Determining electrophysiological (EP) wave propagation vectors by analyzing multielectrode catheter signals

Abstract

To perform cardiac electrophysiological mapping.SOLUTION: A method includes receiving multiple electrophysiological (EP) signals acquired by multiple electrodes of a multi-electrode catheter that are in contact with tissue in a region of a cardiac chamber, and respective tissue locations at which the electrodes acquired the EP signals. The region is divided into two sections. Using the EP signals acquired by the electrodes, local activation times (LAT) are calculated for the respective tissue locations, and a first section of the two sections having a smaller average LAT value and a second section of the two sections having a higher average value are found. Determined are a first representative location in the first section, and a second representative location in the second section. A propagation vector is calculated between the first and second representative locations, indicative of propagation of an EP wave that has generated the EP signals. The propagation vector is presented to a user.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to electrophysiological mapping, and more particularly to cardiac electrophysiological mapping. [Background technology]

[0002] Invasive cardiac techniques for mapping electrophysiological (EP) properties of cardiac tissue have previously been proposed in the patent literature. For example, U.S. Patent Application Publication No. 2017 / 0311833 describes an efficient system for diagnosing arrhythmias and guiding catheter therapy capable of measuring, classifying, analyzing, and mapping spatial electrophysiological (EP) patterns within the body. The efficient system can further guide arrhythmia therapy and provide map updates as treatment is delivered. The efficient system can use medical devices with high density sensors in known spatial configurations to collect EP data and positioning data. Furthermore, the efficient system can also use an electronic control unit (ECU) to calculate and provide various metrics, derived metrics, high-definition (HD) maps, HD composite maps, and general visual aids to the user to correlate with geometric anatomical models shown on a display device.

[0003] As another example, U.S. Patent Application Publication No. 2017 / 0042449 describes a system for determining EP data, the system comprising an electronic control unit configured to acquire electrophysiology signals from multiple electrodes of one or more catheters, select at least one clique of electrodes from the multiple electrodes to determine multiple local E-field data points, determine positions and orientations of the multiple electrodes, process the electrophysiology signals from the at least one clique from a full set of dipole sub-cliques to derive local E-field data points associated with the at least one clique of electrodes, derive at least one orientation-independent signal from the at least one clique of electrodes from information content corresponding to weighted portions of the electrogram signals, and display or output the catheter orientation-independent EP information to a user or process.

[0004] U.S. Patent Application Publication No. 2018 / 0153426 describes a method and system for mapping an anatomical structure, the method and system including sensing activation signals of intrinsic physiological activity with a plurality of mapping electrodes positioned in or near the anatomical structure, each of the plurality of mapping electrodes having an electrode location. A vector field map representing the propagation direction of the activation signal at each electrode location is generated, and signature patterns and locations within the vector field map are identified according to at least one vector field template. Target locations of the identified signature patterns are identified according to the corresponding electrode locations. Summary of the Invention [Means for solving the problem]

[0005] One embodiment of the present invention provides a method including receiving (i) a plurality of electrophysiological (EP) signals acquired by a plurality of electrodes of a multi-electrode catheter in contact with tissue within a region of a heart chamber, and (ii) respective tissue locations at which the electrodes acquired the EP signals. The region is divided into two sections. Using the EP signals acquired by the electrodes, a local activation time (LAT) for each tissue location is calculated to find a first of the two sections having a smaller average LAT value and a second of the two sections having a higher average value. A first representative location within the first section and a second representative location within the second section are determined. A propagation vector indicating the propagation of the EP wave that generated the EP signal is calculated between the first representative location and the second representative location. The propagation vector is presented to a user.

[0006] In some embodiments, presenting the propagation vectors includes overlaying arrows on the map of the heart chamber, hi other embodiments, overlaying the arrows includes using a graphical property of the arrow to indicate the velocity of the EP wave between the first representative location and the second representative location.

[0007] In some embodiments, the graphical characteristics of the arrow include one or more of color, length, width, and a graphical pattern such as a gradient or dashes.

[0008] In one embodiment, the method further comprises, if a re-penetrating EP wave is detected, calculating an additional propagation vector for the re-penetrating EP wave.

