprising monitoring systemic blood pressure and modulating the baroreflex therapy based on the blood pressure.

10. The method of claim 8, wherein monitoring systemic blood pressure includes monitoring blood pressure in the pulmonary artery.

11. The method of claim 8, further comprising monitoring a surrogate parameter of systemic blood pressure and modulating the baroreflex therapy based on the surrogate parameter.

12. A method, comprising:

detecting an event corresponding to a myocardial infarction; and

in response to a detected event corresponding to a myocardial infarction, applying a baroreflex therapy using an electrode positioned proximate to a baroreflex target, p1 wherein applying a baroreflex therapy using an electrode positioned proximate to a baroreflex target includes applying a baroreflex therapy using an electrode positioned in a pulmonary artery.

13. The method of claim 12, wherein monitoring systemic blood pressure includes monitoring blood pressure in the pulmonary artery.

14. A system for providing baroreflex stimulation, comprising:

an adverse event detector to sense an adverse event and provide a signal indicative of the adverse event; and

a baroreflex stimulator, including;

a pulse generator to provide a baroreflex stimulation signal adapted to provide a baroreflex therapy; and

a modulator to receive the signal indicative of the adverse event and modulate the baroreflex stimulation signal based on the signal indicative of the adverse event to change the baroreflex therapy from a first baroreflex therapy to a second baroreflex therapy,

wherein the stimulator is implantable, the stimulator further comprising a lead adapted to be electrically connected to the pulse generator and to be fed through a right ventricle and into a pulmonary artery, the lead including the electrode, the electrode to be positioned in the pulmonary artery and to deliver the baroreflex stimulation signal to a baroreceptor site in the pulmonary artery.

15. A method for operating an implantable medical device, comprising:

receiving a signal regarding a detected adverse event at a baroreceptor stimulator

performing a first baropacing therapy using the baroreceptor stimulator when the adverse event is not detected;

automatically performing a second baropacing therapy using the baroreceptor stimulator when the adverse event is detected; and

delivering baroreflex stimulation through a lead adapted to be fed through a right ventricle and pulmonary valve into a pulmonary artery.

16. A method, comprising:

detecting an adverse event; and

in response to detecting the adverse event, applying a desired baroreflex stimulation therapy to a baroreceptor site in a pulmonary artery.

17. The method of claim 16, wherein detecting an adverse event includes detecting an arrhythmic cardiac event.

18. The method of claim 16, wherein detecting an adverse event includes detecting a non-arrhythmic cardiac event.

19. The method of claim 16, wherein applying a desired baroreflex stimulation therapy to a baroreceptor site in a pulmonary artery includes increasing the baroreflex stimulation therapy to the baroreceptor site in the pulmonary artery.

20. A baroreflex stimulator, including:

a pulse generator to provide a baroreflex stimulation signal through an electrode; and

a modulator to modulate the baroreflex stimulation signal to increase the baroreflex stimulation therapy by a predetermined rate of change to lower systemic blood pressure to a target pressure.

21. The system of claim 20, further comprising a waveform generator to produce baroreceptor signals of a desired morphology, wherein the modulator includes a modulator to change the morphology of the baroreflex stimulation signal to increase the baroreflex stimulation therapy by the predetermined rate of change.

22. The system of claim 20, further comprising a cardiac output monitor to modify the predetermined rate of change if a monitored cardiac output is not acceptable.

23. The system of claim 20, further comprising a pressure detector to monitor arterial pressure and provide an arterial pressure signal, wherein the modulator receives the arterial pressure signal to modulate the baroreflex stimulation signal adjust the predetermined rate of change.

24. The system of claim 20, wherein the baroreflex stimulation therapy is increased over a period of two or more weeks.

25. The system of claim 20, wherein the baroreflex stimulation therapy is increased over a period of two or more months.

26. An implantable medical system, comprising:

means for applying baroreflex stimulation to a pressoreceptive region in the pulmonary artery to lower systemic blood pressure; and

means for increasing the baroreflex stimulation therapy by a predetermined rate of change to lower systemic blood pressure to a target pressure.

