Identifying ventricular tachycardia (VT) targets by selective pacing

Abstract

The invention relates to identification of ventricular tachycardia (VT) targets by selective pacing. A method includes applying pacing to a ventricle of a heart of a patient from a plurality of electrode locations on a circumference of a multi-electrode catheter region. A cardiac signal is received in response to the pacing. A correlation algorithm is applied to the received signals to calculate a plurality of correlations between the received signals. Based on the calculated correlation, it is checked whether the region includes an arrhythmic location identified at a predefined sufficient spatial resolution. If the resolution is insufficient, the sub-region to be paced is defined. Subsequent pacing is applied to the ventricle from a plurality of electrode locations on the circumference of the sub-region. A subsequent cardiac signal is received in response to the subsequent pacing. A subsequent correlation between the subsequently received signals is calculated. Based on the subsequent correlations, it is determined whether to find the arrhythmic location in the sub-region. If an arrhythmic location is found with sufficient spatial resolution, the identified arrhythmic location is indicated to the user.

Description

Technical Field

[0001] This disclosure relates generally to electrophysiological (EP) signals, and more specifically to the assessment of electrical propagation in the heart. Background Technology

[0002] Electrophysiological signal estimation for determining the location of ventricular arrhythmias has been previously proposed in patent literature. For example, U.S. Patent 7,907,994 describes how to induce ventricular tachycardia (VT) signals in a living subject. Pacing mapping signals are then obtained from multiple points within the ventricle and automatically numerically compared with the induced signals. By identifying a high cross-correlation between the induced signals and one or more pacing mapping signals, arrhythmogenic lesions or pathways can be identified, which can then be ablated to prevent further arrhythmia induction.

[0003] As another example, U.S. Patent 10,891,728 describes a method for identifying isthmuses in a three-dimensional mapping of a heart chamber by means of a processing unit configured to perform the following steps: a) finding correlations between a set of stimulation sites of the heart chamber, each stimulation site being represented by a set of signals obtained from a surface electrocardiogram (ECG) excluding ventricular tachycardia; b) identifying watershed lines based on the above correlation results and the 3D coordinates of these stimulation sites in the 3D mapping; and c) determining the isthmus based on 3D channels substantially transverse to the watershed lines.

[0004] This disclosure will be more fully understood through the following detailed description of embodiments thereof, taken in conjunction with the accompanying drawings, in which: Attached Figure Description

[0005] Figure 1 This is a schematic illustration of a catheter-based electrophysiological (EP) pacing, mapping, and ablation system according to an example of this disclosure;

[0006] Figure 2 An example of a relation to this disclosure is illustrated schematically. Figure 1 EP mapping of the left ventricle with a large-area multi-electrode distal end assembly superimposed;

[0007] Figure 3A and Figure 3B Two examples of use according to this disclosure are illustrated schematically. Figure 1 Methods for detecting candidate left ventricular arrhythmogenic locations using catheters and regional reference correlation (3A) or regional intra-regional correlation (3B);

[0008] Figure 4This is a flowchart illustrating an example of a method for detecting left ventricular arrhythmogenic locations using a large-area multi-electrode catheter, according to this disclosure; and

[0009] Figure 5 This is a flowchart illustrating in detail an example of the method described in this disclosure: the method is used to describe Figure 4 Some steps of the method for detecting arrhythmogenic locations of the left ventricle using a large-area multi-electrode catheter. Detailed Implementation

[0010] Overview

[0011] To characterize arrhythmias in cardiac chambers such as the left ventricle (LV), physicians can use catheters to perform pacing at multiple LV tissue locations (e.g., applying a bipolar pacing signal between two adjacent catheter electrodes) to search for suspicious tissue pathways and circuits within the LV. During pacing, if a transient arrhythmic event occurs, such as an ectopic beat, premature beat, or ventricular premature beat (PVC), the event can be recorded using a 12-lead ECG device, displaying the abnormal signal pattern.

[0012] Various methods can be used to identify evoked arrhythmogenic events at a given ventricular location. For example, a physician can sample different regions of the ventricle and perform pattern matching (e.g., pattern matching of 12-lead ECG waveforms) between the acquired waveforms and stored pattern waveform characteristics of arrhythmias (e.g., VT) to identify correlations. High correlation indicates that the pacing site is part of the arrhythmogenic tissue. As another example, a physician can compare waveforms acquired only at different cardiac locations. In this case, low correlation indicates that at least one pacing site is closer to the arrhythmogenic tissue location.

