BLOOD VOLUME REDISTRIBUTION THERAPY FOR HEART FAILURE

• US 20110022127A1
• Filed: 07/26/2010
• Published: 01/27/2011
• Est. Priority Date: 07/27/2009
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Ruble, Stephen, Hamann, Jason J., Shuros, Allan C., Averina, Viktoria A.
• Granted Patent: US 8,483,821 B2
• Time in Patent Office: Days
• US Class Current: 607/62
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/0538 invasively, e.g. using a catheter
• CPC Class Codes: A61B 5/0809 by impedance pneumography
• CPC Class Codes: A61B 5/4035 Evaluating the autonomic nervous system
• CPC Class Codes: A61B 5/4869 Determining body composition
• CPC Class Codes: A61N 1/3601 of respiratory organs
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters

Abstract

A first fluid status indicator of a pulmonary fluid status associated with pulmonary edema and a second fluid status indicator of a non-pulmonary fluid status can be used to provide an alert or to control a therapy for pulmonary edema. Additionally, intermittent cardiac blood volume redistribution therapy can be used to provide cardiac conditioning in heart failure patients.

Claims

1. A medical device comprising:

a first fluid status monitoring circuit configured to monitor a first fluid status indicator of a pulmonary fluid status associated with pulmonary edema, wherein an increase in the first fluid status indicator correlates to an increase in pulmonary fluid associated with pulmonary edema;

a second fluid status monitoring circuit configured to monitor a separate and different second fluid status indicator of a non-pulmonary fluid status, wherein an increase in the second fluid status indicator correlates to an increase in the non-pulmonary fluid;

a controller coupled to the first and second fluid status monitoring circuits, the controller configured to use information about the first and second fluid status indicators to determine a therapy control signal to control a therapy; and

a therapy circuit coupled to the controller to receive the therapy control signal, the therapy circuit configured to provide therapy, in response to the therapy control signal, to adjust at least one of the pulmonary fluid status or the non-pulmonary fluid status.

2. The device of claim 1, wherein the second fluid status monitoring circuit is configured to monitor a splanchnic impedance measurement representative of fluid status associated with a splanchnic organ.

3. The device of claim 1, wherein the controller is configured to trigger providing the therapy in response to at least one of a decrease in the second fluid status indicator below a specified threshold value, an increase in the first fluid status indicator above a specified threshold value, a heart failure decompensation alert provided by the medical device, a patient-initiated alert, or a user input.

4. The device of claim 1, wherein the therapy circuit includes a neuromodulation circuit configured to provide a neuromodulation therapy to adjust the non-pulmonary fluid status, and wherein the neuromodulation therapy includes stimulation or inhibition of at least one of a sympathetic nervous system or a parasympathetic nervous system.

5. The device of claim 1, wherein the therapy circuit is configured to concurrently deliver at least one of a localized vasodilation therapy or a localized vasoconstriction therapy to at least two separate localized vascular regions to adjust a balance between fluid status in the two separate localized regions.

6. The device of claim 1, wherein the controller is configured to decrease or stop therapy in response to at least one of:

an increase in the first fluid status indicator above a first specified threshold value;

a decrease in the first fluid status indicator below a second specified threshold value;

an increase in the second fluid status indicator above a third specified threshold value;

or a decrease in the second fluid status indicator below a fourth specified threshold value.

7. The device of claim 1, wherein the controller is configured to use information about the first and second fluid status indicators to stop therapy after a specified period of time.

8. The device of claim 1, wherein the controller circuit configured to control the therapy circuit to provide neuromodulation therapy to a splanchnic region during a specified period of time in an amount sufficient to modulate cardiac blood volume during at least a portion of the specified period of time.

9. The device of claim 1, comprising a heart signal detection circuit configured to detect a heart signal of a subject, and wherein the controller is coupled to the heart signal detection circuit and configured to trigger providing the therapy synchronized with a specified portion of the subject'"'"'s cardiac cycle.

10. The device of claim 1, comprising a posture sensing circuit configured to detect a posture of a subject, and wherein the controller is configured to use (1) information about the first and second fluid status indicators, and (2) information about the posture of the subject to determine the therapy control signal to control the therapy.