27. A method, comprising:

applying a baroreflex stimulation therapy to a baroreceptor site using a lead extending into the pulmonary artery; and

implementing a process to increase the baroreflex stimulation therapy by a predetermined rate of change until a systemic blood pressure is lowered to a target level.

28. The method of claim 27, wherein implementing an algorithm to increase the baroreflex stimulation therapy includes implementing an algorithm to modulate a characteristic of the baroreflex stimulation signal selected from the group consisting of:

an amplitude, a frequency, a burst frequency and a morphology.

29. The method of claim 27, wherein implementing an algorithm to increase the baroreflex stimulation therapy by a predetermined rate of change includes increasing the baroflex stimulation therapy over a time duration of approximately one to eight weeks.

30. The method of claim 27, wherein implementing an algorithm to increase the baroreflex stimulation therapy by a predetermined rate of change includes increasing the baroflex stimulation therapy over a time duration of approximately two to twelve months.

31. A baroreceptor stimulator, including:

a pulse generator to provide a baroreceptor stimulation signal through an electrode positioned in the pulmonary artery; and

a modulator to modulate the baroreceptor stimulation signal to increase the baroreceptor stimulation therapy by a predetermined rate of change to lower systemic blood pressure to a target pressure.

32. A method, comprising:

applying a baroreceptor stimulation therapy to a baroreceptor site using a lead extending into a pulmonary artery; and

implementing a process to increase the baroreflex stimulation therapy by a predetermined rate of change until a systemic blood pressure is lowered to a target level.

33. An apparatus comprising:

a flexible lead body extending from a proximal end to a distal end, the distal end having a biased portion having an outer diameter dimensioned to abut a wall of a pulmonary artery;

an electrode coupled proximate the distal end; and

an implantable pulse generator electrically coupled to the electrode, wherein the implantable pulse generator is adapted to deliver a baroreflex stimulation signal to a baroreceptor in the pulmonary artery via the electrode.

34. The apparatus of claim 33, wherein the electrode includes a porous surface.

35. The apparatus of claim 33, wherein the lead includes a second electrode located proximally from the distal end.

36. The apparatus of claim 33, wherein the pulse generator delivers at least a 10 hertz pulse train via the electrode.

37. The apparatus of claim 33, wherein the electrode is adapted to be chronically implanted in the pulmonary artery.

38. The apparatus of claim 33, wherein the lead further includes a sensor to monitor blood pressure.

39. The apparatus of claim 33, wherein the electrode is adapted to be located near the ligamentum arteriosum of the left pulmonary artery.

40. The apparatus of claim 33, further including a sensor to sense a physiological parameter regarding an efficacy of the baroreflex therapy and to provide a signal indicative of the efficacy of the baroreflex therapy.

41. The apparatus of claim 40, further including a controller connected to the pulse generator to control the baroreflex stimulation signal and to the sensor to receive the signal indicative of the efficacy of the baroreflex therapy.

42. The apparatus of claim 33, wherein the lead is adapted to be fed through a right ventricle and a pulmonary valve into the pulmonary artery to position the electrode in the pulmonary artery.

43. The apparatus of claim 33, wherein the pulse generator is further adapted to generate a cardiac pacing signal, the lead further including a second electrode to be positioned to deliver the cardiac pacing signal to capture the heart.

44. An apparatus comprising:

a flexible lead body extending from a proximal end to a distal end;

an electrode coupled to the distal end of the lead body; and

an implantable pulse generator electrically coupled to the electrode, the implantable pulse generator being adapted to deliver a baroreflex stimulation signal to a baroreceptor in the pulmonary artery via the electrode;

wherein a biased portion of the distal end is adapted to passively fixate the electrode within the pulmonary artery.

45. The apparatus of claim 44, wherein the pulse generator delivers at least a 10 hertz waveform via the electrode.

46. A method comprising:

positioning an electrode on a distal end of a lead within a pulmonary artery, such that the electrode is adjacent a baroreceptor site; and

delivering a baroreflex stimulation pulse train to a baroreceptor in the pulmonary artery via the electrode.

