Display of transition zones between cardiac chambers

Abstract

The system includes: (i) a processor configured to receive one or more signals in a zone between a first region and a second region of an organ of a patient, at least one of the signals including a first component and a second component indicative of an electrophysiological (EP) characteristic of the organ, and based on a relationship between the first component and the second component, the processor configured to estimate a location of at least a transition zone between the first region and the second region; and (ii) a display configured to display at least the estimated transition zone on a map of the organ.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to medical devices, and more particularly to methods and systems for improving the estimated location of transition zones between heart chambers. [Background technology]

[0002] Various techniques have been published for estimating the transition zone between cardiac chambers, and accurate mapping of the transition zone is important for performing various types of medical procedures, such as tissue ablation.

[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] FIG. 1 is a schematic, pictorial illustration of a catheter-based system for electrophysiological mapping and ablation, according to one embodiment of the present disclosure. [Figure 2] 1 is a schematic, pictorial illustration of a catheter positioned between the left atrium and the pulmonary veins and signals generated by electrodes of the catheter, according to one embodiment of the present disclosure. FIG. [Figure 3] 1 is a flow chart that schematically illustrates a method for seamlessly switching between PFA-based ablation mode and RF-based ablation mode, according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0005] overview Some medical procedures require accurate mapping of the transition zone between organ regions. For example, in a pulmonary vein (PV) isolation procedure, an ablation signal is applied to tissue at the ostium of the PV to transform the tissue into a lesion, thereby reducing or eliminating arrhythmias such as atrial fibrillation (AF) in a patient's heart. Ablation is applied using one or more ablation electrodes of an ablation catheter, which are positioned in contact with the tissue along an angular portion of the transition zone. If at least one of the ablation electrodes is not positioned at the intended location, the lesion may not completely block the propagation of electrophysiological (EP) waves between the PV and the atrium, and therefore will not eliminate AF.

[0006] Examples of the present disclosure described below provide techniques for improving the accuracy of estimating and displaying the transition zone between two chambers of a patient's heart.

[0007] In some embodiments, a system for treating arrhythmia in a patient's heart includes one or more catheters, at least one of the catheters having one or more ablation electrodes configured to apply radio frequency (RF) energy to perform ablation of tissue in the patient's heart, and at least one of the catheters having one or more sensing electrodes configured to sense signals, such as electrical potential and / or impedance, on the tissue of interest when placed in contact with the tissue.

[0008] In some embodiments, the system includes a processor configured to receive signals from one or more electrodes positioned in contact with tissue. The signals are indicative of cardiac electrophysiological (EP) characteristics, such as electrical potentials. For example, when a sensing electrode is positioned in contact with tissue in a transition zone between the PV and left atrium of the heart, the signal indicative of the tissue's electrical potential may include a first component indicative of the electrical potential at the left atrium, also referred to herein as the left atrial potential (LAP), and a second component indicative of the electrical potential at the PV, also referred to herein as the PV potential (PVP). When the sensing electrode is positioned closer to the atrium, the LAP has a larger amplitude, and when the sensing electrode is positioned closer to the PV, the PVP has a larger amplitude. Based on the relationship between the LAP and PVP, the processor is configured to estimate the location of the transition zone (e.g., the ostium) between the LA and PV. In another example, the location of the LAP and PVP along a time axis representing the time interval of the signal can be used to estimate the location of the transition zone. The above and additional examples are described in detail in FIGS. 2 and 3 below.

[0009] In some examples, the system comprises a display device, also referred to herein as a display for simplicity, configured to display at least the estimated transition zone on an anatomical map of the heart.

[0010] The disclosed techniques improve the estimation and display of transition zones between chambers of the heart, as well as between regions of other organs (which have electroanatomical signals) of the patient.

[0011] System Description FIG. 1 is a schematic, pictorial illustration of a catheter-based electrophysiological mapping and ablation system 10, according to one embodiment of the present disclosure.

[0012] In some embodiments, the system 10 includes multiple catheters that are percutaneously inserted by a physician 24 through the patient's vascular system into the cavities or vasculature of the heart 12. Typically, a delivery sheath catheter is inserted into the left or right atrium near a desired location in the heart 12. One or more catheters may then be inserted into the delivery sheath catheter to reach the desired location within the heart 12. The multiple catheters may include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters adapted for both sensing and ablation. An exemplary catheter 14 configured for sensing IEGMs is illustrated herein.

