METHOD AND APPARATUS FOR DELIVERING CHRONIC AND POST-ISCHEMIA CARDIAC THERAPIES

• US 20100121391A1
• Filed: 01/18/2010
• Published: 05/13/2010
• Est. Priority Date: 08/19/2005
• Status: Active Grant

• Current Assignee: Allan Shuros, Carlos Ricci, Joseph M. Pastore, Marina Brockway, Rodney W. Salo, Yi Zhang
• Original Assignee: Allan Shuros, Carlos Ricci, Joseph M. Pastore, Marina Brockway, Rodney W. Salo, Yi Zhang
• Inventors: Pastore, Joseph M., Zhang, Yi, Salo, Rodney W., Brockway, Marina, Shuros, Allan, Ricci, Carlos
• Granted Patent: US 8,306,615 B2
• Time in Patent Office: Days
• US Class Current: 607/3
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• 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 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36557 controlled by chemical substances in blood
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters

Abstract

An implantable cardiac rhythm management (CRM) device delivers a chronic therapy while detecting an ischemic state. When the ischemic state indicates the occurrence of an ischemic event, the implantable CRM device delivers a post-ischemia therapy. The post-ischemia therapy and the chronic therapy are adjusted using feedback control with the ischemic state and parameters indicative of the effectiveness of the post-ischemic therapy and the effectiveness of the chronic therapy as inputs.

Claims

1. A system for pacing a heart having an ischemic region, the system comprising:

an implantable medical device including;

a sensing circuit configured to sense one or more ischemia-indicating signals and one or more therapy-monitoring signals;

an ischemia detector coupled to the sensing circuit, the ischemic detector configured to detect an ischemic state indicative of an occurrence of an ischemic event from the one or more ischemia-indicating signals;

a pacing circuit configured to deliver pacing pulses to the heart during a chronic pacing therapy and a post-ischemia pacing therapy;

a therapy monitor coupled to the sensing circuit, the therapy monitor configured to produce one or more therapy-monitoring parameters using the one or more therapy-monitoring signals, the one or more therapy-monitoring parameters each indicative of effectiveness of at least one of the post-ischemia therapy and the chronic pacing therapy; and

a controller coupled to the ischemia detector, the therapy delivery device, and the therapy monitor, the controller configured to control the delivery of the pacing pulses using the detected ischemic state and the one or more therapy-monitoring parameters and including;

a post-ischemic pacing controller configured to adjust one or more regional pacing parameters of the post-ischemia pacing therapy to provide pre-excitation of the ischemic region to reduce stress and workload of the ischemic region in response to the occurrence of the ischemic event; and

a chronic pacing controller configured to adjust one or more global pacing parameters of the chronic pacing therapy to reduce overall workload on the heart in response to the occurrence of the ischemic event.

2. The system of claim 1, wherein the sensing circuit is configured to sense one or more cardiac signals, and the ischemic detector is configured to detect the ischemic state from the one or more cardiac signals.

3. The system of claim 2, comprising a plurality of subcutaneous electrodes incorporated onto the implantable medical device, and wherein the sensing circuit is configured to sense one or more subcutaneous electrocardiogram (ECG) signals using the plurality of subcutaneous electrodes, and the ischemic detector is configured to detect the ischemic state from the one or more subcutaneous ECG signals.

4. The system of claim 1, wherein the sensing circuit is configured to sense one or more impedance signals, and the ischemic detector is configured to detect the ischemic state from the one or more impedance signals.

5. The system of claim 1, wherein the sensing circuit is configured to sense one or more signals indicative of heart sounds, and the ischemic detector is configured to detect the ischemic state from the one or more signals indicative of heart sounds.

6. The system of claim 1, wherein the sensing circuit is configured to sense one or more pressure signals, and the ischemic detector is configured to detect the ischemic state from the one or more pressure signals.

7. The system of claim 1, further comprising:

a neural stimulation circuit configured to deliver a post-ischemia neural stimulation therapy; and

a neural stimulation controller configured to initiate and control the post-ischemia neural stimulation therapy.

8. The system of claim 1, further comprising:

a drug delivery device configured to deliver a post-ischemia drug therapy; and

a drug delivery controller configured to initiate and control the post-ischemia drug therapy.

