System and method for assessing cardiac performance through cardiac vibration monitoring

• US 8,025,624 B2
• Filed: 03/03/2006
• Issued: 09/27/2011
• Est. Priority Date: 02/19/2004
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Wariar, Ramesh, Carlson, Gerrard M.
• Primary Examiner(s): Mallari; Patricia
• Assistant Examiner(s): D'ANGELO, MICHAEL J
• Application Number:
  US11/367,852
• Publication Number:
  US 20060155204A1
• Time in Patent Office: 2,034 Days
• Field of Search: 600/481, 600/300, 600/483, 600/485, 600/528, 600/508, 607/23, 607/30
• US Class Current: 600/528
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R

Abstract

A system and method for assessing cardiac performance through cardiac vibration monitoring is described. Cardiac vibration measures are directly collected through an implantable medical device. Cardiac events including at least one first heart sound reflected by the cardiac vibration measures are identified. The first heart sound is correlated to cardiac dimensional measures relative to performance of an intrathoracic pressure maneuver. The cardiac dimensional measures are grouped into at least one measures set corresponding to a temporal phase of the intrathoracic pressure maneuver. The at least one cardiac dimensional measures set is evaluated against a cardiac dimensional trend for the corresponding intrathoracic pressure maneuver temporal phase to represent cardiac performance.

Claims

1. A system for assessing cardiac performance through cardiac vibration monitoring, comprising:

an implantable medical device to directly collect cardiac vibration measures;

a correlation component to identify cardiac events comprising at least one first heart sound reflected by the cardiac vibration measures, to correlate the first heart sound to measures related to cardiac dimensional changes relative to performance of an intrathoracic pressure maneuver, and to group the measures related to cardiac dimensional changes into at least one measures set corresponding to a temporal phase of the intrathoracic pressure maneuver; and

an analysis component to evaluate the at least one set of measures related to cardiac dimensional changes against a cardiac dimensional trend for the corresponding intrathoracic pressure maneuver temporal phase to represent cardiac performance.

2. A system according to claim 1, further comprising:

an evaluation component to derive the measures related to cardiac dimensional changes by proportionately extrapolating an intensity of the first heart sound to a rate of rise of left ventricular pressure.

3. A system according to claim 1, further comprising:

an evaluation component to determine amplitude and frequency spectrum parameters for the cardiac events for at least one of intensity of the first heart sound, ratio of first heart sound acoustic energy to total acoustic energy, and ratio of first heart sound intensity to pulmonary artery pressure.

4. A system according to claim 1, further comprising:

an evaluation component to process the cardiac vibration measures by performing at least one of ensemble averaging, signal rectifying, and low-pass or band-pass filtering.

5. A system according to claim 1, wherein the measures related to cardiac dimensional changes comprise at least one of cardiac stroke volume, left ventricular ejection fraction, left ventricular end diastolic pressure, and left ventricular end systolic pressure.

6. A system according to claim 1, further comprising:

a history component to evaluate a history of cardiac performance representations; and

a trending component to recognize a trend within the history indicating at least one of cardiovascular disease absence, onset, progression, regression, and status quo.

7. A system according to claim 1, further comprising:

a characteristic signature formed with the cardiac dimensional trends over the performance of the intrathoracic pressure maneuver; and

a comparison component to compare an overall cardiac dimensional profile comprising the at least one set of measures related to cardiac dimensional changes to the characteristic signature to form a cardiac performance assessment.

8. A system according to claim 1, further comprising:

at least one of;

a notification generated responsive to a substantially non-complying cardiac performance assessment; and

a programmer to program support to the implantable medical device.

9. A system according to claim 1, wherein the intrathoracic pressure maneuver is selected from the group comprising Valsalva and Mü

ller maneuvers, further comprising;

a collection component to collect the cardiac vibration measures relative to performance of the selected intrathoracic pressure maneuver.

10. A method for assessing cardiac performance through cardiac vibration monitoring, comprising:

directly collecting cardiac vibration measures through an implantable medical device;

identifying cardiac events comprising at least one first heart sound reflected by the cardiac vibration measures;

correlating the first heart sound to measures related to cardiac dimensional changes relative to performance of an intrathoracic pressure maneuver on a server;

grouping the measures related to cardiac dimensional changes into at least one measures set corresponding to a temporal phase of the intrathoracic pressure maneuver on a server; and

evaluating the at least one set of measures related to cardiac dimensional changes against a cardiac dimensional trend for the corresponding intrathoracic pressure maneuver temporal phase to represent cardiac performance on a server.

11. A method according to claim 10, further comprising:

deriving the measures related to cardiac dimensional changes by proportionately extrapolating an intensity of the first heart sound to a rate of rise of left ventricular pressure.

12. A method according to claim 10, further comprising:

determining amplitude and frequency spectrum parameters for the cardiac events for at least one of intensity of the first heart sound, ratio of first heart sound acoustic energy to total acoustic energy, and ratio of first heart sound intensity to pulmonary artery pressure.

13. A method according to claim 10, further comprising:

processing the cardiac vibration measures by performing at least one of ensemble averaging, signal rectifying, and low-pass or band-pass filtering.

14. A method according to claim 10, wherein the measures related to cardiac dimensional changes comprise at least one of cardiac stroke volume, left ventricular ejection fraction, left ventricular end diastolic dimension, and left ventricular end systolic dimension.

15. A method according to claim 10, further comprising:

evaluating a history of cardiac performance representations; and

recognizing a trend within the history indicating at least one of cardiovascular disease absence, onset, progression, regression, and status quo.

16. A method according to claim 10, further comprising:

forming a characteristic signature with the cardiac dimensional trends over the performance of the intrathoracic pressure maneuver; and

comparing an overall cardiac dimensional profile comprising the at least one set of measures related to cardiac dimensional changes to the characteristic signature to form a cardiac performance assessment.

17. A method according to claim 10, further comprising:

performing at least one of;

generating a notification responsive to a substantially non-complying cardiac performance assessment; and

providing programming support to the implantable medical device.

18. A method according to claim 10, further comprising:

selecting the intrathoracic pressure maneuver from the group comprising Valsalva and Mü

ller maneuvers; and

collecting the cardiac vibration measures relative to performance of the selected intrathoracic pressure maneuver.

19. A computer-readable storage medium holding code for performing the method of claim 10.