[0013] Reference is now made to inset 17, which shows a cross-sectional view of an atrium of heart 12. In some embodiments, physician 24 may position distal tip 28 of catheter 14 in contact with the heart wall to sense a target site in heart 12. Additionally or alternatively, for ablation, physician 24 similarly positions the distal end of the ablation catheter in contact with a target site for ablation of the tissue intended to be ablated. In this example, catheter 14 is inserted through the right atrium (RA) and punctures the interatrial septum to enter left atrium (LA) 48 of heart 12. As shown in inset 17, distal tip 28 is positioned in the transition zone, in this example, at the ostium 47 of pulmonary vein (PV) 46, located between LA 48 and PV 46. In this example, PV 46 includes the left inferior PV, although the procedures for sensing signals and applying ablation signals (as described below) are also applicable to the left superior PV, as well as the right superior and right inferior PVs.

[0014] Reference is now made to inset 19, which shows the distal tip 28. In some embodiments, the catheter 14 comprises one and preferably multiple electrodes 26, optionally distributed along splines 15 connected to the shaft 22 at the distal tip 28 of the catheter 14. The electrodes 26 are configured to sense IEGM signals. The catheter 14 may additionally include a position sensor 29 embedded in or near the distal tip 28 to track the position and orientation of the distal tip 28. Optionally and preferably, the position sensor 29 is a magnetic-based position sensor including three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0015] Referring again to the overall view of Figure 1, in some embodiments, the magnetic-based position sensor 29 may operate in conjunction with a location pad 25 that includes multiple (e.g., three) magnetic coils 32 configured to generate multiple (e.g., three) magnetic fields within a predetermined workspace. 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 techniques are described, for example, in U.S. Pat. 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, which are incorporated herein by reference.

[0016] In some embodiments, system 10 includes one or more electrode patches 38 that are placed on patient 23 in skin contact to establish a location reference for location pads 25 and for impedance-based tracking of electrodes 26. For impedance-based tracking, current is directed to electrodes 26 and sensed at electrode skin patches 38, allowing the location of each electrode to be triangulated via electrode patches 38. This technique is also referred to herein as advanced current localization (ACL), and details of impedance-based location 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. In some embodiments, magnetic-based position sensing and ACLs may be applied simultaneously to improve position sensing, for example, of one or more electrodes coupled to flexible arms or splines on the shaft of a rigid catheter or on the distal tip of another type of catheter, such as a basket catheter 14 and a PentaRay® or OPTRELL® catheter available from Biosense Webster, Inc. (31A Technology Drive, Irvine, CA 92618).

[0017] In some embodiments, recorder 11 displays electrograms 21 captured by body surface ECG electrodes 18 and intracardiac electrograms (IEGMs) captured by electrodes 26 on catheter 14. Recorder 11 may include pacing capability for pacing the cardiac rhythm and / or may be electrically connected to a stand-alone pacer.

[0018] In some embodiments, system 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more electrodes at the distal tip of the catheter configured for ablation. The energy generated by ablation energy generator 50 may include, but is not limited to, pulse trains of radiofrequency (RF) energy or pulsed-field ablation (PFA) energy, including unipolar or bipolar high-voltage direct current pulses such as may be used to effect irreversible electroporation (IRE), or combinations thereof. In another embodiment, catheter 14 may include one or more ablation electrodes (not shown) positioned at distal tip 28 and configured to apply pulse trains of RF energy and / or PFA energy to tissue in the wall of heart 12.

[0019] In some embodiments, the patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, the electrophysiology equipment, the power source, and the workstation 55 to control the operation of the system 10.

[0020] 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 capabilities for implementing real-time calculations of catheter locations and performing ECG calculations.

[0021] In one embodiment, one or more electrodes 26 are configured to receive current from the PIU 30, and impedance is measured between at least one electrode 26 and either (i) a respective electrode patch 38, or (ii) a respective body surface ECG electrode 18.

[0022] In some embodiments, workstation 55 includes a memory device, a processor 77 with suitable random access memory or memory device having suitable operating software stored thereon, an interface 56 configured to exchange data signals (e.g., between processor 77 and another entity of system 10), and user interface capabilities. In one embodiment, processor 77 is configured to generate signals indicative of electrophysiological (EP) characteristics of heart 12, such as (i) a first signal indicative of electrical potentials measured on tissue of interest having one or more electrodes 26 placed in contact therewith, and (ii) a second signal indicative of the measured impedance described above. Workstation 55 may optionally provide multiple functions, including: (1) modeling endocardial anatomy in three dimensions (3D) and rendering a model or anatomical map 20 for display on display device 27 (also referred to herein as a display, for brevity); (2) displaying activation sequences (or other data) compiled from recorded electrograms 21 on display device 27 in a representative visual representation or image superimposed on rendered anatomical map 20; (3) displaying real-time locations and orientations of multiple catheters within cardiac chambers; and (4) displaying sites of interest, such as where ablation energy is being applied, on display device 27. One commercially available product embodying each element of system 10 is available as the CARTO® 3 system, commercially available from Biosense Webster, Inc. (31A Technology Drive, Irvine, CA 92618).

