Ventricular tachycardia (VT) target identification by selective pacing

Abstract

To provide a method for evaluation of electrical propagation in the heart.SOLUTION: A method includes applying pacing to ventricle of heart of patient from multiple electrode locations over circumference of multi-electrode catheter area. Cardiac signals are received in response to the pacing. A correlation algorithm is applied to the received signals to calculate a plurality of correlations among the received signals. Based on calculated correlations, the area is checked if it includes an arrhythmogenic location identified with predefined sufficient spatial resolution. If the resolution is insufficient, sub-area to pace is defined. Subsequent pacing is applied to ventricle from multiple electrode locations over a circumference of the sub-area. Subsequent cardiac signals are received in response to the subsequent pacing. Subsequent correlations among the subsequent received signals are calculated. Based on the subsequent correlations, it is ascertained whether the arrhythmogenic location is found in the sub-area. If an arrhythmogenic location is found with sufficient spatial resolution, the identified arrhythmogenic location is indicated to user.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to electrophysiological (EP) signals, and specifically to methods for the assessment of electrical propagation within the heart. [Background technology]

[0002] Estimation of electrophysiological signals to determine the location of ventricular arrhythmias has previously been suggested in the patent literature. For example, U.S. Patent No. 7,907,994 describes ventricular tachycardia (VT) signals being induced in a living subject. Pace-mapped signals are then obtained from multiple points within the ventricle and automatically compared numerically to the induced signals. Recognition of a high degree of cross-correlation between one or more of the induced and pace-mapped signals identifies arrhythmogenic foci or pathways, which can then be ablated so that the arrhythmia becomes non-inducible.

[0003] As another example, U.S. Pat. No. 10,891,728 describes a method for identifying isthmuses in a three-dimensional map of a heart cavity by a processing unit configured to perform: a) a correlation step between a set of stimulation points of the heart cavity, each stimulation point being represented by a set of signals obtained after surface electrocardiography (ECG), excluding ventricular tachycardia; b) a watershed line identification step based on the correlation results and 3D coordinates of the stimulation points in the 3D map; and c) a determination step of an isthmus based on a 3D corridor that substantially crosses the watershed line.

[0004] A more complete understanding of the present disclosure will be obtained from the following detailed description of the embodiments of the present disclosure when read in conjunction with the drawings. [Brief explanation of the drawings]

[0005] [Figure 1]1 is a schematic, pictorial illustration of a catheter-based electrophysiology (EP) pacing, mapping and ablation system, in accordance with an embodiment of the present disclosure; [Figure 2] 2A and 2B schematically illustrate an EP map of the left ventricle overlaid with the large-area multi-electrode distal tip assembly of FIG. 1, in accordance with an embodiment of the present disclosure. [Figure 3A] 3A and 3B illustrate schematic diagrams of methods for detecting candidate left ventricular arrhythmogenic locations using the catheter of FIG. 1 using area-level reference correlation (3A) or area-level internal correlation (3B), according to two embodiments of the present disclosure. [Figure 3B] 3A and 3B illustrate schematic diagrams of methods for detecting candidate left ventricular arrhythmogenic locations using the catheter of FIG. 1 using area-level reference correlation (3A) or area-level internal correlation (3B), according to two embodiments of the present disclosure. [Figure 4] 1 is a flowchart with a general description of a method for detecting left ventricular arrhythmogenic locations using a large-area multi-electrode catheter, according to an embodiment of the present disclosure. [Figure 5] 5 is a flowchart with a detailed schematic description of a method for illustrating several steps of the method described in FIG. 4 for detecting left ventricular arrhythmogenic locations using a large-area multi-electrode catheter according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0006] overview To characterize arrhythmias in a heart chamber such as the left ventricle (LV), physicians may use a catheter to explore suspect tissue pathways and circuits within the LV and pace multiple LV tissue locations (e.g., by applying a bipolar pacing signal between two adjacent catheter electrodes). If a transient arrhythmogenic event, such as an ectopic beat, extrasystole, or premature ventricular complex (PVC), occurs during pacing, the event may be recorded by a 12-lead ECG device, showing an abnormal signal pattern.