[0009] In another embodiment, the method further includes overlaying an additional arrow on the map of the heart chamber, hi yet another embodiment, overlaying the additional arrow includes using a graphical characteristic of the additional arrow to indicate at least one of a LAT difference of the re-entrant EP wave and a cycle time of the re-entry.

[0010] In some embodiments, determining the first representative location includes determining a tissue location having a minimum LAT value among the tissue locations in the first section, and determining the second representative location includes determining a tissue location having a maximum LAT value among the tissue locations in the second section.

[0011] In some embodiments, determining the first representative location includes calculating a first center of mass of the tissue location within the first section, and determining the second representative location includes calculating a second center of mass of the tissue location within the second section.

[0012] In one embodiment, calculating the first center of mass includes calculating a first weighted average of tissue locations in the first section using two or more of the LAT values ​​of the first section as weights, and calculating the second center of mass includes calculating a second weighted average of tissue locations in the second section using two or more of the LAT values ​​of the second section as weights.

[0013] According to another embodiment of the present invention, there is additionally provided a system including an interface and a processor. The interface is configured to receive (i) a plurality of electrophysiological (EP) signals acquired by a plurality of electrodes of a multi-electrode catheter in contact with tissue within a region of a heart chamber and (ii) respective tissue locations at which the electrodes acquired the EP signals. The processor is configured to (a) divide the region into two sections, (b) calculate a local activation time (LAT) value for each tissue location using the EP signals acquired by the electrodes, find a first section of the two sections having a smaller average LAT value and a second section of the two sections having a higher average LAT value, (c) determine a first representative location within the first section and a second representative location within the second section, (d) calculate a propagation vector between the first and second representative locations indicating the propagation of the EP wave that generated the EP signals, and (e) present the propagation vector to a user.

[0014] The present invention will be more fully understood from the following detailed description taken in conjunction with the drawings, in which: [Brief explanation of the drawings]

[0015] [Figure 1] 1A-1C are schematic, pictorial illustrations of electrophysiological (EP) mapping systems including different possible multi-electrode catheters, according to embodiments of the present invention. [Figure 2A] 2 is a schematic distal view of an electrode of one of the catheters of FIG. 1 contacting tissue and measuring electrophysiological (EP) signals, in accordance with an embodiment of the present invention. [Figure 2B] 2 is a schematic distal view of an electrode of one of the catheters of FIG. 1 contacting tissue and measuring electrophysiological (EP) signals, in accordance with an embodiment of the present invention. [Figure 3] 2 is a schematic distal view of an electrode of one of the catheters of FIG. 1 contacting tissue and measuring electrophysiological (EP) signals, according to another embodiment of the present invention. [Figure 4]1 is a flowchart that schematically illustrates a method and algorithm for estimating and presenting the propagation vector of an electrophysiological (EP) wave, according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Overview Intracardiac electrophysiological (EP) mapping is a catheter-based method sometimes applied to characterize cardiac EP wave propagation abnormalities, such as those that cause arrhythmias. In a typical catheter-based procedure, the distal end of a catheter containing multiple sensing electrodes is inserted into the heart to sense a set of data points, including measured locations on the wall tissue of a heart chamber, and a respective set of EP signals, from which an EP mapping system can generate a map, such as an EP map of a heart chamber.

[0017] Specifically, the direction of propagation of the EP wave in a region of the wall tissue may also be required for diagnosis. The direction of propagation of the cardiac wave can be found by creating a specific EP timing diagram map called a local activation arrival time (LAT) map of the region of the heart chamber.

[0018] However, determining the propagation vector of an EP wave within a heart chamber for any given region is a time-consuming process. Typically, the LAT for multiple locations around the region must be calculated, and then a vector derived from the LAT and the location must be calculated. Embodiments of the present invention described below provide an efficient method for acquiring EP data and automatically calculating such propagation vectors in real time for a region within a heart chamber.

[0019] Among other features, the disclosed methods can use various types of multi-electrode catheters, such as basket catheters or multi-arm catheters (e.g., Biosense Webster's PentaRay™ or OctaRay™), in certain ways. The multi-electrode catheter is brought into contact with tissue (e.g., pressed against tissue) in a region of the heart chamber so that its "pole" (e.g., the distal tip where the basket spines connect, or where the multiple arms originate) is over a selected cardiac tissue region, and the electrodes of the spine / arm contact wall tissue in the tissue region of the heart chamber to acquire EP signals.