[0023] FIG. 2 is a schematic illustration of an electrode 26 at a distal tip 28 positioned in contact with tissue at an ostium 47 of a PV 46 located between the LA 48 and the PV 46, and a signal 60 received from the electrode 26, according to one embodiment of the present disclosure.

[0024] In some embodiments, distal tip 28 is positioned within ostium 47 and has several electrodes 26 disposed in contact with tissue of ostium 47, LA 48, and PV 46. For example, electrodes 26a, 26f, and 26g are disposed in contact with tissue of LA 48, electrodes 26c and 26d are disposed in contact with tissue of PV 46, and electrodes 26b and 26e are disposed in contact with tissue of ostium 47, also referred to herein as the transition zone between LA 48 and PV 46.

[0025] In some examples, the processor 77 receives signals 60 indicative of EP characteristics of the heart 12 from the electrodes 26. In this example, the EP characteristics include electrical potentials measured on tissue in contact with each electrode 26. Additionally or alternatively, the processor 77 may receive another signal from the electrodes 26 indicative of the impedance measured between the selected electrode 26 and either (i) the respective electrode patch 38, or (ii) the respective body-surface ECG electrode 18.

[0026] In some examples, signal 60 includes one or more components indicative of the location of electrode 26 and the type of signal. For example, when electrode 26 is positioned in contact with tissue in the transition zone (e.g., ostium 47) between PV 46 and LA 48, the signal indicative of the tissue potential may include a first component indicative of the potential sensed at LA 48, also referred to herein as the left atrial potential (LAP), and a second component indicative of the potential measured at PV 46, also referred to herein as the PV potential (PVP). Note that LAP and PVP have respective morphologies, as shown in legend 59. Furthermore, the morphologies of LAP and PVP may be modified by, for example, the sensed amplitude and the proximity between the region of interest (e.g., LA 48 and PV 46) and the location of the respective electrode 26, as described below.

[0027] Some non-limiting examples of signals 61, 62, 63, 64, 65, and 66 illustrate the relationship between LAP and PVP in signals received from electrodes 26. In signal 61 received from electrode 26g positioned within LA 48, the LAP has a large amplitude (e.g., approximately 1 mv), and the amplitude of the PVP (e.g., approximately 0.16 mv) is below a predetermined threshold, e.g., approximately 0.2 mv (e.g., stored in processor 77), and therefore does not appear in signal 61. In signal 62 received from electrode 26d positioned within PV 46, the PVP has a large amplitude (e.g., greater than approximately 0.5 mv), and the amplitude of the LAP is below another threshold (e.g., approximately 0.15 mv) stored in processor 77, and therefore the LAP does not appear in signal 62.

[0028] In signal 63 received from electrode 26a positioned closer to LA 48 than to PV 46, the amplitude of the LAP is greater than the amplitude of the PVP (e.g., 0.8 mv LAP and 0.2 mv PVP). Furthermore, in the time interval of signal 63, (i) the LAP occupies a first subinterval of the time interval of signal 63, and (ii) the PVP, which is sensed later than the LAP (because electrode 26a is closer to LA 48 than to PV 46), occupies a second (later) subinterval of the time interval of signal 63. In the example of signal 63, the relationship between the first and second components (e.g., LAP and PVP) includes (i) a calculated difference in amplitude size between the LAP and PVP (and / or a calculated ratio between the voltages of the amplitudes of the LAP and PVP), and (ii) a calculated duration between the first location of the LAP and the second (later) location of the PVP along time axis 58 of signal 60. In other words, because electrode 26a is positioned closer to LA 48 than to PV 46, LAP appears before PVP and has a larger amplitude compared to the amplitude of PVP. Furthermore, the widths of the LAP and PVP signals along time axis 58 may differ from one another, as shown in FIG.