[0007] Various methods can be used to recognize arrhythmogenic events induced at a given ventricular location. For example, a physician may sample different areas of the ventricle and perform pattern matching (e.g., of 12-lead ECG waveforms) between the acquired waveforms and stored pattern waveform characteristics of arrhythmias (e.g., VT) to identify correlations. A high degree of correlation indicates that the paced location is part of the arrhythmogenic tissue. As another example, a physician may compare only waveforms acquired at different cardiac locations. In this case, a low degree of correlation indicates that at least one paced location is closer to the arrhythmogenic tissue location.

[0008] However, sometimes a physician may have difficulty finding a position that induces a consistent correlation, whatever the correlation method, and when this occurs, it may be particularly difficult for the physician to determine in which direction the catheter should be moved to obtain a meaningful correlation.

[0009] One method for guiding a physician to an arrhythmogenic ventricular area is described in commonly assigned U.S. Patent Application Publication No. 18 / 19599, entitled "Spatial Correlation to Identify Ventricle Location of Pattern Matching," filed May 11, 2023. The method includes comparing cardiac signals received from multiple locations within the ventricle with reference signals indicative of arrhythmia. Based on the comparison, a processor calculates a direction toward a VT target location that may demonstrate an increased correlation between the received signal and the reference signal, and indicates the direction to the user.

[0010] Yet, acquiring a large amount of quality data and finding meaningful correlations involves stabilizing the catheter at multiple tissue locations and performing multiple respective pacings, a workflow that can be difficult to meet in real-world clinical scenarios.

[0011] Several embodiments of the present disclosure described below rely on the advantages of using a large-area multi-electrode catheter placed within the LV to identify VT target locations with little or no catheter movement and minimal pacing steps during clinical procedures.

[0012] In one embodiment, a system is provided that includes an interface and a processor. The interface is configured to transmit signals to a multi-electrode catheter and receive cardiac signals, such as ECG signals from a 12-lead recorder, acquired in response to the transmitted signals. The processor is configured to apply pacing to a ventricle from multiple electrode locations around an area of ​​the catheter. The processor receives the cardiac signals acquired in response to the pacing and applies a correlation algorithm to calculate multiple correlations between the received signals. Based on the calculated correlations, the processor checks whether the area contains the identified arrhythmogenic location with a predetermined sufficient spatial resolution (e.g., an area on the order of the area surrounded by adjacent catheter electrodes). If the resolution is insufficient, the processor defines a subarea to be paced. The processor then applies subsequent pacing to a second region of the ventricle from multiple electrode locations around the subarea and receives subsequent cardiac signals in response to the subsequent pacing. The processor calculates subsequent correlations between subsequent received signals. Based on the subsequent correlation, the processor determines whether an arrhythmogenic location is found within the sub-area, and if an arrhythmogenic location is found with sufficient spatial resolution, the processor presents the identified arrhythmogenic location to the user.

[0013] The disclosed method is applicable for use with any correlation calculation method, including both the reference correlation (high correlation) search method, such as that described in U.S. Pat. No. 7,907,994, and the internal correlation (low correlation) search method, such as that described in U.S. Pat. No. 10,891,728.

[0014] The disclosed technology allows bipolar pacing schemes to detect highly localized indications of tissue types (e.g., up to a few mm) that make detection difficult. 2 The authors use the observation that using large-area multielectrode catheters produces a search area for tissue type indicators that is several hundred mm2 depending on the catheter type. 2 We have found that the bipolar pacing coverage extends to areas as large as 100 msec. The disclosed technique covers such areas with a minimal number of bipolar pacing steps. By reducing the number of pacing events and the number of required catheter movements, the disclosed technique makes detecting VT location targets a much more efficient process.

[0015] In one embodiment, a rectangular shape (e.g., 12x30 mm 2 ) catheter is used. After the physician places the catheter, the interface of the system used in this technique applies bipolar pacing to LV locations at the periphery (e.g., apex) of the rectangle. The interface receives 12-lead ECG signals acquired in response to the pacing. Based on the spatial distribution of correlation between the ECG signals, analysis of these signals allows the processor to determine whether narrowing the search to a subarea (e.g., quadrant) is recommended without moving the catheter. In a second iteration, paced locations around the periphery of the subarea are analyzed, which further narrows the search.

[0016] Typically, two iterations are sufficient if the arrhythmogenic location is located under the catheter; however, additional iterations involving receiving signals from locations within a subarea may be used to pinpoint the target location.

[0017] The search shape selected may depend on the catheter shape. For example, when using different catheters (e.g., multi-arm catheters), it may be useful to search using a triangular grid or special grid shape.