47. The method of claim 46, wherein positioning the electrode includes providing the distal end with a positive fixation mechanism to implant the electrode against a wall of the pulmonary artery.

48. The method of claim 46, wherein the electrode is adapted to be chronically implanted in the pulmonary artery.

49. The method of claim 46, further including monitoring a blood pressure to sense an efficacy of the baroreflex stimulation pulse train and to provide a signal indicative of the efficacy of the baroreflex stimulation pulse train.

50. The method of claim 46, wherein positioning includes positioning the electrode proximate the ligamentum arteriosum of the left pulmonary artery.

51. The method of claim 46, wherein positioning includes feeding the electrode through a right ventricle and a pulmonary valve into the pulmonary artery to position the electrode in the pulmonary artery.

52. The method of claim 46, wherein delivering a baroflex stimulation pulse train includes an at least 10 hertz pulse train via the electrode.

53. An apparatus comprising:

a flexible lead body extending from a proximal end to a distal end, the lead body having an outer diameter dimensioned to abut a wall of a pulmonary artery;

an electrode coupled to the flexible lead body; and

an implantable pulse generator electrically coupled to the electrode, wherein the implantable pulse generator is adapted to deliver a baroreceptor stimulation signal to a baroreceptor in the pulmonary artery via the electrode.

54. An apparatus comprising:

a flexible lead body;

an electrode coupled to the lead body; and

an implantable pulse generator electrically coupled to the electrode, the implantable pulse generator being adapted to deliver a baroreceptor stimulation signal to a baroreceptor in the pulmonary artery via the electrode;

wherein the electrode is expandable to passively fixate the electrode within the pulmonary artery.

55. A method comprising:

positioning an electrode on a lead within a pulomonary artery, such that the electrode is adjacent a baroreceptor site; and

delivering a baroreceptor stimulation pulse train to a baroreceptor in the pulmonary artery via the electrode.

56. An apparatus comprising:

a flexible lead body extending from a proximal end to a distal end;

an expandable electrode coupled proximate the distal end, the expandable electrode having an expanded diameter dimensioned to abut a wall of a pulmonary artery; and

an implantable pulse generator electrically coupled to the expandable electrode, wherein the implantable pulse generator is adapted to deliver a baroreflex stimulation signal to a baroreceptor in the pulmonary artery via the electrode.

57. The apparatus of claim 56, wherein the expandable electrode includes a mesh surface.

58. The apparatus of claim 56, wherein the expandable electrode expands to fix the lead in place by frictional forces.

59. The apparatus of claim 56, wherein the expandable electrode includes a length of at least about 1 cm.

60. The apparatus of claim 56, wherein the expandable electrode includes an expanded diameter of about 10 to 20 mm.

61. The apparatus of claim 56, wherein the expandable electrode includes at least a partially electrically insulated surface.

62. The apparatus of claim 56, wherein the lead includes a second electrode located proximally from the expandable electrode.

63. The apparatus of claim 56, wherein the pulse generator delivers at least a 10 hertz pulse train via the electrode.

64. The apparatus of claim 56, wherein the electrode is adapted to be chronically implanted in the pulmonary artery.

65. The apparatus of claim 56, wherein the electrode is adapted to be located near the ligamentum arteriosum of the left pulmonary artery.

66. The apparatus of claim 56, further including a sensor to sense a physiological parameter regarding an efficacy of the baroreflex therapy and to provide a signal indicative of the efficacy of the baroreflex therapy.

67. The apparatus of claim 66, further including a controller connected to the pulse generator to control the baroreflex stimulation signal and to the sensor to receive the signal indicative of the efficacy of the baroreflex therapy.

68. The apparatus of claim 56, wherein the lead is adapted to be fed through a right ventricle and a pulmonary valve into the pulmonary artery to position the electrode in the pulmonary artery.

69. The apparatus of claim 56, wherein the pulse generator is further adapted to generate a cardiac pacing signal, the lead further including a second electrode to be positioned to deliver the cardiac pacing signal to capture the heart.

