System and method for pacing parameter optimization using heart sounds

• US 9,643,014 B2
• Filed: 11/15/2011
• Issued: 05/09/2017
• Est. Priority Date: 07/29/2011
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Zhang, Xusheng, Gillberg, Jeffrey M., Mullen, Thomas J.
• Primary Examiner(s): Lee, Erica
• Application Number:
  US13/296,605
• Publication Number:
  US 20130030484A1
• Time in Patent Office: 2,002 Days
• Field of Search: None
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• 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: A61N 1/36578 controlled by mechanical motion of the heart wall, e.g. measured by an accelerometer or microphone
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36842 Multi-site stimulation in the same chamber
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation
• CPC Class Codes: A61N 1/3686 configured for selecting the electrode configuration on a lead A61N1/3688 takes precedence
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/37264 Changing the program; Upgrading firmware

Abstract

A medical device system and associated method predict a patient response to a cardiac therapy. The system includes for delivering cardiac pacing pulses to a patient'"'"'s heart coupled to a cardiac sensing module and a cardiac pacing module for generating cardiac pacing pulses and controlling delivery of the pacing pulses at multiple pace parameter settings. An acoustical sensor obtains heart sound signals. A processor is enabled to receive the heart sound signals, derive a plurality of heart sound signal parameters from the heart sound signals, and determine a trend of each of the plurality of heart sound signal parameters with respect to the plurality of pace parameter settings. An external display is configured to present the trend of at least one heart sound parameter with respect to the plurality of pace parameter settings.

Claims

1. A medical device system, comprising:

a plurality of electrodes for delivering cardiac pacing pulses to a patient'"'"'s heart;

a cardiac sensing module coupled to the plurality of electrodes;

a cardiac pacing module coupled to the plurality of electrodes for generating cardiac pacing pulses and controlling delivery of the pacing pulses at a plurality of pace parameter settings;

an acoustical sensor for obtaining heart sound signals;

a processor enabled to;

control the pacing module to deliver the cardiac pacing pulses at the plurality of pace parameter settings comprising a plurality of settings of a pacing time interval,

receive the heart sound signals during the delivery of the cardiac pacing pulses at the plurality of pace parameter settings comprising the plurality of settings of the pacing time interval,

derive a plurality of heart sound signal parameters from the heart sound signals, the heart sound signal parameters comprising at least a first heart sound signal parameter and a second heart sound signal parameter, wherein the first heart sound signal parameter comprises a V-S2 interval measured as a time interval between a ventricular electrical event and an S2 heart sound for each of the plurality of settings of the pacing time interval,

determine a trend of at least the V-S2 interval with respect to the plurality of settings of the pacing time interval,

identify an inflection point of the trend of the V-S2 interval,

identify one of the plurality of settings of the pacing time interval that occurs at the identified inflection point as a maximum optimal setting of the pacing time interval,

determine a trend of the second heart sound signal parameter with respect to the plurality of settings of the pacing time interval, the second heart sound signal parameter different than the V-S2 interval, and

identify an optimal setting of the pacing time interval from the plurality of settings of the pacing time interval that corresponds to a maximum value of the second heart sound signal parameter when the pacing time interval is equal to or less than the identified maximum optimal setting of the pacing time interval; and

an external display configured to present the trend of at least one of the V-S2 interval or the second heart sound signal parameter with respect to the plurality of settings of the pacing time interval.

2. The system of claim 1, wherein

the external display is further configured to present the identified optimal setting of the pacing time interval from the plurality of settings of the pacing time interval that corresponds to the maximum value of the second heart sound signal parameter when the pacing time interval is equal to or less than the identified maximum optimal setting of the pacing time interval.

3. The system of claim 1, wherein the plurality of electrodes comprises a plurality of electrodes positioned along a ventricular chamber,

the plurality of pace parameter settings comprising a plurality of pacing vectors selected from the plurality of electrodes positioned along a ventricular chamber.

4. The system of claim 3, wherein the cardiac pacing module is configured to deliver pacing pulses using each of the plurality of pacing vectors and, for each of the plurality of pacing vectors, deliver pacing pulses at each of the plurality of settings of the pacing time interval.

5. The system of claim 4, wherein the processor is configured to determine a trend of at least one of the plurality of heart sound signal parameters with respect to the plurality of settings of the pacing time interval for each of the plurality of pacing vectors, and identify an optimal pacing vector in response to the trends with respect to the plurality of pacing time interval settings.

6. The system of claim 5, wherein the processor is configured to determine the trend of the V-S2 interval with respect to the plurality of settings of the pacing time interval for the optimal pacing vector.

7. The system of claim 4, wherein the plurality of electrodes comprises a plurality of electrodes positioned along a left ventricle of the patient'"'"'s heart and the plurality of pacing time interval settings comprises a plurality of atrial-ventricular intervals.

8. The system of claim 7, wherein the processor is configured to identify the optimal pacing vector in response to one of the plurality of pacing vectors presenting a desired trend.