[0018] Finally, even if no arrhythmogenic (e.g., VT) target location is found, the processor performing the iterative area-level correlation analysis can recommend a direction to move the catheter in search of the arrhythmogenic location based on the spatial distribution of the correlations. Such a direction may represent, for example, the direction of the steepest change in correlation.

[0019] System Description FIG. 1 is a schematic, pictorial illustration of a catheter-based electrophysiology (EP) pacing, mapping and ablation system 10 according to an embodiment of the present disclosure.

[0020] System 10 includes a catheter 14 that is percutaneously inserted through a sheath by a physician 24 through a patient's vasculature into the left ventricle of heart 12. The catheter 14 shown by way of example herein is configured for bipolar pacing. The physician 24 brings a distal end assembly 28 of catheter 14 into contact with the heart wall to pace locations over a given area of ​​heart 12 of patient 23.

[0021] As shown, the catheter 14 carries multiple electrodes 26 on multiple splines 22 and includes a large-area flat distal tip assembly 28 configured to apply bipolar pacing signals. The catheter 14 may additionally include a position sensor 29 embedded in or near the distal tip 28 on the shaft 46 of the catheter 14 for tracking the position and orientation of the distal tip 28. Optionally, and preferably, the position sensor 29 is a magnetic-based position sensor including three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0022] The magnetic-based position sensor 29 may be operated in conjunction with a location pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined working volume. The real-time position of the distal tip 28 of the catheter 14 may be tracked based on the magnetic fields generated by the location pad 25 and sensed by the magnetic-based position sensor 29. Details of magnetic-based position sensing technology are described in U.S. Patent Nos. 5,5391,199; 5,443,489; 5,558,091; 6,172,499; 6,239,724; 6,332,089; 6,484,118; 6,618,612; 6,690,963; 6,788,967; and 6,892,091.

[0023] System 10 includes one or more electrode patches 38 positioned for skin contact with patient 23 to establish a position reference for location pads 25, as well as impedance-based tracking of electrodes 26. For impedance-based tracking, current is directed to electrodes 26 and sensed at electrode skin patches 38, thereby allowing the position of each electrode to be triangulated via electrode patches 38. Details of impedance-based position tracking techniques are described in U.S. Patent Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182.

[0024] Recorder 11 displays cardiac signals 21 (e.g., electrograms from a 12-lead ECG device acquired using body surface ECG electrodes 18). Recorder 11 may include pacing capability for pacing the cardiac rhythm and / or may be electrically connected to a stand-alone pacer.

[0025] Patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheters, electrophysiology equipment, power supply, and workstation 55 to control the operation of system 10 and to receive EP signals from the catheters or apply pacing signals. The electrophysiology equipment of system 10 may include, for example, multiple catheters, location pads 25, body surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally and preferably, PIU 30 additionally includes processing capability to perform real-time calculations of catheter position and to perform ECG calculations.

[0026] The workstation 55 includes a memory 57, a processor 56 unit with memory or loaded with appropriate operating software, and user interface functionality. The workstation 55 may optionally provide multiple functions, including (i) modeling the endocardial anatomical structure in three dimensions (3D) and rendering the model or anatomical map 20 for display on the display device 27, (ii) displaying activation sequences (or other data) compiled from the recorded cardiac signals 21 on the display device 27 in a representative visual representation or image superimposed on the rendered anatomical map 20, (iii) displaying the real-time position and orientation of multiple catheters within the cardiac chambers, and (iv) displaying sites of interest, such as locations where ablation energy has been applied, on the display device 27. One commercially available product embodying elements of the system 10 is available as the CARTO™ 3 system, available from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618.

[0027] In some embodiments, processor 56 typically comprises a general-purpose computer that is programmed with software to perform the functions described herein. The software may be downloaded to the computer in electronic form, for example, over a network, or alternatively or additionally, may be provided and / or stored on non-transitory, tangible media, such as magnetic, optical, or electronic memory.

[0028] The system 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more electrodes at the distal tip of a catheter configured for ablation. The energy generated by the ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy or pulsed-field ablation (PFA) energy, including monopolar or bipolar high-voltage DC pulses used to effect irreversible electroporation (IRE), or a combination thereof.

