Method and apparatus for monitoring and optimizing atrial function

1. A method for use in an implantable medical device, comprising:

sensing a signal corresponding to ventricular wall acceleration during a ventricular filling phase; and

determining a metric of atrial function using the ventricular wall acceleration signal sensed during the ventricular filling phase, wherein sensing the ventricular wall acceleration signal includes sensing a signal corresponding to left ventricular wall acceleration.

2. A method according to claim 1 wherein the medical device comprises a cardiac pacemaker, and further comprising:

delivering pacing pulses on expirations of pacing intervals; and

adjusting durations of the pacing intervals responsive to the determined metric of atrial function.

3. A method according to claim 1 wherein the medical device comprises a cardiac pacemaker, and further comprising:

delivering ventricular pacing pulses on expirations of AV intervals; and

adjusting durations of the AV intervals responsive to the determined metric of atrial function.

4. A method for use in an implantable medical device, comprising:

sensing a signal corresponding to ventricular wall acceleration during a ventricular filling phase; and

determining a metric of atrial function using the ventricular wall acceleration signal sensed during the ventricular filling phase, wherein determining a metric of atrial function includes detecting a first ventricular filling phase peak during the ventricular filling phase and detecting if a second ventricular filling phase peak during the ventricular filling phase follows the first ventricular filling phase peak.

5. A method according to claim 4 wherein the medical device comprises a cardiac pacemaker, and further comprising:

delivering pacing pulses on expirations of pacing intervals; and

adjusting durations of the pacing intervals responsive to the detection of a second ventricular filling phase peak.

6. A method according to claim 4 wherein the medical device comprises a cardiac pacemaker, and further comprising:

delivering ventricular pacing pulses on expirations of AV intervals; and

adjusting durations of the AV intervals responsive to the detection of a second ventricular filling phase peak.

7. A method for use in an implantable medical device, comprising:

sensing a signal corresponding to ventricular wall acceleration during a ventricular filling phase; and

determining a metric of atrial function using the ventricular wall acceleration signal sensed during the ventricular filling phase, wherein determining a metric of atrial function includes determining a time interval between a first ventricular filling phase peak and a second ventricular filling phase peak during the ventricular filling phase.

8. A method according to claim 7 wherein the medical device comprises a cardiac pacemaker, and further comprising:

delivering pacing pulses on expirations of pacing intervals; and

adjusting durations of the pacing intervals responsive to the determined time interval.

9. A method according to claim 7 wherein the medical device comprises a cardiac pacemaker, and further comprising:

delivering ventricular pacing pulses on expirations of AV intervals; and

adjusting durations of the AV intervals responsive to the determined time interval.

10. An implantable medical device comprising:

means for generating a signal corresponding to ventricular wall acceleration during a ventricular filling phase;

means for receiving the signal from the generating means;

means for deriving a metric of atrial function using the acceleration signal sensed during the ventricular filling phase; and

means for storing the atrial function metric, wherein the means for deriving the atrial function metric includes means for detecting a first ventricular filling phase peak during the ventricular filling phase and means for detecting if a second ventricular filling phase peak during the ventricular filling phase follows the first ventricular filling phase peak.

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

means for delivering pacing pulses on expirations of pacing intervals; and

means for adjusting durations of the pacing intervals responsive to the detection of a second ventricular filling phase peak.

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

means for delivering ventricular pacing pulses on expirations of AV intervals; and

means for adjusting durations of the AV intervals responsive to the detection of a second ventricular filling phase peak.

13. An implantable medical device comprising:

means for generating a signal corresponding to ventricular wall acceleration during a ventricular filling phase;

means for receiving the signal from the generating means;

means for deriving a metric of atrial function using the acceleration signal sensed during the ventricular filling phase; and

means for storing the atrial function metric, wherein the means for deriving the atrial function metric includes means for determining a time interval between a first ventricular filling phase peak during the ventricular filling phase and a second ventricular filling phase peak during the ventricular filling phase.

14. A non-transitory computer readable medium storing a set of instructions which when implemented in an implantable medical device system cause the system to:

sense a signal corresponding to ventricular wall acceleration during a ventricular filling phase;

determine a metric of atrial function using the ventricular wall acceleration signal sensed during the ventricular filling phase, wherein the instructions for determining a metric of atrial function include:

instructions for detecting a first ventricular filling phase peak during the ventricular filling phase; and

instructions for detecting if a second ventricular filling phase peak during the ventricular filling phase follows the first ventricular filling phase peak.

15. A medium according to claim 14 , further storing instructions which when implemented in an implantable medical device system cause the system to:

deliver pacing pulses on expirations of pacing intervals; and

adjust durations of the pacing intervals responsive to the determined time interval.

16. A medium according to claim 14 , further storing instructions which when implemented in an implantable medical device system cause the system to:

deliver ventricular pacing pulses on expirations of AV intervals; and

adjust durations of the AV intervals responsive to the determined time interval.

17. A non-transitory computer readable medium storing a set of instructions which when implemented in an implantable medical device system cause the system to:

sense a signal corresponding to ventricular wall acceleration during a ventricular filling phase; and

determine a metric of atrial function using the ventricular wall acceleration signal sensed during the ventricular filling phase, wherein the instructions for determining a metric of atrial function include instructions for determining a time interval between a first ventricular filling phase peak during the ventricular filling phase and a second ventricular filling phase peak during the ventricular filling phase.

18. A medium according to claim 17 , further storing instructions which when implemented in an implantable medical device system cause the system to:

deliver pacing pulses on expirations of pacing intervals; and

adjust durations of the pacing intervals responsive to the detection of a second ventricular filling phase peak.

19. A medium according to claim 17 , further storing instructions which when implemented in an implantable medical device system cause the system to:

deliver ventricular pacing pulses on expirations of AV intervals; and

adjust durations of the AV intervals responsive to the detection of a second ventricular filling phase peak.