Method and system for identifying conduction flow pathways in an anatomical map

Abstract

To provide a system and method for real-time planning and monitoring of cardiac ablation using an anatomical map.SOLUTION: The method includes receiving an anatomical map of wall tissue of at least a portion of a cardiac chamber, the map being overlaid with ablation tags. A non-conductive zone is defined around each ablation tag for at least some of the ablation tags to calculate a block area. Markings of a start point and an end point on the map of potential conduction flow are received from a user. One or more possible conduction flow paths are searched from the start point to the end point using a search algorithm, wherein the one or more existing paths take into account the blocked region. The one or more flow paths found by the search algorithm are overlaid on the anatomical map. The overlaid anatomical map is presented to the user.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates generally to cardiac ablation, and more particularly to systems and methods for real-time planning and monitoring of cardiac ablation using anatomical maps. [Background technology]

[0002] Providing an indication of ablation gaps on an anatomical map of the inner wall of a cardiac chamber has been proposed in the patent literature. For example, U.S. Patent No. 9,757,182 describes a method that includes receiving the locations of multiple ablation sites formed on the surface of the heart. Distances are measured between at least some of the ablation sites based on the locations. One or more gaps between the ablation sites that meet alarm criteria are identified. The identified gaps are displayed to the operator.

[0003] The present disclosure will be more fully understood from the following detailed description of the embodiments thereof, taken in conjunction with the drawings, in which: [Brief explanation of the drawings]

[0004] [Figure 1] 1 is a schematic, pictorial illustration of a catheter-based electroanatomical (EA) mapping and ablation system, according to one embodiment of the present disclosure; [Figure 2A] 1A-1B are anatomical maps of cardiac wall tissue schematically superimposed with (a) ablation tags and derived non-conducting zones, and (b) simulated conduction pathways, respectively, according to one embodiment of the present disclosure. [Figure 2B] 1A-1B are anatomical maps of cardiac wall tissue schematically superimposed with (a) ablation tags and derived non-conducting zones, and (b) simulated conduction pathways, respectively, according to one embodiment of the present disclosure. [Figure 3]1 is a flowchart that schematically illustrates a method for deriving and displaying possible surviving conduction flow pathways on an anatomical map, according to one embodiment of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram of a graphical user interface (GUI) used to select preferences in modeling potential residual conduction flow, according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0005] overview In catheter-based cardiac ablation procedures designed to treat arrhythmias such as pulmonary vein isolation (PVI) and atrial fibrillation (AFib), physicians ablate tissue in specific anatomical regions (e.g., around the entire circumference of a pulmonary vein ostium). Ablation procedures, such as those using pulsed-field ablation (PFA) techniques, may require multiple iterations to cover the entire circumference of the pulmonary vein ostium. Each iteration requires moving the ablation catheter to an area where arrhythmogenic conduction has not yet been blocked by the ablation.

[0006] To successfully complete the ablation, the physician can be assisted by ablation tags distributed across the surface of the 3D anatomical map (seen schematically in Figure 2A) that identify clinically relevant superficial tissue regions that have not yet been ablated.

[0007] Several ablation tag types can be used, such as (i) small, densely spread tags (applied on a grid of ablation points) to delineate tissue regions that receive diffuse ablation power, and (ii) larger, more dispersed tags that specify the point locations where the catheter applies ablation.

[0008] However, a large number of ablation tags superimposed on the map surface can cause visual clutter, and it remains difficult to make a definitive decision about any region that displays a mix of ablation tags indicating partial (e.g., incomplete) ablation along with tags indicating complete ablation.

[0009] The above-mentioned challenges due to visual noise caused by tags can adversely affect the physician's ability to (i) align the visualized 3D position of the catheter with the previous ablation location, (ii) assess the extent of tissue damage that has occurred, and (iii) identify gaps in the ablation.