[0013] However, sometimes, regardless of the correlation method used, physicians find it difficult to locate the site that elicits a consistent correlation. When this happens, it can be particularly challenging for physicians to determine the direction in which to move the catheter to obtain a meaningful correlation.

[0014] A method for guiding a physician to locate arrhythmogenic ventricular region is described in U.S. Patent Application 18 / 19599, filed May 11, 2023, entitled "Spatial Correlation to Identify Ventricle Location of Pattern Matching," which has been assigned to the assignee of this application. The method includes comparing cardiac signals received from multiple locations within the ventricle with reference signals indicating arrhythmia. Based on this comparison, a processor calculates a direction toward the target VT location and indicates this direction to the user, where the received signals may exhibit an enhanced correlation with the reference signal.

[0015] However, acquiring large amounts of high-quality data and finding meaningful correlations involves stabilizing catheters at multiple tissue locations and performing multiple corresponding pacing procedures. In real-world clinical scenarios, this workflow can be difficult to implement.

[0016] Some examples of this disclosure described below benefit from the use of large-area multi-electrode catheters placed in the LV, enabling the identification of VT target locations during clinical procedures with little or no catheter movement and minimal pacing steps.

[0017] In one example, a system is provided that includes an interface and a processor. The interface is configured to send signals to a multi-electrode catheter and receive cardiac signals, such as ECG signals from a 12-lead recorder, acquired in response to the sent signals. The processor is configured to apply pacing to the ventricle from multiple electrode locations on the circumference of a region of the catheter. The processor receives the cardiac signals acquired in response to pacing and applies a correlation algorithm to calculate multiple correlations between the received signals. Based on the calculated correlations, the processor checks whether the region includes an arrhythmogenic location identified with a predefined sufficient spatial resolution (e.g., to a region substantially equivalent to the region surrounded by adjacent catheter electrodes). If the resolution is insufficient, the processor defines a sub-region to be paced. The processor then applies subsequent pacing to a second region of the ventricle from multiple electrode locations on the circumference of the sub-region and receives subsequent cardiac signals in response to the subsequent pacing. The processor calculates subsequent correlations between the subsequently received signals. Based on these subsequent correlations, the processor determines whether an arrhythmogenic location is found in the sub-region. If a location of arrhythmogenicity is found with sufficient spatial resolution, the processor indicates the identified location of arrhythmogenicity to the user.

[0018] The disclosed method is applicable to use with any relevance calculation method, including both reference relevance (high relevance) search methods (such as those described in U.S. Patent 7,907,994) and internal relevance (low relevance) search methods (such as those described in U.S. Patent 10,891,728).

[0019] The disclosed technique utilizes the following observation: the bipolar pacing protocol produces very localized tissue type indication (e.g., covering at most a few mm). 2 This makes searching challenging (for tissue type indication). The authors found that using a large-area multi-electrode catheter could extend the search area for tissue type indication to several hundred mm. 2 The area covered depends on the catheter type. The disclosed technique covers this area with a minimal number of bipolar pacing steps. By reducing the number of pacing events and the number of catheter movements required, the disclosed technique makes the detection of VT location targets a more efficient process.

[0020] In one example, a rectangular geometry (e.g., 12×30mm) is used. 2 The catheter is placed by the physician. After placement, the system interface for this technique applies bipolar pacing to the LV location at the circumference (e.g., apex) of a rectangle. This interface receives 12-lead ECG signals acquired in response to pacing. Based on the spatial distribution of the correlations between the ECG signals, analysis of these signals allows the processor to determine whether it is advisable to narrow the search to a sub-region (e.g., quadrant) without moving the catheter. In a second iteration, the pacing location on the circumference of the sub-region is analyzed, which further narrows the search.

[0021] Typically, two iterations are sufficient if an arrhythmogenic location is present below the catheter. However, additional iterations involving receiving signals from locations within sub-regions can be used to pinpoint the target location.

[0022] The chosen search geometry may depend on the catheter geometry. For example, when using different catheters (e.g., multi-arm catheters), it may be useful to use a triangular mesh or a specialized mesh shape for the search.

