IMPLANTED DEVICE DATA TO GUIDE ABLATION THERAPY

• US 20120165811A1
• Filed: 04/05/2011
• Published: 06/28/2012
• Est. Priority Date: 12/23/2010
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gillberg, Jeffrey M., Brown, Mark L., Gennaro, Christopher J.
• Granted Patent: US 9,061,155 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/30 Input circuits therefor
• 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 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61N 1/3621 for treating or preventing abnormally high heart rate
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/371 Capture, i.e. successful stimulation

Abstract

A medical device system and associated method for guiding ablation therapy sense cardiac signals using implantable electrodes and detect spontaneous cardiac events from the sensed cardiac signals. Pacing pulses are delivered and a return cycle length is measured in response to the plurality of pacing pulses. The spontaneous cardiac event is clustered with a previously detected cardiac event in response to the measured return cycle length, and a targeted ablation site is estimated in response to the measured return cycle length. A transit time interval, corresponding to a distance traversed by a depolarization associated with a last one of the plurality of pacing pulses when a reset condition occurs, is computed using the return cycle length, and the ablation site is estimated in response to the computed transit time interval.

Claims

1. A medical device system for guiding a cardiac ablation therapy, comprising;

a plurality of implantable electrodes for sensing cardiac signals;

an implantable cardiac event detector coupled to the plurality of

implantable electrodes for detecting spontaneous cardiac events from the sensed cardiac signals;

an implantable pulse generator coupled to the plurality of implantable

electrodes for delivering pacing pulses;

an implantable controller to control the pulse generator to deliver a

plurality of pacing pulses in response to detecting a spontaneous cardiac event using a first electrode of the plurality of implantable electrodes and measure a return cycle length in response to the plurality of pacing pulses; and

a processor configured to cluster the spontaneous cardiac event with a

previously detected cardiac event in response to the measured return cycle length, wherein the controller is further configured to compute a transit time interval using the return cycle length, the computed transit time interval corresponding to a distance traversed by a depolarization associated with the last one of the plurality of pacing pulses when a reset condition occurs, and wherein the processor is further configured to estimate a target ablation site in response to the computed transit time interval.

2. The system of claim 1, further comprising an external display to display the estimated ablation site for the clustered cardiac events.

3. The system of claim 1, wherein the controller is further configured to measure a cardiac event cycle length in response to the detected tachycardia event, compute a total prematurity of the plurality of pacing pulses, detect a reset condition when the return cycle length is less than a sum of the cycle length and the total prematurity, and determine the transit time interval in response to detecting the reset condition.

4. The system of claim 1, further comprising an ablation system, the ablation system comprising:

a cardiac electrophysiology mapping system;

an ablation electrode; and

an ablation source coupled to the ablation electrode, wherein the display displays the estimated ablation site superimposed with electrophysiology mapping results produced by the mapping system.

5. The system of claim 1, wherein the ablation system, the controller, and the processor are further configured to cooperatively induce a tachycardia, compare the induced tachycardia to a cluster of spontaneous cardiac events and identify a matching cluster of spontaneous cardiac events in response to the comparison, the estimated ablation site corresponding to the matching cluster of spontaneous cardiac events.

6. The system of claim 1, further comprising an ablation system, the ablation system comprising:

a cardiac electrophysiology mapping system;

an ablation electrode; and

an ablation source coupled to the ablation electrode, the ablation system, the controller and the processor configured to cooperatively induce a tachycardia, deliver a plurality of pacing pulses in response to inducing the tachycardia, measure a transit time interval at the estimated ablation site using the ablation electrode positioned at the estimated ablation site and confirm the estimated ablation site in response to a comparison of the computed transit time interval and the measured transit time interval.

7. The system of claim 6, wherein the processor is further configured to compare the induced tachycardia to a cluster of spontaneous cardiac events and identify a matching cluster of spontaneous cardiac events in response to the comparison, and wherein the controller is configured to deliver a plurality of pacing pulses in response to detecting the induced tachycardia having a total prematurity known to result in a reset of the matching cluster of spontaneous cardiac events.

8. The system of claim 4, wherein the ablation source is controlled to deliver ablation energy at the estimated ablation site.

9. The system of claim 4, wherein the estimated ablation site corresponds to a triggering event location of the clustered spontaneous cardiac events.

