Mechanical Ventricular Pacing Non-Capture Detection for a Refractory Period Stimulation (RPS) Pacing Therapy Using at Least One Lead-Based Accelerometer

• US 20080269825A1
• Filed: 04/30/2007
• Published: 10/30/2008
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Chinchoy, Edward, Hess, Michael F.
• Granted Patent: US 7,787,942 B2
• Time in Patent Office: Days
• US Class Current: 607/28
• 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 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold

Abstract

A system and method for monitoring at least one chamber of a heart (e.g., a left ventricular chamber) during delivery of a refractory period stimulation (RPS) therapy to determine if the desired non-capture (i.e., lack of ventricular mechanical capture due to refractory period stimulation) occurs. The system includes an implantable or external cardiac stimulation device in association with a set of leads such as epicardial, endocardial, and/or coronary sinus leads equipped with motion sensor(s). The device receives and processes acceleration sensor signals to determine a signal characteristic indicative of chamber capture due to pacing stimulus delivery, non-capture due to RPS therapy delivery, and/or contractile status based on the qualities of evoked response to pacing stimulation.

Claims

1. A method for assessing ventricular chamber status following delivery of a refractory period stimulation (RPS) therapy, comprising:

sensing contraction of a portion of a ventricular chamber of a heart during at least part of the refractory period of the chamber during delivery of a refractory period stimulation (RPS) therapy with a deployed movement transducer and for measuring a signal from the transducer related to the sensed movement;

coupling said signal to a means for detecting the sensed movement during said refractory period of the chamber, wherein the RPS therapy comprises at least one pulse and is delivered during said refractory period of said chamber;

filtering the signal obtained during the period of time; and

one of determining, storing, and programming a logical flag relating to whether or not the ventricular chamber was captured by the RPS therapy.

2. A method for determining the configuration, sequence, waveform, polarity, duration, or timing for delivering left ventricular (LV) electrical pulses and measuring the incidence of mechanical capture and non-capture events due to pacing therapy delivery and refractory period stimulation (RPS) therapy delivery during a given cardiac cycle, comprising:

disposing a transducer that is adapted to directly sense movement of a portion of a LV chamber of a heart and providing a signal related to the movement;

coupling said signal to a means for detecting the movement during at least a part of the refractory period of the LV chamber subsequent to delivery of at least one refractory period stimulation pulse; and

one of determining, storing, and programming a logical flag relating to whether or not the LV chamber contracted due to delivery of the at least one refractory period stimulation pulse.

3. A method according to claim 2, wherein said transducer is adapted to be disposed in a portion of one of the coronary sinus vessel and a blood vessel fluidly coupled to said coronary sinus.

4. A method according to claim 3, wherein said transducer comprises an accelerometer.

5. A method according to claim 4, wherein the accelerometer comprises a uniaxial accelerometer having a longitudinal sensing axis substantially aligned toward the left ventricular apex portion of the heart.

6. A method according to claim 3, wherein said transducer comprises a biaxial accelerometer.

7. A method according to claim 3, wherein said transducer comprises a triaxial accelerometer.

8. A method according to claim 2, wherein said transducer is adapted to be disposed adjacent to a portion of the epicardium of the left ventricle of the heart.

9. A method according to claim 8, wherein the portion of the epicardium is a portion of the lateral wall of the left ventricle.

10. A method according to claim 9, wherein the portion of the lateral wall is a basal portion of the lateral wall.

11. A method according to claim 10, wherein the portion of the lateral wall is a mid-basal portion of the lateral wall.

12. A method according to claim 2, wherein said transducer is adapted to be disposed within the pericardium of the heart.

13. A method according to claim 4, wherein the device comprises an implantable medical device.

14. A method according to claim 13, wherein the first pacing electrode or the second pacing electrode further comprises a sense electrode in electrical communication with a sensing circuit coupled to the device.

15. A computer readable medium programmed with instructions for determining the configuration, sequence, waveform, polarity, duration, or timing for delivering left ventricular (LV) electrical pulses and measuring the incidence of mechanical capture events during the refractory period for a given cardiac cycle, comprising:

instructions for sensing movement of a portion of a LV chamber of a heart and providing a signal related to the movement;

instructions for coupling said signal to a means for detecting the movement during at least a part of the refractory period of the LV chamber subsequent to delivery of at least one refractory period stimulation pulse; and

instructions for one of determining, storing, and programming a logical flag relating to whether or not the LV chamber contracted due to delivery of the at least one refractory period stimulation pulse.

16. A computer readable medium according to claim 15, wherein said transducer is adapted to be disposed in a portion of the coronary sinus vessel or a blood vessel fluidly coupled to said coronary sinus.

17. A computer readable medium according to claim 16, wherein said transducer comprises an accelerometer.

18. A computer readable medium according to claim 17, wherein the accelerometer comprises a uniaxial accelerometer having a longitudinal sensing axis substantially aligned toward the left ventricular apex portion of the heart.

19. An apparatus for confirming capture of a left ventricular (LV) chamber due to LV pacing stimulus delivery and confirming non-capture due to delivery of refractory period stimulation (RPS) therapy, comprising:

transducer means for measuring movement of a portion of the lateral wall of a LV chamber and providing a movement signal related to such movement;

a movement measurement circuit operatively coupled to the transducer means;

a pulse generator coupled to the measurement circuit;

a left pacing electrode in electrical communication with a portion of the LV chamber and electrically coupled to a RPS therapy delivery circuit of the pulse generator; and

an LV chamber movement threshold circuit coupled to the movement signal and adapted to generate a signal relating to one of a capture, non-capture and relative contractility status of the LV chamber.

20. An apparatus according to claim 19, wherein the pulse generator comprises an implantable pulse generator.