Circuit-based devices and methods for pulse control of endocardial pacing in cardiac rhythm management

• US 8,812,105 B2
• Filed: 10/26/2011
• Issued: 08/19/2014
• Est. Priority Date: 12/20/2004
• Status: Active Grant

• Current Assignee: Newstim, Inc.
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Zhu, Qingsheng, Ortega, Daniel Felipe
• Primary Examiner(s): Gedeon, Brian T
• Application Number:
  US13/282,163
• Publication Number:
  US 20120041503A1
• Time in Patent Office: 1,028 Days
• Field of Search: None
• US Class Current: 607/9
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy

Abstract

Tools and methods are particularly suited for certain cardiac conditions involving use of a catheter for pacing of the right and left ventricles from a lead in the right ventricle, e.g., to facilitate mechanically and/or electrically synchronous contractions for resynchronization. Certain aspects involve pacing and/or mapping by generating pulses for delivery to a cardiac site useful for improving heart function as measured, e.g., by QRS width, fractionation, late LV activation timing, mechanical synchronicity of free wall and septal wall, effective throughput/pressure, or a combination thereof. In one embodiment, an implantable pulse generator includes circuitry for generating pacing profiles, with signals of opposite polarities, specifically selected for delivery on electrodes at a site near the septal wall of a right ventricle of the heart.

Claims

1. A method for treating an asynchronous condition of a heart of a patient, the method comprising:

generating an electrostimulation profile that includes pulse waveforms for delivery via respective electrodes, the pulse waveforms including opposing polarities that are at least partially overlapping in time; and

delivering the electrostimulation profile via the respective electrodes, the electrodes located in a right ventricle of the heart, at or near the septum of the heart and distal from an apex of the right ventricle;

wherein the delivering the electrostimulation profile includes capturing the myocardium so as to improve synchronization of the right and left ventricles as compared to delivering pacing at the apex of the right ventricle; and

wherein the generating the electrostimulation profile includes;

in a first stage of a switching circuit, selecting one of a bi-ventricular switch configuration and a single-ventricle switch configuration to provide the pulse waveforms to a second stage of the switching circuit;

in the second stage of the switching circuit, selecting an initial pulse polarity for providing the pulse waveforms to the respective electrodes; and

recurrently alternating the pulse polarity using the second stage of the switching circuit.

2. The method of claim 1, comprising locating at least one of the electrodes in the right ventricle at a pacing location in response to information indicative of one or more of a:

QRS width narrowing, a decrease in electrogram fractionation, or an earlier activation of a late activation site, the improvement elicited via delivery of the electrostimulation profile at or near the pacing location.

3. The method of claim 1, comprising:

determining a pacing location using a catheter arranged to provide the electrostimulation profile in the right ventricle of the heart;

assessing the effectiveness of the delivered electrostimulation profile as a function of at least one of a;

QRS width narrowing, a decrease in electrogram fractionation, or an earlier activation of a late activation site;

adjusting the catheter to change the pacing location; and

repeating, for the changed pacing location, the steps of assessing the pacing location and assessing the effectiveness.

4. The method of claim 1, wherein the electrostimulation profile is delivered by an implantable pulse generator and wherein the electrodes are individually addressable by the implantable pulse generator.

5. The method of claim 4, wherein at least one of the electrodes is included as a portion of an implantable lead, the implantable lead mechanically and electrically coupled to the implantable pulse generator.

6. The method of claim 1, comprising monitoring at least one of:

a QRS width of the patient, an electrogram fractionation of the patient, and a timing activation of a late activation site of the left ventricle.

7. The method of claim 6, wherein one or more parameters of the pacing signal are adjusted so as to produce a QRS width narrowing, a decrease in electrogram fractionation, or an earlier activation of a late activation site as compared with the unadjusted pacing parameters.

8. The method claim 7 wherein at least one parameter includes a pulse waveform overlap duration.

9. The method of claim 7, wherein at least one parameter includes a pulse waveform amplitude.

10. The method of claim 1, wherein at least one of the pulse waveforms comprises a biphasic waveform.

11. A machine-readable medium that stores instructions which when performed by a machine, causes the machine to perform the operations comprising:

generating an electrostimulation profile that includes pulse waveforms for delivery via respective electrodes, the pulse waveforms including opposing polarities that are at least partially overlapping in time; and

delivering the electrostimulation profile via the respective electrodes, the electrodes located in a right ventricle of the heart, at or near the septum of the heart and distal from an apex of the right ventricle;

wherein the delivering the electrostimulation profile includes capturing the myocardium so as to improve synchronization of the right and left ventricles as compared to delivering pacing at the apex of the right ventricle; and

wherein the generating the electrostimulation profile includes;

in a first stage of a switching circuit, selecting one of a bi-ventricular switch configuration and a single-ventricle switch configuration to provide the pulse waveforms to a second stage of the switching circuit;

in the second stage of the switching circuit, selecting an initial pulse polarity for providing the pulse waveforms to the respective electrodes; and

recurrently alternating the pulse polarity using the second stage of the switching circuit.

12. The machine-readable medium of claim 11, wherein the electrodes are individually addressable.

13. The machine-readable medium of claim 11, wherein the instructions comprise instructions that cause the machine to monitor at least one of:

a QRS width of the patient, an electrogram fractionation of the patient, and a timing activation of a late activation site of the left ventricle.

14. The machine-readable medium of claim 13, wherein the instructions comprise instructions that cause the machine to send the results of the monitoring to an external device.

15. The machine-readable medium of claim 11, wherein the instructions comprise instructions that cause the machine to adjust one or more parameters of the pacing signal.

16. The machine-readable medium of claim 15, wherein at least one parameter includes a pulse waveform overlap duration.

17. The machine-readable medium of claim 15, wherein at least one parameter includes an amplitude.

18. The machine-readable medium of claim 15, wherein at least one of the pulse waveforms comprises a biphasic waveform.

19. The machine-readable medium of claim 18, wherein the at least one parameter includes a frequency at which the pulse waveforms reverse polarity.

20. The machine-readable medium of claim 11, wherein one or more pulses of the pulse waveforms are withheld in response to information indicative that an intrinsic heart rate that is above a specified threshold.