Method for analyzing intracardiac electrograms

Abstract

The present invention relates to a method for analyzing intracardiac electrograms (1) via a control system (3), in particular for detecting pulmonary vein isolation, wherein the intracardiac electrograms (1) are recorded via a catheter (5) inserted into the human body, in particular at a predetermined target region (4), the catheter (5) comprising a plurality of electrodes (7), wherein a plurality of channels (10) of the intracardiac electrograms (1) are recorded by, preferably between, the electrodes (7), the electrodes (7) being arranged in a fixed order on the catheter (5), and wherein in an analysis routine (11), the control system (3) determines the electrical status of the target region (4) by analyzing at least three of the channels (10). The order of the electrodes (7) on the catheter (5) is provided to the control system (3) or stored in the memory (13) of the control system (3), and in an analysis routine (11), the control system (3) determines the electrical state of the target region (4) based on the relative spatial information, including the order of placement of the electrodes (7) on the catheter (5).

Description

[Technical Field]

[0001] The present invention relates to a method for analyzing intracardiac electrograms according to the preamble of claim 1 and to a control system according to claim 15.

[0002] This method is particularly relevant to atrial fibrillation and atrial flutter. Atrial fibrillation is the uncontrolled electrical activation of atrial muscle cells. During atrial fibrillation, the atria contribute minimally to cardiac function. Therefore, atrial fibrillation reduces cardiac output, but this is not imminently dangerous. However, when atrial fibrillation becomes chronic, it is associated with increased morbidity and mortality. One treatment option for atrial fibrillation is ablation therapy. Ablation is the destruction of cells, allowing re-entry of electrical waves to reduce the uncontrolled activation of atrial muscle cells.

[0003] A recommended treatment for atrial fibrillation is pulmonary vein isolation, which can be achieved by a variety of ablation techniques, including radiofrequency ablation, cryoballoon ablation, and pulsed-field ablation. These techniques vary in the energy they apply, and their common goal is to isolate the electrical activity of the pulmonary veins from the rest of the atrium.

[0004] Generally, ablation therapy is successful when the target area is electrically isolated from the rest of the heart. There are various methods for assessing the success of ablation therapy. These methods include costly 3D mapping of the ablation point, force or temperature measurements during ablation, and electrogram analysis.

[0005] A known method (EP 3139828 A1) determines pulmonary vein isolation based on the morphology of local activation measured in the pulmonary veins. While this method provides good results, there is still room for improvement. Furthermore, this method detects local activations based on their timing relative to atrial activation. During atrial fibrillation, this temporal dependency between local activation in the pulmonary veins and the atrial beat can be disrupted, making it difficult to distinguish between local activation and far-field potentials or artifacts.

[0006] It is a goal to improve upon the prior art described above. In particular, it is desirable to more reliably detect the electrical status of a target region within the heart, preferably within the pulmonary veins.

[0007] The present invention is based on the task of improving the known method in such a way that further optimization with respect to the stated goal is achieved.

[0008] The above-mentioned problem is solved by the features of the characterizing part of claim 1.

[0009] The main realization of the present invention is that even when using a catheter without a localization system, it is still possible to derive spatial information and use this spatial information to improve the determination of the electrical status of a target region in the heart or pulmonary veins. While the use of spatial information is known from mapping systems (sometimes also called localization systems) that use external references to locate electrodes in a fixed coordinate system, the proposed method uses relative spatial information. This relative spatial information includes the order of the electrodes on the catheter. While this order does not allow for the derivation of absolute electrode positions, this order can be used to find the wavefront propagation in the channels of the intracardiac electrogram. Thus, it is possible to use spatial information in the system without external spatial references.

[0010] In particular, it is proposed that the order of the electrodes on the catheter is provided to the control system or stored in the memory of the control system, and that in an analysis routine the control system determines the electrical state of the target region based on spatial information including the order of placement of the electrodes on the catheter.