9. The system of claim 1, wherein the chronic pacing controller is configured to lower a lower rate limit of the chronic pacing therapy in response to the occurrence of the ischemic event, and the post-ischemia pacing controller is configured to shorten at least an atrioventricular delay of the post-ischemia pacing therapy.

10. The system of claim 9, wherein the ischemic detector comprises an ischemia locator adapted to locate the ischemic region using the one or more ischemia-indicating signals, and wherein the post-ischemia pacing therapy controller is configured to control the delivery of the pacing pulses to the located ischemic region.

11. A method for pacing a heart having an ischemic region, the method comprising:

delivering a chronic pacing therapy;

sensing one or more ischemia-indicating signals and one or more therapy-monitoring signals;

detecting an ischemic state indicative of an occurrence of an ischemic event from the one or more ischemia-indicating signals;

initiating delivery of a post-ischemia pacing therapy in response to the occurrence of the ischemic event as indicated by the detected ischemic state;

producing one or more therapy-monitoring parameters from the one or more therapy-monitoring signals, the one or more therapy-monitoring parameters each indicative of effectiveness of at least one of the chronic pacing therapy and the post-ischemia therapy; and

adjusting the delivery of the chronic pacing therapy and the delivery of the post-ischemia therapy using the detected ischemic state and the one or more therapy-monitoring parameters, including adjusting one or more global pacing parameters of the chronic pacing therapy to reduce overall workload on the heart in response to the occurrence of the ischemic event and adjusting one or more regional pacing parameters of the post-ischemia pacing therapy to provide pre-excitation of the ischemic region to reduce stress and workload of the ischemic region in response to the occurrence of the ischemic event.

12. The method of claim 11, wherein sensing the one or more ischemia-indicating signals comprises sensing one or more cardiac signals, and detecting the ischemic state comprises detecting the ischemic state from the one or more cardiac signals.

13. The method of claim 12, wherein sensing the one or more cardiac signals comprises sensing one or more subcutaneous electrocardiogram (ECG) signals using a plurality of subcutaneous electrodes incorporated on to an implantable medical device, and detecting the ischemic state from the one or more cardiac signals comprises detecting the ischemic state from the one or more subcutaneous ECG signals.

14. The method of claim 11, wherein sensing the one or more ischemia-indicating signals comprises sensing one or more impedance signals, and detecting the ischemic state comprises detecting the ischemic state from the one or more impedance signals.

15. The method of claim 11, wherein sensing the one or more ischemia-indicating signals comprises sensing one or more signals indicative of heart sounds, and detecting the ischemic state comprises detecting the ischemic state from the one or more signals indicative of heart sounds.

16. The method of claim 11, wherein sensing the one or more ischemia-indicating signals comprises sensing one or more pressure signals, and detecting the ischemic state comprises detecting the ischemic state from the one or more pressure signals.

17. The method of claim 11, wherein sensing the one or more ischemia-indicating signals comprises sensing one or more signals indicative one or more of regional cardiac wall motion, heart rate variability (HRV), and changes in blood enzyme levels, and detecting the ischemic state comprises detecting the ischemic state from the one or more signals indicative the one or more of the regional cardiac wall motion, the HRV, and the changes in blood enzyme levels.

18. The method of claim 11, further comprising delivering one or more of a post-ischemia neural stimulation therapy and a post-ischemia drug therapy in response to the occurrence of the ischemic event.

19. The method of claim 11, wherein adjusting the one or more global pacing parameters of the chronic pacing therapy comprises lowering a lower rate limit of the chronic pacing therapy, and adjusting the one or more regional pacing parameters of the post-ischemia pacing therapy comprises shortening at least an atrioventricular delay of the post-ischemia pacing therapy.

20. The method of claim 19, wherein sensing the one or more ischemia-indicating signals comprises sensing one or more of regional electrograms, regional impedance signals, and strain signals, and further comprising locating the ischemic region using the one or more of the regional electrograms, the regional impedance signals, and the strain signals, and delivering the pacing pulses to the heart comprises delivering the pacing pulses to the located ischemic region during the post-ischemia pacing therapy.