Method and apparatus for evaluating and optimizing ventricular synchronization

• US 20040172077A1
• Filed: 02/28/2003
• Published: 09/02/2004
• Est. Priority Date: 02/28/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Chinchoy, Edward
• Granted Patent: US 7,269,460 B2
• Time in Patent Office: Days
• US Class Current: 607/17
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/36564 controlled by blood pressure
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

A method and apparatus for determining a metric of cardiac ventricular synchronization and optimizing a cardiac therapy based on the ventricular synchronization metric are provided. A ventricular synchronization metric is determined by: monitoring right and left ventricular pressure; plotting right ventricular pressure as a function of left ventricular pressure to form an RVP-LVP loop; and integrating with respect to direction to determine an area of the RVP-LVP loop which, according to one convention, is mathematically negative during left ventricular led pressure development and is mathematically positive during right ventricular led pressure development. Timing parameters used to control the delivery of cardiac resynchronization therapy or ventricular assist device therapy are adjusted as needed according to the ventricular synchronization metric.

Claims

1. A closed loop method of improving cardiac resynchronization therapy based upon detected physiologic characteristics of a heart, comprising:

measuring a pressure development characteristic of a first ventricle and a second ventricle and based on individual measurements of pressure development for said first ventricle and for said second ventricle during at least one cardiac cycle;

determining whether the first ventricle or the second ventricle relatively leads pressure development and proceeding to the next step if the determination is affirmative or halting the method if the determination is negative; and

adjusting a timing parameter of a first pacing electrode in electrical communication with the first ventricle relative to a second pacing electrode in electrical communication with the second ventricle so that pressure development in the first ventricle and the second ventricle occurs substantially at the same time.

2. A method according to claim 1, wherein measuring pressure development comprises deploying a first pressure transducer in fluid communication with the first ventricle and a second pressure transducer in fluid communication with the second ventricle.

3. A method according to claim 1, wherein the first pacing electrode is adapted to be coupled to a portion of endocardial tissue of the first ventricle.

4. A method according to claim 1, wherein the second pacing electrode is adapted to be coupled to a portion of endocardial tissue of the second ventricle.

5. A method according to claim 1, wherein the first pacing electrode is adapted to be coupled to a portion of epicardial tissue of the first ventricle.

6. A method according to claim 1, wherein the second pacing electrode is adapted to be coupled to a portion of epicardial tissue of the second ventricle.

7. A method according to claim 1, wherein the pressure development of the first ventricle is measured by a pressure transducer disposed within the first ventricle.

8. A method according to claim 1, wherein the pressure development of the second ventricle is measured by a pressure transducer disposed within the second ventricle

9. A method according to claim 1, wherein the pressure development of the first ventricle is measured by a pressure transducer adapted to be disposed within a portion of the coronary sinus or the great cardiac vein.

10. A method according to claim 1, and further comprising a ventricular assist device fluidly coupled to the first ventricle.

11. A method according to claim 10, wherein the pressure development of the first ventricle is measured by a pressure transducer coupled to the ventricle assist device.

12. A method according to claim 1, wherein the pressure development of the first ventricle is measured by a pressure transducer adapted to be coupled to a septal wall portion between the first ventricle and the second venticle.

13. A method according to claim 1, wherein the pressure development of the first ventricle is measured by a pressure transducer adapted to pass through a septal wall portion between the first ventricle and the second venticle.

14. A method according to claim 1, wherein the method is performed by an integrated implantable medical device.

15. A method according to claim 14, wherein said integrated implantable medical device further comprises means for providing telemetry of a set of information to an external computational processing and control engine and wherein said set of information comprises data regarding at least a one of the following:

a pressure development of the first ventricle,

a pressure development characteristic of the second ventricle,

a pressure development characteristic of an ventricular assist device,

a pacing stimulus timing characteristic for a ventricular chamber or an atrial chamber,

a pacing stimulus interval timing characteristic for a ventricular chamber or an atrial chamber,

a withhold pacing stimulus command for a ventricular chamber,

a control sequence for a ventricular assist device.