[0011] Claim 2 lists several preferred features that further define the use of the preferred method, mainly explaining how the idea of ​​using electrode order as spatial information can be used in various systems and use cases where no other localization is provided.

[0012] The preferred embodiment of claim 3 relates to the difference between measuring the channel and providing spatial information.

[0013] A preferred catheter used to measure intracardiac electrograms is the subject of claim 4. In particular, an ablation catheter may be used to measure electrograms before and / or after ablation to assess the need for ablation and / or the success of ablation. Using the same catheter for both measurement and ablation leads to an effective, rapid and cost-effective approach for ablation.

[0014] Following this line of thinking, claim 5 describes a preferred application for the proposed method in pulmonary veins. The ostia of the pulmonary veins are the primary target for ablation therapy. By enabling efficient measurement of the electrical isolation status of the pulmonary veins, the procedure time is reduced and the success rate of the patient treatment is increased.

[0015] The success of pulmonary vein ablation therapy can be determined by analyzing local activation in the pulmonary veins. If activation spreads toward the left atrium and the left atrium is activated, the pulmonary veins are not completely isolated. If this activation is separated from atrial activation, successful isolation is more likely. Conclusions regarding isolation can be derived from the waveform of the local activation. To do this, it is necessary to distinguish between actual local activation and artifacts or far-field interference, such as left atrial activation spreading toward the pulmonary veins. One difference between far-field interference or artifacts and local activation is that local activation spreads around the pulmonary veins, while far-field interference and artifacts hardly spread at all.

[0016] Claim 6 relates to the classification of activation candidates: If exclusively or mainly local activations are grouped together, further analysis can be performed on this group of activations.

[0017] A preferred embodiment of claim 7 relates to using timing differences between activations detected in different channels together with spatial information to determine wave propagation in a target area and thereby distinguish between local activations and far-field interference.

[0018] Combining spatial information with channel-independently derived features allows for improved determination of the electrical state as claimed in claim 8.

[0019] Measurement of the time between activation and something that causes or is caused by said activation, such as the onset of a heartbeat, may vary between channels and convey information about the electrical activity in the target region, which can be used to determine the electrical state of the target region, as recited in claim 9.

[0020] As mentioned above, the waveform of local activation indicates the isolation of the target region. Furthermore, as recited in claim 10, the changes in the waveform can be used to distinguish between components of the wave that undergo rapid changes during propagation and those that remain stable, thereby providing further information about the waveform.

[0021] A further advantage of using the order of electrodes on the catheter as spatial information is that the signal quality of a channel can be estimated by comparing it with its neighboring channels and determining which signal components are local physiological noise and which components are true noise. Claim 11 relates to such an implementation.

[0022] Claims 12 to 14 relate to specific algorithms for analyzing the waveforms of local activation. The proposed improved method allows for better detection of local activation, and allows for a more accurate estimation of the state of electrical isolation, especially of the pulmonary veins. Claim 12 relates to morphological analysis and morphological groups.

[0023] Claim 13 further defines the use of the characteristic peaks for morphological analysis, and claim 14 defines morphological groups.

[0024] Another teaching of equal importance, as set forth in claim 15, relates to a control system configured to carry out the method according to the first teaching, the control system being configured to receive and / or measure intracardiac electrograms, preferably the control system being connectable to a catheter.

[0025] All the explanations of the proposed method are fully applicable to control systems.

[0026] In the following, one embodiment of the invention will be described with reference to the drawings. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a schematic diagram of a human heart and the use of the proposed control system during surgery to measure intracardiac electrograms. [Figure 2] FIG. 1 illustrates a coronary sinus electrogram, an intracardiac electrogram, and schematic analysis and classification routines.

[0028] The proposed method is used to analyze intracardiac electrograms 1, which can be particularly well used to detect isolation of pulmonary veins 2. The intracardiac electrograms 1 are analyzed via a control system 3. The intracardiac electrograms 1 are recorded via a catheter 5 inserted into the human body, particularly at a predetermined target region 4.