[0029] In signal 64, received from electrode 26b, located at port 47 but slightly closer to PV 46 than LA 48, the amplitudes of the LAP and PVP are approximately equal. Furthermore, in the time interval of signal 64, the PVP appears slightly before the LAP because electrode 26b is located slightly closer to PV 46 than LA 48. Note that the subinterval in which the LAP and PVP appear in the signal is also affected by the direction of the EP wave propagating between PV 46 and LA 48. For example, if the EP wave propagates from PV 46 toward LA 48, the PVP may appear before the LAP along time axis 58, but the location of the PVP and LAP is also affected by the location of the respective electrodes 26.

[0030] In the example of signal 65, which is the potential measured between electrodes 26d and 26g, the EP wave propagates from PV 46 towards LA 48, so the PVP appears before the LAP and the amplitudes of the PVP and LAP are approximately equal.

[0031] In the example of signal 66, which is the potential measured between electrodes 26e and 26b located approximately in the transition zone (e.g., port 47), the LAP and PVP sensed by each of electrodes 26e and 26b are approximately overlapping with each other and are equal in amplitude.

[0032] In some examples, based on the relationship between the LAP and PVP of signals 61-66, processor 77 is configured to estimate the location of the transition zone (e.g., ostium 47) between LA 48 and PV 46. In such embodiments, processor 77 is configured to estimate that electrodes 26b and 26e are positioned approximately at ostium 47, electrodes 26a, 26f, and 26g are positioned closer to LA 48, and electrodes 26c and 26d are positioned closer to PV 46. Based on the above position sensing (using magnetic-based position sensor 29 and the ACL described in FIG. 1 above), processor 77 is configured to estimate the location of ostium 47, as well as the locations of PV 46 and LA 48.

[0033] In some examples, the display device 27 is configured to receive the estimated positions from the processor 77 and display the estimated positions of the ostium 47 and the PVs 46 and LAs 48 on the rendered anatomical map 20 described above in FIG. 1. In such examples, the physician 24 can use the displayed estimated positions of the ostium 47 to position ablation electrodes along the angular portions of the ostium 47 to perform a PV isolation procedure by applying ablation signals to the ablation electrodes positioned along the angular portions of the ostium 47.

[0034] In some examples, the processor 77 can control the PIU 30 to apply current to one or more (e.g., all) of the electrodes 26. The processor 77 then receives additional signals from the PIU 30 (e.g., from the electrodes 26 or from the generator 50) indicating the impedance measured between each selected electrode 26 and a reference electrode, such as the electrode patch 38 or the body-surface ECG electrode 18 described above in FIG. 1. Note that typically, the impedance (resistance to electrical flow) measured using a given electrode 26 (e.g., electrode 26d) positioned at the PV 46 is higher compared to the impedance measured using an electrode 26 (e.g., electrode 26g) positioned at the LA 48. In such examples, based on the measured impedance and the position of each electrode 26, the processor 77 can estimate the location of the PV 46, the LA 48, and the ostium 47, which is the transition zone between the PV 46 and the LA 48.

[0035] In a non-limiting example, if the average impedance measured using electrode 26g (located in LA 48) is approximately 100 ohms, the average impedance measured using electrode 26d (located in PV 46) is approximately 120 ohms, and the average impedance measured using electrodes 26b or 26e (located approximately at ostium 47) is approximately 110 ohms. Note that the actual number of measured impedances depends on (i) the many elements of the electrical circuit comprising electrode 26, the reference electrode, and the hardware used to apply current and measure impedance, and (ii) the physiological and electrophysiological properties of the tissue in question, as well as other electrical and / or electronic entities located in proximity to the aforementioned electrical circuit. Thus, processor 77 can use calculated differences in the impedances measured using electrodes placed in contact with tissue in PV 46, ostium 47, and LA 48.

[0036] In some examples, the processor 77 and / or physician 24 may use the relationship between the LAP and the PVP as the primary source for estimating the exact location of the ostium 47, and the impedance data may be used as supplemental information for estimating the locations of the ostium 47, the PV 46, and the LA 48.

[0037] In some examples, the techniques described above may be used to estimate other transition zones within heart 12. For example, the techniques described above may be used to estimate the location of an atrioventricular valve (AVV) located between LA 48 and the left ventricle (not shown) of heart 12, as well as to estimate the location of an AVV located between the right atrium and right ventricle of heart 12. It should be noted that to apply the disclosed techniques, catheters having sensing electrodes such as electrode 26 must be inserted into each atrium, ventricle, and AVV, or any other suitable number of catheters must be used, each having an electrode configured to generate a signal indicative of the electrical potential and / or impedance measured at the respective location of the atrium, ventricle, and AVV.

