Methods and systems for controlling blood pressure by controlling atrial pressure
Systems and methods for controlling blood pressure by controlling atrial pressure and atrial stretch are disclosed. In some embodiments, a stimulation circuit may be configured to deliver a stimulation pulse to at least one cardiac chamber of a heart of a patient, and at least one controller may be configured to execute delivery of one or more stimulation patterns of stimulation pulses to the at least one cardiac chamber, wherein at least one of the stimulation pulses stimulates the heart such that an atrial pressure resulting from atrial contraction of an atrium overlaps in time a passive pressure build-up of the atrium, such that an atrial pressure of the atrium resulting from the stimulation is a combination of the atrial pressure resulting from atrial contraction and the passive pressure build-up and is higher than an atrial pressure of the atrium would be without the stimulation, and such that the blood pressure of the patient is reduced.
1. A method for setting a stimulation pattern for reducing blood pressure in a patient, the method comprising:
setting a target blood pressure value for the patient;
applying to a heart of the patient a first stimulation pattern having first stimulation parameters;
while applying the first stimulation pattern, continuously measuring systemic blood pressure of the patient;
comparing the measured systemic blood pressure to the target blood pressure value;
adjusting the first stimulation parameters into second stimulation parameters configured to change systemic blood pressure of the patient to be closer to the target blood pressure value; and
applying to the heart of the patient a second stimulation pattern having the second stimulation parameters,
wherein the second stimulation pattern is configured to at least one of control atrial pressure, control atrial stretch, or reduce atrial kick in a ventricle.
2. The method of claim 1 , wherein continuously measuring the systemic blood pressure comprises sensing a blood pressure parameter and determining systemic blood pressure based on the blood pressure parameter.
3. The method of claim 2 , wherein the blood pressure parameter comprises at least one of systolic blood pressure, diastolic blood pressure, mean arterial blood pressure, blood pressure in an atria, or blood pressure in a ventricle.
4. The method of claim 2 , wherein sensing a blood pressure parameter comprises using at least one of a pressure sensor, an impedance sensor, an ultrasound sensor, an audio sensor, a blood flow sensor, a piezoelectric sensor, a MEMS-based accelerometer sensor, a ventilation sensor, an electrical activity sensor, or an AV valve sensor.
5. The method of claim 1 , wherein continuously measuring the systemic blood pressure comprises sensing a plurality of blood pressure parameters, and
wherein adjusting the first stimulation parameters comprises:
comparing:
sensed blood pressure parameter values to a target,
sensed blood pressure parameter values between two or more stimulation patterns,
calculated values relating to two or more stimulation patterns, and/or
additional sensed parameters between two or more stimulation patterns,
determining the second stimulation parameters based on the comparing, and
adjusting the first stimulation parameters to the determined second stimulation parameters.
6. The method of claim 1 , wherein the second stimulation parameters reduce the systemic blood pressure of the patient to be equal to or less than the target blood pressure value.
7. The method of claim 1 , wherein the second stimulation pattern comprises different stimulation parameters in different heartbeats, and wherein the systemic blood pressure of the patient is an average blood pressure over the different heartbeats.
8. The method of claim 1 , wherein the target blood pressure value comprises a reduction of at least 4% from a pretreatment blood pressure of the patient.
9. The method of claim 1 , wherein the target blood pressure value comprises a reduction from the pretreatment blood pressure of the patient within a range of about 4% to about 30%.
10. The method of claim 1 , wherein the target blood pressure value comprises a reduction from the pretreatment blood pressure of the patient within a range of about 8 mmHg to about 30 mmHg.
11. The method of claim 1 , wherein the second stimulation pattern maintains the systemic blood pressure of the patient below the pretreatment blood pressure of the patient.
12. The method of claim 1 , wherein the second stimulation pattern maintains the systemic blood pressure of the patient so as not to exceed a predetermined average value during a predetermined interval by more than a predetermined degree.
13. The method of claim 12 , wherein the predetermined degree is a difference of about 20 mmHg or less.
14. The method of claim 1 , wherein the target blood pressure value is at least one of an absolute blood pressure value or a relative value.
15. The method of claim 1 , wherein the second stimulation pattern is configured to prevent blood pressure from spiking more than about 80% of a baseline blood pressure value between pulses.
16. A system for reducing blood pressure comprising:
at least one stimulation electrode for stimulating at least one chamber of a heart of a patient; and
at least one controller configured to:
deliver through the at least one stimulation electrode, to the heart of the patient, a first stimulation pattern having first stimulation parameters,
continuously receive, during delivery of the first stimulation pattern, input data relating to systemic blood pressure of the patient,
determine a measured systemic blood pressure based on the input data,
compare the measured systemic blood pressure to a target blood pressure value set for the patient;
adjust the first stimulation parameters into second stimulation parameters configured to change systemic blood pressure of the patient to be closer to the target blood pressure value by:
comparing:
sensed blood pressure parameter values to a target,
sensed blood pressure parameter values between two or more stimulation patterns,
calculated values relating to two or more stimulation patterns, and/or
additional sensed parameters between two or more stimulation patterns,
determining the second stimulation parameters based on the comparing, and
adjusting the first stimulation parameters to the determined second stimulation parameters; and
deliver through the at least one electrode, to the heart of the patient, a second stimulation pattern having the second stimulation parameters.
17. The system of claim 16 , further comprising a sensor that continuously measures the input data relating to the systemic blood pressure of the patient and provides the at least one controller with the input data.
18. The system of claim 17 , wherein the sensor comprises at least one of a pressure sensor, an impedance sensor, an ultrasound sensor, an audio sensor, a blood flow sensor, a piezoelectric sensor, a MEMS-based accelerometer sensor, a ventilation sensor, an electrical activity sensor, or an AV valve sensor.
19. The system of claim 17 , wherein the sensor is configured to operate as a closed loop with the at least one controller.
20. A method for setting a stimulation pattern for reducing blood pressure in a patient, the method comprising:
setting a target blood pressure value for the patient, wherein the target blood pressure value comprises a reduction of at least 4% from a pretreatment blood pressure of the patient;
applying to a heart of the patient a first stimulation pattern having first stimulation parameters;
while applying the first stimulation pattern, continuously measuring systemic blood pressure of the patient;
comparing the measured systemic blood pressure to the target blood pressure value;
adjusting the first stimulation parameters into second stimulation parameters configured to change systemic blood pressure of the patient to be closer to the target blood pressure value; and
applying to the heart of the patient a second stimulation pattern having the second stimulation parameters.