METHOD TO ASSESS HEMODYNAMIC PERFORMANCE DURING CARDIAC RESYNCHRONIZATION THERAPY OPTIMIZATION USING ADMITTANCE WAVEFORMS AND DERIVATIVES

• US 20130110190A1
• Filed: 10/30/2012
• Published: 05/02/2013
• Est. Priority Date: 10/31/2011
• Status: Abandoned Application

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Hettrick, Douglas A., Cho, Yong K.
• Application Number:
  US13/663,951
• Publication Number:
  US 20130110190A1
• Time in Patent Office: Days
• US Class Current: 607/25
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• 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

Abstract

An implantable medical device and associated method to determine an optimal control parameter setting for controlling a cardiac therapy that includes a plurality of electrodes, a therapy module to deliver cardiac pacing signals between the plurality of electrodes at a plurality of pacing rates, an admittance measurement module to determine admittance signals associated with each of the plurality of pacing rates, and a control unit to determine, for each pacing rate of the plurality of pacing rates, intervals between admittance signals associated with the pacing rate, compare the determined intervals, and determine a pacing rate of the plurality of pacing rates as an optimal rate for delivering the cardiac therapy in response to the determined intervals.

Claims

1. A medical device for delivering a cardiac therapy, comprising:

a plurality of electrodes;

a therapy module to deliver cardiac pacing signals between the plurality of electrodes at a plurality of pacing rates;

an admittance measurement module to determine admittance signals associated with each of the plurality of pacing rates; and

a control unit configured to determine, for each pacing rate of the plurality of pacing rates, intervals between admittance signals associated with the pacing rate, compare the determined intervals, and determine a pacing rate of the plurality of pacing rates as an optimal rate for delivering the cardiac therapy in response to the determined intervals.

2. The medical device of claim 1, wherein the plurality of pacing rates comprise differing interventricular rates.

3. The medical device of claim 1, the control unit further configured to sense signals along a plurality of ventricular only vectors, wherein the determined admittance signals correspond to the ventricular only vectors.

4. The medical device of claim 3, the control unit further configured to determine a measurement window for determining the admittance signals, wherein determining the measurement window comprises:

determining a minimum peak of the admittance signal as a first endpoint;

determining a maximum peak of the admittance signal as a second endpoint; and

determining the measurement window in response to the first endpoint and the second endpoint.

5. The medical device of claim 3, the control unit further configured to determine, for each of the plurality of ventricular only pacing vectors, a shortest time difference between the determined admittances, compare the determined shortest time differences between the plurality of ventricular only pacing vectors, and determine a pacing rate of the plurality of pacing rates as the optimal rate for delivering the cardiac therapy in response to the comparing.

6. The medical device of claim 5, wherein the plurality of pacing rates comprise differing interventricular rates.

7. The medical device of claim 3, the control unit further configured to determine, for each of the plurality of ventricular only pacing vectors, an amplitude difference between the determined admittances, compare the determined amplitude differences between the plurality of ventricular only pacing vectors, and determine a pacing rate of the plurality of pacing rates as the optimal rate for delivering the cardiac therapy in response to the comparing.

8. The medical device of claim 7, wherein the plurality of pacing rates comprise differing interventricular rates.

9. The medical device of claim 1, the control unit further configured to deliver a signal between a first pair of electrodes of the plurality of electrodes positioned along a left ventricle of a patient'"'"'s heart, and determine a signal sensed between a second pair of electrodes of the plurality of electrodes positioned along the left ventricle of the patient heart.

10. The medical device of claim 1, the control unit further configured to deliver a signal between a first pair of electrodes of the plurality of electrodes positioned to be correlated to right ventricular blood volume, and determine a signal sensed between a second pair of electrodes of the plurality of electrodes positioned to be correlated to left ventricular blood volume.

11. A method of delivering a cardiac therapy, comprising:

delivering cardiac pacing signals at a plurality of pacing rates;

determining admittance signals associated with each of the plurality of pacing rates;

determining, for each pacing rate of the plurality of pacing rates, intervals between admittance signals associated with the pacing rate;

comparing the determined intervals; and

determining a pacing rate of the plurality of pacing rates as an optimal rate for delivering the cardiac therapy in response to the determined intervals.

12. The method of claim 11, wherein the plurality of pacing rates comprise differing interventricular rates.

13. The method of claim 11, further comprising sensing signals along a plurality of ventricular only vectors, wherein the determined admittance signals correspond to the ventricular only vectors.

14. The method of claim 13, further comprising determining a measurement window for determining the admittance signals, wherein determining the measurement window comprises:

determining a minimum peak of the admittance signal as a first endpoint;

determining a maximum peak of the admittance signal as a second endpoint; and

determining the measurement window in response to the first endpoint and the second endpoint.

15. The method of claim 13, further comprising:

determining, for each of the plurality of ventricular only pacing vectors, a shortest time difference between the determined admittances;

comparing the determined shortest time differences between the plurality of ventricular only pacing vectors; and

determining a pacing rate of the plurality of pacing rates as an optimal rate for delivering the cardiac therapy in response to the comparing.

16. The method of claim 15, wherein the plurality of pacing rates comprise differing interventricular rates.

17. The method of claim 13, further comprising:

determining, for each of the plurality of ventricular only pacing vectors, an amplitude difference between the determined admittances;

comparing the determined amplitude differences between the plurality of ventricular only pacing vectors; and

determining a pacing rate of the plurality of pacing rates as an optimal rate for delivering the cardiac therapy in response to the comparing.

18. The method of claim 17, wherein the plurality of pacing rates comprise differing interventricular rates.

19. The method of claim 11, further comprising:

delivering a signal between a first pair of electrodes of the plurality of electrodes positioned along a left ventricle of a patient'"'"'s heart; and

determining a signal sensed between a second pair of electrodes of the plurality of electrodes positioned along the left ventricle of the patient heart.

20. The method of claim 11, further comprising:

delivering a signal between a first pair of electrodes of the plurality of electrodes positioned to be correlated to right ventricular blood volume; and

determining a signal sensed between a second pair of electrodes of the plurality of electrodes positioned to be correlated to left ventricular blood volume.

21. A non-transitory computer readable medium storing instructions which cause a control unit of an implantable medical device to perform a method, the method comprising:

delivering cardiac pacing signals at a plurality of pacing rates;

determining admittance signals associated with each of the plurality of pacing rates;

determining, for each pacing rate of the plurality of pacing rates, intervals between admittance signals associated with the pacing rate;

comparing the determined intervals; and

determining a pacing rate of the plurality of pacing rates as an optimal rate for delivering the cardiac therapy in response to the determined intervals.