70. An apparatus comprising:

a flexible lead body extending from a proximal end to a distal end;

an electrode coupled to the lead body;

an implantable pulse generator electrically coupled to the electrode, the implantable pulse generator being adapted to deliver a baroreflex stimulation signal to a baroreceptor in the pulmonary artery via the electrode; and

means for passively fixating the electrode within the pulmonary artery.

71. The apparatus of claim 70, wherein the means for passively fixating includes an expandable stent structure coupled to the lead.

72. The apparatus of claim 71, wherein the stent structure includes an expanded diameter dimensioned to abut a wall of a pulmonary artery.

73. The apparatus of claim 72, wherein the expanded diameter is about 10 to 20 mm.

74. The apparatus of claim 71, wherein the expandable stent expands to fix the lead in place by frictional forces.

75. The apparatus of claim 71, wherein the expandable stent structure includes a length of at least about 1 cm.

76. The apparatus of claim 70, wherein the pulse generator delivers at least a 10 hertz pulse train via the electrode.

77. A method comprising:

implanting an expandable electrode within a pulmonary artery such that an outer surface of the expandable electrode abuts a wall of the pulmonary artery; and

delivering a baroreflex stimulation signal to a baroreceptor in the pulmonary artery via the electrode.

78. The method of claim 77, wherein implanting includes implanting an expandable electrode having an expanded diameter dimensioned to fix the electrode in place by frictional forces.

79. The method of claim 77, wherein implanting is accomplished with an electrode that is adapted to be chronically implanted in the pulmonary artery.

80. The method of claim 77, further including monitoring a blood pressure.

81. The method of claim 77, wherein implanting includes implanting the electrode proximate the ligamentum arteriosum of the left pulmonary artery.

82. The method of claim 77, wherein implanting includes feeding the electrode through a right ventricle and a pulmonary valve into the pulmonary artery to position the electrode in the pulmonary artery.

83. The method of claim 77, wherein implanting includes implanting an expandable electrode having an expanded diameter of about 10 to 20 mm.

84. The method of claim 77, wherein delivering a baroflex stimulation signal includes an at least 10 hertz pulse train via the electrode.

85. An apparatus comprising:

a flexible lead body;

an expandable electrode coupled to the lead body, the expandable electrode having an expanded diameter dimensioned to abut a wall of a pulmonary artery; and

an implantable pulse generator electrically coupled to the expandable electrode, wherein the implantable pulse generator is adapted to deliver a baroreceptor stimulation signal to a baroreceptor in an artery via the electrode.

86. An apparatus comprising:

a flexible lead body;

an electrode coupled to the lead body;

an implantable pulse generator electrically coupled to the electrode, the implantable pulse generator being adapted to deliver a baroreceptor stimulation signal to a baroreceptor in an artery via the electrode; and

means for passively fixating the electrode within the artery.

87. An implantable medical device, comprising:

a pulse generator to generate baroreflex stimulation pulses;

a sensor circuitry;

a lead adapted to be electrically connected to the pulse generator and to the sensor circuitry, the lead including an electrode to distribute the baroreflex stimulation pulses to a baroreflex site and a pressure sensor to provide a signal indicative of blood pressure to the sensor circuitry;

the lead adapted to be fed through a right ventricle and a pulmonary valve into a pulmonary artery, the electrode positioned to stimulate the baroreflex site in the pulmonary artery;

the pressure sensor is positioned to sense blood pressure in the pulmonary artery; and

a controller connected to the pulse generator and the sensor circuitry, the controller adapted to adjust the baroreflex stimulation pulses based on the blood pressure.

88. An implantable medical device, comprising:

means for delivering baroreflex therapy to a baroreflex neural target site in the pulmonary using an intravascular lead and an electrode on the lead positioned in the pulmonary artery;

means for monitoring blood pressure near the baroreflex neural target site in the pulmonary artery using a pressure sensor on the lead positioned in the pulmonary artery; and

means for adjusting the baroreflex therapy based on the blood pressure.