9. The system of claim 8, wherein the desired trend comprises a generally bell-shaped trend having a maximum peak.

10. The system of claim 8 wherein the desired trend comprises a sudden slope change.

11. A medical device system, comprising:

a plurality of electrodes for delivering cardiac pacing pulses to a patient'"'"'s heart;

a cardiac sensing module coupled to the plurality of electrodes;

a cardiac pacing module coupled to the plurality of electrodes for generating cardiac pacing pulses and controlling delivery of the pacing pulses at a plurality of pace parameter settings;

an acoustical sensor for obtaining heart sound signals;

a processor enabled to;

control the pacing module to deliver the cardiac pacing pulses at the plurality of pace parameter settings comprising a plurality of settings of an atrial-ventricular interval,

receive the heart sound signals during the delivery of the cardiac pacing pulses at the plurality of pace parameter settings comprising the plurality of settings of the atrial-ventricular interval,

derive a plurality of heart sound signal parameters from the heart sound signals, the heart sound signal parameters comprising at least a V-S2 interval measured as a time interval between a ventricular electrical event and an S2 heart sound for each of the plurality of settings of the atrial-ventricular interval,

determine a trend of the V-S2 interval with respect to a plurality of settings for the atrial-ventricular interval,

identify a sudden change from a flat slope to a descending slope of the trend of the V-S2 interval, and

identify one of the plurality of settings for the atrial-ventricular interval at which the sudden change from the flat slope to the descending slope of the determined V-S2 trend occurs as a maximum optimal setting of the atrial-ventricular interval; and

an external display configured to present the trend of the V-S2 interval with respect to the plurality of settings for the atrial-ventricular interval.

12. The system of claim 11, wherein the external display is further configured to present the maximum optimal setting of the atrial-ventricular interval.

13. The system of claim 11, wherein the plurality of electrodes comprises a plurality of electrodes positioned along a ventricular chamber, the plurality of pace parameter settings comprising a plurality of pacing vectors selected from the plurality of electrodes positioned along a ventricular chamber.

14. The system of claim 13, wherein the cardiac pacing module is configured to deliver pacing pulses using each of the plurality of pacing vectors and, for each of the plurality of pacing vectors, deliver pacing pulses at each of the plurality of settings of the atrial-ventricular interval.

15. The system of claim 14, wherein the processor is configured to determine a trend of the V-S2 interval with respect to the plurality of settings of the atrial-ventricular interval for each of the plurality of pacing vectors, and identify an optimal pacing vector in response to the trends with respect to the plurality of atrial-ventricular interval settings.

16. The system of claim 15, wherein the processor is further configured to determine a second trend of the V-S2 interval with respect to the plurality of settings of the atrial-ventricular interval for the optimal pacing vector and identify an optimal setting of the atrial-ventricular interval in response to the second trend.

17. The system of claim 15, wherein the processor is configured to identify the optimal pacing vector in response to a pacing vector presenting a desired trend.

18. The system of claim 17, wherein the desired trend comprises a generally bell-shaped trend having a maximum peak.

19. The system of claim 17, wherein the desired trend comprises a sudden slope change.

20. The system of claim 14, wherein the plurality of electrodes comprises a plurality of electrodes positioned along a left ventricle of the patient'"'"'s heart.

21. A medical device system, comprising:

a plurality of electrodes for delivering cardiac pacing pulses to a patient'"'"'s heart;

a cardiac sensing module coupled to the plurality of electrodes;

a cardiac pacing module coupled to the plurality of electrodes for generating cardiac pacing pulses and controlling delivery of the pacing pulses at a plurality of pace parameter settings, wherein the plurality of pace parameter settings comprises a plurality of pacing vectors selectable from the plurality of electrodes;

an acoustical sensor for obtaining heart sound signals;

a processor enabled to;

control the pacing module to deliver the cardiac pacing pulses at the plurality of pace parameter settings comprising a plurality of settings of a pacing time interval,

receive the heart sound signals during the delivery of the cardiac pacing pulses at the plurality of pace parameter settings comprising the plurality of settings of the pacing time interval,

derive a plurality of heart sound signal parameters from the heart sound signals, the heart sound signal parameters comprising at least a V-S2 interval measured as a time interval between a ventricular electrical event and an S2 heart sound for each of the plurality of settings of the pacing time interval,

determine a trend of at least the V-S2 interval with respect to the plurality of settings of the pacing time interval,

identify an inflection point of the trend of the V-S2 interval,

identify one of the plurality of settings of the pacing time interval that occurs at the identified inflection point as a maximum optimal setting of the pacing time interval,

for each of the plurality of pacing vectors determine a trend of at least one of the plurality of heart sound signal parameters with respect to the plurality of settings of the pacing time interval,

compare a shape of each of the determined trends over the plurality of settings of the pacing time interval to a desired shape of the trend,

determine whether at least one of the plurality of pacing vectors has a trend matching the desired shape, and

identify an optimal pacing vector from the plurality of pacing vectors when at least one of the plurality of pacing vectors has a trend matching the desired shape; and

an external display configured to present the trend of at least one of the plurality of heart sound signal parameters with respect to the plurality of settings of the pacing time interval.

22. The system of claim 21, wherein the processor is further configured to:

determine the trend for each of the plurality of pacing vectors as the trend of the V-S2 interval with respect to the plurality of settings of the pacing time interval;

compare the shapes of each of the determined V-S2 interval trends to a desired shape of the V-S2 interval trend comprising a sudden change from a flat slope to a decreasing slope;

when at least one of the V-S2 interval trends determined for the plurality of pacing vectors matches the desired shape, identify the optimal pacing vector as the pacing vector having the V-S2 interval trend matching the desired shape;

identify the maximum optimal setting as one of the plurality of settings of the pacing time interval that occurs at the sudden change; and

select an optimal setting of the pacing time interval that is less than or equal to the maximum optimal setting for delivering therapeutic pacing pulses using the optimal pacing vector.

23. The system of claim 21, wherein the external display is further configured to present the maximum optimal setting of the pacing time interval.