Method and apparatus for optimizing ventricular synchrony during DDD resynchronization therapy using adjustable atrio-ventricular delays

• US 7,529,585 B2
• Filed: 08/08/2006
• Issued: 05/05/2009
• Est. Priority Date: 05/08/1998
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Spinelli, Julio C., Yu, Yinghong, Ding, Jiang, Kramer, Andrew P.
• Primary Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US11/463,176
• Publication Number:
  US 20060276847A1
• Time in Patent Office: 1,001 Days
• Field of Search: 607/9, 607/17, 607 23- 25, 607/27
• US Class Current: 607/9
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• 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 1/36564 controlled by blood pressure
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay

Abstract

A pacing system for providing optimal hemodynamic cardiac function for parameters such as ventricular synchrony or contractility (peak left ventricle pressure change during systole or LV+dp/dt), or stroke volume (aortic pulse pressure) using system for calculating atrio-ventricular delays for optimal timing of a ventricular pacing pulse. The system providing an option for near optimal pacing of multiple hemodynamic parameters. The system deriving the proper timing using electrical or mechanical events having a predictable relationship with an optimal ventricular pacing timing signal.

Claims

1. A method, comprising:

delivering an atrial pacing pulse;

detecting an intrinsic ventricular event;

measuring an atrio-ventricular time interval (AV) between the delivery of the atrial pacing pulse and the ventricular event;

calculating an atrio-ventricular delay (AVD) based on the AV and a predetermined equation relating the AV to an optimal AVD associated with an approximately maximum positive rate of left ventricular pressure change during systole, LV+dp/dt; and

delivering ventricular pacing pulses with the AVD.

2. The method of claim 1, wherein detecting the intrinsic ventricular event comprises detecting an intrinsic ventricular contraction from a cardiac signal sensed from a right ventricle.

3. The method of claim 1, wherein detecting the intrinsic ventricular event comprises detecting an intrinsic ventricular contraction from a cardiac signal sensed from a left ventricle.

4. The method of claim 1, wherein calculating the AVD comprises mapping the AVD to the AV using a predetermined relationship between the AVD and the AV.

5. The method of claim 1, wherein calculating the AVD comprises calculating AVD using a linear equation:

AVD=N1·

AV−

N2, where N1 and N2 are predetermined coefficients.

6. The method of claim 5, further comprising deriving values of N1 and N2 empirically.

7. The method of claim 6, wherein deriving the values of N1 and N2 empirically comprises mapping the AV to an approximately optimal AVD for each of a plurality of patients, the approximately optimal AVD providing for the approximately maximum LV+dp/dt.

8. The method of claim 7, wherein N1 is approximately 0.82, and N2 is approximately 112 milliseconds.

9. The method of claim 7, wherein N1 is approximately 1.0, and N2 is approximately 159 milliseconds.

10. A system, comprising:

a pacing output circuit to deliver an atrial pacing pulse;

a sensing circuit to sense a cardiac signal indicative of an intrinsic ventricular event; and

an atrio-ventricular delay (AVD) calculation system, including;

a signal input to receive the cardiac signal;

an event detector to detect the intrinsic ventricular event;

a measurement module to measure an atrio-ventricular time interval (AV) between the delivery of the atrial pacing pulse and the intrinsic ventricular event; and

an AVD calculator adapted to calculating the AVD using the AV and a predetermined equation relating the AV to an optimal AVD to provide an approximately maximum positive rate of left ventricular pressure change during systole, LV+dp/dt, wherein the pacing output circuit is adapted to deliver ventricular pacing pulses with the optimal AVD.

11. The system of claim 10, comprising an implantable medical device including the pacing output circuit, the sensing circuit, and the AVD calculation system.

12. The system of claim 10, comprising:

an implantable medical device including the pacing output circuit and the sensing circuit; and

a programmer, communicatively coupled to the implantable medical device, including the AVD calculation system.

13. The system of claim 10, comprising:

an implantable medical device including the pacing output circuit and the sensing circuit; and

a programmer communicatively coupled to the implantable medical device,

wherein the implantable medical device and the programmer each include at least a portion of the AVD calculation system.

14. The system of claim 13, wherein the implantable medical device comprises the signal input, the event detector, and the measurement module, and the programmer comprises the AVD calculator.

15. The system of claim 10, wherein the AVD calculator is adapted to calculate the AVD by using an equation:

AVD=N1·

AV−

N2, where N1 and N2 are predetermined coefficients.

16. The system of claim 15, wherein the AVD calculation system further comprises a memory circuit to store N1 and N2.

17. A system, comprising:

means for measuring an atrio-ventricular time interval (AV) between an atrial pacing pulse and an intrinsic ventricular event;

means for calculating an atrio-ventricular delay (AVD) based on the AV and a predetermined equation relating the AV to an optimal AVD associated with an approximately maximum positive rate of left ventricular pressure change during systole, LV+dp/dt; and

means for delivering ventricular pacing pulses with the AVD.

18. The method of claim 17, further comprising means for detecting the intrinsic ventricular event from a cardiac signal sensed from a right ventricle.

19. The method of claim 17, further comprising means for detecting the intrinsic ventricular event from a cardiac signal sensed from a left ventricle.

20. The method of claim 17, wherein the means for calculating the AVD comprises means for mapping the AVD to the AV using a predetermined relationship between the AVD and the AV.