10. The system of claim 1, wherein the processor is configured to generate an alert when a cluster of spontaneous cardiac events reaches an alert threshold indicating ablation therapy.

11. The system of claim 1, further comprising a communication system coupled to a network for transferring the data corresponding to the clustered cardiac events in an electronic format to a data destination.

12. A method for guiding a cardiac ablation therapy in a medical device system, comprising;

sensing cardiac signals using a plurality of implantable electrodes;

detecting spontaneous cardiac events from the sensed cardiac signals using an implantable cardiac event detector coupled to the plurality of implantable electrodes;

delivering pacing pulses using a first electrode of the plurality of

implantable electrodes using an implantable pulse generator coupled to the implantable electrodes in response to detecting a spontaneous cardiac event;

measuring a return cycle length in response to the plurality of pacing

pulses;

clustering the spontaneous cardiac event with a previously detected

cardiac event in response to the measured return cycle length;

estimating a targeted ablation site in response to the measured return cycle length;

computing a transit time interval using the return cycle length, the computed transit time interval corresponding to a distance traversed by a depolarization associated with a last one of the plurality of pacing pulses when a reset condition occurs; and

estimating the ablation site in response to the computed transit time interval.

13. The method of claim 12, further comprising displaying the estimated ablation site for the clustered cardiac events.

14. The method of claim 12, further comprising:

measuring a cardiac event cycle length in response to the detected tachycardia event;

computing a total prematurity of the plurality of pacing pulses;

detecting a reset condition when the return cycle length is less than a sum of the cycle length and the total prematurity; and

determining the transit time interval in response to detecting the reset condition.

15. The method of claim 12, further comprising performing a cardiac electrophysiology mapping procedure using an ablation system, the ablation system comprising:

a mapping system;

an ablation electrode; and

an ablation source coupled to the ablation electrode, the method further comprising displaying the estimated ablation site superimposed with electrophysiology mapping results produced by the mapping system.

16. The method of claim 15, further comprising:

inducing a tachycardia;

comparing the induced tachycardia to a cluster of spontaneous cardiac events;

identifying a matching cluster of spontaneous cardiac events in response to the comparison; and

displaying the estimated ablation site corresponding to the matching cluster of spontaneous cardiac events.

17. The method of claim 12, further comprising:

inducing a tachycardia;

delivering a plurality of pacing pulses using the first electrode in response to inducing the tachycardia;

measuring a transit time interval at the estimated ablation site using the ablation electrode positioned at the estimated ablation site; and

confirming the estimated ablation site in response to a comparison of the computed transit time interval and the measured transit time interval.

18. The method of claim 17, further comprising:

comparing the induced tachycardia to a cluster of spontaneous cardiac events;

identifying a matching cluster of spontaneous cardiac events in response to the comparison; and

delivering the plurality of pacing pulses in response to detecting the induced tachycardia having a total prematurity known to result in a reset of the matching cluster of spontaneous cardiac events.

19. The method of claim 15, further comprising controlling the ablation source to deliver ablation energy at the estimated ablation site.

20. The method of claim 15, wherein the estimated ablation site corresponds to a triggering event location of the clustered spontaneous cardiac events.

21. The method of claim 12, further comprising generating an alert when a cluster of spontaneous cardiac events reaches an alert threshold indicating ablation therapy.

22. The system of claim 12, further comprising a communication system coupled to a network for transferring the data corresponding to the clustered cardiac events in an electronic format to a data destination.

23. A computer-readable medium storing a set of instructions which cause a medical device system to perform a method, the method comprising:

sensing cardiac signals using a plurality of implantable electrodes;

detecting spontaneous cardiac events from the sensed cardiac signals using an implantable cardiac event detector coupled to the plurality of implantable electrodes;

delivering pacing pulses using a first electrode of the plurality of implantable electrodes using an implantable pulse generator coupled to the implantable electrodes in response to detecting a spontaneous cardiac event;

measuring a return cycle length in response to the plurality of pacing

pulses;

clustering the spontaneous cardiac event with a previously detected

cardiac event in response to the measured return cycle length;

estimating a targeted ablation site in response to the measured return cycle length;

computing a transit time interval using the return cycle length, the computed transit time interval corresponding to a distance traversed by a depolarization associated with a last one of the plurality of pacing pulses when a reset condition occurs; and

estimating the ablation site in response to the computed transit time interval.