[0029] 1 shows in highly schematic fashion how the control system 3 can interact with a catheter 5, for example, inserted through the femoral vein into the left atrium 6 and from there into a pulmonary vein 2. The catheter 5 may be a cryoballoon ablation catheter 5, which is inflated at the entrance to the pulmonary vein 2 and used to isolate the pulmonary vein 2.

[0030] The catheter 5 includes a plurality of electrodes 7. In the illustrated embodiment, the catheter 5 includes a spiral strand 8 with electrodes 7 that is insertable into the pulmonary vein 2 for measuring intracardiac electrograms 1 before, during, and after ablation.

[0031] The control system 3 may further interact with the coronary sinus electrode 9, as shown in Figure 1. Figure 1 shows only the sleeve of the coronary sinus electrode 9 that enters the heart, with the remainder of the coronary sinus electrode 9 located on the outer surface of the visible surface.

[0032] In the proposed method, multiple channels 10 of an intracardiac electrogram 1 are recorded by electrodes 7. If the intracardiac electrogram 1 is a bipolar electrogram, it may be measured between electrodes 7. The electrodes 7 are arranged in a fixed order on the catheter 5. It should be noted that all method steps that are not described as part of the proposed method but are described as features of the intracardiac electrogram 1 may alternatively be part of the proposed method.

[0033] In analysis routine 11, control system 3 determines the electrical status of target region 4 by analyzing at least three of channels 10. This analysis may preferably be performed in real time during surgery and / or by analyzing ongoing measurements of intracardiac electrograms 1.

[0034] A preferred use case of this method is to analyze the electrical isolation status of a target region 4 for atrial fibrillation, preferably during atrial fibrillation surgery. As will be explained hereinafter, one advantage of the proposed method is that the analysis of the electrical isolation status of the pulmonary veins 2 in particular can be performed during episodes of atrial fibrillation.

[0035] 2 shows a channel 10 of an intracardiac electrogram 1 and a coronary sinus electrogram 12. There may be more than one coronary sinus electrode 9 and more than one coronary sinus electrogram 12. One of these coronary sinus electrograms 12 may be selected for this method, or more than one coronary sinus electrogram 12 may be used for this method.

[0036] The control system 3 may be a local unit including a processor, possibly a user interface, etc., as shown in FIG. 1. The processor may, in one embodiment, include a cloud processor. Thus, the control system 3 need not be limited to a single device. The control system 3 may include a memory 13 and other necessary components; in particular, the control system 3 may include an interface for the catheter 5 and / or the coronary sinus electrode 9.

[0037] The term "predetermined target region" means that the target region 4 is intentionally selected and not randomly selected. The predetermined target region 4 may be a pulmonary vein 2 that is to be isolated or has been isolated, and may be measured to confirm the need for or success of isolation. In this case, the exact location of the catheter 5 within the pulmonary vein 2 is not important, since the entire vein is to be electrically isolated from the left atrium 6. The predetermined target region 4 may also be a region associated with the spiral excitation waves that drive atrial fibrillation, as identified by a mapping system independent of the proposed analysis routine 11. Systems that electrically map the entire atrium 14 or both atria 14 typically do not measure a predetermined region, but instead measure multiple regions sequentially throughout the atrium 14.

[0038] The term "channel" relates to a time sequence of electrical values, preferably voltages, measured by a unipolar electrode 7 or measured between at least two electrodes 7. Preferably, a channel 10 herein is one measured between adjacent electrodes 7.

[0039] The term "intracardiac" should be understood in a broad sense and relates to measurements inside the human heart 15 and in the immediate vicinity of the human heart 15, for example in the pulmonary veins 2.

[0040] A routine, such as analysis routine 11, is a collection of steps that have a purpose. The routines and steps may be implemented entirely in control system 3 as software, but may also include physical measuring instruments, etc. Everything described as part of a routine serves this purpose of the routine, and therefore other calculations, such as those that may be performed simultaneously with the routine but are unrelated to this purpose of the routine, are not part of the routine. These steps of a routine may be performed at separate times, simultaneously, and in any suitable order.

