PREDICTING CHRONIC OPTIMAL A-V INTERVALS FOR BIVENTRICULAR PACING VIA OBSERVED INTER-ATRIAL DELAY

• US 20080027488A1
• Filed: 07/26/2006
• Published: 01/31/2008
• Est. Priority Date: 07/26/2006
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Coles, James A., Ujhelyi, Michael R., Levin, Vadim, Razavi, Mehdi
• Granted Patent: US 7,877,144 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/4884 inducing physiological or psychological stress, e.g. applications for stress testing
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 2001/0585 Coronary sinus electrodes

Abstract

Herein provided are methods for optimizing the atrio-ventricular (A-V) delay for efficacious delivery of cardiac resynchronization therapy. The A-V delay is set such that pacing-induced left ventricular contraction occurs following completion of left atrial (LA) contraction. This maximizes left ventricular filling (preload) which theoretically results in optimal LV contraction via the Frank-Starling mechanism. In CRT devices, the programmed A-V delay starts with detection of electrical activity in the right atrium (RA). Thus, a major component of the A-V delay is the time required for inter-atrial conduction time (IACT) from the RA to the LA. This IACT can be measured during implantation as the time from the atrial lead stimulation artifact to local electrograms in a coronary sinus (CS) catheter. Assuming that the beginning of LA contraction closely corresponds with the beginning of LA electrical activity, the optimal AV delay should be related to the time between the start of RA electrical activity and the start of LA electrical activity plus the duration of LA atrial contraction. Thus the inventors hypothesized that during atrial pacing the IACT measured at implantation correlated with the echocardiographically defined optimal paced AV delay (PAV).

Claims

1. A method for programming an atrio-ventricular (A-V) delay interval for a bi-ventricular implantable pulse generator, comprising:

determining an inter-atrial conduction time (IACT) between an evoked depolarization of a right atrium (RA) and a conducted depolarization of a left atrium (LA);

calculating an atrio-ventricular (AV) delay interval based upon the IACT; and

subsequently delivering for at least one cardiac cycle a bi-ventricular pacing therapy to a right ventricle (RV) and to a left ventricle (LV) upon expiration of the calculated AV delay interval.

2. A method according to claim 1, wherein the calculating step comprises:

adding about 100 milliseconds to the IACT value and reducing the added value by about 31 percent.

3. A method according to claim 2, wherein the step of determining the IACT comprises stimulating the RA and sensing conducted depolarization of the LA via a bi-polar electrode pair deployed upon an acutely implantable catheter.

4. A method according to claim 3, wherein the catheter comprises one of an electrophysiology (EP) catheter and a chronically implantable medical electrical lead having at least four discretely addressable electrodes operatively coupled to a distal portion thereof.

5. A method according to claim 4, wherein the EP catheter is adapted for deployment via a guiding sheath portion.

6. A method according to claim 4, wherein the EP catheter is adapted for deployment via the coronary sinus (CS) and into a portion of a great vein.

7. A method according to claim 6, wherein the portion of the great vein comprises a posterolateral portion of the great vein.

8. A method according to claim 1, further comprising an external pulse generator and a medical electrical lead, and wherein the generator coupled to the lead is adapted to initiate the evoked depolarization of the RA.

9. An apparatus for programming an atrio-ventricular (A-V) delay interval for a bi-ventricular implantable pulse generator, comprising:

means for determining an inter-atrial conduction time (IACT) between an evoked depolarization of a right atrium (RA) and a conducted depolarization of a left atrium (LA);

means for calculating an atrio-ventricular (AV) delay interval based upon the IACT; and

means for subsequently delivering for at least one cardiac cycle a bi-ventricular pacing therapy to a right ventricle (RV) and to a left ventricle (LV) upon expiration of the calculated AV delay interval.

10. An apparatus according to claim 9, wherein the means for calculating further includes adding about 100 milliseconds to the IACT value and reducing the added value by about 31 percent.

11. An apparatus according to claim 10, wherein the mean for determining the IACT further includes means for stimulating the RA and means for sensing conducted depolarization of the LA via a bi-polar electrode pair deployed upon an acutely implantable catheter.

12. An apparatus according to claim 11, wherein the catheter comprises an electrophysiology (EP) catheter having at least four discretely addressable electrodes operatively coupled to a distal portion thereof.

13. An apparatus according to claim 12, wherein the EP catheter is adapted for deployment via a guiding sheath portion.

14. An apparatus according to claim 12, wherein the EP catheter is adapted for deployment via the coronary sinus (CS) and into a portion of a great vein.

15. An apparatus according to claim 14, wherein the portion of the great vein comprises a posterolateral portion of the great vein.

16. An apparatus according to claim 9, further comprising an external pulse generator and a medical electrical lead, and wherein the generator coupled to the lead is adapted to initiate the evoked depolarization of the RA.

20. A medium according to claim 11, wherein the catheter comprises an electrophysiology (EP) catheter having at least four discretely addressable electrodes operatively coupled to a distal portion thereof.

17. A computer readable medium for storing executable instructions for performing a method of programming an atrio-ventricular (A-V) delay interval for a bi-ventricular implantable pulse generator, comprising:

instructions for determining an inter-atrial conduction time (IACT) between an evoked depolarization of a right atrium (RA) and a conducted depolarization of a left atrium (LA);

instructions for calculating an atrio-ventricular (AV) delay interval based upon the IACT; and

instructions for subsequently delivering for at least one cardiac cycle a bi-ventricular pacing therapy to a right ventricle (RV) and to a left ventricle (LV) upon expiration of the calculated AV delay interval.

18. A medium according to claim 17, wherein the instructions for calculating further includes adding about 100 milliseconds to the IACT value and reducing the added value by about 31 percent.

19. A medium according to claim 18, wherein the instructions for determining the IACT further includes instructions for stimulating the RA and instructions sensing conducted depolarization of the LA via a bi-polar electrode pair deployed upon an acutely implantable catheter.