Identifying heart failure patients suitable for resynchronization therapy using QRS complex width from an intracardiac electrogram

• US 8,849,399 B2
• Filed: 10/01/2013
• Issued: 09/30/2014
• Est. Priority Date: 03/30/2001
• Status: Expired due to Term

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Ding, Jiang, Yu, Yinghong, Spinelli, Julio C.
• Primary Examiner(s): BOCKELMAN, MARK
• Application Number:
  US14/043,678
• Publication Number:
  US 20140031887A1
• Time in Patent Office: 364 Days
• Field of Search: 607/9, 607/25, 607/27
• US Class Current: 607/25
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening
• 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 1/36592 controlled by the heart rate variability
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay

Abstract

Methods and systems are disclosed for determining whether a patient is a responder to cardiac resynchronization therapy. The beginning and ending of the intrinsic ventricular depolarization are determined through signals measured from one or more electrodes implanted in the patient'"'"'s heart. An interval between the beginning and ending of the intrinsic ventricular depolarization is computed and is compared to a threshold. The threshold may be determined empirically. The pacing parameters of a heart stimulation device, such as a pacemaker, may then be configured, for example, by setting the paced atrio-ventricular delay based on whether the patient responds positively to cardiac resynchronization therapy.

Claims

1. A system comprising:

a signal analyzer configured to provide an atrio-ventricular delay of a patient and information for a QRS interval for the patient, the QRS interval occurring between the beginning of the intrinsic ventricular depolarization and the ending of the intrinsic ventricular depolarization, wherein the information for the QRS interval is indicative of whether a wide QRS interval is present in the QRS interval for the patient; and

a controller coupled to the signal analyzer and configured to set a paced atrioventricular delay to be substantially less than an atrio-ventricular delay of the patient when the wide QRS interval is present.

2. The system of claim 1, wherein the signal analyzer is communicatively linked to a ventricular electrode and configured to:

detect a beginning of an intrinsic ventricular depolarization and an ending of the intrinsic ventricular depolarization; and

compute an interval between the beginning of the intrinsic ventricular depolarization and the ending of the intrinsic ventricular depolarization to determine when the wide QRS interval is present.

3. The system of claim 2, wherein the signal analyzer is configured to detect the beginning and the ending of the intrinsic ventricular depolarization and compare the interval periodically other than for each cardiac cycle.

4. The system of claim 2, wherein the signal analyzer is configured to detect the beginning of the intrinsic ventricular depolarization and the ending of the intrinsic ventricular depolarization from an electrical signal received from the ventricular electrode.

5. The system of claim 2, wherein the ventricular electrode is configured to be positioned within a left ventricle.

6. The system of claim 2, further comprising:

a device programmer configured to compare the computed interval to a threshold to determine whether the wide QRS interval is present.

7. The system of claim 2, wherein the signal analyzer is configured to statistically analyze multiple intervals detected from multiple intrinsic ventricular depolarizations.

8. The system of claim 7, wherein the statistical analysis involves calculating a median of the multiple intervals.

9. The system of claim 1, further comprising:

a device programmer communicatively linked to a ventricular electrode and configured to compute an interval between a beginning of the intrinsic ventricular depolarization and an ending of the intrinsic ventricular depolarization to determine when the wide interval is present.

10. The system of claim 1, wherein the wide QRS interval is at least 175 milliseconds.

11. The system of claim 1, wherein the paced atrio-ventricular delay is set to one-half of the atrio-ventricular delay of the patient when the wide QRS interval is present.

12. The system of claim 1, wherein the paced atrioventricular delay is set to approximately 30 milliseconds less than the atrio-ventricular delay when the wide QRS interval is not present.

13. The system of claim 1, wherein the signal analyzer is contained in a device programmer that is in communication with a heart stimulation device that is electrically connected to an electrode, and wherein the device programmer is configured to transmit an instruction to the heart stimulation device to set the paced atrio-ventricular delay of the heart stimulation device.

14. The system of claim 1, wherein the beginning of the ventricular depolarization is Q* and the ending of the ventricular depolarization is S*.

15. The system of claim 14, wherein Q* is computed by smoothing a depolarization signal and finding a point in time in a cardiac cycle prior to an R wave peak where a value of the smoothed depolarization first exceeds a baseline standard deviation value computed from the smoothed waveform and wherein S* is computed by finding a point in time after the R wave peak where a value of the smoothed depolarization last exceeds the baseline standard deviation value.

16. The system of claim 1, wherein the signal analyzer and the controller are contained in an implantable device.

17. A system comprising:

a signal analyzer configured to provide an atrioventricular delay of a patient and information for a QRS interval for the patient, the QRS interval occurring between the beginning of the intrinsic ventricular depolarization and the ending of the intrinsic ventricular depolarization, wherein the information for the QRS interval is indicative of whether a wide QRS interval is present in the QRS interval for the patient; and

a controller coupled to the signal analyzer and configured to set a paced atrioventricular delay to one-half of an atrio-ventricular delay of the patient when the wide QRS interval is present.

18. The system of claim 17, wherein the wide QRS interval is at least 175 milliseconds.

19. A system comprising:

a signal analyzer configured to provide an atrio-ventricular delay of a patient and information for a QRS interval for the patient, the QRS interval occurring between the beginning of the intrinsic ventricular depolarization and the ending of the intrinsic ventricular depolarization, wherein the information for the QRS interval is indicative of whether a wide QRS interval is present in the QRS interval for the patient; and

a controller coupled to the signal analyzer and configured to

set a paced atrio-ventricular delay to approximately 30 milliseconds less than an atrio-ventricular delay of the patient when the wide QRS interval is not present; and

set a paced atrioventricular delay to about one-half of an atrio-ventricular delay of the patient when the wide QRS interval is present.

20. The system of claim 19, wherein the wide QRS interval is at least 175 milliseconds.