Baroreflex modulation to gradually decrease blood pressure
An aspect of the present subject matter relates to a baroreflex stimulator. An embodiment of the stimulator includes a pulse generator to provide a baroreflex stimulation signal through an electrode, and a modulator. The modulator modulates 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. Other aspects are provided herein.
1. A method, comprising:
sensing blood pressure using an implantable medical device; and
using a programmed algorithm in the implantable medical device, progressively lowering blood pressure from a start time and over a period of time following the start time so that the sensed blood pressure reaches a target blood pressure,
wherein progressively lowering the sensed blood pressure includes delivering neural stimulation that is effective in lowering blood pressure, and using the programmed algorithm to adjust an intensity of the neural stimulation during the period of time to cause the blood pressure to be progressively lowered toward the target pressure during the period of time so that the sensed blood pressure reaches the target blood pressure after the period of time.
2. The method of claim 1 , wherein using the programmed algorithm to increase the intensity of the neural stimulation includes using the programmed algorithm to determine a rate for changing the intensity of the neural stimulation as a function of the sensed blood pressure and the programmed target pressure.
3. The method of claim 2 , further comprising determining cardiac output, wherein using the programmed algorithm to adjust the intensity of the neural stimulation further includes using the programmed algorithm to determine the rate for changing the intensity of the neural stimulation as a function of cardiac output.
4. The method of claim 3 , wherein determining cardiac output includes directly measuring cardiac output.
5. The method of claim 3 , wherein determining cardiac output includes indirectly measuring cardiac output.
6. The method of claim 3 , further comprising preventing the blood pressure from causing an unacceptable decrease in cardiac output.
7. The method of claim 1 , wherein using the programmed algorithm to adjust the intensity of the neural stimulation includes preventing a central nervous system from adapting to increased neural stimulation.
8. The method of claim 1 , wherein using the programmed algorithm to adjust the intensity of the neural stimulation includes adjusting the intensity of the neural stimulation in a manner to improve an ability of a patient to tolerate increased neural stimulation.
9. The method of claim 1 , wherein using the programmed algorithm to adjust the intensity of the neural stimulation includes adjusting the intensity of the neural stimulation in a manner to slowly revert a stiffening process caused by hypertension.
10. The method of claim 1 , wherein progressively lowering the sensed blood pressure includes progressively lowering the sensed blood pressure to the target pressure over a period of weeks or months.
11. The method of claim 1 , further comprising:
receiving an event trigger to initiate a process performed by the implantable medical device to gradually tower blood pressure;
interrupting the programmed algorithm when the neural stimulation reaches the target pressure; and
determining if cardiac output is acceptable and if cardiac output is not acceptable, modifying the programmed algorithm to modify how the blood pressure is gradually lowered.
12. The method of claim 11 , further comprising using the implantable medical device to sense parameters, and interrupting the programmed algorithm based on sensed parameters.
13. The method of claim 11 , further comprising receiving an event interrupt, and interrupting the programmed algorithm based on receiving the event interrupt.
14. The method of claim 11 , wherein the period of time is a period of weeks or months.
15. The method of claim 11 , wherein the neural stimulation includes stimulating a baroreceptor.
16. The method of claim 11 , wherein the neural stimulation includes stimulating an afferent nerve.
17. A method, comprising:
sensing blood pressure;
determining cardiac output; and
implementing a programmed algorithm in an implantable medical device to control an intensity of neural stimulation delivered by the implantable medical device to gradually lower blood pressure with time from a start, time and over a period of time following the start time to reach a programmed target blood pressure, wherein the programmed algorithm adjusts the intensity of the neural stimulation and determining the rate of change as a function of the sensed blood pressure, the programmed target blood pressure and the cardiac output.
18. The method of claim 17 , wherein the programmed algorithm prevents the blood pressure from causing an unacceptable decrease in cardiac output.
19. The method of claim 17 , wherein the programmed algorithm stimulates to slightly decrease blood pressure, and then gradually increases the intensity of the neural stimulation.
20. The method of claim 17 , wherein the programmed algorithm controls the intensity of the neural stimulation to gradually lower blood pressure over a period of weeks or months to reach the programmed target blood pressure after the period of weeks or months.