[0023] Finally, even if the target location of arrhythmogenicity (e.g., VT) is not found, the processor performing iterative regional correlation analysis can recommend the direction for moving the catheter to search for the arrhythmogenic location based on the spatial distribution of the correlation. This direction can represent, for example, the direction in which the correlation changes abruptly.

[0024] System Description

[0025] Figure 1This is a schematic illustration of a catheter-based electrophysiological (EP) pacing, mapping, and ablation system 10 according to an example of this disclosure.

[0026] System 10 includes catheter 14, which is percutaneously inserted by physician 24 into the left ventricle of heart 12 via a sheath through the patient's vascular system. Catheter 14, illustrated herein by way of example, is configured for bipolar pacing. Physician 24 contacts the distal end assembly 28 of catheter 14 against the heart wall to perform pacing localization in a given area of ​​heart 12 in patient 23.

[0027] As shown in the figure, catheter 14 includes a large-area, flat distal end assembly 28 that carries multiple electrodes 26 located on multiple splines 22 and is configured to apply bipolar pacing signals. Catheter 14 may additionally include a positioning sensor 29 embedded in or near the distal end 28 on the axis 46 of catheter 14 for tracking the position and orientation of its distal end 28. Optionally and preferably, the positioning sensor 29 is a magnetic positioning sensor that includes three magnetic coils for sensing three-dimensional (3D) positioning and orientation.

[0028] The magnetic-based positioning sensor 29 operates in conjunction with a positioning pad 25, which includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predefined workspace. Real-time positioning of the distal end 28 of the conduit 14 can be tracked based on the magnetic field generated by the positioning pad 25 and sensed by the magnetic-based positioning sensor 29. Details of the magnetic-based positioning sensing technology are described in U.S. Patents 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.

[0029] System 10 includes one or more electrode patches 38 positioned to contact the skin of patient 23 to establish a position reference for impedance-based tracking of positioning pad 25 and electrodes 26. For impedance-based tracking, current is directed toward electrodes 26 and sensed at the electrode skin patch 38, allowing triangulation of the position of each electrode via the electrode patch 38. Details of the impedance-based position tracking technique are described in U.S. Patents 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182.

[0030] Recorder 11 displays cardiac signals 21 (e.g., an electrogram from a 12-lead ECG device acquired using surface ECG electrodes 18). Recorder 11 may include pacing capabilities for pacing rhythms and / or may be electrically connected to a separate pacemaker.

[0031] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, electrophysiological equipment, power supply, and workstation 55 to control the operation of system 10 and to receive EP signals or apply pacing signals from the catheter. The electrophysiological equipment of system 10 may include, for example, multiple catheters, positioning pads 25, surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally and preferably, the PIU 30 further includes processing capabilities for real-time calculation of catheter position and for performing ECG calculations.

[0032] Workstation 55 includes memory 57, a processor 56 unit with a memory or storage device in which appropriate operating software is loaded, and user interface capabilities. Workstation 55 may provide a variety of functions, optionally including: (i) three-dimensional (3D) modeling of the endocardial anatomy and rendering the model or anatomical mapping 20 for display on display device 27; (ii) displaying, on display device 27, activation sequences (or other data) compiled from recorded cardiac signals 21, on representative visual markers or images superimposed on the rendered anatomical mapping 20; (iii) displaying the real-time position and orientation of multiple catheters within the cardiac chambers; and (iv) displaying sites of interest on display device 27, such as where ablation energy has been applied. A commercial product embodying the elements of system 10 could be CARTO. TM The 3 system was purchased from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618.

[0033] In some examples, processor 56 typically includes a general-purpose computer programmed in software to perform the functions described herein. This software may be downloaded to the computer electronically via a network, or alternatively or additionally located and / or stored on a non-transitory tangible medium, such as magnetic storage, optical storage, or electronic storage.

[0034] System 10 may include an ablation energy generator 50 adapted to conduct ablation energy to one or more electrodes at the distal end of a catheter configured for ablation. The energy generated by the ablation energy generator 50 may include, but is not limited to, radio frequency (RF) energy or pulsed field ablation (PFA) energy (including monopolar or bipolar high-voltage DC pulses to be used to achieve irreversible electroporation (IRE), or combinations thereof.