[0010] Some examples of the present disclosure described herein provide a real-time visualization technique for identifying possible surviving conduction flow pathways on a map (as seen in FIG. 2B ) that can assist physicians in addressing the above-mentioned challenges. The technique uses ablation tag information to calculate possible pathways through candidate breakthrough regions left after previous ablations. The visualized pathways focus the physician's consideration of whether and where further ablations may be needed to eliminate the arrhythmia, while simultaneously hiding the ablation tags to eliminate visual clutter.

[0011] The viable paths are identified using A(n) algorithms, one of many first-order search algorithm types widely discussed in the scientific and engineering literature. * The algorithm is calculated using a "first search" algorithm, such as the algorithm. An example is "Generalized Best First Search Strategies and the Optimality of A" by R. Dechter and J. Pearl. * ” (The Journal of the Association for Computing Machinery, Volume 32, No. 3, pp. 505-536 (1985)).

[0012] D suitable for real-time use * Other pathfinding algorithms, such as the D * The algorithm may further assist the physician in terminating the ablation as the physician progressively interrupts (e.g., ablates) residual conduction pathways. * Algorithm for Real-Time Re-planning" * A paper describing the algorithm was published by A. Stentz in Proceedings of the International Joint Conference on Classification on Artificial Intelligence, pp. 1652-1659, (1995).

[0013] In one example of the disclosed technology, a processor executes an algorithm that performs the following steps: 1. For at least some of the ablation tags, define a scar region (e.g., a sphere of a given radius) around each ablation tag. The size of the scar region (e.g., the radius of the sphere) can be customized by the algorithm according to the level of ablation (e.g., using an existing ablation index scale or touch proximity index (TPI)) to reflect likely blocking regions and possible conductive regions in addition to gaps, as seen in FIG. 2A. In another example, the user can also configure the radius based on other considerations (e.g., experience) independent of the ablation index or TPI. A * The algorithm uses the scar area defined as "blocked" to the possible pathway as the first spatial input. 2. As seen in Figure 2A, to inquire whether conduction flow can occur through the candidate breakthrough region, the user is asked to indicate on the map the start and end points of possible paths on either side of the ablation line in the candidate breakthrough region. A* The algorithm uses the user's start (origin) location on the map and the end (target) location on the map as second spatial input to define the possible route directions. 3. A first search algorithm (e.g., A) is run to calculate possible existing pathways and, optionally, indicate possible conduction block zones within the map region of interest. * algorithm). A * The algorithm uses the first spatial input and the second spatial input in calculating all possible paths between the marked origin and the marked target, taking into account the "blocked" area. 4. Visualize the calculated path on a map to show the user only the possible surviving pathways of conduction flow, as seen in Figure 2B. Ablation tags are then hidden to reduce visual clutter.

[0014] In one example shown in Figure 4, a graphical user interface (GUI) provided by the disclosed technology allows a user to determine whether the algorithm should consider the level of ablation at each tag location. The exemplary GUI also allows a user to include block regions created during previous surgical procedures. The user can further determine whether ablation tags remain visible on the map that is overlaid with the path.

[0015] Displaying potential surviving conduction flow pathways on the map can facilitate the physician's work because (a) only a portion of the map needs to be confirmed and (b) clearer guidance regarding ambiguous map regions is received. Note that while the presented pathways can help optimize workflow (e.g., focus attention and reduce physician workload), they are not intended as suggestions for any specific ablation locations. Rather, such later clinical steps are left to the physician's discretion.

[0016] Finally, although the disclosed techniques have been demonstrated for the ablation treatment of AFib, they are also applicable to the ablation treatment of other types of arrhythmias, such as ventricular arrhythmias.

[0017] System Description FIG. 1 is a schematic, pictorial illustration of a catheter-based electroanatomical (EA) mapping and ablation system 10, according to one embodiment of the present disclosure.