[0029] For ablation, physician 24 similarly brings the distal end of an ablation catheter to the target site. One or more additional catheters may be inserted through the sheath. These may include a catheter for sensing intracardiac electrogram signals, a catheter dedicated to ablation, and / or a catheter dedicated to both EP mapping and ablation.

[0030] This configuration of system 10 is presented as an example to illustrate the particular problem addressed by embodiments of the present disclosure and to demonstrate the application of these embodiments in improving the performance of such systems. However, embodiments of the present disclosure are in no way limited to this particular type of exemplary system, and the principles described herein may be applied to other types of medical systems as well. For example, other multi-electrode catheter types, such as an OCTARAY™ catheter or basket catheter, may be used.

[0031] Use of large-area multielectrode catheters for pacing Figure 2 schematically illustrates an EP map 202 of the left ventricle overlaid with the large-area multi-electrode distal tip assembly 28 of Figure 1, in accordance with an embodiment of the present disclosure. Figure 2 also illustrates an arrhythmogenic region 204, which may include an isthmus that needs to be ablated to eliminate VT.

[0032] As can be seen, the area of ​​distal end assembly 28 can be larger than or equal to the typical area of ​​region 204. As a result, arrhythmogenic locations are more likely to be found below the catheter area. Even if the search area is larger than the catheter area, the disclosed technique covers such an extended search area with a minimal number of bipolar pacing steps and catheter movements. This use of a large-area multi-electrode catheter for pacing makes detecting VT location targets, such as within or near region 204, a much more efficient process.

[0033] As can further be seen, region 204 is within the capture range, but not entirely below, distal tip assembly 28. This means that, in some cases, based on an area-level analysis of the correlation values, the processor can recommend a direction to move distal tip assembly 28 to cover region 204 (i.e., move upward in FIG. 2).

[0034] Area-level iterative search for VT target location 3A and 3B schematically illustrate a method for detecting candidate left ventricular arrhythmogenic locations using the catheter of FIG. 1 using area-level reference correlation (3A) or area-level internal correlation (3B), according to two embodiments of the present disclosure.

[0035] 3A, ECG signals (not shown) are received in response to bipolar pacing at locations 302, 304, 306, and 308 around the perimeter of a rectangular catheter area 310. The respective baseline correlation values ​​(%) for the locations are calculated as 95, 85, 85, and 85. The higher baseline correlation value at location 302 indicates that a candidate arrhythmogenic location or region lies in the direction of location 302 (e.g., the upper left quadrant in a coordinate system with the origin at the center of rectangle 310).

[0036] In a second iteration of the disclosed method, ECG signals are received in response to bipolar pacing at locations 312, 314, and 316 around the periphery of subarea 320 of assembly 28. The respective baseline correlation values ​​(%) for locations at the vertices of subarea 320 are calculated to be 95, 97, 90, and 94. The higher baseline correlation values ​​at locations 302 and 312 indicate arrhythmogenic locations or regions in the direction of locations 302 and 312.

[0037] To pinpoint the target location, additional ECG signals are received in response to bipolar pacing locations 318 and 319, resulting in baseline correlation values ​​(%) of 99 and 97, respectively.

[0038] Based on these results, the processor designates location 318 as a target location (e.g., for ablation). Further mapping (additional locations not shown) around arrhythmogenic location 318 can be performed to determine the shape of the arrhythmogenic region (e.g., the shape of the isthmus).

[0039] 3B, ECG signals are received in response to bipolar pacing at locations 332, 334, 336, 338, and 340 around the periphery of catheter area 330. Locations 336 and 338 were selected after edge rectangle locations marked with an "X" gave unstable readings.

[0040] The respective intercorrelation values ​​(%) of the ECG signals between paced locations 332-334, 332-334, 334-336, 336-338, 338-340, and 340-332 are calculated to be 75, 85, 90, 75, and 75, respectively. The lower intercorrelation values ​​received when locations on the left side are involved indicate an arrhythmogenic location or region to the left of area 330.

[0041] In a second iteration of the disclosed method, ECG signals are received in response to bipolar pacing at locations 342, 344, and 346 around the periphery of a catheter trapezoidal shaped area 350. The calculated intercorrelation value 75% around the upper left quadrant of the catheter indicates a potentially arrhythmogenic location or region in that quadrant.

