ASSESSING INTRA-CARDIAC ACTIVATION PATTERNS AND ELECTRICAL DYSSYNCHRONY

• US 20120283587A1
• Filed: 05/02/2012
• Published: 11/08/2012
• Est. Priority Date: 05/03/2011
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gillberg, Jeffrey M., Stadler, Robert W., Gosh, Subham
• Granted Patent: US 9,510,763 B2
• Time in Patent Office: Days
• US Class Current: 600/510
• CPC Class Codes: A61B 5/02 Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61N 1/0476 Array electrodes (including any electrode arrangement with more than one electrode for at least one of the polarities)
• CPC Class Codes: A61N 1/0484 Garment electrodes worn by the patient
• 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 1/3682 with a variable atrioventricular delay
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36842 Multi-site stimulation in the same chamber
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation

Abstract

Techniques for evaluating cardiac electrical dyssynchrony are described. In some examples, an activation time is determined for each of a plurality of torso-surface potential signals. The dispersion or sequence of these activation times may be analyzed or presented to provide variety of indications of the electrical dyssynchrony of the heart of the patient. In some examples, the locations of the electrodes of the set of electrodes, and thus the locations at which the torso-surface potential signals were sensed, may be projected on the surface of a model torso that includes a model heart. The inverse problem of electrocardiography may be solved to determine electrical activation times for regions of the model heart based on the torso-surface potential signals sensed from the patient.

Claims

1. A method comprising:

receiving, with a processing unit, a torso-surface potential signal from each of a plurality of electrodes distributed on a torso of a patient;

for at least a subset of the plurality of electrodes, calculating, with the processing unit, a torso-surface activation time based on the signal sensed from the electrode; and

presenting, by the processing unit, to a user, an indication of a degree of dyssynchrony of the torso-surface activation times via a display.

2. The method of claim 1,

wherein receiving the torso-surface potential signals and calculating the torso-surface activation times comprises receiving first torso-surface potential signals and calculating first torso-surface activation times a first time during intrinsic conduction of a heart of the patient and receiving second torso-surface potential signals and calculating second torso-surface activation times a second time during CRT pacing of the heart, and

wherein presenting the indication of the degree of dyssynchrony comprises presenting an indication of a change in dyssynchrony from the intrinsic conduction to the CRT pacing of the heart.

3. The method of claim 1, wherein presenting the indication of the degree of dyssynchrony comprises:

calculating at least one index of dyssynchrony based on the torso-surface activation times; and

presenting the calculated index to the user.

4. The method of claim 3,

wherein receiving the torso-surface potential signals and calculating the torso-surface activation times comprises receiving first torso-surface potential signals and calculating first torso-surface activation times a first time during intrinsic conduction of a heart of the patient and receiving second torso-surface potential signals and calculating second torso-surface activation times a second time during CRT pacing of the heart,

wherein calculating the at least one index of dyssynchrony comprises calculating the at least one index of dyssynchrony based at least on comparing the first torso-surface activation times during intrinsic conduction of the heart to the second torso-surface activation times during CRT pacing of the heart.

5. The method of claim 3, wherein calculating the at least one index of dyssynchrony comprises calculating a standard deviation index (SDAT) computed as a standard deviation of the torso-surface activation times.

6. The method of claim 3, wherein calculating the at least one index of dyssynchrony comprises calculating a range of activation times (RAT) computed as a difference between a maximum of the torso-surface activation times and a minimum of the torso-surface activation times.

7. The method of claim 3, wherein calculating the at least one index of dyssynchrony comprises calculating a percentage of late activation times (PLAT) computed as a percentage of subset of the torso-surface activation times within a region of the torso that are later than a percentage of a QRS complex duration.

8. The method of claim 3, wherein calculating the at least one index of dyssynchrony comprises:

calculating a first index for a first region of the torso based on torso-surface activation times from the first region of the torso; and

calculating a second index for a second region of the torso based on torso-surface activation times from the second region of the torso.

9. The method of claim 3, wherein calculating the at least one index of dyssynchrony comprises:

calculating a first set of two or more indices for a first region of the torso based on torso-surface activation times from the first region of the torso; and

calculating a second set of two or more indices for a second region of the torso based on torso-surface activation times from the second region of the torso.

10. The method of claim 3, wherein calculating the at least one index of dyssynchrony comprises, for each of several regions of the torso, calculating a set of two or more indices for the region of the torso based on torso-surface activation times from region of the torso.

11. The method of claim 1, wherein presenting the indication of the degree of dyssynchrony comprises:

calculating a torso-surface activation time isochrone map based on the calculated torso-surface activation times, wherein the isochrones map depicts a spatial distribution of torso-surface activation times; and

presenting the torso-surface activation time isochrone map via the display.