[0038] FIG. 3 is a flow chart that schematically illustrates a method for estimating and displaying a transition zone between a PV 46 and an LA 48, according to an example of the present disclosure.

[0039] The method begins with a catheter insertion step 100 in which the physician 24 inserts the distal tip 28 of the catheter 14 between the LA 48 and PV 46 of the heart 12, as shown and described in detail in Figures 1 and 2 above. Note that the electrode 26 of the distal tip 28 is placed in contact with tissue of the heart 12.

[0040] In a signal receiving step 102, processor 77 receives signals 60 from electrodes 26 indicative of the electrical potentials measured at PV 46, ostium 47, and LA 48. In addition, processor 77 may also receive signals indicative of the impedance measured between each electrode 26 and a reference electrode, such as electrode patch 38, or a body surface ECG electrode 18 described above in FIG.

[0041] In a location estimation step 104, based on the relationship between the LAP and PVP in signal 60, processor 77 estimates the location of ostium 47, which is the transition zone between LA 48 and PV 46. Additionally or alternatively, processor 77 may also estimate the location of ostium 47 based on one or more signals indicating measured impedance. As described above in FIG. 2 , because the impedance of PV 46 is typically high compared to the impedance of LA 48, processor 77 can estimate the locations of ostium 47, LA 48, and PV 46. In one example, processor 77 can use the relationship between LAP and PVP in each signal as a primary source for estimating the location of ostium 47 and can use the impedance data to verify or adjust the exact location of ostium 47.

[0042] In a display step 106, which concludes the estimation and display method, based on the estimated location of the ostium 47, the display device 27 is configured to display the estimated locations of the ostium 47, LAs 48, and PVs 46 on the anatomical map 20, as described in detail in FIG. 2 above.

[0043] In some examples, after completing the estimation and display method in step 106, physician 24 can use the information displayed on anatomical map 20 to perform a PV isolation procedure or any other suitable type of tissue ablation. For example, in tissue ablation step 108, physician 24 may position an ablation electrode of catheter 14 or another catheter (not shown) along the angular portion of ostium 47, which is the estimated transition zone. Processor 77 can then control generator 50 to apply an ablation signal to tissue in the angular portion located at ostium 47. [Example]

[0044] The system (20) includes a processor (77) and a display (27). The processor (77) is configured to receive one or more signals (60) in a zone between a first region (46) and a second region (48) of an organ (12) of a patient (23), at least one of the signals (60) including a first component (LAP) and a second component (PVP) indicative of an electrophysiological (EP) characteristic of the organ (12). Based on a relationship between the first component (LAP) and the second component (PVP), the processor (77) is configured to estimate a location of at least a transition zone (47) between the first region (46) and the second region (48). The display (27) is configured to display at least the estimated transition zone (47) on a map (20) of the organ (12). [Example]

[0045] 2. The system of example 1, wherein the first component has a first amplitude, the second component has a second amplitude, and the relationship between the first component and the second component comprises a ratio between the first amplitude and the second amplitude. [Example]

[0046] 10. The system of example 1, wherein the first component occupies a first subinterval of the signal's time interval and the second component occupies a second subinterval of the time interval, and the relationship between the first component and the second component comprises a duration between a first position of the first subinterval and a second position of the second subinterval. [Example]

[0047] A system described in any one of Examples 1 to 3, wherein the signal includes an electrical potential measured by one or more electrodes placed in contact with tissue of the organ in one or more of: (i) the transition zone, (ii) the first region, and (iii) the second region. [Example]

[0048] A system described in any one of Examples 1 to 3, wherein the signal includes an additional signal indicative of the impedance measured between a reference electrode and an electrode placed in contact with tissue of the organ in the transition zone. [Example]

[0049] The system of any one of Examples 1 to 3, wherein the organ includes a heart, the first region includes an atrium of the heart, the second region includes pulmonary veins (PVs) extending from the atrium, the transition zone includes ostia of the PVs, the first component and the second component represent measurements of first and second EP characteristics of the atrium and PV, respectively, and the processor is configured to estimate a location of the ostium between the PVs and the atrium based on a relationship between the first component and the second component. [Example]

[0050] The system of any one of Examples 1 to 3, wherein the organ includes a heart, the first region includes a given atrium on a given side of the heart, the second region includes a given ventricle on the given side of the heart, the ventricle is connected to the given atrium via an atrioventricular valve (AVV), the transition zone includes the AVV on the given side of the heart, and the processor is configured to estimate the location of the AVV between the given atrium and the given ventricle based on the relationship between the first component and the second component. [Example]