[0035] For ablation, the physician 24 similarly guides the distal end of the ablation catheter to the target site. One or more additional catheters may be inserted via a sheath. These catheters may include catheters for sensing intracardiac electrogram signals, catheters dedicated to ablation, and / or catheters dedicated to both EP mapping and ablation.

[0036] This configuration of System 10 is illustrated by way of example to illustrate certain problems solved by the examples of this disclosure and to demonstrate the application of these examples in enhancing the performance of such systems. However, the examples of this disclosure are by no means limited to this particular category of example systems, and the principles described herein can be similarly applied to other categories of medical systems. For example, other types of multi-electrode catheters, such as OCTARAY, can be used. TM A catheter or basket-shaped catheter.

[0037] Pacing using a large-area multi-electrode catheter

[0038] Figure 2 An example of a relation to this disclosure is illustrated schematically. Figure 1 EP mapping of the left ventricle with a large-area multi-electrode distal end assembly 28 superimposed. Figure 2 A possible arrhythmogenic region 204 is also shown. This region may include isthmuses that require ablation to eliminate VT.

[0039] As shown in the figure, the area of ​​the distal end assembly 28 can be larger than or equivalent to the typical area of ​​region 204. Therefore, the likelihood of finding an arrhythmogenic location below the catheter region is high. Even if the search area is larger than the catheter region, the disclosed technique covers this 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 more efficient process.

[0040] As further observed, region 204 is not entirely located below the distal end assembly 28, but rather within the capture range. This means that, in some cases, based on region-level analysis of correlation values, the processor can recommend directions for moving the distal end assembly 28 to cover region 204 (i.e., within...). Figure 2 (Move upwards from the center).

[0041] Regional iterative search for VT target location

[0042] Figure 3A and Figure 3B Two examples of use according to this disclosure are illustrated schematically. Figure 1Methods for detecting candidate left ventricular arrhythmogenic locations using catheters and regional reference correlation (3A) or regional intra-regional correlation (3B).

[0043] exist Figure 3A In this process, bipolar pacing ECG signals (not shown) are received in response to positions 302, 304, 306, and 308 on the circumference of the catheter rectangular region 310. The corresponding reference correlation values ​​(in percentage) for these positions are calculated as 95, 85, 85, and 85. The higher reference correlation value at position 302 indicates that the candidate arrhythmogenic location or region is located in the direction of position 302 (e.g., in the upper left quadrant in a coordinate system with the center of rectangle 310 as the origin).

[0044] In the second iteration of the disclosed method, bipolar pacing ECG signals are received in response to positions 312, 314, and 316 on the circumference of sub-region 320 of component 28. The corresponding reference correlation values ​​(in percentage) for the positions at the vertices of sub-region 320 are calculated to be 95, 97, 90, and 94. Higher reference correlation values ​​at positions 302 and 312 indicate that the arrhythmogenic location or region is located in the direction of positions 302 and 312.

[0045] To accurately pinpoint the target location, additional ECG signals in response to bipolar pacing positions 318 and 319 are received, thereby generating reference correlation values ​​(in percentage) of 99 and 97, respectively.

[0046] Based on these results, the processor designates location 318 as the target location (e.g., for ablation). Further mapping can be performed around the arrhythmogenic location 318 (an additional location not shown) to determine the shape of the arrhythmogenic region (e.g., the shape of an isthmus).

[0047] exist Figure 3B The system receives bipolar pacing ECG signals at positions 332, 334, 336, 338, and 340 on the circumference of catheter region 330. Positions 336 and 338 are selected after an unstable reading is given at the edge rectangle position marked with an "X".

[0048] The corresponding internal correlation values ​​(in percentage) of the ECG signals between pacing positions (332-334), (332-334), (334-336), (336-338), (338-340), and (340-332) were calculated to be 75, 85, 90, 75, and 75, respectively. A lower internal correlation value received when the position involves the left side indicates that the arrhythmogenic location or region is located to the left of region 330.

[0049] In the second iteration of the disclosed method, ECG signals pacing bipolarly at positions 342, 344, and 346 on the circumference of the catheter trapezoidal region 350 are received. 75% of the calculated internal correlation values ​​around the upper left quadrant of the catheter indicate the possible location or region of arrhythmia within that quadrant.

