METHOD AND APPARATUS FOR OPTIMIZING STROKE VOLUME DURING DDD RESYNCHRONIZATION THERAPY USING ADJUSTABLE ATRIO-VENTRICULAR DELAYS

• US 20070179546A1
• Filed: 12/07/2006
• Published: 08/02/2007
• 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: Yu, Yinghong, Ding, Jiang, Spinelli, Julio, Kramer, Andrew
• Granted Patent: US 7,974,695 B2
• Time in Patent Office: Days
• US Class Current: 607/23
• 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 1/3682 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 predetermined pressure event;

measuring a time interval between the delivery of the atrial pacing pulse and the predetermined pressure event;

calculating an atrio-ventricular delay (AVD) based on the time interval to provide an approximately maximum aortic pulse pressure by delivering ventricular pacing pulses with the AVD; and

delivering the ventricular pacing pulses with the AVD.

2. The method of claim 1, wherein detecting the predetermined pressure event comprises detecting the predetermined pressure event from a left atrial pressure.

3. The method of claim 2, wherein detecting the predetermined pressure event comprises detecting an end of a left atrial systolic pressure.

4. The method of claim 1, wherein detecting the predetermined pressure event comprises detecting the predetermined pressure event from a left ventricular pressure.

5. The method of claim 4, wherein detecting the predetermined pressure event comprises detecting a peak of a left ventricular pre-systolic pressure.

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

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

AVD=M3·

AX−

M4, where M3 and M4 are predetermined coefficients and AX is the time interval.

8. The method of claim 7, further comprising deriving values of M3 and M4 empirically.

9. The method of claim 8, wherein deriving the values of M3 and M4 empirically comprises mapping the time interval to an approximately optimal AVD for each of a plurality of patients, the approximately optimal AVD providing for the approximately maximum aortic pulse pressure.

10. The method of claim 9, wherein M3 is approximately 1.22, and M4 is approximately 132 milliseconds.

11. A system, comprising:

a pacing output circuit to deliver atrial pacing pulses and ventricular pacing pulses; and

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

a signal input to receive at least one pressure signal indicative of a predetermined pressure event;

an event detector to detect the predetermined pressure event;

a measurement module to measure a time interval between the delivery of one of the atrial pacing pulses (A) and the predetermined pressure event; and

an AVD calculator adapted to calculate an AVD using the time interval and a predetermined equation relating the time interval to an optimal AVD to provide a maximum aortic pulse pressure by delivering the ventricular pacing pulses with the optimal AVD.

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

13. The system of claim 11, comprising:

an implantable medical device including the pacing output circuit; and

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

14. The system of claim 11, comprising:

an implantable medical device including the pacing output 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.

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

16. The system of claim 11, further comprising a pressure sensor adapted to sense a left atrial pressure, and wherein the event detector is adapted to detect the predetermined pressure event from the left atrial pressure.

17. The system of claim 16, wherein the event detector is adapted to detect an end of a left atrial systolic pressure.

18. The system of claim 11, further comprising a pressure sensor adapted to sense a left ventricular pressure, and wherein the event detector is adapted to detect the predetermined pressure event from the left ventricular pressure.

19. The system of claim 16, wherein the event detector is adapted to detect a peak of a left ventricular pre-systolic pressure.

20. The system of claim 11, wherein the AVD calculator is adapted to calculate the AVD by using a linear equation:

AVD=M3·

AX−

M4, where M3 and M4 are predetermined coefficients and AX is the time interval.

21. A system, comprising:

means for measuring a time interval between a delivery of an atrial pacing pulse and a predetermined pressure event; and

means for calculating an atrio-ventricular delay (AVD) based on the time interval to provide an approximately maximum aortic pulse pressure by delivering ventricular pacing pulses with the AVD.

22. The system of claim 21, further comprising:

means for sensing a pressure signal; and

means for detecting the predetermined pressure event from the pressure signal.

23. The system of claim 22, wherein the means for calculating the AVD comprises means for mapping the AVD to the time interval using a predetermined relationship between the AVD and the time interval.