TRACKING PROGRESSION OF CONGESTIVE HEART FAILURE VIA A FORCE-FREQUENCY RELATIONSHIP

• US 20100087890A1
• Filed: 12/09/2009
• Published: 04/08/2010
• Est. Priority Date: 08/19/2005
• Status: Active Grant

• Current Assignee: Gerrard M. Carlson, Ramesh Wariar
• Original Assignee: Gerrard M. Carlson, Ramesh Wariar
• Inventors: WARIAR, RAMESH, CARLSON, GERRARD M.
• Granted Patent: US 8,755,883 B2
• Time in Patent Office: Days
• US Class Current: 607/27
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• 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 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• CPC Class Codes: A61B 7/023 for introduction into the body, e.g. into the oesophagus oesophageal ECG probes A61B5/285
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy

Abstract

A system, method, or device monitor a force-frequency relationship exhibited by a patient'"'"'s heart. A contractility characteristic, such as a heart sound characteristic of an S1 heart sound, is measured. The contractility characteristic indicates the forcefulness of a contraction of the heart. The frequency at which the heart is contracting is determined. A group of (contractility characteristic, heart rate) pairs is stored in a memory device. The group of pairs defines a force-frequency relationship for the heart. The method may be implemented by an implantable device, or by a system including a implantable device.

Claims

1. A system comprising:

a transducer configured to receive heart contraction information of a heart and to produce a contractility signal; and

a control circuit configured to receive the contractility signal, to determine a first contractility characteristic of the heart at a first pacing rate and a second contractility characteristic of the heart at a second pacing rate, the second pacing rate different than the first pacing rate, and to provide a force-frequency relationship of the heart using the first and second contractility characteristics and the respective first and second pacing rates.

2. The system of claim 1, wherein the control circuit is configured to alter the pacing rate from the first pacing rate to the second pacing rate.

3. The system of claim 1, wherein the force-frequency relationship includes a trend of contractility characteristics and heart rates corresponding to the respective contractility characteristics.

4. The system of claim 1, wherein the control circuit is configured to provide an indication of a cardiac status of the heart using the force-frequency relationship.

5. The system of claim 4, wherein the control circuit is configured to provide an indication of congestive heart failure status of the heart using the force-frequency relationship.

6. The system of claim 1, including an implantable medical device, and wherein the implantable medical device includes the transducer and the control circuit.

7. The system of claim 1, wherein the heart contraction information includes at least one of left ventricular pressure information or heart sound information, and wherein the contractility signal includes at least one of a left ventricular pressure signal or a heart sound signal.

8. The system of claim 1, wherein the force-frequency relationship of the heart includes a slope of contractility characteristic and heart rate information.

9. An implantable medical device comprising:

a control circuit configured to;

receive a contractility signal indicative of the forcefulness of a cardiac contraction of a heart;

determine a first contractility characteristic of the heart at a first pacing rate;

determine a second contractility characteristic of the heart at a second pacing rate, the second pacing rate different than the first pacing rate; and

provide a force-frequency relationship of the heart using the first and second contractility characteristics and the first and second pacing rates.

10. The implantable medical device of claim 9, including a transducer configured to receive heart contraction information of a heart and to produce the contractility signal.

11. The implantable medical device of claim 9, wherein the heart contraction information includes heart sound information indicative of left ventricular pressure of the heart;

and

wherein the control circuit is configured to alter the pacing rate from the first pacing rate to the second pacing rate to determine a group of (contractility characteristic, heart rate) pairs to provide the force frequency relationship of the heart.

12. The implantable medical device of claim 9, wherein the control circuit is configured to provide an indication of congestive heart failure status of the heart using the force-frequency relationship.

13. A method comprising:

receiving heart contraction information of a heart;

determining a first contractility characteristic of the heart at a first pacing rate;

determining a second contractility characteristic of the heart at a second pacing rate, the second pacing rate different than the first pacing rate; and

providing a force-frequency relationship of the heart using the first and second contractility characteristics and the respective first and second pacing rates.

14. The method of claim 13, including altering the pacing rate from the first pacing rate to the second pacing rate.

15. The method of claim 13, wherein the providing the force-frequency relationship includes providing a trend of contractility characteristics and heart rates corresponding the respective contractility characteristics.

16. The method of claim 13, wherein the providing the force-frequency relationship includes providing an indication of a cardiac status of the heart using the first and second contractility characteristics and the first and second pacing rates.

17. The method of claim 16, wherein the providing the indication of cardiac status of the heart includes providing an indication of congestive heart failure of the heart.

18. The method of claim 13, wherein the receiving the heart contraction information includes implantably receiving the heart contraction information.

19. The method of claim 13, wherein the receiving the heart contraction information includes implantable receiving at least one of left ventricular pressure information or heart sound information.

20. The method of claim 13, wherein the providing the force-frequency relationship of the heart includes providing a slope of contractility characteristic and heart rate information.