[0020] In one embodiment, to calculate the propagation vector, the processor first divides (e.g., arbitrarily divides) the cardiac tissue region in which the electrode locations are located into two sections using an imaginary plane containing the axis of the catheter. Then, using the EP signals acquired from each electrode, the processor calculates the LAT values ​​at the electrode locations (i.e., each tissue location) within each section to find the first of the two sections with the smaller average LAT value and the second of the two sections with the higher average value.

[0021] The processor then determines a first representative location within the first section and a second representative location within the second section, calculates a propagation vector between the first and second representative locations indicating the propagation of the EP wave that generated the EP signal, and presents the propagation vector to a user.

[0022] In one embodiment, for sections with lower average LAT values, the processor finds the location with the minimum LAT value therein. For sections with higher average LAT values, the processor finds the location with the maximum LAT value therein. From the known displacement (distance and direction) between the two locations and the known time difference between the respective LAT values, the processor calculates the propagation (e.g., velocity) vector (velocity and direction) of the EP wave. The processor can then draw an arrow corresponding to the vector on a map of the heart chamber. The length of the arrow, its color, or graphic pattern (e.g., gradient or hatching pattern) may be set to correspond to the velocity.

[0023] In another embodiment, rather than calculating a velocity vector from the minimum LAT value in the section with a lower mean LAT value to the maximum LAT value in the section with a higher mean LAT value, the processor calculates a vector between the center-of-mass wall tissue location of the lower mean LAT value and the center-of-mass wall tissue location of the higher mean LAT value. To this end, the processor performs a center-of-mass calculation in a first section at a first wall tissue location with a lower mean LAT value and a center-of-mass calculation in a second section at a second wall tissue location with a higher mean LAT value. The processor then generates an estimable EP signal, calculates a center-of-mass propagation vector between the first and second center-of-mass locations of the EP wave, and presents the center-of-mass vector to the user. The center-of-mass calculation typically involves calculating a weighted average of each center-of-mass location using two or more LAT values ​​in each section as weights.

[0024] In some clinical cases, such as reentrant arrhythmias, the velocity vector oscillates in direction (backward and forward) while the catheter remains in a nearly fixed position. This typically occurs when the catheter is at a junction, for example, when the wave actually alternates direction because it encounters abnormal unidirectional propagation-blocking tissue. In this case, the processor calculates an additional vector, and the two vectors may be displayed on the screen as two arrows distinguished by different brightness / thickness / length / color depending on their relative magnitude.

[0025] Typically, the processor is programmed with software containing specific algorithms that enable the processor to perform each of the processor-related steps and functions outlined above.

[0026] The disclosed systems and methods for efficient derivation and clear presentation of EP wave propagation direction(s) can improve catheter-based arrhythmia diagnosis and therapy procedures.

[0027] System Description FIG. 1 is a schematic depiction of an electrophysiological (EP) mapping system 10 including different possible multi-electrode catheters, according to an embodiment of the present invention. System 10 can be configured to analyze virtually any physiological parameter or combination of such parameters. In this description, by way of example, the analyzed signal is assumed to be the potential-time relationship of an intracardiac electrogram. To fully characterize such a relationship, it is necessary to reference the signals to each other in time at various locations, as is done, for example, during LAT map generation. Time referencing is achieved by measuring relative to a reference time (e.g., a time point), such as the onset of each QRS complex (i.e., the start of each heartbeat) of an ECG reference signal. Methods for generating LAT maps are described in the aforementioned U.S. Pat. No. 9,050,011.

[0028] As mentioned above, system 10 includes a multi-electrode catheter, which may be a basket catheter 14 or a multi-arm catheter 114 (e.g., a PentaRay™ catheter), among many possible options, both of which are shown in inset 37. The following description will refer collectively to the above catheter options, and "catheter 14 / 114" refers to the embodiments described below to include either of these multi-electrode catheter types. Each catheter tip 14, 114 extends along a longitudinal axis LL.