[0051] 4. The system of any one of Examples 1 to 3, wherein at least one of the signals includes (i) a first component associated with a first region or (ii) a second component associated with a second region, and wherein the processor is configured to estimate an additional location of the first region or the second region based on the components in the signal. [Example]

[0052] The system described in any one of Examples 1 to 3, further comprising a catheter having a first electrode and a second electrode configured to be inserted into the organ and to generate a first signal and a second signal, respectively, indicative of an EP characteristic of the organ, and wherein the processor is configured to estimate at least one of (i) a first region, (ii) a second region, and (iii) a transition zone based on the first signal and the second signal. [Example]

[0053] The system of Example 9, wherein the catheter comprises one or more pairs of electrodes, and at least one of the first signal and the second signal comprises a bipolar signal measured between a given pair of electrodes. [Example]

[0054] A method for displaying a transition zone between a first region and a second region of an organ, the method comprising: receiving one or more signals in a zone between the first region and the second region of the organ of a patient, at least one of the signals including a first component and a second component indicative of an electrophysiological (EP) characteristic of the organ. Based on a relationship between the first component and the second component, a location of the transition zone between the first region and the second region is estimated. At least the estimated transition zone is displayed on a map of the organ.

[0055] The examples described herein primarily address electrophysiological procedures involving sensing signals to estimate the location of the ostia of left atrial PVs. The methods and systems described herein can also be used in other applications, such as estimating the transition zones between any chambers of a patient's heart and between chambers and connected blood vessels. Furthermore, the disclosed techniques may be used to estimate the location of any region in any suitable organ of a patient based on appropriate electroanatomical signals.

[0056] It will be understood that the above-described embodiments are given by way of example, and that the present disclosure is not limited to what is particularly shown and described hereinabove. Rather, the scope of the present disclosure includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof 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, provided that, to the extent that any term in these incorporated documents is defined in a manner that contradicts a definition expressly or implicitly made herein, only the definition herein shall be considered.

[0057] [Embodiment] (1) A system comprising: a processor configured to receive one or more signals in a zone between a first region and a second region of an organ of a patient, at least one of the signals comprising a first component and a second component indicative of an electrophysiological (EP) characteristic of the organ, and based on a relationship between the first component and the second component, the processor configured to estimate a location of at least a transition zone between the first region and the second region; a display configured to display at least the estimated transition zone on a map of the organ. (2) The system of embodiment 1, wherein the first component has a first amplitude, the second component has a second amplitude, and the relationship between the first component and the second component comprises a ratio between the first amplitude and the second amplitude. (3) The system of embodiment 1, wherein the first component occupies a first subinterval of a time interval of the signal, the second component occupies a second subinterval of the time interval, and the relationship between the first component and the second component comprises a duration between a first position of the first subinterval and a second position of the second subinterval. (4) The system of embodiment 1, wherein the signal includes an electrical potential measured by one or more electrodes placed in contact with tissue of the organ in one or more of: (i) the transition zone, (ii) the first region, and (iii) the second region. (5) The system of embodiment 1, wherein the signal includes an additional signal indicative of the impedance measured between a reference electrode and an electrode placed in contact with tissue of the organ in the transition zone.

[0058] (6) The system of embodiment 1, wherein the organ includes a heart, the first region includes an atrium of the heart, the second region includes a pulmonary vein (PV) extending from the atrium, the transition zone includes an ostium of the PV, the first component and the second component represent measurements of the first and second EP characteristics of the atrium and the PV, respectively, and the processor is configured to estimate the location of the ostium between the PV and the atrium based on a relationship between the first component and the second component. (7) The system of embodiment 1, wherein the organ includes a heart, the first region includes a given atrium on a given side of the heart, the second region includes a given ventricle on the given side of the heart, the ventricle connected to the given atrium via an atrioventricular valve (AVV), the transition zone includes the AVV on the given side of the heart, and the processor is configured to estimate the location of the AVV between the given atrium and the given ventricle based on a relationship between the first component and the second component. (8) The system of embodiment 1, wherein at least one of the signals includes (i) a first component associated with the first region or (ii) a second component associated with the second region, and wherein the processor is configured to estimate an additional location of the first region or the second region based on the components in the signal. (9) A system described in any of embodiments 1 to 8, comprising a catheter inserted into the organ and having a first electrode and a second electrode configured to generate a first signal and a second signal, respectively, indicative of the EP characteristic of the organ, and the processor configured to estimate at least one of (i) the first region, (ii) the second region, and (iii) the transition zone based on the first signal and the second signal. (10) The system described in embodiment 9, wherein the catheter comprises one or more pairs of electrodes, and at least one of the first signal and the second signal comprises a bipolar signal measured between a given pair of the electrodes.