89. An implantable medical device, comprising:

means for delivering baroreflex therapy to a baroreflex neural target site in the pulmonary using an intravascular lead and an electrode on the lead positioned in the pulmonary artery;

means for monitoring blood pressure near the baroreflex neural target site in the pulmonary artery using a pressure sensor on the lead positioned in the pulmonary artery;

including a wireless device adapted to be positioned in the pulmonary artery, the wireless device includes means for wirelessly communicating with another device; and

means for adjusting the baroreflex therapy based on the blood pressure.

90. A method, comprising:

delivering baroreflex therapy to a baroreflex neural target site near the pulmonary using an intravascular lead fed through a right ventricle and a pulmonary valve into the pulmonary artery and an electrode on the lead;

monitoring blood pressure in the pulmonary artery near the pulmonary artery baroreflex neural target site using a pressure sensor on the lead; and

adjusting the baroreflex therapy based on the blood pressure.

91. A system for providing baroreflex stimulation, comprising:

a cardiac activity monitor to sense cardiac activity and provide a signal indicative of the cardiac activity; and

an implantable baroreflex stimulator, including;

a pulse generator to provide a baroreflex stimulation signal adapted to provide a baroreflex therapy, a lead adapted to be electrically connected to the pulse generator and to be fed through a right ventricle and a pulmonary valve into the pulmonary artery and an electrode on the lead, the electrode to be positioned in the pulmonary artery and to deliver the baroreflex stimulation signal to the baroreceptor site in the pulmonary artery; and

a modulator to receive the signal indicative of the cardiac activity and modulate the baroreflex stimulation signal based on the signal indicative of the cardiac activity to change the baroreflex therapy from a first baroreflex therapy to a second baroreflex therapy.

92. An implantable baroreflex stimulator, comprising:

an implantable pulse generator to provide a baroreflex stimulation signal adapted to provide a baroreflex therapy;

a lead adapted to be electrically connected to the pulse generator and to be fed through a right ventricle and a pulmonary valve into the pulmonary artery, and to deliver the baroreflex stimulation signal to the baroreceptor site in the pulmonary artery; and

means for modulating the baroreflex stimulation signal based on a signal indicative of cardiac activity to change the baroreflex therapy from a first baroreflex therapy to a second baroreflex therapy.

93. A method for operating an implantable medical device, comprising:

receiving a signal regarding an activity level;

setting a baroreflex stimulation level for a baroreflex stimulator of the device based on the signal regarding the activity level; and

delivering baroreflex stimulation through a lead adapted to be fed through a right ventricle and pulmonary valve into a pulmonary artery.

94. An implantable medical device, comprising:

a pulse generator to generate a baroreflex stimulation signal as part of a baroreflex therapy;

a lead to be electrically connected to the pulse generator and to be intravascularly fed through a right ventricle and a pulmonary valve into a pulmonary artery, the lead including an electrode to be positioned in a pulmonary artery to deliver the baroreflex signal to a baroreceptor region in or proximate to the heart;

a sensor to sense a physiological parameter regarding an efficacy of the baroreflex therapy and to provide a signal indicative of the efficacy of the baroreflex therapy; and

a controller connected to the pulse generator to control the baroreflex stimulation signal and to the sensor to receive the signal indicative of the efficacy of the baroreflex therapy.

95. An implantable baroreflex stimulator, comprising:

means for delivering baroreflex therapy through a lead intravascularly fed through at least a portion of the heart to a baroreceptor region in a pulmonary artery to inhibit sympathetic activity; and

means for providing feedback regarding an efficacy of the baroreflex therapy for use to control delivery of the baroreflex therapy.

96. A method, comprising:

applying baroreflex therapy, including electrically stimulating a baroreceptor region in a pulmonary artery using a lead fed into a right ventricle and through a pulmonary valve into the pulmonary artery,

sensing a physiologic parameter indicative of an efficacy of the baroreflex therapy; and

modifying the baroreflex therapy based on the physiological parameter.