[0029] The multi-electrode catheter 14 / 114 is percutaneously inserted by a physician 32 through the patient's vascular system into a chamber or vasculature of the heart 12. The physician 32 brings the distal tip 18 / 118 of the catheter into contact with the wall tissue 19 of the heart chamber 21 at the EP mapping target tissue site (e.g., by pushing the tip distally). The multi-electrode catheter 14 / 114 typically includes a handle 20 with suitable controls that allow the physician 32 to steer, position, and orient the distal end of the catheter as needed for EP mapping.

[0030] The multi-electrode catheter 14 / 114 is connected to a console 24, which allows a physician 32 to observe and adjust the catheter's function. To assist the physician 32, the distal portion of the catheter may include various sensors, such as a contact force sensor (not shown) and a magnetic sensor 33 / 133, which provide position, direction, and orientation signals to a processor 22 located within the console 24. The processor 22 may perform several processing functions, as described below. In particular, electrical signals may be transmitted from electrodes 16 / 116 located at or near the distal tip 18 of the catheter 14 / 114 via a cable 34 to the heart 12 and from the heart 12 to the console 24. Pacing and other control signals may be transmitted from the console 24 via the cable 34 and the electrodes 16 / 116 to the heart 12.

[0031] The console 24 includes a monitor 29 driven by the processor 22. Signal processing circuitry within the electrical interface 34 typically receives, amplifies, filters, and digitizes signals from the catheter 14 / 114, including signals generated by the sensors and multiple sensing electrodes 16 described above. The digitized signals are received by the console 24 and the positioning system and used to calculate the position and orientation of the catheter 14 / 114 and to analyze the EP signals from the electrodes 16 / 116, as described in more detail below.

[0032] During the disclosed procedure, the position of each of the electrodes 16 / 116 is tracked. Tracking can be performed, for example, using the CARTO® 3 system produced by Biosense Webster. Such a system measures the impedance between the electrodes 16 / 116 and multiple external conductive patches 30 coupled to the patient's body. For example, three external electrodes 30 may be coupled to the patient's chest and three external electrodes may be coupled to the patient's back. (For ease of illustration, only the external electrodes are shown in FIG. 1 .) Wire connections 35 connect the console 24 to the body surface electrodes 30 and other components of a positioning subsystem for measuring coordinates of the position and orientation of the catheter 14 / 114. A method for tracking the position of the electrodes 16 based on electrical signals is called Active Current Location (ACL), and is implemented in various medical applications, for example, as the aforementioned CARTO® 3 system. Details of the ACL subsystem and process are provided in U.S. Patent No. 8,456,182, assigned to the assignee of the present patent application, the disclosure of which is incorporated herein by reference, a copy of which is provided in the Appendix.

[0033] In some embodiments, the system 10 includes, in addition to or instead of the ACL tracking subsystem, a magnetic position tracking subsystem that determines the position and orientation of a magnetic sensor 33 at the distal end of the catheter 14 / 114 by generating magnetic fields within a predetermined working volume and sensing these fields at the catheter using field generating coils 28. Because the electrodes 16 / 116 have known positions on the arms 15 / 115 and known relationships to one another, when the catheter 14 / 114 is magnetically tracked within the heart, the position of each of the electrodes 16 / 116 within the heart is known. Suitable magnetic position tracking subsystems are described in U.S. Patent Nos. 7,756,576 and 7,536,218, assigned to the assignee of the present patent application, the disclosures of which are incorporated herein by reference, copies of which are provided in the Appendix.

[0034] Based on the EP signals from the electrodes 16 / 116 having tracked positions, an electrical activation map can be prepared according to the methods disclosed in U.S. Patent Nos. 6,226,542, 6,301,496, and 6,892,091, assigned to the assignee of the present patent application, the disclosures of which are incorporated herein by reference, copies of which are provided in the Appendix.

[0035] Processor 22 operates system 10 using software stored in memory 25. The software may be downloaded to processor 22 in electronic form, for example, over a network; alternatively or additionally, the software may be provided and / or stored on a non-transitory, tangible medium, such as magnetic, optical, or electronic memory. In particular, processor 22 executes the dedicated algorithms disclosed herein, included in FIG. 4, which enable processor 22 to perform the disclosed processes, as further described below.