[0018] The system 10 includes multiple catheters that are percutaneously inserted by a physician 24 through the patient's vascular system into the chambers or vasculature of the heart 12 (seen in inset 45). Typically, a delivery sheath catheter is inserted into a chamber, such as the left or right atrium, near a desired location within the heart 12. Multiple catheters can then be inserted into the delivery sheath catheter to reach the desired location. The multiple catheters can include catheters dedicated to pacing, catheters for sensing intracardiac electrogram signals, catheters dedicated to ablation, and / or catheters dedicated to both EA mapping and ablation. The exemplary catheter 14 shown herein is configured to sense bipolar electrograms and pulsed field ablation (PFA). The physician 24 brings a distal tip 28 (hereinafter also referred to as a distal end assembly 28) of the catheter 14 into contact with the heart wall to ablate a target site in the heart 12.

[0019] As seen in inset 65, catheter 14 is an exemplary catheter that optionally includes a lasso distal tip assembly 28 that includes one, and preferably multiple, electrodes 26 distributed across curved spline 22. Catheter 14 may further include a position sensor 29 embedded in or near distal tip 28 on shaft 46 of catheter 14 for tracking the position and orientation of distal tip 28. Optionally, and preferably, position sensor 29 is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0020] The magnetic-based position sensor 29 may operate 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.

[0021] 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.

[0022] Recorder 11 displays cardiac signals 21 (e.g., electrograms acquired at each tracked cardiac tissue location) acquired using body surface ECG electrodes 18 and intracardiac electrograms acquired using electrodes 26 of catheter 14. Recorder 11 may include pacing capability for pacing the cardiac rhythm and / or may be electrically connected to a stand-alone pacer.

[0023] 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 (PF) energy, or combinations thereof, including monopolar or bipolar and monophasic, biphasic high-voltage DC pulses used to produce irreversible electroporation (IRE).

[0024] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheters, electrophysiology equipment, power source, and workstation 55 to control the operation of system 10 and to receive EA signals from the catheters. 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.

[0025] The workstation 55 includes a memory 57, a processor 56 unit having memory or storage 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 in a representative visual representation or image superimposed on the rendered anatomical map 20 on the display device 27, (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.

[0026] In the disclosed example, processor 56 executes an algorithm to define, for at least some of the ablation tags on an anatomical map, such as map 20, a non-conductive zone around each ablation tag. Physician 24 marks the start and end points of potential conducted wave flow on the map, and processor 56 then applies a first search algorithm to simulate the conducted wave flow from the start point to the end point. The processor overlays any found conducted flow paths on the anatomical map and presents the resulting map (e.g., as seen in FIG. 2B ) to the physician.

[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] 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 basket catheters, may be used.

[0029] Arrhythmia breakthrough flow simulation 2A and 2B are anatomical maps 200 and 201 of cardiac wall tissue, respectively, schematically superimposed with (a) ablation tags (205, 212) and derived non-conducting zones 214, and (b) simulated conduction pathways 210, according to one embodiment of the present disclosure.

[0030] Ablation tags 205 designate the point locations where the catheter applied ablation. Ablation tags 212 delineate the ablated tissue region (e.g., tags 212 trace the surface tissue locations that received the diffused ablation power). Small, densely spread tags 212 are applied on a grid of ablation points that cover the ablated region. Larger, more dispersed tags 205 are applied after the ablation event.

[0031] A processor executing the disclosed algorithm defines, for at least some of the ablation tags, a scar region (e.g., a sphere 209 or 222 of a given radius depending on the ablation index or custom user configuration unrelated to any of the ablation parameters) around each respective ablation tag 205 or 212. The intersection of each sphere with the surface of the map defines an area. Each intersection region or the union of these intersection regions defines a block region 214. The user can customize the scar tag configuration (e.g., radius size) according to the ablation index scale to reflect a likely block region 214, as seen in FIG. 2A .

[0032] The user marks a start point 206A and an end point 206B on the map 200 to inquire whether any potential conduction pathways remain between the points. The start and end points are located on either side of the ablation line and mark the region of interest where the user wishes to determine potential residual conduction.