[0041] What is important here is that the order of the electrodes 7 on the catheter 5 is provided to the control system 3 or stored in the memory 13 of the control system 3, and that in the analysis routine 11, the control system 3 determines the electrical state of the target region 4 based on the relative spatial information including the order of placement of the electrodes 7 on the catheter 5.

[0042] Preferably, the order of the electrodes 7 herein implicitly or explicitly provides information about the order of the channels 10. Generally, it is known from so-called mapping or localization systems to use absolute spatial information from a localization system by external interrogation. This can be a magnetic localization system assisted by bioimpedance measurements between a patch on the patient's chest and the catheter 5. This method does not rely on such external interrogation. In the main implementation of the present invention, by using the order of the electrodes 7 as spatial information, even if relative, it is possible to continue to use some of the advantages of the localization system in the form of relative spatial information. Preferably, the relative spatial information herein is based solely on the order of the electrodes 7. This order is fixed information based on the manufacture of the catheter 5 and can be derived, for example, from a standard numbering of the channels 10 provided to the control system 3 simply by the measurement order of the channels 10. The control system 3 of the proposed method preferably does not use absolute spatial information at all.

[0043] The electrical state may generally be any state, and in particular any property, of the target region 4. In a preferred embodiment, this is the electrical isolation state of the target region 4 relative to the left and / or right atrium 14 and / or the remainder of the left and / or right atrium 14. It may also comprise the electrical conduction properties of the target region 4 itself.

[0044] Hereinafter, the term "determining based on" means that the characteristic, feature, property, etc. is determined by using in a manner that is not entirely unrelated the information on which the determination is "based." Thus, in each case, preferably the determination is primarily based on the respective information.

[0045] As used herein, preferably, the intracardiac electrogram 1 is recorded during the surgical procedure without electrical mapping of the atrium 14 by a localization system based on the recorded electrogram during the recording of the intracardiac electrogram 1. A mapping system may additionally and independently be present, but in the preferred embodiment is not present. Preferably, this is the case during the entire surgical procedure.

[0046] In analysis routine 11, control system 3 preferably determines the electrical state by analyzing simultaneously measured channels 10 of electrograms in target region 4 without using channels 10 of electrograms measured after repositioning of catheter 5. One advantage of this method is that it eliminates the need for complex repositioning of catheter 5 and measurements of multiple regions. It may be noted that target region 4 is much smaller than the entire left atrium 6.

[0047] In this specification, preferably, the spatial information is represented in a coordinate system without using reference points outside the body, in particular without using reference points determined from magnetic and / or bioimpedance measurements between electrodes 7 or magnetic localization devices outside the body and catheter 5, or even without using a coordinate system.

[0048] Imaging systems such as CT-scanners are not included in the above, if they do not provide a fixed interrogation system to which the catheter 5 is associated.

[0049] As used herein, these channels 10 are preferably measured at least partially, and preferably completely, simultaneously over the same period of time. The spatial information may be primarily or exclusively passive spatial information that is not measured over time, preferably not measured at all. In this last case, the term "measured" may not be understood in a broad sense. Determining the order of the electrodes 7 from the numbering of the channels 10 or providing the order of the electrodes 7 from an external source where the order is manually entered is not included in measuring the order. Preferably, the spatial information is not measured in a reference coordinate system and / or does not include or relate to a reference coordinate system.

[0050] The spatial information may be constant during the measurement of the intracardiac electrogram. Here, the order of electrodes 7 is constant, and therefore the spatial information may not change or change relevantly over time, and / or may not comprise information that is regularly updated, particularly in real time or near real time.

[0051] As already mentioned and partially shown in FIG. 1 , the catheter 5 may be an ablation catheter 5, in particular a cryoballoon catheter 5 and / or a spiral catheter 5, and preferably the catheter 5 may comprise only one strand 8 on which the electrodes 7 are arranged. An example of a preferred catheter 5 is a LASSO™ catheter 5. Alternatively, the catheter may be a multi-strand catheter 5. In this case, the order of arrangement of the electrodes 7 may be for only one strand 8 or for multiple strands 8.