[0036] The illustration shown in Figure 1 has been chosen solely for conceptual clarity. Other types of EP sensing geometries, such as balloon catheters with electrode segments as described in U.S. Patent Application No. 16 / 708,285 (Attorney Docket No. BIO6163USNP), filed December 9, 2019, entitled "Catheter with Plurality of Sensing Electrodes Used as Ablation Electrodes," the disclosure of which is incorporated herein by reference (with a copy in the Appendix), may also be used.

[0037] System 20 typically includes additional modules and elements not directly relevant to the disclosed technology and therefore intentionally omitted from Figure 1 and the corresponding description. The elements of system 20 and the methods described herein may be further applied, for example, to control the ablation of tissue in heart 12.

[0038] Determining EP wave propagation vectors by analyzing multielectrode catheter signals 2A and 2B are schematic distal views of an electrode 16 / 116 of one of the catheters of FIG. 1 contacting tissue and measuring electrophysiological (EP) signals, according to an embodiment of the present invention. The figures further show the tissue 50 and distal portions 40 of the spines or arms 15 / 115 of the catheter 14 / 114, which are pressed against the tissue 50 when viewed distally from a position proximal to the spine or arms on the catheter axis LL. The spines or arms 15 / 115 are joined together at the distal tip 18 / 118 of the catheter.

[0039] In some embodiments, processor 22 divides the spine / arm into two sections using a virtual plane 55 that includes the catheter's axis LL. Processor 22 may select the sections, i.e., select plane 55, optionally or according to certain selection criteria. For example, virtual plane 55 may be configured to intersect with the catheter's central longitudinal axis LL and not intersect with any of the spines or arms of catheter 14 or 114. Then, using the EP signals acquired from each electrode 16 / 116, processor 22 calculates LAT values ​​at the electrode locations within each section. Processor 22 then finds which of the two sections (S1 or S2) is characterized by a lower average LAT value (e.g., has the lower average LAT value of the two sections) and which is characterized by a higher average LAT value (e.g., has the higher average value from the two sections).

[0040] In the embodiment shown in FIG. 2A, imaginary plane 55 separates the spine or arm into two sections: a first section S1 having a lower average LAT value and another or second section S2 having a higher average LAT value. First section S1 is determined by the processor to find the minimum LAT value, the location of which is determined to be at point 60 (which may be the location of a sensing electrode on the spine or arm of catheter 14 or 114). In the other or second section S2 having the higher average LAT value, the processor finds the maximum LAT value and its location 66 (which may be the location of a sensing electrode on the spine or arm of catheter 14 or 114). Locations 60 and 66 are referred to herein as "representative locations" because each of them represents the entire respective section with a single data point.

[0041] From the known displacement (distance and direction) and known time (difference in LAT values) between the two representative locations, the processor calculates the velocity vector (velocity and direction) of the EP wave 100 that generates the signal as it propagates in the tissue beneath the catheter. The processor may then draw an arrow 65 corresponding to the vector on a map of the heart chamber and provide this on the display screen 29. The length of the arrow 65 and / or its color may be set to correspond to the velocity.

[0042] In the embodiment shown in FIG. 2B, rather than calculating a velocity vector from the minimum LAT value in the section with the lower average LAT value to the maximum LAT value in the section with the higher average LAT value, a vector is calculated between the center of mass locations of the lower and higher average LAT values ​​to find the center of mass location using the following equation:

[0043]

number

[0044] In FIG. 2B , for example, i=1, 2 for each center of mass location. That is, center of mass wall tissue location 70 is calculated from Eq. 1 using the LAT values ​​and respective locations 68 and 72, and center of mass wall tissue location 80 is calculated using the LAT values ​​and respective locations 78 and 82. The processor can then draw arrow 75 corresponding to the vector between locations 70 and 80. Thus, in the example of FIG. 2B , the centers of mass of the two sections (locations 70 and 80) serve as representative locations. In alternative embodiments, processor 22 may select representative locations within the two sections in any other suitable manner.

[0045] The diagrams in Figures 2A and 2B are conceptual and are provided as examples. The actual catheter structure may vary. For example, the number of spines or arms may be greater than those shown.

[0046] Figure 3 is a schematic distal view of an electrode 16 / 116 of one of the catheters of Figure 1 contacting tissue and measuring electrophysiological (EP) signals, according to another embodiment of the invention. The layout of the catheter 14 / 114 is the same in Figures 2A and 2B, but the catheters are placed at different tissue locations where EP wave re-entry occurs.

