REVERSE HYSTERESIS AND MODE SWITCHING FOR INTERMITTENT PACING THERAPY

• US 20100121402A1
• Filed: 11/09/2009
• Published: 05/13/2010
• Est. Priority Date: 11/10/2008
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Dong, Yanting, Lee, Kent, Shuros, Allan C., Arcot-Krishnamurthy, Shantha, Seim, Gary T., Whitehouse, David L.
• Granted Patent: US 8,929,983 B2
• Time in Patent Office: Days
• 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 1/3688 configured for switching the pacing mode, e.g. from AAI to DDD

Abstract

Cardioprotective pre-excitation pacing may be applied to stress or de-stress a particular myocardial region delivering of pacing pulses in a manner that causes a dyssynchronous contraction. Such dyssynchronous contractions are responsible for the desired cardioprotective effects of pre-excitation pacing. A method and device for applying reverse hysteresis and mode switching to the delivery of such cardioprotective pacing are described.

Claims

1. A cardiac device, comprising:

one or more sensing amplifiers for sensing electrical cardiac activity through one or more sensing channels;

one or more pulse generators for delivering pacing pulses to one or more myocardial sites through one or more pacing channels;

a controller programmed to operate the device in either a normal operating mode or an intermittent pacing therapy (IPT) mode;

wherein, in the IPT mode, the controller is programmed to deliver paces to the one or more myocardial sites using a pacing mode that results in some degree of dyssynchrony as compared with the normal operating mode;

wherein the controller is programmed to intermittently switch to the IPT mode and, upon switching to the IPT mode, adjust the value of an escape interval used to deliver pacing pulses to the one or more myocardial sites to an IPT value; and

,

wherein, when operating in the IPT mode, the controller is further programmed to monitor for senses that inhibit pacing pulses to the one or more myocardial sites and shorten the escape interval used to deliver pacing pulses to the one or more myocardial sites if a specified number of such senses have occurred.

2. The device of claim 1 wherein the controller is further programmed to exit the IPT mode if the escape interval has been shortened to a specified minimum limit value.

3. The device of claim 1 wherein the controller is further programmed to continue operating in the IPT mode without shortening the escape interval if the escape interval has been shortened to a specified minimum limit value.

4. The device of claim 1 wherein the escape interval is a ventricular escape interval.

5. The device of claim 1 wherein the escape interval is an atrial escape interval.

6. The device of claim 1 wherein the escape interval is an AV delay used in an atrial tracking pacing mode.

7. The device of claim 1 wherein the controller is programmed to set the value of the escape interval to a programmed IPT value.

8. The device of claim 1 wherein the controller is programmed to measure one or more intrinsic cardiac intervals and set the value of the escape interval to an IPT value as a function of the intrinsic cardiac interval measurement.

9. The device of claim 1 wherein the controller is programmed to shorten the escape interval by a programmed amount of time.

10. The device of claim 1 wherein the controller is programmed to shorten the escape interval by a programmed percentage of the value of the escape interval currently being used.

11. A cardiac device, comprising:

one or more sensing amplifiers for sensing electrical cardiac activity through one or more sensing channels;

one or more pulse generators for delivering pacing pulses to one or more myocardial sites through one or more pacing channels;

a controller programmed to operate the device in either a normal operating mode or an intermittent pacing therapy (IPT) mode;

wherein, in the IPT mode, the controller is programmed to deliver paces to the one or more ventricular sites using a pacing mode that results in some degree of ventricular dyssynchrony as compared with the normal operating mode;

wherein the controller is programmed to intermittently switch to the IPT mode in accordance with a predetermined duty cycle;

wherein the controller is programmed to measure a present normal sinus rhythm (NSR);

wherein the controller is programmed to initially use a non-atrial tracking ventricular pacing mode with an IPT LRL set above the NSR for the IPT mode unless the NSR is above a specified limit value, in which case an atrial tracking ventricular pacing mode is used for the IPT mode.

12. The device of claim 11 wherein the controller is programmed to:

when operating in the IPT mode using non-atrial tracking pacing, monitor for senses that inhibit pacing pulses to the one or more myocardial sites and increase the IPT LRL used to deliver pacing pulses to the one or more ventricular sites if a specified number of such senses have occurred; and

,

switch to an atrial tracking pacing mode for the IPT mode if the LRL is above a specified limit value.

13. A method for operating a cardiac device, comprising:

sensing electrical cardiac activity through one or more sensing channels;

delivering pacing pulses to one or more myocardial sites through one or more pacing channels;

operating the device in either a normal operating mode or an intermittent pacing therapy (IPT) mode;

in the IPT mode, delivering paces to the one or more myocardial sites using a pacing mode that results in some degree of dyssynchrony as compared with the normal operating mode;

intermittently switching to the IPT mode and, upon switching to the IPT mode, adjusting the value of an escape interval used to deliver pacing pulses to the one or more myocardial sites to an IPT value; and

,

when operating in the IPT mode, monitoring for senses that inhibit pacing pulses to the one or more myocardial sites and shortening the escape interval used to deliver pacing pulses to the one or more myocardial sites if a specified number of such senses have occurred.

14. The method of claim 13 further comprising exiting the IPT mode if the escape interval has been shortened to a specified minimum limit value.

15. The method of claim 13 further comprising continuing operating in the IPT mode without shortening the escape interval if the escape interval has been shortened to a specified minimum limit value.

16. The method of claim 13 wherein the escape interval is a ventricular escape interval.

17. The method of claim 13 wherein the escape interval is an atrial escape interval.

18. The method of claim 13 wherein the escape interval is an AV delay used in an atrial tracking pacing mode.

19. The method of claim 13 further comprising setting the value of the escape interval to a programmed IPT value.

20. The method of claim 13 further comprising measuring one or more intrinsic cardiac intervals and setting the value of the escape interval to an IPT value as a function of the intrinsic cardiac interval measurement.