[0052] As used herein, the electrical state preferably refers to an electrical isolation state. Preferably, the target region 4 is located within a pulmonary vein 2, and the electrical isolation state refers to an electrical isolation state of the pulmonary vein 2. Pulmonary vein isolation is one of the primary ablation therapies used. An intracardiac electrogram 1 may be recorded within the isolated pulmonary vein 2 after isolating the pulmonary vein 2, and thus, in analysis routine 11, the control system 3 determines the isolation state of the pulmonary vein 2. As noted above, the intracardiac electrogram 1 may be recorded during execution of analysis routine 11. It should be understood that when referring to isolation of a pulmonary vein 2, an isolation attempt is intended, with success being determined.

[0053] The electrical isolation status may be a binary yes / no option as shown in FIG. 2, or may be the probability of isolation of the target region 4, or any other suitable measure of success.

[0054] In the analysis routine 11, the control system 3 may identify activation candidates 16 in at least three channels 10, and particularly in all channels 10. Activation candidates 16 are sections of channels 10 identified by the algorithm that may be local activations. These candidates may be identified using peak detection algorithms, waveform detection such as correlation, etc.

[0055] Preferably, in the analysis routine 11, the control system 3 executes a classification routine 17 for at least some, preferably all, of the activation candidates 16, which classifies the activation candidates 16 into groups. These groups include at least one group assigned to local activations, and / or at least one group assigned to far-field interference, particularly atrial activations, and / or at least one group assigned to noise. Thus, the control system 3 can separate the activation candidates 16 into true activations that do not originate within or near the target region 4, i.e., far-field interference and possibly artifacts from pacing, noise, particularly false positives, i.e., signals not originating from physiological activations, and local activations. Local activations may be the primary target of the proposed method and can be used to determine the electrical isolation state.

[0056] As will be explained further below, poor quality channels 10 may be ignored in the classification routine 17 .

[0057] When it is stated that a group is assigned to a particular type of signal, it is intended that this type of signal or a subset of this type of signal is the primary focus of said group, and that this classification is specifically intended simply to group occurrences of said type of signal into said group.

[0058] By placing a catheter 5, particularly a spiral catheter, within the pulmonary vein 2, it is possible to detect the propagation of local activation around the pulmonary vein 2. This is based on the realization that far-field interference, such as atrial beats, and artifacts, such as pacing artifacts, reach most of the pulmonary vein 2 simultaneously, particularly in the pulmonary vein 2, when the electrodes 7 are positioned more or less perpendicular to the extension of the pulmonary vein 2 around the pulmonary vein 2, for example, by using a circular or spiral catheter 5 or strand 8. However, the local activation propagates around the pulmonary vein 2. This propagation can be measured as the time difference between the onset or peak of the local activation. Figure 2 shows local activation in some channels 10 with different timings.

[0059] Preferably, the identification of local activations in the classification routine 17 herein is based, at least in part, on detecting this timing difference.

[0060] In particular, in the classification routine 17, the control system 3 may identify timing sequences and / or timing differences between at least two, preferably at least three, more preferably at least four activation candidates 16 of different channels 10 based on spatial information, in particular the order of the electrodes 7, preferably to distinguish between local activation and far-field interference.

[0061] Furthermore, in the classification routine 17, the control system 3 can distinguish between local activation and far-field interference by identifying a propagation sequence along the order of the electrodes 7 and classifying the activation candidate 16 as local activation if the control system 3 identifies a propagation sequence, and / or classifying the activation candidate 16 as far-field interference if the control system 3 does not identify a propagation sequence.