16. A method according to claim 15, wherein said external computational processing engine further comprises a control system for a ventricular assist device.

17. A method according to claim 1, wherein in lieu of adjusting a timing parameter of a first pacing electrode in electrical communication with the first ventricle relative to a second pacing electrode in electrical communication with the second ventricle so that pressure development in the first ventricle and the second ventricle occurs substantially at the same time, performing the following step:

adjusting the timing of only the first pacing electrode and providing no timing to the second pacing electrode to compensate for the effects of a bundle branch block condition of the second ventricle.

18. A computer readable medium for performing a method of improving cardiac resynchronization therapy based upon detected physiologic characteristics of a heart, comprising:

instructions for measuring a pressure development characteristic of a first ventricle and a second ventricle and based on individual measurements of pressure development for said first ventricle and for said second ventricle during at least one cardiac cycle;

instructions for determining whether the first ventricle or the second ventricle relatively leads pressure development and proceeding to the next step if the determination is affirmative or halting the method if the determination is negative; and

instructions for adjusting a timing parameter of a first pacing electrode in electrical communication with the first ventricle relative to a second pacing electrode in electrical communication with the second ventricle so that pressure development in the first ventricle and the second ventricle occurs substantially at the same time.

19. A method according to claim 18, wherein measuring pressure development comprises deploying a first pressure transducer in fluid communication with the first ventricle and a second pressure transducer in fluid communication with the second ventricle.

20. A method according to claim 18, wherein the first pacing electrode is adapted to be coupled to a portion of endocardial tissue of the first ventricle.

21. A method according to claim 18, wherein the second pacing electrode is adapted to be coupled to a portion of endocardial tissue of the second ventricle.

22. A method according to claim 18, wherein the first pacing electrode is adapted to be coupled to a portion of epicardial tissue of the first ventricle.

23. A method according to claim 18, wherein the second pacing electrode is adapted to be coupled to a portion of epicardial tissue of the second ventricle.

24. A method according to claim 18, wherein the pressure development of the first ventricle is measured by a pressure transducer disposed within the first ventricle.

25. A method for optimizing ventricular synchronization comprising:

measuring a right ventricular pressure and a left ventricular pressure during at least one cardiac cycle;

determining a metric of ventricular synchronization based on the relationship between the measured right ventricular pressure and the measured left ventricular pressure so that said metric compensates for the ventricle leading in pressure development during ventricular asynchrony;

comparing the metric to a predetermined criterion that distinguishes acceptable ventricular synchrony from unacceptable ventricular asynchrony; and

adjusting a therapy when the metric does not meet the criterion for acceptable ventricular synchrony.

26. A closed loop method of improving cardiac resynchronization therapy based upon detected physiologic characteristics of a heart, comprising:

means for measuring a pressure development characteristic of a first ventricle and a second ventricle and based on individual measurements of pressure development for said first ventricle and for said second ventricle during at least one cardiac cycle;

means for determining whether the first ventricle or the second ventricle relatively leads pressure development and proceeding to the next step if the determination is affirmative or halting the method if the determination is negative; and

means for adjusting a timing parameter of a first pacing electrode in electrical communication with the first ventricle relative to a second pacing electrode in electrical communication with the second ventricle so that pressure development in the first ventricle and the second ventricle occurs substantially at the same time.

27. A method according to claim 26, wherein measuring pressure development comprises deploying a first pressure transducer in fluid communication with the first ventricle and a second pressure transducer in fluid communication with the second ventricle.

28. A method according to claim 26, wherein the first pacing electrode is adapted to be coupled to a portion of endocardial tissue of the first ventricle.

29. A method according to claim 26, wherein the second pacing electrode is adapted to be coupled to a portion of endocardial tissue of the second ventricle.

30. A method according to claim 26, wherein the first pacing electrode is adapted to be coupled to a portion of epicardial tissue of the first ventricle.

31. A method according to claim 26, wherein the second pacing electrode is adapted to be coupled to a portion of epicardial tissue of the second ventricle.

32. A method according to claim 26, wherein the pressure development of the first ventricle is measured by a pressure transducer disposed within the first ventricle.