METHOD AND APPARATUS FOR DETECTING ATRIAL FILLING PRESSURE

• US 20070066913A1
• Filed: 11/13/2006
• Published: 03/22/2007
• Est. Priority Date: 12/30/2002
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Patangay, Abhilash, Siejko, Krzysztof
• Granted Patent: US 8,048,001 B2
• Time in Patent Office: Days
• US Class Current: 600/528
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36528 the parameter being measured by means of ultrasound

Abstract

A cardiac rhythm management system provides for ambulatory monitoring of hemodynamic performance based on quantitative measurements of heart sound related parameters for diagnostic and therapeutic purposes. Monitoring of such heart sound related parameters allows the cardiac rhythm management system to determine a need for delivering a therapy and/or therapy parameter adjustments based on conditions of a heart. This monitoring also allows a physician to observe or assess the hemodynamic performance for diagnosing and making therapeutic decisions. Because the conditions of the heart may fluctuate and may deteriorate significantly between physician visits, the ambulatory monitoring, performed on a continuous or periodic basis, ensures a prompt response by the cardiac rhythm management system that may save a life, prevent hospitalization, or prevent further deterioration of the heart.

Claims

1. A system comprising:

an implantable medical device, including;

a heart sound sensor, configured to sense a heart sound signal of a heart;

a heart sound detector, coupled to the heart sound sensor, the heart sound detector configured to detect at least one parameter indicative of an atrial filling pressure of the heart using the heart sound signal; and

a processor, coupled to the heart sound detector, the processor configured to compare the at least one parameter to a threshold.

2. The system of claim 1, wherein the atrial filling pressure includes a left atrial filling pressure.

3. The system of claim 1, wherein the at least one parameter includes at least one measurement, feature, characteristic, computation, or interval of the heart sound signal.

4. The system of claim 3, wherein the at least one measurement, feature, characteristic, computation, or interval of the heart sound signal includes at least one of an amplitude of a third heart sound (S3), a split second heart sound (S2) time interval, an S2-S3 time interval, and a normalized amplitude or interval of at least one measurement, feature, or characteristic of the heart sound signal.

5. The system of claim 1, wherein the implantable medical device includes a cardiac sensor, coupled to the heart sound detector, the cardiac sensor configured to sense a cardiac signal of the heart;

and

wherein the heart sound detector is configured to detect the at least one parameter using the heart sound signal and the cardiac signal.

6. The system of claim 5, wherein the at least one parameter includes at least one measurement, feature, characteristic, computation, or interval between at least one cardiac signal feature and at least one heart sound signal feature.

7. The system of claim 5, wherein the at least one parameter includes a systolic time interval (STI).

8. The system of claim 1, wherein the threshold includes a predefined threshold.

9. The system of claim 1, wherein the threshold includes an absolute threshold.

10. The system of claim 1, including a posture sensor, coupled to the processor, the posture sensor configured to sense a posture signal;

and

wherein the processor is configured to compare the at least one parameter to the threshold using the posture signal.

11. The system of claim 1, including an alert module, coupled to the processor, the alert module configured to generate an alert using the at least one parameter.

12. The system of claim 11, wherein the alert is configured to be generated with a predefined specificity.

13. The system of claim 12, wherein the alert is configured to be generated with a predefined specificity equal to or greater than 85%.

14. The system of claim 13, wherein the alert is configured to be generated with a predefined specificity equal to or greater than 90%.

15. A system comprising:

means for sensing a heart sound signal of a heart using an implanted heart sound sensor;

means for detecting at least one parameter indicative of an atrial filling pressure of the heart using the heart sound signal; and

means for comparing the at least one parameter to a threshold.

16. A method comprising:

sensing a heart sound signal of a heart using an implanted heart sound sensor;

detecting at least one parameter indicative of an atrial filling pressure of the heart using the heart sound signal; and

comparing the at least one parameter to a threshold.

17. The method of claim 16, wherein detecting the at least one parameter indicative of an atrial filling pressure includes detecting at least one parameter indicative of a left atrial filling pressure.

18. The method of claim 16, wherein detecting the at least one parameter includes detecting at least one measurement, feature, characteristic, computation, or interval of the heart sound signal.

19. The method of claim 18, wherein detecting the at least one measurement, feature, characteristic, computation, or interval of the heart sound signal includes detecting at least one of an amplitude of a third heart sound (S3), a split second heart sound (S2) time interval, an S2-S3 time interval, and a normalized amplitude or interval of at least one measurement, feature, or characteristic of the heart sound signal.

20. The method of claim 16, including:

sensing a cardiac signal of the heart using an implanted cardiac sensor; and

wherein detecting the at least one parameter includes using the heart sound signal and the cardiac signal.

21. The method of claim 20, wherein detecting the at least one parameter includes detecting at least one measurement, feature, characteristic, computation, or interval between at least one cardiac signal feature and at least one heart sound signal feature.

22. The method of claim 20, wherein detecting the at least one parameter includes detecting at least one systolic time interval (STI).

23. The method of claim 16, wherein comparing the at least one parameter to a threshold includes comparing the at least one parameter to a predefined threshold.

24. The method of claim 16, wherein comparing the at least one parameter to a threshold includes comparing the at least one parameter to an absolute threshold.

25. The method of claim 16, including:

sensing a posture signal using a posture sensor; and

wherein comparing the at least one parameter to a threshold includes using the posture signal.

26. The method of claim 16, including generating an alert using the at least one parameter.

27. The method of claim 26, wherein generating an alert includes generating an alert with a predefined specificity.

28. The method of claim 27, wherein generating an alert with a predefined specificity includes generating an alert with a predefined specificity of at least 85%.

29. The method of claim 28, generating an alert with a predefined specificity includes generating an alert with a predefined specificity of at least 90%.