[0050] To pinpoint the target location, an additional ECG signal in response to bipolar pacing position 348 is received, generating a calculated internal correlation value (in percentage) of 25. Based on these results, the processor designates position 348 as the target location (e.g., for ablation). Similarly, further mapping can be performed around position 348 (not shown) to determine the shape of the arrhythmogenic region (e.g., the shape of an isthmus).

[0051] As mentioned above, if the target location is not found below component 28, then... Figure 3A and Figure 3B The results given in the first iteration are quite significant, but less obvious in subsequent iterations. These results will still indicate the presence of a correlation gradient in the direction of the upper left quadrant, prompting the user to move the catheter in this direction to search for arrhythmogenic regions.

[0052] VT target location region-level iterative search method

[0053] Figure 4 This is a flowchart illustrating an example of a method for detecting left ventricular arrhythmogenic locations using a large-area multi-electrode catheter, according to one example of this disclosure. According to the given example, the algorithm performs the following process: the process begins at signal pacing step 402 where system 10 uses multi-electrode catheter 14 to pace multiple locations within the left ventricular region. Most or all locations are on the circumference of the region of catheter 14, as shown in Figure 3.

[0054] At signal receiving step 403, system 10 receives the corresponding ECG signal from the body surface electrode in response to pacing. Figure 5 A more detailed workflow for signal application and acquisition steps 402-403 is provided in the document.

[0055] Next, at waveform correlation step 404, the processor may correlate the received ECG waveform with a reference ECG waveform indicating VT (reference correlation method) and / or search for low correlations between the received waveforms (internal correlation method).

[0056] At identification check step 406, processor 56 attempts to identify whether a region of component 28 is a candidate region that includes arrhythmogenic locations based on the spatial distribution of correlation.

[0057] If the processor identifies a candidate sub-region at step 406, the processor checks at step 408 whether the identified region meets the required spatial resolution (e.g., a few millimeters of inert electrode spacing in a conduit).

[0058] If the answer is no, the processor uses the correlation information at subregion definition step 420 to determine the subregion of the catheter to be paced.

[0059] Then, the processor repeats step 402 to adjust the electrodes associated with the sub-region.

[0060] If the answer is yes, the processor outputs an indication of the arrhythmogenic location to the user at output step 418, for example by marking the location on the EP mapping map 202.

[0061] If the processor does not identify a candidate region for arrhythmogenic location at check step 406, the processor checks at mapping check step 415 whether there is another LV region that has not yet been explored (e.g., mapped). If the answer is no, the process ends (step 417).

[0062] If the answer is yes, the processor instructs the user (e.g., physician 24) to move the catheter to an unexplored area at catheter movement instruction step 425. The processor then repeats step 402 in the new area.

[0063] In some cases, the processor can determine a direction defined toward such a location at the orientation check step (not shown) based on the spatial distribution of the correlation, such as the presence of a consistent correlation gradient. If a direction is found, the physician moves the catheter in that direction, and the process returns to step 402.

[0064] Figure 4 The flowchart is given by way of example. For example, additional steps may be included, such as repeated acquisitions within the sub-region to plot the EP mapping of the arrhythmogenic region; these steps are omitted for simplicity.

[0065] Figure 5 This is based on an example of the present disclosure at a more detailed level. Figure 4 A flowchart illustrating some steps of the method is provided, which uses a large-area multi-electrode catheter to detect arrhythmogenic locations in the left ventricle.

[0066] Acquisition selection step 502 details the acquisition using catheter 14. Referring to Figure 3, step 502 includes selecting one of positions 302, 304, 306, and 308 on the circumference of rectangular region 310 for bipolar pacing during the first iteration.

[0067] Next, at signal quality check step 504, processor 56 checks whether the selected electrode pair to be used for bipolar pacing at the selected location can generate a valid signal. For example, in this step, the system ensures that the electrode-tissue contact is sufficient. This step may include checking whether other criteria listed in the system definition are met.

[0068] If the answer to step 504 is no, the processor replaces at least one electrode in the pair of electrodes with the nearest neighboring electrode at electrode replacement step 510, and the process returns to step 502.

[0069] If the answer to step 504 is yes, the process continues to step 506 to perform pacing.

[0070] At capture check step 508, the processor checks whether the ECG waveform has been received with the required quality.

[0071] If the capture quality is insufficient, the processor replaces at least one electrode in the electrode pair with the nearest electrode at electrode replacement step 510, and the process returns to step 502.

