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

• US 7,974,695 B2
• Filed: 12/07/2006
• Issued: 07/05/2011
• 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:
  US11/567,933
• Publication Number:
  US 20070179546A1
• Time in Patent Office: 1,671 Days
• Field of Search: 607/9, 607/17, 607/18, 607 23- 25, 607/27
• 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 a 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 and a predetermined mapping of a relationship between the time interval and an optimal AVD that provides a maximum aortic pulse pressure when ventricular pacing pulses are delivered with the AVD; and

delivering the ventricular pacing pulses with the calculated 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 calculating AVD using a linear equation:

AVD=M3·

AX−

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

7. The method of claim 6, further comprising deriving values of M3 and M4 empirically.

8. The method of claim 7, 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.

9. The method of claim 8, wherein M3 is approximately 1.22, and M4 is approximately 132 milliseconds.

10. The method of claim 1, wherein delivering the atrial pacing pulse comprises delivering the atrial pacing pulse from an implantable medical device.

11. The method of claim 10, wherein calculating the AVD comprises calculating the AVD in the implantable medical device.

12. The method of claim 10, wherein calculating the AVD comprises calculating the AVD in a programmer communicatively coupled to the implantable medical device.

13. The method of claim 10, wherein detecting the predetermined pressure event comprises using a sensor of the implantable medical device to detect the predetermined pressure event.

14. The method of claim 1, further comprising:

measuring a further time interval between a sensed atrial event and the predetermined pressure event;

calculating a further AVD based on the further time interval to provide the approximately maximum aortic pulse pressure by delivering further ventricular pacing pulses with the further AVD; and

delivering the ventricular pacing pulses with the AVD and the further ventricular pacing pulses with the further AVD according to a DDD pacing mode.