[0062] It is interesting to note that during atrial fibrillation, this temporal relationship between atrial beating and local activation in the pulmonary veins 2 can be disrupted. Therefore, known algorithms have difficulty distinguishing local activation from far-field interference, particularly atrial activation. The above can be used to aid in this distinction. Therefore, the proposed method performs well during episodes of atrial fibrillation. Using this method, a surgeon would not need to cardiovert the patient's atrium 14 into a normal rhythm to measure the success of the isolation procedure.

[0063] In a preferred embodiment, in the analysis routine 11, the control system 3 determines the electrical state based on a set of features determined independently from the analysis of the channels 10 and a set of features determined from the analysis based on spatial information, in particular the order of the electrodes 7. Possible sets of features determined independently for each channel 10 are described further below.

[0064] In the analysis routine 11, and particularly in the classification routine 17, the control system 3 may determine the electrical state based on the order of the electrodes 7, particularly based on the time difference of local activation between adjacent channels 10. The activation may be atrial activation detected in the coronary sinus electrogram 12, and the local activation time may be measured as the time difference between the onset of a particular event, e.g., activation candidate 16, and the atrial activation. Preferably, the local activation time is measured relative to any coronary activation, particularly measured by the coronary sinus electrode 9. The coronary activation may be atrial activation.

[0065] It may be reiterated that adjacent channels 10 are preferably channels that share an electrode 7 in a typical bipolar measurement. Additionally or alternatively, adjacent channels 10 may be separated by, for example, one electrode 7. In particular, some catheters 5 may have pairs of electrodes 7, the spacing between the electrodes 7 of a pair being smaller than the spacing between the electrodes 7 of adjacent pairs.

[0066] Furthermore, in the analysis routine 11, and in particular in the classification routine 17, the control system 3 can determine the electrical state and / or classification of the activation candidate 16 based on the change in the activation or activation candidate 16 over its spatial propagation, thereby determining the spatial propagation based on spatial information, in particular the order of the electrodes 7 and the timing of the activation or activation candidate 16. The change can be a change in waveform.

[0067] Another advantage of using relative spatial information is the ability to estimate the quality of channels 10. Preferably, in a quality estimation routine, preferably prior to analysis routine 11, control system 3 estimates quality indicators, particularly signal-to-noise ratios, of channels 10, preferably all channels 10, based on the spatial information, particularly the order of electrodes 7. Preferably, in analysis routine 11, particularly classification routine 17, this quality indicator can be used to remove some channels 10 from further analysis. Preferably, in the quality estimation routine, control system 3 estimates quality indicators based on a comparison of adjacent channels 10, particularly the waveforms of activations or activation candidates 16 of adjacent channels 10. Additionally or alternatively, control system 3 uses only a subset of channels 10 selected based on the quality indicators to determine the electrical state of target region 4 in analysis routine 11.

[0068] Herein, preferably, the subset comprises at least two, preferably at least three, but less than the maximum number of channels 10 .

[0069] As already mentioned, for the purpose of determining the electrical isolation state, in analysis routine 11 control system 3 analyzes the morphology of local activation to determine the electrical isolation state of target region 4. Preferably, in analysis routine 11 control system 3 classifies the local activation into morphological groups and preferably determines the electrical isolation state based on the distribution of local activation across the groups.

[0070] Preferably, in the analysis routine 11 herein, the control system 3 classifies local activations into morphology groups based on the number of characteristic peaks of the local activations. Thus, not all plateaus of the local activations are necessarily counted as characteristic peaks. Preferably, the control system 3 classifies peaks as characteristic peaks using at least a predetermined amplitude, and / or using at least a predetermined slope, and / or using a maximum predetermined slope, and / or using at least a predetermined minimum peak distance, and / or using a maximum predetermined maximum peak distance, and / or based on peak morphology, in particular the minimum peak angle and / or the maximum peak angle.

[0071] Further, the morphological groups may comprise groups for local activation having one characteristic peak and / or groups for local activation having exactly two characteristic peaks and / or groups for local activation having exactly three characteristic peaks and / or groups for local activation having more than three characteristic peaks and / or groups for local activation having at least two characteristic peaks separated by a predetermined time.