[0042] To pinpoint the target location, an additional ECG signal is received in response to bipolar pacing location 348, resulting in a calculated intercorrelation value (%) of 25. Based on these results, the processor designates location 348 as the target location (e.g., for ablation). Again, additional mapping (not shown) around location 348 can be performed to determine the shape of the arrhythmogenic region (e.g., the shape of the isthmus).

[0043] As mentioned above, if no target location is found under assembly 28, results comparable to those given in the first iteration of Figures 3A and 3B, but less clear in subsequent iterations, still indicate the presence of a correlation gradient in the direction of the upper left quadrant, prompting the user to move the catheter in such direction in search of the arrhythmogenic region.

[0044] A method for area-level iterative search of VT target locations. 4 is a flow chart with a general description of a method for detecting left ventricular arrhythmogenic locations using a large-area multi-electrode catheter, according to an embodiment of the present disclosure. The algorithm executes a process that, according to the embodiment presented, begins with the system 10 pacing multiple locations in the left ventricular region using the multi-electrode catheter 14 in a signal pacing step 402. As can be seen in FIG. 3, most or all of the locations are around the area of ​​the catheter 14.

[0045] In response to pacing, system 10 receives respective ECG signals from the body surface electrodes in signal receiving step 403. A more detailed workflow of signal applying and acquiring steps 402-403 is provided in FIG.

[0046] The processor may then correlate the received ECG waveform with a reference ECG waveform indicative of VT (reference correlation method) and / or search for low correlation between the received waveforms (internal correlation method) in a waveform correlation step 404.

[0047] In an identification check step 406, processor 56 attempts to identify whether areas of assembly 28 are candidates for containing arrhythmogenic locations based on the spatial distribution of correlations.

[0048] If the processor identifies a candidate sub-area in step 406, the processor checks in required spatial resolution step 408 whether the area has been identified to the required resolution (e.g., catheter inactive electrode spacing of a few millimeters).

[0049] If the answer is no, the processor uses the correlation information to determine the subarea of ​​the catheter to pace in a subarea definition step 420 .

[0050] The processor then repeats step 402 for the electrodes associated with the sub-area.

[0051] If the answer is yes, then in an output step 418 the processor outputs an indication of the arrhythmogenic location to the user, for example, by marking the location on the EP map 202 .

[0052] If the processor does not identify a candidate area for an arrhythmogenic location in check step 406, the processor checks whether there are additional LV areas that have not yet been investigated (e.g., mapped) in mapping check step 415. If the answer is no, the process ends (step 417).

[0053] If the answer is yes, the processor instructs the user (e.g., physician 24) to move the catheter to the unsurveyed area in a catheter movement instruction step 425. The processor then repeats step 402 in the new area.

[0054] In some cases, the processor may determine, based on the spatial distribution of the correlation, in a direction check step (not shown), that a direction can be defined toward such a location, for example, based on the presence of a consistent gradient in the correlation. If a direction is found, the physician moves the catheter in that direction, and the process returns to step 402.

[0055] The flowchart in Figure 4 is an example, and additional steps may be included, such as repeated acquisitions in subareas for EP mapping of arrhythmogenic regions, which are omitted for simplicity.

[0056] FIG. 5 is a flowchart outlining, at a more detailed level, some steps of the method illustrated in FIG. 4 for detecting left ventricular arrhythmogenic locations using a large-area multi-electrode catheter, according to an embodiment of the present disclosure.

[0057] Acquisition selection step 502 details acquisition using catheter 14. Referring to Figure 3, step 502 involves selecting, in a first iteration, one of locations 302, 304, 306, and 308 around rectangular area 310 for bipolar pacing.

[0058] Next, in a signal quality check step 504, processor 56 checks whether the selected electrode pair used for bipolar pacing at the selected location is capable of generating a valid signal. For example, in this step, the system ensures that electrode-tissue contact is sufficient. This step may include checking that other criteria, such as those listed in the system definition, are met.

[0059] If the answer to step 504 is no, the processor exchanges at least one of the electrodes of the pair with the nearest adjacent electrode in an electrode exchange step 510 and the process returns to step 502 .

[0060] If the answer to step 504 is yes, the process proceeds to pacing at pacing step 506 .

[0061] The processor checks whether the ECG waveform has been received with the required quality in an acquisition check step 508 .

[0062] If the capture quality is insufficient, the processor replaces at least one of the pair of electrodes with the nearest adjacent electrode in an electrode replacement step 510 and the process returns to step 502 .

