Method and device for cardiac vasoactive therapy

• US 8,600,499 B2
• Filed: 12/05/2006
• Issued: 12/03/2013
• Est. Priority Date: 12/05/2006
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Shuros, Allan C., Arcot-Krishnamurthy, Shantha, Walker, Joseph
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): D ABREU, MICHAEL JOSEPH
• Application Number:
  US11/566,896
• Publication Number:
  US 20080132972A1
• Time in Patent Office: 2,555 Days
• Field of Search: 607/2, 607/42, 607/60, 607/62, 607 9- 11
• US Class Current: 607/11
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• 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

A method and device for treating myocardial ischemia in which an implantable pulse generator delivers electrical stimulation to electrodes disposed near a coronary artery. The stimulation parameters may be adjusted to produce vasodilation and/or vasoconstriction of the artery. The device may be configured to operate in a vasodilation and/or vasoconstriction mode in accordance with specified entry and exit conditions.

Claims

1. A cardiac device, comprising:

a pulse generator for outputting vasoactive stimulation pulses, wherein the pulse generator is connectable to a vasoactive stimulation electrode disposed in proximity to a coronary artery;

a sensing amplifier for sensing cardiac electrical activity;

an impedance sensor for measuring cardiac blood flow;

a controller programmed to intermittently switch between a normal mode in which no vasoactive stimulation pulses are delivered or a vasodilation mode in which vasoactive stimulation pulses are delivered in a manner that causes vasodilation of the coronary artery; and

,

wherein the controller is further programmed to deliver vasoactive stimulation pulses in the vasodilation mode such that the delivery of vasoactive stimulation pulses is timed to occur coincidentally with mechanical ventricular diastole as determined from the measured cardiac blood flow.

2. The device of claim 1 wherein the controller is programmed to measure heart rate from the sensed cardiac electrical activity and to switch from the normal mode to the vasodilation mode if the heart rate reaches a value indicating myocardial ischemia in a particular patient.

3. The device of claim 1 further comprising:

a patient-operated switch; and

,

wherein the controller is programmed to switch from the normal mode to the vasodilation mode upon actuation of the patient-operated switch.

4. The device of claim 1 further comprising:

a telemetry transceiver; and

,

wherein the controller is programmed to switch from the normal mode to the vasodilation mode upon receipt of a telemetry command to do so.

5. The device of claim 1 further comprising:

a sensor for sensing a variable that can be correlated with the occurrence of myocardial ischemia in a patient; and

,

wherein the controller is programmed to switch from the normal mode to the vasodilation mode when the sensed variable indicates myocardial ischemia.

6. The device of claim 5 wherein the sensed variable that can be correlated with the presence of myocardial ischemia is selected from a group that includes features derived from sensed cardiac electrical activity, minute ventilation, and activity level.

7. The device of claim 1 wherein the controller is programmed to switch from the vasodilation mode to the normal mode upon occurrence of a specified vasodilation exit condition and wherein the exit condition is selected from a group that includes non-detection of the presence of myocardial ischemia, a lapsed time interval, actuation of a patient-operated switch, and receipt of a telemetry command to terminate the mode.

8. The device of claim 1 wherein the controller is further programmed to operate in a vasoconstriction mode in which vasoactive stimulation pulses are delivered during a cardiac refractory period as determined from the sensed cardiac electrical activity in a manner that causes vasoconstriction of the coronary artery.

9. The device of claim 8 wherein the controller is programmed to intermittently switch from the normal mode or vasodilation mode to the vasoconstriction mode according to a defined schedule.

10. The device of claim 8 wherein the controller is programmed to exit the vasoconstriction mode if a measured heart rate or other variable reflective of exertion level is above a specified threshold value.

11. The device of claim 1 wherein the controller is programmed to deliver vasoactive stimulation pulses during a cardiac refractory period as determined from the sensed cardiac electrical activity.

12. A method, comprising:

implanting a pulse generator and an impedance sensor for measuring cardiac blood flow in a patient;

implanting a vasoactive stimulation electrode connected to the pulse generator near a coronary artery and delivering vasoactive stimulation pulses to the coronary artery;

programming the pulse generator to intermittently switch between a normal mode in which no vasoactive stimulation pulses are delivered or a vasodilation mode in which vasoactive stimulation pulses are delivered in a manner that causes vasodilation of the coronary artery; and

,

further programming the pulse generator such that the delivery of vasoactive stimulation pulses in the vasodilation mode is timed to occur coincidentally with mechanical ventricular diastole as determined from the measured cardiac blood flow.

13. The method of claim 12 further comprising programming the pulse generator to measure heart rate from the sensed cardiac electrical activity and to switch from the normal mode to the vasodilation mode if the heart rate reaches a value indicating myocardial ischemia in a particular patient.

14. The method of claim 12 further comprising programming the pulse generator to switch from the normal mode to the vasodilation mode upon actuation of a patient-operated switch.

15. The method of claim 12 further comprising programming the pulse generator to switch from the normal mode to the vasodilation mode upon receipt of a telemetry command to do so.

16. The method of claim 12 further comprising programming the pulse generator to switch from the normal mode to the vasodilation mode when a sensed variable indicates myocardial ischemia.

17. The method of claim 16 wherein the sensed variable indicative of the presence of myocardial ischemia is selected from a group that includes features derived from sensed cardiac electrical activity, mechanical activity, minute ventilation, and activity level.

18. The method of claim 12 further comprising programming the pulse generator to switch from the vasodilation mode to the normal mode upon occurrence of a specified vasodilation exit condition and wherein the exit condition is selected from a group that includes non-detection of the presence of myocardial ischemia, a lapsed time interval, actuation of a patient-operated switch, and receipt of a telemetry command to terminate the mode.

19. The method of claim 12 further comprising programming the pulse generator to operate in a vasoconstriction mode in which vasoactive stimulation pulses are delivered during a cardiac refractory period as determined from the sensed cardiac electrical activity in a manner that causes vasoconstriction of the coronary artery.

20. The method of claim 19 further comprising programming the pulse generator to intermittently switch from the normal mode or vasodilation mode to the vasoconstriction mode according to a defined schedule.

21. The method of claim 19 further comprising programming the pulse generator to exit the vasoconstriction mode if a measured heart rate or other variable reflective of exertion level is above a specified threshold value.

22. The method of claim 12 further comprising delivering vasoactive stimulation pulses during a cardiac refractory period as determined from sensed cardiac electrical activity.