MEASURES OF CARDIAC CONTRACTILITY VARIABILITY DURING ISCHEMIA

• US 20100274141A1
• Filed: 04/15/2010
• Published: 10/28/2010
• Est. Priority Date: 04/22/2009
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Patangay, Abhilash, Zhang, Yi, Thompson, Julie A., Lewicke, Aaron
• Granted Patent: US 8,951,203 B2
• Time in Patent Office: Days
• US Class Current: 600/485
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

Systems and methods include obtaining a measure of cardiac contractility. A cardiac contractility variability is determined from the measure of cardiac contractility. Analyzing the cardiac contractility variability, an indication of cardio-vasculature health is provided.

Claims

1. A system, comprising:

a machine-readable media; and

one or more processors communicatively coupled to the machine-readable media, the machine-readable media including instructions, which when executed by the one or more processors, cause the one or more processors to;

obtain a measure of cardiac contractility;

determine a cardiac contractility variability from the measure of cardiac contractility; and

analyze the cardiac contractility variability to provide an indication of cardio-vasculature health.

2. The system of claim 1, wherein the instructions to obtain the measure of cardiac contractility comprise instructions to:

obtain a measure at least one of a heart sound, a pulmonary artery pressure, a coronary venous pressure, a left ventricular pressure, a right ventricular pressure, or a timing interval to provide the measure of cardiac contractility.

3. The system of claim 1, wherein the instructions to determine the cardiac contractility variability comprise instructions to:

use a time domain variability parameter to measure cardiac contractility variability.

4. The system of claim 1, wherein the instructions to determine the cardiac contractility variability comprise instructions to:

use a frequency domain variability parameter to measure cardiac contractility variability.

5. The system of claim 1, wherein the instructions to determine the cardiac contractility variability comprise instructions to:

use a time-frequency domain variability parameter to measure cardiac contractility variability.

6. The system of claim 1, wherein the instructions to determine the cardiac contractility variability comprise instructions to:

use a nonlinear variability parameter to measure cardiac contractility variability.

7. The system of claim 6, wherein the instructions to use the parameter from the class of nonlinear variability parameters comprise instructions to:

measure an approximate entropy (ApEn) of an S1 amplitude.

8. The system of claim 1, wherein the instructions to determine the cardiac contractility variability are performed using a time period to provide a variability measurement and wherein the instructions to analyze the cardiac contractility variability comprise instructions to:

trend the variability measurement to provide a trended variability measurement;

compare the trended variability measurement to a threshold value to provide a comparison; and

use the comparison to detect a cardiac state.

9. The system of claim 1, wherein the machine-readable media includes instructions, which when executed by the one or more processors, cause the one or more processors to:

after determining the cardiac contractility variability, adjust at least one of;

a CRT timing parameter or an electrical position;

measure the contractility variability after the adjusting; and

continue to adjust in a closed-loop feedback manner to increase the cardiac contractility variability.

10. The system of claim 1, wherein the machine-readable media includes instructions, which when executed by the one or more processors, cause the one or more processors to:

normalize the cardiac contractility variability by the measure of cardiac contractility.

11. The system of claim 1, wherein the machine-readable media includes instructions, which when executed by the one or more processors, cause the one or more processors to:

normalize the cardiac contractility variability by an associated heart rate.

12. A method, comprising:

obtaining a measure of cardiac contractility;

determining a cardiac contractility variability from the measure of cardiac contractility; and

analyzing the cardiac contractility variability to provide an indication of cardio-vasculature health.

13. The method of claim 12, wherein obtaining the measure of cardiac contractility comprises:

obtaining a measure at least one of a heart sound, a pulmonary artery pressure, a coronary venous pressure, a left ventricular pressure, a right ventricular pressure, or a timing interval to provide the measure of cardiac contractility.

14. The method of claim 12, wherein determining the cardiac contractility variability comprises:

using a time domain variability parameter to measure cardiac contractility variability.

15. The method of claim 12, wherein determining the cardiac contractility variability comprises:

using a frequency domain variability parameter to measure cardiac contractility variability.

16. The method of claim 12, wherein determining the cardiac contractility variability comprises:

using a time-frequency domain variability parameter to measure cardiac contractility variability.

17. The method of claim 12, wherein determining the cardiac contractility variability comprises:

using a nonlinear variability parameter to measure cardiac contractility variability.

18. The method of claim 12, wherein determining the cardiac contractility variability is performed using a time period to provide a variability measurement and wherein analyzing the cardiac contractility variability comprises:

trending the variability measurement to provide a trended variability measurement;

comparing the trended variability measurement to a threshold value to provide a comparison; and

using the comparison to detect a cardiac state.

19. The method of claim 12, further comprising:

after determining the cardiac contractility variability, adjusting at least one of;

a CRT timing parameter, a lead position, or an electrical position;

measuring the contractility variability after the adjusting; and

continuing adjusting in a closed-loop feedback manner to increase the cardiac contractility variability.

20. An apparatus comprising:

a memory device;

a sensor device coupled to the memory device, the sensor configured to sense a plurality of indications of a plurality of cardiac cycles, and to store the plurality of indications of the plurality of cardiac cycles in the memory device;

means for obtaining a measure of cardiac contractility using the plurality of indications of the plurality of cardiac cycles;

means for determining a cardiac contractility variability from the measure of cardiac contractility; and

means for analyzing the cardiac contractility variability to provide an indication of cardio-vasculature health.