Variable shortening of AV delay for treatment of cardiac disease

• US 20090082823A1
• Filed: 09/25/2007
• Published: 03/26/2009
• Est. Priority Date: 09/25/2007
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Shuros, Allan C., Hopper, Donald L., Arcot-Krishnamurthy, Shantha
• Granted Patent: US 8,972,007 B2
• Time in Patent Office: Days
• US Class Current: 607/17
• 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 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36535 controlled by body position or posture
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay
• CPC Class Codes: A61N 1/3688 configured for switching the pacing mode, e.g. from AAI to DDD

Abstract

An implantable pacing device for delivering ventricular pacing may be configured to intermittently and variably reduce the AV delay interval used in an atrial triggered pacing mode in a manner that simulates exercise. The device may be programmed to intermittently switch to and from a variably shortened AV delay mode according to defined entry and exit conditions.

Claims

1. A cardiac device, comprising:

one or more ventricular pacing channels for delivering pacing pulses to one or more ventricular sites;

an atrial sensing channel;

a controller programmed to operate the device in either a normal operating mode or variably shortened AV delay (VSAVD) mode;

wherein, in the VSAVD mode, the controller is programmed to deliver paces to the one or more ventricular sites using an atrial triggered pacing mode that decreases atrial preloading of the ventricles as compared with the normal operating mode using an AV delay that varies during the VSAVD mode; and

,

wherein the controller is programmed to intermittently switch from the normal operating mode to the VSAVD mode according to a one or more specified entry conditions and switch from the VSAVD mode to the normal operating mode according to one or more specified exit conditions.

2. The device of claim 1 wherein the VSAVD mode includes pacing a ventricular site using an atrial triggered pacing mode with an AV delay made to vary within a range selected from a value shorter than a patient'"'"'s measured intrinsic AV delay interval, a value shorter than a nominal intrinsic AV delay interval based upon demographic data, or a value shorter than a nominal intrinsic AV delay interval based upon hemodynamic measurements.

3. The device of claim 2 wherein the range is 10-80% of a value selected from the patient'"'"'s measured intrinsic AV delay interval, a nominal intrinsic AV delay interval based upon demographic data, or a nominal intrinsic AV delay interval based upon hemodynamic measurements.

4. The device of claim 1 wherein the controller is programmed to vary the AV delay during the VSAVD mode according to a predetermined sequence of values.

5. The device of claim 1 wherein the controller is programmed to vary the AV delay during the VSAVD mode according to a pseudo-random sequence of values.

6. The device of claim 1 wherein the controller is programmed to vary the AV delay during the VSAVD mode according to one or more measured triggering parameters that trigger variation of the AV delay.

7. The device of claim 6 wherein the AV delay is constrained to remain within a reduced AV delay range while made to vary during the VSAVD mode.

8. The device of claim 6 wherein the one or more measured triggering parameters may be selected from previous PP intervals, previous RR intervals, measured heart rate variability, patient posture as detected by an accelerometer, respiratory inspiration and expiration as detected by a minute ventilation sensor, blood pressure, heart sounds, and cardiac stroke volume as measured by an impedance sensor.

9. The device of claim 6 further comprising a respiratory sensor and wherein, during the VSAVD mode, the controller is programmed to shorten the AV delay with inspiration and lengthen the AV delay with expiration.

10. The device of claim 1 wherein the controller is programmed to use different pacing channels in the VSAVD mode than in the normal operating mode.

11. A method for operating a cardiac pacing device, comprising:

delivering pacing pulses to one or more ventricular sites in an atrial triggered pacing mode with an AV delay;

operating the device in either a normal operating mode or variably shortened AV delay (VSAVD) mode;

in the VSAVD mode, delivering paces to the one or more ventricular sites using an atrial triggered pacing mode that decreases atrial preloading of the ventricles as compared with the normal operating mode using an AV delay that varies during the VSAVD mode; and

,

intermittently switching from the normal operating mode to the VSAVD mode according to a one or more specified entry conditions and switching from the VSAVD mode to the normal operating mode according to one or more specified exit conditions.

12. The method of claim 11 wherein the VSAVD mode includes pacing a ventricular site using an atrial triggered pacing mode with an AV delay made to vary within a range selected from a value shorter than a patient'"'"'s measured intrinsic AV delay interval, a value shorter than a nominal intrinsic AV delay interval based upon demographic data, or a value shorter than a nominal intrinsic AV delay interval based upon hemodynamic measurements.

13. The method of claim 12 wherein the range is 10-80% of a value selected from the patient'"'"'s measured intrinsic AV delay interval, a nominal intrinsic AV delay interval based upon demographic data, or a nominal intrinsic AV delay interval based upon hemodynamic measurements.

14. The method of claim 11 further comprising varying the AV delay during the VSAVD mode according to a predetermined sequence of values.

15. The method of claim 11 further comprising varying the AV delay during the VSAVD mode according to a pseudo-random sequence of values.

16. The method of claim 11 further comprising varying the AV delay during the VSAVD mode according to one or more measured triggering parameters that trigger variation of the AV delay.

17. The method of claim 16 wherein the AV delay is constrained to remain within a reduced AV delay range while made to vary during the VSAVD mode.

18. The method of claim 16 wherein the one or more measured triggering parameters may be selected from previous PP intervals, previous RR intervals, measured heart rate variability, patient posture as detected by an accelerometer, respiratory inspiration and expiration as detected by a minute ventilation sensor, blood pressure, heart sounds, and cardiac stroke volume as measured by an impedance sensor.

19. The method of claim 16 further comprising, during the VSAVD mode, shortening the AV delay with inspiration and lengthening the AV delay with expiration.

20. The method of claim 11 further comprising using different pacing channels in the VSAVD mode than in the normal operating mode.