11. A method comprising:

monitoring a first fluid status indicator of a pulmonary fluid status associated with pulmonary edema;

monitoring a separate and different second fluid status indicator of a non-pulmonary fluid status; and

using information about the first and second fluid status indicators, controlling a therapy to adjust at least one of the pulmonary fluid status or the non-pulmonary fluid status.

12. The method of claim 11, wherein monitoring the second fluid status indicator includes monitoring a splanchnic impedance measurement representative of fluid status associated with a splanchnic organ;

and

wherein monitoring a splanchnic impedance includes;

measuring a first impedance vector across both a pulmonary region and a splanchnic region of interest;

measuring a second impedance vector across a pulmonary region but not across the splanchnic region of interest; and

subtracting the second impedance vector from the first impedance vector to determine the splanchnic impedance.

13. The method of claim 11, wherein the controlling the therapy comprises triggering providing the therapy by a decrease in the second fluid status indicator below a specified threshold value.

14. The method of claim 11, comprising concurrently controlling at least one of vasodilation or vasoconstriction in at least two separate localized vascular regions to adjust a balance between fluid status in the two separate localized regions.

15. The method of claim 11, wherein the controlling the therapy includes decreasing or stopping therapy in response to at least one of:

an increase in the first fluid status indicator above a first specified threshold value;

a decrease in the first fluid status indicator below a second specified threshold value;

an increase in the second fluid status indicator above a third specified threshold value;

or

a decrease in the second fluid status indicator below a fourth specified threshold value.

16. The method of claim 11, wherein the controlling the therapy includes using information about the first and second fluid status indicators to stop therapy after a specified period of time.

17. The method of claim 11, wherein the controlling the therapy includes synchronizing delivery of the therapy with a specified portion of the subject'"'"'s cardiac cycle.

18. The method of claim 11, comprising detecting a patient posture, and wherein the controlling the therapy comprises using (1) information about the first and second fluid status indicators, and (2) information about the patient posture to adjust at least one of the pulmonary fluid status or the non-pulmonary fluid status.

19. A device-readable medium comprising instructions that, when performed by a previously-implanted medical device, cause the device to perform acts comprising:

monitoring a first fluid status indicator of a pulmonary fluid status associated with pulmonary edema;

monitoring a separate and different second fluid status indicator of a non-pulmonary fluid status; and

using information about the first and second fluid status indicators, providing a control signal to control a therapy to adjust at least one of the pulmonary fluid status or the non-pulmonary fluid status.

20. The device-readable medium of claim 19, wherein monitoring the second fluid status indicator includes monitoring a splanchnic impedance measurement representative of fluid status associated with a splanchnic organ;

and

wherein monitoring a splanchnic impedance includes;

measuring a first impedance vector across both a pulmonary region and a splanchnic region of interest;

measuring a second impedance vector across a pulmonary region but not across the splanchnic region of interest; and

subtracting the second impedance vector from the first impedance vector to determine the splanchnic impedance.

21. The device-readable medium of claim 19, comprising instructions that, when performed by the previously-implanted medical device, cause the device to perform acts comprising concurrently providing a control signal to control at least one of vasodilation or vasoconstriction in at least two separate localized vascular regions to adjust a balance between fluid status in the two separate localized regions.

22. The device-readable medium of claim 19, wherein the providing the control signal to control the therapy includes providing a control signal to decrease or stop therapy in response to at least one of:

an increase in the first fluid status indicator above a first specified threshold value;

a decrease in the first fluid status indicator below a second specified threshold value;

an increase in the second fluid status indicator above a third specified threshold value;

or

a decrease in the second fluid status indicator below a fourth specified threshold value.

23. The device-readable medium of claim 19, wherein the providing the control signal to control the therapy includes providing a control signal to synchronize delivery of the therapy with a specified portion of the subject'"'"'s cardiac cycle.

24. The device-readable medium of claim 19, comprising instructions that, when performed by the previously-implanted medical device, cause the device to perform acts comprising detecting a patient posture, and wherein the providing the control signal to control the therapy comprises using (1) information about the first and second fluid status indicators, and (2) information about the patient posture to adjust at least one of the pulmonary fluid status or the non-pulmonary fluid status.