[0072] If the answer to step 508 is yes, the signal is saved for use in step 515, and the process returns to step 502 to start pacing from another of the remaining positions.

[0073] After capturing all the desired signals, analysis step 515 corresponds to Figure 4 Steps 403-406, in which the processor runs a correlation method to identify arrhythmogenic sub-regions.

[0074] If a subregion is found, then in the corresponding Figure 4 In step 525 of the analysis in steps 402-404, Figure 5 The algorithm (e.g., steps 502-510) is applied to the electrode pairs in the sub-region.

[0075] Example

[0076] Example 1

[0077] A system (10) includes an interface (30) and a processor (56). The interface (30) is configured to send signals to a multi-electrode catheter (14) placed in the ventricle of a patient's heart (12) and to receive cardiac signals (21) acquired in response to the sent signals. The processor (56) is configured to apply pacing to the ventricle from multiple electrode (26) locations on the circumference of a region (310) of the catheter (14), receive cardiac signals (21) acquired in response to pacing, apply a correlation algorithm to the received signals (21) to calculate multiple correlations between the received signals, and, based on the calculated correlations, check whether the region (310) includes a cardiac arrhythmogenic location (318) identifiable with a predefined sufficient spatial resolution. If the resolution is insufficient, the processor (56) is configured to: define a sub-region (320) to be paced; apply subsequent pacing to the ventricle from the locations of a plurality of electrodes (26) on the circumference of the sub-region (320); receive subsequent cardiac signals (21) in response to the subsequent pacing; calculate subsequent correlations between these subsequently received signals (21); determine, based on these subsequent correlations, whether the arrhythmogenic location (318) is found in the sub-region (320); and if the arrhythmogenic location (318) is found with the sufficient spatial resolution, indicate the identified arrhythmogenic location (318) to the user (24).

[0078] Example 2

[0079] According to the system (10) of Embodiment 1, the processor (56) is configured to inspect the region (310) with sufficient spatial resolution by inspecting the region surrounded by a set of adjacent conduit electrodes (26).

[0080] Example 3

[0081] According to any one of Embodiments 1 and 2, the system (10) wherein, in response to the failure to find an arrhythmogenic location (318), the processor (56) is further configured to calculate and indicate the direction for moving the catheter (14) based on the calculated correlation.

[0082] Example 4

[0083] According to any one of embodiments 1 to 3, the system (10) wherein the interface (30) is configured to receive a cardiac signal (21) acquired in response to a transmitted signal by receiving an ECG signal from a surface ECG electrode (18).

[0084] Example 5

[0085] The system (10) according to any one of embodiments 1 to 4, wherein the multi-electrode conduit (14) includes a distal end assembly (28) in a flat rectangular shape.

[0086] Example 6

[0087] The system (10) according to any one of embodiments 1 to 4, wherein the multi-electrode conduit (14) includes a multi-arm distal end assembly.

[0088] Example 7

[0089] According to any one of embodiments 1 to 6, the system (10) 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 these signals with a reference signal.

[0090] Example 8

[0091] According to any one of embodiments 1 to 7, the system (10) wherein the processor (56) is configured to apply a correlation algorithm to the received signals (21) to calculate multiple correlations between the received signals by correlating them (21).

[0092] Example 9

[0093] According to any one of Embodiments 1 to 8, the system (10) wherein the signals (21) acquired in response to the pacing are ECG signals acquired using a body surface electrode (18).

[0094] Example 10

[0095] A method comprising applying pacing to the ventricle of a patient’s heart (12) from multiple electrode (26) locations on the circumference of a region (310) of a multi-electrode catheter (14). Receiving cardiac signals (21) acquired in response to the pacing. Applying a correlation algorithm to the received signals (21) to calculate multiple correlations between the received signals (21). Based on the calculated correlations, checking whether the region (310) includes a cardiogenic arrhythmogenic location (318) identifiable with a predefined sufficient spatial resolution. If the resolution is insufficient, defining a sub-region (320) to be paced. Applying subsequent pacing to the ventricle from multiple electrode (26) locations on the circumference of the sub-region (320). Receiving subsequent cardiac signals (21) in response to the subsequent pacing. Calculating subsequent correlations between the subsequently received signals (21). Based on these subsequent correlations, determining whether the cardiogenic arrhythmogenic location (318) is found in the sub-region (310). If an arrhythmogenic location (318) is found with sufficient spatial resolution, the identified arrhythmogenic location (318) is indicated to the user (24).