[0063] If the answer to step 508 is yes, the signal is saved for use in step 515 and the process returns to step 502 for pacing from another of the remaining locations.

[0064] After all required signals have been acquired, analysis step 515 corresponds to steps 403-406 of FIG. 4, in which the processor performs correlation techniques to identify arrhythmogenic subareas.

[0065] If a sub-area is found, the algorithm of FIG. 5 (eg, steps 502-510) is applied to the electrode pairs of the sub-area in an analysis step 525, which corresponds to steps 402-404 of FIG. [Example]

[0066] Example 1 The system 10 includes an interface 30 and a processor 56. The interface 30 is configured to transmit signals to a multi-electrode catheter 14 positioned within a ventricle of a patient's heart 12 and receive cardiac signals 21 acquired in response to the transmitted signals. The processor 56 is configured to apply pacing to the ventricle from multiple electrode 26 locations around an area 310 of the catheter 14, receive the cardiac signals 21 acquired in response to the pacing, apply a correlation algorithm to the received signals 21 to calculate multiple correlations between the received signals, and check whether the area 310 includes an identified arrhythmogenic location 318 with sufficient spatial resolution based on the calculated correlations. If the resolution is insufficient, the processor (56) is configured to define a subarea (320) to be paced, apply subsequent pacing to the ventricle from multiple electrode (26) locations around the subarea (320), receive subsequent cardiac signals (21) in response to the subsequent pacing, calculate subsequent correlations between the subsequent received signals (21) based on the subsequent correlations, determine whether an arrhythmogenic location (318) has been found within the subarea (320), and, if an arrhythmogenic location (318) is found with sufficient spatial resolution, indicate the identified arrhythmogenic location (318) to the user (24).

[0067] Example 2 The system (10) of Example 1, wherein the processor (56) is configured to check the area (310) with sufficient spatial resolution by checking an area surrounded by a set of adjacent catheter electrodes (26).

[0068] Example 3 A system (10) as described in any one of Examples 1 and 2, wherein in response to failure to find an arrhythmogenic location (318), the processor (56) is further configured to calculate and indicate a direction in which to move the catheter (14) based on the calculated correlation.

[0069] Example 4 The system (10) of any one of Examples 1 to 3, wherein the interface (30) is configured to receive an ECG signal from the body surface ECG electrodes (18) and thereby receive a cardiac signal (21) acquired in response to the transmitted signal.

[0070] Example 5 The system (10) of any one of Examples 1 to 4, wherein the multi-electrode catheter (14) comprises a flat, rectangular-shaped distal end assembly (28).

[0071] Example 6 The system (10) of any one of Examples 1 to 4, wherein the multi-electrode catheter (14) comprises a multi-arm distal tip assembly.

[0072] Example 7 7. The system (10) of any one of Examples 1 to 6, wherein the processor (56) is configured to apply a correlation algorithm to the received signals (21) to calculate multiple correlations between the received signals (21) by correlating the signals with a reference signal.

[0073] Example 8 8. The system (10) of any one of Examples 1 to 7, wherein the processor (56) is configured to apply a correlation algorithm to the received signals (21) to calculate a plurality of correlations between the received signals (21) by correlating the signals (21).

[0074] Example 9 9. The system (10) of any one of Examples 1 to 8, wherein the signal (21) acquired in response to pacing is an ECG signal acquired using body surface electrodes (18).

[0075] Example 10 The method includes applying pacing to a ventricle of a patient's heart (12) from multiple electrode (26) locations around an area (310) of a multi-electrode catheter (14). Cardiac signals (21) acquired in response to the pacing are received. A correlation algorithm is applied to the received signals (21) to calculate multiple correlations between the received signals (21). Based on the calculated correlations, the area (310) is checked to see if it contains the identified arrhythmogenic location (318) with a predetermined sufficient spatial resolution. If the resolution is insufficient, a subarea (320) for pacing is defined. Subsequent pacing is applied to the ventricle from multiple electrode (26) locations around the subarea (320). Subsequent cardiac signals (21) are received in response to the subsequent pacing. Subsequent correlations are calculated (21) between the subsequent received signals. Based on the subsequent correlation, it is determined whether an arrhythmogenic location 318 is found within the subarea 310. If an arrhythmogenic location 318 is found with sufficient spatial resolution, the identified arrhythmogenic location 318 is presented to the user 24.