[0033] The processor searches for the existence of a possible conduction path from the starting point 206A to the ending point 206B (e.g., A * (The algorithm simulates this.) Any possible pathways 210 of conduction flow found are superimposed on the anatomical map 200. The ablation tags are then hidden to avoid visual clutter, as seen in map 201 of FIG. 2B.

[0034] A * The algorithm uses as a first spatial input the scar region (209, 222) defined as "blocked" (214) relative to the possible pathway (210). * The algorithm uses the user's start (origin) location on the map 200 and the end (target) location on the map 200 as a second spatial input to define the possible route directions. *The algorithm uses the first spatial input and the second spatial input in calculating all possible paths between the marked origin and the marked target, taking into account the "blocked" area.

[0035] Map 201 typically allows a physician to explore possible pathways 210 of remaining conduction flow, for example, using electrophysiology analysis tools, to determine specific locations on the pathways worth ablation. To this end, map 200 may be an EA map, such as a late activation (LAT) map.

[0036] The diagrams of Figures 2A and 2B are shown by way of example: the user may select different start and end points on the map to inquire about other possible paths of the conducted wave, as an example.

[0037] Methods for deriving and displaying potential conductive flow paths 3 is a flow chart that schematically illustrates a method for deriving and displaying possible surviving conduction flow pathways 210 on an anatomical map 200, according to one embodiment of the present disclosure. According to the embodiment presented, the algorithm executes a process that begins with processor 56 receiving an anatomical map 200 superimposed with ablation tags (205, 212) in an ablation map receive step 302.

[0038] Processor 56 then defines, for at least some of the ablation tags, a sphere of non-conductive zones (eg, a sphere) around each ablation tag in a non-conductive zone definition step 304 .

[0039] Next, the processor calculates the block area 214 as described in FIG. 2A in a block area calculation step 306 .

[0040] In a user query step 308, the processor receives from the user markings of start and end points on the map 200 and queries any possible remaining conduction flow paths between the points. For example, the user may click on either side of the ablation line created by the block region 214, as seen in FIG. 2A, in which the user wishes to determine candidate remaining conduction paths.

[0041] Using the block region 214 and the user query as input, the processor, in a path simulation step 310, executes an algorithm (e.g., A * algorithm).

[0042] In a superposition step 312, the processor superimposes any found possible surviving pathways 210 of conduction flow onto the anatomical map 200, resulting in the map 201 of Figure 2B. Ablation tags may or may not be presented on the map 201 based on the visualization settings configuration (e.g., using the GUI 111 as described in Figure 3). Algorithmically defined block regions are not presented / visualized on the map 201.

[0043] Finally, in a map presentation step 314, the processor presents the superimposed map 201 to the user on a display.

[0044] A preference setting GUI for deriving and displaying potential surviving conduction flow paths FIG. 4 is a schematic diagram of a graphical user interface (GUI) 111 used to select 444 preferences for modeling potential residual conduction flow, according to one embodiment of the present disclosure.

[0045] A user of GUI 111 may choose to define a sphere size around the scar zone according to their professional judgment by marking one of the checkboxes on the GUI (444). Selecting another checkbox displays the resulting map without the ablation tags (presenting only any possible surviving pathways), as shown in Figure 2B.

[0046] The user can choose to include surgically induced occlusion areas if recorded.

[0047] Finally, the user may choose to mark (eg, using a computer mouse) areas that the physician deems irrelevant for tracing pathways.

[0048] The GUI of Figure 4 is presented as an example, and different GUI alternatives may be included in the disclosed technology. For example, a GUI may be provided that includes a menu for controlling the graphical encoding of any found path. Another GUI may allow a user to select and mark multiple pairs of start and end points for path searching and graphically encode any found path in different ways according to the different start and end points. [Example]

[0049] Example 1 The method includes receiving an anatomical map (200) of wall tissue of at least a portion of a cardiac chamber, the map being overlaid with ablation tags (205, 212). A non-conductive zone (209) is defined around each ablation tag (205, 212) for at least some of the ablation tags to calculate a blockage region (214). Markings of start points (206A) and end points (206B) on the map (200) of potential conduction flow are received from a user. One or more possible conduction flow paths (210) are searched for from the start points (206A) to the end points (206B) using a search algorithm, where one or more existing paths (210) take into account the blockage region (214). The one or more flow paths (210) found by the search algorithm are overlaid on the anatomical map. The overlaid anatomical map (201) is presented to the user.