[0096] It should be understood that the above embodiments are cited by way of example, and this disclosure is not limited to the content specifically shown and described above. Rather, the scope of this disclosure includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which should be apparent to those skilled in the art upon reading the above description, and which are not disclosed in the prior art.

Claims

1. A system comprising: An interface configured to send signals to a multi-electrode catheter placed in the ventricle of a patient's heart and to receive cardiac signals acquired in response to the sent signals; and Processor, the processor being configured to: Pacing is applied to the ventricle from multiple electrode locations on the circumference of the region of the catheter; Receive cardiac signals acquired in response to the pacing; A correlation algorithm is applied to the received signals to calculate multiple correlations between the received signals; Based on the calculated correlation, check whether the region includes arrhythmogenic locations identified with a predefined sufficient spatial resolution. If the resolution is insufficient, define the sub-region to be paced; Subsequent pacing is applied to the ventricle from multiple electrode locations on the circumference of the sub-region; Receive subsequent cardiac signals in response to the subsequent pacing; Calculate the subsequent correlation between subsequently received signals; Based on the subsequent correlation, determine whether the arrhythmogenic location is found in the sub-region; as well as If an arrhythmogenic location is found with the said sufficient spatial resolution, the user is indicated to the identified arrhythmogenic location.

2. The system according to claim 1, wherein, The processor is configured to inspect the region with sufficient spatial resolution by inspecting a region surrounded by a set of adjacent conduit electrodes.

3. The system according to claim 1, wherein, In response to the failure to find a location of arrhythmogenicity, the processor is further configured to calculate and indicate the direction for moving the catheter based on the calculated correlation.

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

5. The system according to any one of claims 1 to 4, wherein, The multi-electrode conduit includes a distal end assembly in a flat rectangular shape.

6. The system according to any one of claims 1 to 4, wherein, The multi-electrode conduit includes a multi-arm distal end assembly.

7. The system according to any one of claims 1 to 4, wherein, The processor is configured to apply a correlation algorithm to the received signal to calculate multiple correlations between the received signals by correlating the signal with a reference signal.

8. The system according to any one of claims 1 to 4, wherein, The processor is configured to apply a correlation algorithm to the received signals to calculate multiple correlations between the received signals by correlating them.

9. The system according to any one of claims 1 to 4, wherein, The signal acquired in response to the pacing is an ECG signal acquired using a surface electrode.

10. A method comprising: Pacing is applied to the ventricles of the patient's heart from multiple electrode positions on the circumference of the region of the multi-electrode catheter; Receive cardiac signals acquired in response to the pacing; A correlation algorithm is applied to the received signals to calculate multiple correlations between the received signals; Based on the calculated correlation, check whether the region includes arrhythmogenic locations identified with a predefined sufficient spatial resolution. If the resolution is insufficient, define the sub-region to be paced; Subsequent pacing is applied to the ventricle from multiple electrode locations on the circumference of the sub-region; Receive subsequent cardiac signals in response to the subsequent pacing; Calculate the subsequent correlation between subsequently received signals; Based on the subsequent correlation, determine whether the arrhythmogenic location is found in the sub-region; as well as If an arrhythmogenic location is found with the said sufficient spatial resolution, the user is indicated to the identified arrhythmogenic location.

11. The method according to claim 10, wherein, Examining the region with sufficient spatial resolution includes examining the region surrounded by a set of adjacent conduit electrodes.

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

13. The method according to claim 10, wherein, Receiving cardiac signals acquired in response to transmitted signals includes receiving ECG signals from surface ECG electrodes.

14. The method according to any one of claims 10 to 13, wherein, The multi-electrode conduit includes a distal end assembly in a flat rectangular shape.

15. The method according to any one of claims 10 to 13, wherein, The multi-electrode conduit includes a multi-arm distal end assembly.

16. The method according to any one of claims 10 to 13, 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 according to any one of claims 10 to 13, wherein, Applying a correlation algorithm to the received signals to calculate multiple correlations between the received signals includes performing correlation between the signals.

18. The method according to any one of claims 10 to 13, wherein, The signal acquired in response to the pacing is an ECG signal acquired using a surface electrode.

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