[0076] It will be understood that the above-described embodiments are given by way of example, and that the present disclosure is not limited to what is particularly shown and described hereinabove. Rather, the scope of the present disclosure includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof not disclosed in the prior art that would occur to one skilled in the art upon reading the foregoing description.

[0077] [Embodiment] (1) A system comprising: an interface configured to transmit signals to a multi-electrode catheter positioned within a chamber of the patient's heart and to receive cardiac signals acquired in response to the transmitted signals; 1. A processor, comprising: applying pacing to the ventricle from multiple electrode locations around the area of ​​the catheter; receiving a cardiac signal acquired in response to the pacing; applying a correlation algorithm to the received signals to calculate a plurality of correlations between the received signals; checking whether the area contains an arrhythmogenic location identified with a predetermined sufficient spatial resolution based on the calculated correlation; If the resolution is insufficient, defining a subarea to be paced; applying subsequent pacing to the ventricle from multiple electrode locations around the subarea; receiving a subsequent cardiac signal in response to the subsequent pacing; calculating subsequent correlations between the subsequent received signals; determining whether the arrhythmogenic location is found within the sub-area based on the subsequent correlation; a processor configured to, if an arrhythmogenic location is found with sufficient spatial resolution, indicate the identified arrhythmogenic location to a user. (2) The system of embodiment 1, wherein the processor is configured to check the area with sufficient spatial resolution by checking an area surrounded by a set of adjacent catheter electrodes. (3) The system of embodiment 1, wherein in response to failure to find an arrhythmogenic location, the processor is further configured to calculate and indicate a direction in which to move the catheter based on the calculated correlation. (4) The system of embodiment 1, wherein the interface is configured to receive cardiac signals acquired in response to the transmitted signals by receiving ECG signals from body surface ECG electrodes. (5) The system of embodiment 1, wherein the multi-electrode catheter comprises a flat, rectangular-shaped distal end assembly.

[0078] (6) The system of embodiment 1, wherein the multi-electrode catheter comprises a multi-arm distal end assembly. (7) The system of embodiment 1, wherein the processor is configured to apply a correlation algorithm to the received signals to calculate multiple correlations between the received signals by correlating the signals with a reference signal. (8) The system of embodiment 1, wherein the processor is configured to calculate multiple correlations between the received signals by applying a correlation algorithm to the received signals to correlate the signals. (9) The system described in embodiment 1, wherein the signal obtained in response to the pacing is an ECG signal obtained using body surface electrodes. (10) applying pacing to a ventricle of the patient's heart from multiple electrode locations around an area of ​​the multi-electrode catheter; receiving a cardiac signal acquired in response to the pacing; applying a correlation algorithm to the received signals to calculate a plurality of correlations between the received signals; checking, based on the calculated correlation, whether the area contains an arrhythmogenic location identified with a predetermined sufficient spatial resolution; If the resolution is insufficient, defining a subarea to pace; applying subsequent pacing to the ventricle from multiple electrode locations around the subarea; receiving a subsequent cardiac signal in response to the subsequent pacing; calculating subsequent correlations between the subsequent received signals; determining whether the arrhythmogenic location is found within the subarea based on the subsequent correlation; and and if an arrhythmogenic location is found with sufficient spatial resolution, presenting the identified arrhythmogenic location to a user.

[0079] (11) The method of embodiment 10, wherein checking the area with sufficient spatial resolution includes checking an area surrounded by a set of adjacent catheter electrodes. (12) The method of embodiment 10, further comprising calculating and indicating a direction in which to move the catheter based on the calculated correlation in response to failure to find an arrhythmogenic location. (13) The method of embodiment 10, wherein receiving a cardiac signal acquired in response to the transmitted signal includes receiving an ECG signal from a body surface ECG electrode. (14) The method of embodiment 10, wherein the multi-electrode catheter comprises a flat, rectangular-shaped distal end assembly. (15) The method of embodiment 10, wherein the multi-electrode catheter comprises a multi-arm distal tip assembly.

[0080] (16) The method of embodiment 10, wherein applying a correlation algorithm to the received signals to calculate multiple correlations between the received signals includes correlating the signals with a reference signal. (17) The method of embodiment 10, wherein applying a correlation algorithm to the received signals to calculate a plurality of correlations between the received signals includes correlating the signals. (18) The method of embodiment 10, wherein the signal obtained in response to the pacing is an ECG signal obtained using body surface electrodes.