[0050] Example 2 The method of Example 1, comprising not displaying ablation tags (205, 212) on the superimposed anatomical map (201).

[0051] Example 3 The method described in Example 1 or 2, wherein the non-conductive zone (209) around a given ablation tag (205, 212) is a sphere of a given size derived from the ablation index value of the given ablation tag (205, 212).

[0052] Example 4 4. The method according to any one of Examples 1 to 3, wherein calculating the block region (214) comprises calculating an intersection of a sphere with a surface of the anatomical map (200).

[0053] Example 5 5. The method of any one of Examples 1-4, wherein searching for one or more conductive flow paths (210) comprises using a first search algorithm.

[0054] Example 6 The method according to any one of Examples 1 to 5, wherein using the first search algorithm comprises: A * The method includes using a pathfinding algorithm.

[0055] Example 7 10. The method of any one of Examples 1 to 6, comprising providing a graphical user interface (GUI) (111) configured to allow a user to select (444) at least one of: (i) whether to show ablation tags on the overlaid anatomical map; and (ii) whether to calculate the size of the non-conductive zone according to the level of existing ablation therein.

[0056] Example 8 The method according to any one of Examples 1 to 7, wherein the anatomical maps (200, 201) are electroanatomical (EA) maps.

[0057] Example 9 The system (10) includes an interface (30) and a processor (56). The interface (30) is configured to receive an anatomical map (200) of wall tissue of at least a portion of a cardiac chamber, the map being overlaid with ablation tags (205, 212). The processor (56) is configured to (i) define a non-conductive zone (209) around each ablation tag (205, 212) for at least some of the ablation tags to calculate a block region (214); (ii) receive from a user markings on the map (200) of starting points (206A) and ending points (206B) of potential conductive flow (210); (iii) use a search algorithm to search for one or more possible conductive flow paths (210) from the starting points (206A) to the ending points (206B), where one or more existing paths (210) take into account the block region (214); and overlay one or more flow paths (210) found by the search algorithm on the anatomical map; and (iv) present the overlaid anatomical map (201) to the user.

[0058] Although the examples described herein primarily address cardiac diagnostic applications, the methods and systems described herein may also be used in other medical applications.

[0059] It will be understood that the above embodiments are given by way of example, and that the present disclosure is not limited to what has been particularly shown and described above. 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.

[0060] [Embodiment] (1) A method comprising: receiving an anatomical map of wall tissue of at least a portion of a cardiac chamber, the map being overlaid with ablation tags; calculating a blocking area for at least some of the ablation tags by defining a non-conductive zone around each ablation tag; receiving markings on the map of potential start and end points of conductive flow from a user; searching for one or more possible conduction flow paths from the start point to the end point using a search algorithm, the one or more existing paths taking into account the blocked region; overlaying one or more flow pathways found by the search algorithm onto the anatomical map; presenting the superimposed anatomical map to a user. (2) The method of embodiment 1, further comprising not displaying the ablation tag on the superimposed anatomical map. (3) The method of embodiment 1, wherein the non-conductive zone around a given ablation tag is a sphere of a given size derived from the ablation index value of the given ablation tag. (4) The method of embodiment 3, wherein calculating the block region includes calculating an intersection of the sphere with a surface of the anatomical map. (5) The method of embodiment 1, wherein searching for one or more conductive flow paths includes using a first search algorithm.