[0047] As mentioned above, in the case of reentrant arrhythmias, the velocity vectors in the region may oscillate in direction (backward and forward). This typically occurs when the catheter is at a junction where the EP wave 100 actually alternates direction, for example, due to the wave encountering abnormal unidirectional propagation-blocking tissue 52. In this case, the two EP wave vectors (one of the incident EP wave 100 and the other of the reentrant EP wave 102) may be displayed on the screen as two respective arrows 95 and 97, each with a different brightness / thickness / length / color depending on their relative magnitude. In FIG. 3, the vectors are calculated using the center of mass calculation method of FIG. 2B. One vector points from center of mass location 90 to center of mass location 99, and the other vector points from center of mass location 91 to center of mass location 97.

[0048] 4 is a flow chart that schematically illustrates a method and algorithm for estimating and presenting the propagation vector of an electrophysiological (EP) wave 100, according to one embodiment of the present invention. The algorithm, according to the presented embodiment, implements a catheter placement step 400 in which a physician 30 presses a catheter 14 / 114 against a region of cardiac tissue to bring a portion of an electrode 16 / 116 into contact with the tissue.

[0049] The system 10 then measures the electrode positions on the wall tissue 19 of the heart chamber 21 and each set of EP signals at the locations generated by the EP waves 100 in a measuring step 402 .

[0050] Next, processor 22 arbitrarily divides the region into two sections in a region division step 404 .

[0051] Next, the processor 22 calculates the LAT value at each electrode location in a LAT calculation step 406 .

[0052] Next, processor 22 calculates the average LAT value for each section in an average LAT calculation step 408. Typically, one section will have a lower average LAT value than the other.

[0053] Next, in a calculate average LAT position step 410, processor 22 calculates the center of mass positions of the lower and higher average LAT values ​​using the method described in Figure 2B.

[0054] Using the center of mass location, processor 22 calculates the center of mass EP wave propagation vector of EP wave 100 in a vector calculation step 414 .

[0055] Finally, in a propagation vector presentation step 410, processor 22 overlays (e.g., draws) arrows corresponding to the vectors on the map of the heart chambers, as shown on display 29 of Figure 1. The length and / or color of arrow 65 or 75 may be set to correspond to velocity.

[0056] The exemplary flowchart shown in Figure 4 has been chosen purely for purposes of conceptual clarity, and this embodiment also includes further steps in the algorithm, such as the manipulation of other sensors attached to the catheter, such as a contact force sensor, which are intentionally omitted from this disclosure in order to provide a more simplified flowchart.

[0057] It will be understood that the above-described embodiments are given by way of example, and that the present invention is not limited to what is specifically shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described in the above specification, as well as variations and modifications thereof that would occur to one skilled in the art upon reading the foregoing description, and that are not disclosed in the prior art. Documents incorporated by reference into this patent application are to be considered an integral part of this application, except that if any term is defined in these incorporated documents in a way that contradicts the definition given herein, either expressly or impliedly, then only the definition given herein shall be considered.

[0058] [Embodiment] (1) A method comprising: receiving (i) a plurality of electrophysiological (EP) signals acquired by a plurality of electrodes of a multi-electrode catheter in contact with tissue within a region of a cardiac chamber, and (ii) respective tissue locations at which the electrodes acquired the EP signals; dividing the area into two sections; calculating a local activation time (LAT) value for each of the tissue locations using the EP signals acquired by the electrodes; and finding a first of the two sections having a smaller average LAT value and a second of the two sections having a higher average LAT value. determining a first representative location within the first section and a second representative location within the second section; calculating a propagation vector indicative of the propagation of an EP wave that generated the EP signal between the first representative location and the second representative location; presenting the propagation vector to a user in graphical form. (2) The method of embodiment 1, wherein presenting the propagation vector includes overlaying an arrow on a map of the heart chamber. (3) The method of claim 2, wherein the overlaying of the arrow includes using a graphical characteristic of the arrow to indicate the velocity of the EP wave between the first representative location and the second representative location. (4) The method of claim 3, wherein the graphical characteristics of the arrow include one or more of color, length, width, or graphical pattern. (5) The method of embodiment 1, further comprising, if a reentering EP wave is detected, calculating an additional propagation vector for the reentering EP wave.