Claims

1. 1. A system comprising: an interface configured to transmit signals to a multi-electrode catheter positioned within a chamber of the patient's heart and to receive cardiac signals acquired in response to the transmitted signals; 1. A processor, comprising: applying pacing to the ventricle from multiple electrode locations around the area of ​​the catheter; receiving a cardiac signal acquired in response to the pacing; applying a correlation algorithm to the received signals to calculate a plurality of correlations between the received signals; checking whether the area contains an arrhythmogenic location identified with a predetermined sufficient spatial resolution based on the calculated correlation; If the resolution is insufficient, defining a subarea to be paced; applying subsequent pacing to the ventricle from multiple electrode locations around the subarea; receiving a subsequent cardiac signal in response to the subsequent pacing; calculating subsequent correlations between the subsequent received signals; determining whether the arrhythmogenic location is found within the sub-area based on the subsequent correlation; a processor configured to, if an arrhythmogenic location is found with sufficient spatial resolution, indicate the identified arrhythmogenic location to a user.

2. The system of claim 1 , wherein the processor is configured to check an area with sufficient spatial resolution by checking an area bounded by a set of adjacent catheter electrodes.

3. 2. The system of claim 1, wherein in response to failing to find an arrhythmogenic location, the processor is further configured to calculate and indicate a direction in which to move the catheter based on the calculated correlation.

4. The system of claim 1 , wherein the interface is configured to receive cardiac signals acquired in response to the transmitted signals by receiving ECG signals from body surface ECG electrodes.

5. The system of any one of claims 1 to 4, wherein the multi-electrode catheter comprises a flat, rectangular-shaped distal tip assembly.

6. The system of any one of claims 1 to 4, wherein the multi-electrode catheter comprises a multi-arm distal tip assembly.

7. 5. The system of claim 1, wherein the processor is configured to apply a correlation algorithm to the received signals to calculate multiple correlations between the received signals by correlating the signals with a reference signal.

8. 5. The system of claim 1, wherein the processor is configured to calculate a plurality of correlations between the received signals by applying a correlation algorithm to the received signals to correlate the signals.

9. The system of any one of claims 1 to 4, wherein the signal obtained in response to the pacing is an ECG signal obtained using body surface electrodes.

10. applying pacing to a ventricle of the patient's heart from a plurality of electrode locations circumferentially around an area of ​​the multi-electrode catheter; receiving a cardiac signal acquired in response to the pacing; applying a correlation algorithm to the received signals to calculate a plurality of correlations between the received signals; checking, based on the calculated correlation, whether the area contains an arrhythmogenic location identified with a predetermined sufficient spatial resolution; if the resolution is insufficient, defining a subarea to pace; applying subsequent pacing to the ventricle from multiple electrode locations around the subarea; receiving a subsequent cardiac signal in response to the subsequent pacing; calculating subsequent correlations between the subsequent received signals; determining whether the arrhythmogenic location is found within the subarea based on the subsequent correlation; and and if an arrhythmogenic location is found with sufficient spatial resolution, presenting the identified arrhythmogenic location to a user.

11. The method of claim 10 , wherein checking the area with sufficient spatial resolution comprises checking an area bounded by a set of adjacent catheter electrodes.

12. 11. The method of claim 10, further comprising, in response to failing to find an arrhythmogenic location, calculating and indicating a direction in which to move the catheter based on the calculated correlation.

13. 11. The method of claim 10, wherein receiving cardiac signals acquired in response to the transmitted signals comprises receiving ECG signals from body surface ECG electrodes.

14. The method of any one of claims 10 to 13, wherein the multi-electrode catheter comprises a flat, rectangular-shaped distal tip assembly.

15. The method of any one of claims 10 to 13, wherein the multi-electrode catheter comprises a multi-arm distal tip assembly.

16. 14. The method of claim 10, wherein applying a correlation algorithm to the received signals to calculate a plurality of correlations between the received signals comprises correlating the signals with a reference signal.

17. 14. The method of claim 10, wherein applying a correlation algorithm to the received signals to calculate a plurality of correlations between the received signals comprises correlating the signals.

18. The method of any one of claims 10 to 13, wherein the signal obtained in response to the pacing is an ECG signal obtained using body surface electrodes.

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