[0061] (6) Using the first search algorithm * 6. The method of embodiment 5, comprising using a pathfinding algorithm. (7) The method of embodiment 1, comprising providing a graphical user interface (GUI) configured to allow the user to select at least one of: (i) whether to show the ablation tag on the overlaid anatomical map; and (ii) whether to calculate the size of the non-conductive zone according to the level of existing ablation therein. (8) The method of embodiment 1, wherein the anatomical map is an electroanatomical (EA) map. (9) A system comprising: an interface configured to receive an anatomical map of wall tissue of at least a portion of a cardiac chamber, the map being overlaid with ablation tags; A processor, the processor comprising: calculating a blocking area for at least some of the ablation tags by defining a non-conductive zone around each ablation tag; receiving markings on the map of potential start and end points of conductive flow from a user; searching for one or more possible conduction flow paths from the start point to the end point using a search algorithm, the one or more existing paths taking into account the blocked region; overlaying one or more flow pathways found by the search algorithm onto the anatomical map; and presenting the overlaid anatomical map to a user. (10) The system of embodiment 9, further comprising not displaying the ablation tag on the superimposed anatomical map.

[0062] (11) The system of embodiment 9, wherein the non-conductive zone around a given ablation tag is a sphere of a given size derived from the ablation index value of the given ablation tag. (12) The system of embodiment 11, wherein the processor is configured to calculate the block region by calculating an intersection of the sphere with a surface of the anatomical map. (13) The system of embodiment 9, wherein the processor is configured to search for the one or more conductive flow pathways by using a first search algorithm. (14) The processor,* 14. The system of claim 13, configured to use the first search algorithm by using a path search algorithm. (15) The system of embodiment 9, wherein the processor is further configured to provide a graphical user interface (GUI) configured to allow the user to select at least one of: (i) whether to show the ablation tag on the overlaid anatomical map; and (ii) whether to calculate the size of the non-conductive zone according to the level of existing ablation therein.

[0063] (16) The system described in embodiment 9, wherein the anatomical map is an electroanatomical (EA) map.

Claims

1. 1. A system comprising: an interface configured to receive an anatomical map of wall tissue of at least a portion of a cardiac chamber, the map being overlaid with ablation tags; A processor, the processor comprising: calculating a blocking area for at least some of the ablation tags by defining a non-conductive zone around each ablation tag; receiving markings on the map of potential start and end points of conductive flow from a user; searching for one or more possible conduction flow paths from the start point to the end point using a search algorithm, the one or more existing paths taking into account the blocked region; overlaying one or more flow pathways found by the search algorithm onto the anatomical map; and presenting the overlaid anatomical map to a user.

2. 1. A method comprising: receiving an anatomical map of wall tissue of at least a portion of a cardiac chamber, the map being overlaid with ablation tags; calculating a blocking area for at least some of the ablation tags by defining a non-conductive zone around each ablation tag; receiving markings on the map of potential start and end points of conductive flow from a user; searching for one or more possible conduction flow paths from the start point to the end point using a search algorithm, the one or more existing paths taking into account the blocked region; overlaying one or more flow pathways found by the search algorithm onto the anatomical map; presenting the superimposed anatomical map to a user.

3. The method of claim 2 , comprising not displaying the ablation tag on the overlaid anatomical map.

4. The method of any one of claims 2 to 3, wherein the non-conductive zone around a given ablation tag is a sphere of a given size derived from the Ablation Index value of the given ablation tag.

5. The method of claim 4 , wherein calculating the block region comprises calculating an intersection of the sphere with a surface of the anatomical map.

6. The method of claim 2 , wherein searching for one or more conductive flow paths comprises using a first search algorithm.

7. The method of claim 6 , wherein using the first search algorithm comprises using an A* path search algorithm.

8. 4. The method of claim 2, comprising providing a graphical user interface (GUI) configured to allow the user to select at least one of: (i) whether to show the ablation tag on the overlaid anatomical map; and (ii) whether to calculate the size of the non-conducting zone according to the level of existing ablation therein.

9. The method of any one of claims 2 to 3, wherein the anatomical map is an electroanatomical (EA) map.

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