[0059] (6) The method of embodiment 5, further comprising overlaying the additional arrows on the map of the heart chamber. (7) The method of embodiment 6, wherein overlaying the additional arrows includes using graphical characteristics of the additional arrows to indicate at least one of a LAT difference and a re-entry cycle time of the re-entrant EP wave. (8) The method of embodiment 1, wherein determining the first representative location includes determining a tissue location having a minimum LAT value among the tissue locations within the first section, and determining the second representative location includes determining a tissue location having a maximum LAT value among the tissue locations within the second section. (9) The method of embodiment 1, wherein determining the first representative location includes calculating a first center of mass of the tissue location within the first section, and determining the second representative location includes calculating a second center of mass of the tissue location within the second section. (10) The method of embodiment 9, wherein calculating the first center of mass includes calculating a first weighted average of the tissue locations within the first section using two or more of the LAT values ​​of the first section as weights, and calculating the second center of mass includes calculating a second weighted average of the tissue locations within the second section using two or more of the LAT values ​​of the second section as weights.

[0060] (11) A system comprising: an interface configured to receive (i) a plurality of electrophysiological (EP) signals acquired by a plurality of electrodes of a multi-electrode catheter in contact with tissue within a region of a cardiac chamber, and (ii) respective tissue locations at which the electrodes acquired the EP signals; a processor, the processor comprising: Dividing the area into two sections; calculating a local activation time (LAT) value for each of the tissue locations using the EP signals acquired by the electrodes, and finding a first of the two sections having a smaller average LAT value and a second of the two sections having a higher average LAT value; determining a first representative location within the first section and a second representative location within the second section; calculating a propagation vector indicating the propagation of an EP wave that generated the EP signal between the first representative location and the second representative location; The system is configured to present the propagation vector to a user. (12) The system of embodiment 11, wherein the processor is configured to present the propagation vector by overlaying an arrow on a map of the heart chamber. (13) The system of claim 12, wherein the processor is configured to use a graphical characteristic of the arrow to indicate the velocity of the EP wave between the first representative location and the second representative location. (14) The system of embodiment 13, wherein the graphical characteristics of the arrow include one or more of color, length, width, or graphical pattern. (15) The system of embodiment 11, wherein the processor is further configured to calculate an additional propagation vector for the re-entrant EP wave if the re-entrant EP wave is detected.

[0061] (16) The system of embodiment 15, wherein the processor is further configured to overlay the additional arrows on the map of the heart chamber. (17) The system of embodiment 16, wherein the processor is configured to use a graphical characteristic of the additional arrow to indicate at least one of a LAT difference of the re-entrant EP wave and a cycle time of re-entry. (18) The system of embodiment 11, wherein the processor is configured to determine the first representative location by determining a tissue location having a minimum LAT value between the tissue locations in the first section, and to determine the second representative location by determining a tissue location having a maximum LAT value between the tissue locations in the second section. (19) The system of embodiment 11, wherein the processor is configured to determine the first representative location by calculating a first center of mass of the tissue location within the first section and to determine the second representative location by calculating a second center of mass of the tissue location within the second section. (20) The system of embodiment 19, wherein the processor is configured to calculate the first center of mass by calculating a first weighted average of the tissue locations within the first section using two or more of the LAT values ​​of the first section as weights, and to calculate the second center of mass by calculating a second weighted average of the tissue locations within the second section using two or more of the LAT values ​​of the second section as weights.

Claims

1. 1. A system comprising: an interface configured to receive (i) a plurality of electrophysiological (EP) signals acquired by a plurality of electrodes of a multi-electrode catheter in contact with tissue within a region of a heart chamber, and (ii) respective tissue locations at which the electrodes acquired the EP signals; a processor, the processor comprising: dividing the area contacted by the plurality of electrodes into two sections by a plane intersecting a central longitudinal axis of the multi-electrode catheter; calculating a local activation time (LAT) value for each of the tissue locations using the EP signals acquired by the electrodes, and finding a first of the two sections having a smaller average LAT value and a second of the two sections having a higher average LAT value; determining a first representative location within the first section and a second representative location within the second section; calculating a propagation vector indicative of the propagation of an EP wave that generated the EP signal between the first representative location and the second representative location; The system is configured to present the propagation vector to a user.