[0059] (11) A method for displaying a transition zone between a first region and a second region of an organ, comprising: receiving one or more signals in a zone between the first region and the second region of the organ of the patient, at least one of the signals including a first component and a second component indicative of an electrophysiological (EP) characteristic of the organ; estimating a location of the transition zone between the first region and the second region based on a relationship between the first component and the second component; and displaying at least the estimated transition zone on a map of the organ. (12) The method of embodiment 11, wherein the first component has a first amplitude and the second component has a second amplitude, and wherein estimating the location based on the relationship between the first component and the second component includes calculating a ratio between the first amplitude and the second amplitude. (13) The method of embodiment 11, wherein the first component occupies a first subinterval of a time interval of the signal and the second component occupies a second subinterval of the time interval, and wherein estimating the location based on the relationship between the first component and the second component includes calculating a duration between a first position of the first subinterval and a second position of the second subinterval. (14) The method of embodiment 11, wherein receiving the signal includes receiving an electrical potential measured by one or more electrodes positioned in contact with tissue of the organ in one or more of: (i) the transition zone, (ii) the first region, and (iii) the second region. (15) The method of embodiment 11, wherein receiving the signal includes receiving an additional signal indicative of the impedance measured between a reference electrode and an electrode positioned in contact with tissue of the organ in the transition zone.

[0060] (16) The method of embodiment 11, wherein the organ includes a heart, the first region includes an atrium of the heart, the second region includes a pulmonary vein (PV) extending from the atrium, the transition zone includes an ostium of the PV, the first component and the second component represent measurements of the first and second EP characteristics of the atrium and the PV, respectively, and estimating the location of the transition zone includes estimating the location of the ostium between the PV and the atrium based on the relationship between the first component and the second component. (17) The method of embodiment 11, wherein the organ includes a heart, the first region includes a given atrium on a given side of the heart, the second region includes a given ventricle on the given side of the heart, the ventricle connected to the given atrium via an atrioventricular valve (AVV), the transition zone includes the AVV on the given side of the heart, and estimating the location of the transition zone includes estimating the location of the AVV between the given atrium and the given ventricle based on a relationship between the first component and the second component. (18) The method of embodiment 11, wherein at least one of the signals includes (i) a first component associated with the first region or (ii) a second component associated with the second region, and estimating the location of the transition zone includes estimating the location of an additional location in the first region or the second region based on the first component or the second component in the signal. (19) A method according to any one of embodiments 11 to 18, wherein receiving the one or more signals includes receiving the one or more signals from at least a first electrode and a second electrode of a catheter inserted into the organ to generate a first signal and a second signal, respectively, and estimating the location of the transition zone includes estimating at least one of (i) the first region, (ii) the second region, and (iii) the transition zone based on the first signal and the second signal. (20) The method of embodiment 19, wherein receiving the signal includes receiving a bipolar signal measured between a given pair of electrodes selected from the at least first electrode and second electrode.

Claims

1. 1. A system comprising: a processor configured to receive one or more signals in a zone between a first region and a second region of an organ of a patient, at least one of the signals comprising a first component and a second component indicative of an electrophysiological (EP) characteristic of the organ, and based on a relationship between the first component and the second component, the processor configured to estimate a location of at least a transition zone between the first region and the second region; a display configured to display at least the estimated transition zone on a map of the organ.

2. 2. The system of claim 1, wherein the first component has a first amplitude, the second component has a second amplitude, and the relationship between the first component and the second component comprises a ratio between the first amplitude and the second amplitude.

3. 2. The system of claim 1, wherein the first component occupies a first subinterval of a time interval of the signal, the second component occupies a second subinterval of the time interval, and the relationship between the first component and the second component comprises a duration between a first position of the first subinterval and a second position of the second subinterval.

4. 2. The system of claim 1, wherein the signal includes an electrical potential measured by one or more electrodes positioned in contact with tissue of the organ in one or more of: (i) the transition zone, (ii) the first region, and (iii) the second region.

5. The system of claim 1 , wherein the signals include an additional signal indicative of the impedance measured between a reference electrode and an electrode placed in contact with tissue of the organ in the transition zone.