12. The method of claim 1, wherein presenting the indication of the degree of dyssynchrony comprises:

calculating a wave front animation based on the calculated torso-surface activation times, wherein the wave front animation depicts a spatial a spatial progression of the activation of the heart; and

presenting the wave front animation via the display.

13. The method of claim 1, wherein presenting the indication of the degree of dyssynchrony of the torso-surface activation times comprises displaying one of a plurality of predefined colors, each of the colors indicating a respective degree of change of dyssynchrony.

14. The method of claim 1, wherein presenting the indication of the degree of dyssynchrony comprises presenting the indication during an implantation procedure for a cardiac resynchronization therapy (CRT) device.

15. The method of claim 1, wherein presenting the indication of the degree of dyssynchrony comprises presenting the indication during an adjustment procedure for a cardiac resynchronization therapy (CRT) device.

16. The method of claim 1, wherein presenting the indication of the degree of dyssynchrony comprises presenting the indication during a screening procedure to determine if a given patient might benefit from implantation of a CRT device.

17. A system comprising:

a plurality of electrodes distributed on a torso of a patient; and

a processing unit configured to receive a torso-surface potential signal from each of the plurality of electrodes, calculate, for at least a subset of the plurality of electrodes, a torso-surface activation time based on the signal sensed from the electrode, and present, to a user, an indication of a degree of dyssynchrony of the torso-surface activation times via a display.

18. The system of claim 17, wherein the processing unit is configured to:

receive first torso-surface potential signals and calculate first torso-surface activation times a first time during intrinsic conduction of a heart of the patient, and receive second torso-surface potential signals and calculate second torso-surface activation times a second time during CRT pacing of the heart; and

present an indication of a change in dyssynchrony from the intrinsic conduction to the CRT pacing of the heart.

19. The system of claim 17, wherein the processing unit is configured to:

calculate at least one index of dyssynchrony based on the torso-surface activation times; and

present the calculated index to the user.

20. The system of claim 19, wherein the processing unit is configured to:

receive first torso-surface potential signals and calculate first torso-surface activation times a first time during intrinsic conduction of a heart of the patient, and receive second torso-surface potential signals and calculate second torso-surface activation times a second time during CRT pacing of the heart; and

calculate the at least one index of dyssynchrony based at least on comparing the first torso-surface activation times during intrinsic conduction of the heart to the second torso-surface activation times during CRT pacing of the heart.

21. The system of claim 19, wherein the processing unit is configured to calculate a standard deviation index (SDAT) computed as a standard deviation of the torso-surface activation times.

22. The system of claim 19, wherein the processing unit is configured to calculate a range of activation times (RAT) computed as a difference between a maximum of the torso-surface activation times and a minimum of the torso-surface activation times.

23. The system of claim 19, wherein the processing unit is configured to calculate a percentage of late activation times (PLAT) computed as a percentage of subset of the torso-surface activation times within a region of the torso that are later than a percentage of a QRS complex duration.

24. The system of claim 19, wherein the processing unit is configured to:

calculate a first index for a first region of the torso based on torso-surface activation times from the first region of the torso; and

calculate a second index for a second region of the torso based on torso-surface activation times from the second region of the torso.

25. The system of claim 19, wherein the processing unit is configured to:

calculate a first set of two or more indices for a first region of the torso based on torso-surface activation times from the first region of the torso; and

calculate a second set of two or more indices for a second region of the torso based on torso-surface activation times from the second region of the torso.

26. The system of claim 17, wherein the processing unit is configured to:

calculate a torso-surface activation time isochrone map based on the calculated torso-surface activation times, wherein the isochrones map depicts a spatial distribution of torso-surface activation times; and

present the torso-surface activation time isochrone map via the display.

27. The system of claim 17, wherein the processing unit is configured to:

calculate a wave front animation based on the calculated torso-surface activation times, wherein the wave front animation depicts a spatial a spatial progression of the activation of the heart; and

present the wave front animation via the display.

28. The system of claim 17, wherein the processing unit is configured to display one of a plurality of predefined colors, each of the colors indicating a respective degree of change of dyssynchrony.

29. A computer-readable storage medium comprising instructions that, when executed, cause a processor to:

receive a torso-surface potential signal from each of a plurality of electrodes distributed on a torso of a patient;

calculate, for at least a subset of the plurality of electrodes, a torso-surface activation time based on the signal sensed from the electrodes; and

present to a user, an indication of a degree of dyssynchrony of the torso-surface activation times via a display.