2. The system of claim 1 , wherein the processor is configured to present the propagation vectors by overlaying arrows on a map of the heart chamber.

3. 3. The system of claim 2, wherein the processor is configured to use a graphical characteristic of the arrow to indicate the velocity of the EP wave between the first representative location and the second representative location.

4. The system of claim 3 , wherein the graphical characteristics of the arrow include one or more of color, length, width, or graphical pattern.

5. The system of claim 1 , wherein the processor is further configured to calculate an additional propagation vector for a re-entrant EP wave if the re-entrant EP wave is detected.

6. The system of claim 5 , wherein the processor is further configured to overlay additional arrows on the map of the heart chambers.

7. 7. The system of claim 6, wherein the processor is configured to use the additional arrow graphical characteristics to indicate at least one of a LAT difference and a re-entry cycle time of the re-entrant EP wave.

8. 2. The system of claim 1, wherein the processor is configured to determine the first representative location by determining a tissue location having a minimum LAT value between the tissue locations in the first section, and to determine the second representative location by determining a tissue location having a maximum LAT value between the tissue locations in the second section.

9. 2. The system of claim 1, wherein the processor is configured to determine the first representative location by calculating a first center of mass of the tissue location within the first section and to determine the second representative location by calculating a second center of mass of the tissue location within the second section.

10. 10. The system of claim 9, wherein the processor is configured to calculate the first center of mass by calculating a first weighted average of the tissue locations within the first section using two or more of the LAT values ​​of the first section as weights, and to calculate the second center of mass by calculating a second weighted average of the tissue locations within the second section using two or more of the LAT values ​​of the second section as weights.

11. A method of operating a system including a processor, comprising: The processor receives (i) a plurality of electrophysiological (EP) signals acquired by a plurality of electrodes of a multi-electrode catheter in contact with tissue within a region of a heart chamber, and (ii) respective tissue locations at which the electrodes acquired the EP signals; the processor dividing the area contacted by the plurality of electrodes into two sections by a plane intersecting a central longitudinal axis of the multi-electrode catheter; the processor calculates a local activation time (LAT) value for each tissue location using the EP signals acquired by the electrodes, and finds a first section of the two sections having a smaller average LAT value and a second section of the two sections having a higher average LAT value; the processor determining a first representative location within the first section and a second representative location within the second section; the processor calculating a propagation vector indicative of the propagation of an EP wave that generated the EP signal between the first representative location and the second representative location; the processor presenting the propagation vector to a user in graphical form.

12. The method of claim 11 , wherein presenting the propagation vectors includes the processor overlaying arrows on a map of the heart chambers.

13. 13. The method of claim 12, wherein overlaying the arrow includes the processor using a graphical characteristic of the arrow to indicate the velocity of the EP wave between the first representative location and the second representative location.

14. The method of claim 13 , wherein the graphical characteristics of the arrow include one or more of color, length, width, or graphical pattern.

15. The method of claim 11, further comprising, when the processor detects a re-entering EP wave, the processor calculating an additional propagation vector for the re-entering EP wave.

16. The method of claim 15, wherein the processor overlays additional arrows on the map of the cardiac chambers.

17. 17. The method of claim 16, wherein overlaying the additional arrow includes the processor using graphical characteristics of the additional arrow to indicate at least one of a LAT difference and a re-entry cycle time of the re-entrant EP wave.

18. 12. The method of claim 11, wherein determining the first representative location includes the processor determining a tissue location having a minimum LAT value between the tissue locations in the first section, and determining the second representative location includes the processor determining a tissue location having a maximum LAT value between the tissue locations in the second section.

19. 12. The method of claim 11, wherein determining the first representative location includes the processor calculating a first center of mass of the tissue location within the first section, and determining the second representative location includes the processor calculating a second center of mass of the tissue location within the second section.

20. 20. The method of claim 19, wherein calculating the first center of mass includes the processor calculating a first weighted average of the tissue locations within the first section using two or more of the LAT values ​​of the first section as weights, and calculating the second center of mass includes the processor calculating a second weighted average of the tissue locations within the second section using two or more of the LAT values ​​of the second section as weights.

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