Method and apparatus for determining an efficacious atrioventricular delay interval

• US 7,715,917 B2
• Filed: 12/03/2004
• Issued: 05/11/2010
• Est. Priority Date: 12/03/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Hilpisch, Kathryn E., Chinchoy, Edward, Mullen, Thomas J., Sheth, Nirav V., Burnes, John E.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US11/004,543
• Publication Number:
  US 20050149137A1
• Time in Patent Office: 1,985 Days
• Field of Search: 607/25, 607/27, 607/9, 607/14
• US Class Current: 607/25
• 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 1/368 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
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation

Abstract

Determining an optimal atrioventricular interval is of interest for proper delivery of cardiac resynchronization therapy. Although device optimization is gradually and more frequently being performed through a referral process with which the patient undergoes an echocardiographic optimization, the decision of whether to optimize or not is still generally reserved for the implanting physician. Recent abstracts have suggested a formulaic approach for setting A-V interval based on intrinsic electrical sensing, that may possess considerable appeal to clinicians versus a patient average nominal A-V setting of 100 ms. The present invention presents a methods of setting nominal device settings based on entering patient cardiac demographics to determine what A-V setting may be appropriate. The data is based on retrospective analysis of the MIRACLE trial to determine what major factors determined baseline A-V settings.

Claims

1. A system for providing optimized cardiac chamber resynchronization therapy (CRT) to a patient, comprising:

means for obtaining at least one of an inter-atrial delay value and an intra-atrial delay value for a subject; and

means for utilizing the at least one of the inter-atrial delay value and the intra-atrial delay value to set an operative atrio-ventricular (A-V) delay that enhances the hemodynamic effects of the CRT delivery.

2. A system according to claim 1 further comprising:

means for programming a cardiac pacing therapy which includes the operative A-V delay.

3. A system according to claim 1, wherein the means for obtaining includes at least one of an echocardiographic apparatus and an electrocardiogram apparatus.

4. A system according to claim 1, wherein the means for obtaining comprises a pair of electrodes adapted to be disposed in operative electrical communication with the atrial chambers of a heart.

5. A system according to claim 1, wherein the obtaining means for comprises means for measuring P-wave width.

6. A method for providing optimized cardiac chamber resynchronization therapy (CRT) to a patient, comprising:

obtaining at least one of an inter-atrial delay value and an intra-atrial delay value of a patient; and

programming an operative A-V delay delay correlated to the at least one of the inter-atrial delay value and the intra-atrial delay value and to enhance the hemodynamic effects of the CRT delivery.

7. A method according to claim 6, further comprising:

programming a inter-ventricular (V-V) pacing delay that corresponds to the operative A-V delay delay.

8. A method according to claim 6, wherein the obtaining step is performed using one of an electrocardiogram apparatus and an echocardiographic apparatus.

9. A method according to claim 6, wherein the obtaining step comprises employing a pair of electrodes disposed in operative electrical communication with at least one of the atria of the patient'"'"'s heart.

10. A method according to claim 6, wherein the obtaining step comprises measuring P-wave width.

11. A computer readable medium for storing executable instructions for providing optimized cardiac chamber synchronization to a patient during delivery of a cardiac pacing therapy, comprising:

instructions encoded into a computer readable medium for obtaining at least one of an inter-atrial delay metric and an intra-atrial delay metric; and

instructions encoded into the computer readable medium for correlating the at least one of the inter-atrial delay metric and the intra-atrial delay metric to a physiologically optimized atrio-ventricular (A-V) delay to enhance the hemodynamic effects of the CRT delivery.

12. A medium according to claim 11, further comprising:

instructions encoded into the computer readable medium for programming a cardiac pacing therapy utilizing the operative A-V delay delay.

13. A medium according to claim 11, wherein the instructions for obtaining comprise instructions for obtaining P-wave width.

14. A method or providing optimized cardiac chamber resynchronization therapy (CRT) to a patient using a cardiac pacemaker, comprising:

delivering cardiac pacing using an initial A-V delay delay;

measuring an inter-atrial delay during the pacing delivered using the initial A-V delay delay;

comparing the inter-atrial delay to a predetermined threshold; and

programming the pacemaker to employ an operative A-V delay delay incremented from the initial A-V delay delay in response to the inter-atrial delay exceeding the threshold and the programming the pacemaker to employ an operative A-V delay delay unchanged from the initial A-V delay delay in response to the inter-atrial delay not exceeding the threshold.

15. The method of claim 14 wherein measuring the inter-atrial delay comprises measuring P-wave duration.

16. The method of claim 14 further comprising:

delivering the CRT using the operative A-V delay delay;

measuring a left ventricular end diastolic volume (LVEDV) during the CRT using the operative A-V delay delay;

comparing the LVEDV to a predetermined value; and

programming a next operative A-V delay delay to a decremented delay from the operative A-V delay delay in response to the LVEDV exceeding the threshold value and leaving the operative A-V delay delay unchanged if the LVEDV does not exceed the threshold value.