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

• US 20030144703A1
• Filed: 12/09/2002
• Published: 07/31/2003
• Est. Priority Date: 05/08/1998
• Status: Active Grant

• 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.
• Granted Patent: US 7,110,817 B2
• Time in Patent Office: Days
• US Class Current: 607/17
• 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 synchorny 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 system, comprising:

a signal input to receive at least one cardiac signal indicative of cardiac events including at least one atrial event and one ventricular event;

an event detector, coupled to the signal input, to detect the at least one atrial event and one ventricular event;

a measurement module, coupled to the event detector, to measure an atrio-ventricular time interval (AV) between an atrial event and a ventricular event of the at least one atrial event and one ventricular event; and

an atrio-ventricular delay (AVD) calculator coupled to the measurement module, the AVD calculator adapted to calculate an AVD based on the AV to provide an approximately maximum positive rate of left ventricular pressure change during systole, LV+dp/dt, by delivering ventricular pacing pulses with the AVD.

2. The system of claim 1, 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.

3. The system of claim 2, further comprising a memory circuit to store N1 and N2.

4. The system of claim 1, further comprising an implantable device including a therapy circuit adapted to deliver the ventricular pacing pulses with the AVD.

5. The system of claim 4, wherein the implantable device comprises the signal input, the event detector, the measurement module, and the AVD calculator.

6. The system of claim 4, furthering comprising a programmer communicatively coupled to the implanted device via a telemetry link, the programmer including the signal input, the event detector, the measurement module, and the AVD calculator.

7. The system of claim 4, wherein the implantable device comprises the signal input, the event detector, and the measurement module, and furthering comprising a programmer communicatively coupled to the implanted device via a telemetry link, the programmer including the AVD calculator.

8. The system of claim 4, wherein the implantable device comprises the signal input, and the event detector, and furthering comprising a programmer communicatively coupled to the implanted device via a telemetry link, the programmer including the measurement module and the AVD calculator.

9. 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 to provide an approximately maximum positive rate of left ventricular pressure change during systole, LV+dp/dt, by delivering ventricular pacing pulses with the AVD; and

delivering the ventricular pacing pulses with the AVD.

10. The method of claim 9, wherein detecting the intrinsic ventricular event comprises detecting an intrinsic ventricular contraction from a cardiac signal sensed from a right ventricle.

11. The method of claim 9, wherein detecting the intrinsic ventricular event comprises detecting an intrinsic ventricular contraction from a cardiac signal sensed from a left ventricle.

12. The method of claim 9, wherein calculating the AVD comprises mapping the AVD to the AV using a predetermined relationship between the AVD and the AV.

13. The method of claim 9, wherein calculating the AVD comprises calculating AVD using a linear equation:

AVD=N1·

AV−

N2, where N1 and N2 are predetermined coefficients.

14. The method of claim 13, further comprising deriving values of N1 and N2 empirically.

15. The method of claim 14, 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.

16. The method of claim 15, wherein N1 is approximately 0.82, and N2 is approximately 112 milliseconds.

17. The method of claim 15, wherein N1 is approximately 1.0, and N2 is approximately 159 milliseconds.

18. A computer-readable medium having computer-executable instructions to cause a computer or computer-based system to perform a method comprising:

receiving an atrio-ventricular time interval (AV) between an atrial event and a ventricular event; and

calculating an atrio-ventricular delay (AVD) based on the AV to provide an approximately maximum positive rate of left ventricular pressure change during systole, LV+dp/dt, by delivering ventricular pacing pulses with the AVD.

19. The computer-readable medium of claim 18, wherein receiving the AV comprises receiving a time interval between an intrinsic atrial contraction and an intrinsic ventricular contraction.

20. The computer-readable medium of claim 18, wherein receiving the AV comprises receiving a time interval between a delivery of an atrial pacing pulse and an intrinsic ventricular contraction.

21. The computer-readable medium of claim 18, wherein calculating the AVD comprises calculating the AVD by using an equation:

AVD=N1·

AV−

N2, where N1 and N2 are predetermined coefficients.

22. The computer-readable medium of claim 18, wherein the method further comprises measuring the AV.

23. The computer-readable medium of claim 22, wherein the method further comprises receiving event markers representing the atrial event and the ventricular event.

24. The computer-readable medium of claim 22, wherein the method further comprises detecting at least one of the atrial event and the ventricular event.

25. The computer-readable medium of claim 24, wherein the method further comprises receiving at least one cardiac signal indicative of the atrial event and the ventricular event.