6. 6. The system of claim 1, wherein the organ includes a heart, the first region includes an atrium of the heart, the second region includes a pulmonary vein (PV) extending from the atrium, the transition zone includes an ostium of the PV, the first component and the second component represent measurements of the first and second EP characteristics of the atrium and the PV, respectively, and the processor is configured to estimate the location of the ostium between the PV and the atrium based on a relationship between the first component and the second component.

7. 6. The system of claim 1, wherein the organ includes a heart, the first region includes a given atrium on a given side of the heart, the second region includes a given ventricle on the given side of the heart, the ventricle connected to the given atrium via an atrioventricular valve (AVV), the transition zone includes the AVV on the given side of the heart, and the processor is configured to estimate the location of the AVV between the given atrium and the given ventricle based on a relationship between the first component and the second component.

8. 6. The system of claim 1, wherein at least one of the signals includes (i) a first component associated with the first region or (ii) a second component associated with the second region, and wherein the processor is configured to estimate additional locations of the first region or the second region based on the components in the signal.

9. 6. The system of claim 1, further comprising: a catheter inserted into the organ and having a first electrode and a second electrode configured to generate a first signal and a second signal, respectively, indicative of the EP characteristic of the organ; and wherein the processor is configured to estimate at least one of (i) the first region, (ii) the second region, and (iii) the transition zone based on the first signal and the second signal.

10. 10. The system of claim 9, wherein the catheter comprises one or more pairs of electrodes, and at least one of the first signal and the second signal comprises a bipolar signal measured between the electrodes of a given pair.

11. 1. A method for displaying a transition zone between a first region and a second region of an organ, comprising: receiving one or more signals in a zone between the first region and the second region of the organ of the patient, at least one of the signals including a first component and a second component indicative of an electrophysiological (EP) characteristic of the organ; estimating a location of the transition zone between the first region and the second region based on a relationship between the first component and the second component; and displaying at least the estimated transition zone on a map of the organ.

12. 12. The method of claim 11 , wherein the first component has a first amplitude and the second component has a second amplitude, and wherein estimating the location based on the relationship between the first component and the second component comprises calculating a ratio between the first amplitude and the second amplitude.

13. 12. The method of claim 11 , wherein the first component occupies a first subinterval of a time interval of the signal and the second component occupies a second subinterval of the time interval, and wherein estimating the location based on the relationship between the first component and the second component comprises calculating a duration between a first position of the first subinterval and a second position of the second subinterval.

14. 12. The method of claim 11, wherein receiving the signal comprises receiving an electrical potential measured by one or more electrodes positioned in contact with tissue of the organ in one or more of: (i) the transition zone, (ii) the first region, and (iii) the second region.

15. 12. The method of claim 11, wherein receiving the signal comprises receiving an additional signal indicative of the impedance measured between a reference electrode and an electrode positioned in contact with tissue of the organ in the transition zone.

16. 16. The method of claim 11, wherein the organ comprises a heart, the first region comprises an atrium of the heart, the second region comprises a pulmonary vein (PV) extending from the atrium, the transition zone comprises an ostium of the PV, the first component and the second component represent measurements of the first and second EP characteristics of the atrium and the PV, respectively, and estimating the location of the transition zone comprises estimating the location of the ostium between the PV and the atrium based on the relationship between the first component and the second component.

17. 16. The method of claim 11, wherein the organ comprises a heart, the first region comprises a given atrium on a given side of the heart, the second region comprises a given ventricle on the given side of the heart, the ventricle connected to the given atrium via an atrioventricular valve (AVV), the transition zone comprises the AVV on the given side of the heart, and estimating the location of the transition zone comprises estimating the location of the AVV between the given atrium and the given ventricle based on a relationship between the first component and the second component.

18. 16. The method of claim 11, wherein at least one of the signals includes (i) the first component associated with the first region or (ii) the second component associated with the second region, and wherein estimating the location of the transition zone includes estimating the location of an additional location in the first region or the second region based on the first component or the second component in the signal.

19. 16. The method of claim 11, wherein receiving one or more signals comprises receiving from at least a first electrode and a second electrode of a catheter inserted into the organ to generate a first signal and a second signal, respectively, and estimating the location of the transition zone comprises estimating at least one of (i) the first region, (ii) the second region, and (iii) the transition zone based on the first signal and the second signal.

20. 20. The method of claim 19, wherein receiving the signal comprises receiving a bipolar signal measured between a given pair of electrodes selected from the at least first and second electrodes.

Images