[0072] The channels 10 may be highlighted, and in particular colored, on the display of the control system 3 based on the results or details of the analysis routine 11 by the control system 3 to draw the physician's attention to and facilitate interpretation of the influence and relationship of the channels 10 on the model output.

[0073] According to another teaching of equal importance, a control system 3 is proposed which is configured to carry out the method according to the proposed method, the control system 3 being configured to receive and / or measure intracardiac electrograms 1, and preferably the control system 3 being connectable to a catheter 5.

[0074] All the explanations about the proposed method are fully applicable to the control system 3. [Explanation of symbols]

[0075] 1. Intracardiac electrogram 2. Pulmonary veins 3. Control System 4 Target Area 5 Catheter 6. Left atrium 7 electrodes 8 strands 9. Coronary sinus electrode 10 channels 11 Analysis Routines 12 Coronary sinus electrogram 13. Memory 14 Atrium 15 Human Heart 16 Activation candidates 17 Classification Routines

Claims

1. A control system (3) configured to perform a method for analyzing an intracardiac electrogram (1), comprising: The intracardiac electrogram (1) is recorded at a target region (4) via a catheter (5) inserted into the human body; The catheter (5) is provided with a plurality of electrodes (7), a plurality of channels (10) of the intracardiac electrogram (1) recorded by the electrodes (7); The electrodes (7) are arranged in a fixed order in the catheter (5), A control system (3) configured to execute a method for determining an electrical state of the target area (4) by analyzing at least three of the channels (10) in an analysis routine (11), the control system (3) comprising: the sequence of the electrodes (7) on the catheter (5) is provided to the control system (3) or stored in a memory (13) of the control system (3); In the analysis routine (11), the control system (3) determines the electrical state of the target region (4) based on relative spatial information including the order of placement of the electrodes (7) on the catheter (5); a control system (3) configured to execute a method, characterized in that in the analysis routine (11), the control system (3) identifies activation candidates (16) in at least three channels (10); in the analysis routine (11), the control system (3) executes a classification routine (17) on at least some of the activation candidates (16) to classify the activation candidates (16) into groups, the groups including at least one group assigned to local activation and / or at least one group assigned to far-field interference; and in the classification routine (17), the control system (3) identifies a timing sequence and / or a timing difference between at least two activation candidates (16) in different channels (10) based on spatial information to distinguish between local activation and far-field interference.

2. the intracardiac electrogram (1) was recorded during a surgical procedure without electrical mapping of the atrium (14) by a localization system based on the recorded electrogram; and / or In the analysis routine (11), the control system (3) determines the electrical condition by analyzing simultaneously measured channels (10) of the electrogram in the target region (4) without using channels (10) of the electrogram measured after repositioning of the catheter (5); and / or 2. The control system (3) of claim 1, wherein the spatial information is expressed in a coordinate system without reference points external to the human body.

3. the channels (10) were at least partially measured simultaneously over the same time period; and / or 2. The control system (3) of claim 1, wherein the spatial information is primarily or exclusively passive spatial information that is not measured over time.

4. 2. The control system (3) of claim 1, wherein the catheter (5) is an ablation catheter (5).

5. The control system (3) of claim 1, wherein the electrical condition is an electrical isolation condition.

6. A control system (3) as described in claim 1, wherein in the classification routine (17), the control system (3) distinguishes between local activation and far-field interference by identifying a propagation sequence along the order of the electrodes (7) and classifying the activation candidate (16) as local activation if the control system (3) identifies a propagation sequence, and / or classifying the activation candidate (16) as far-field interference if the control system (3) does not identify a propagation sequence.

7. 2. The control system (3) of claim 1, wherein in the analysis routine (11), the control system (3) determines the electrical state based on a set of features determined independently from an analysis of the channel (10) and a set of features determined from the analysis based on the spatial information.

8. In the analysis routine (11), the control system (3) determines the electrical state based on the time difference between local activations of the channels (10) based on the sequence of the electrodes (7). A control system (3) according to claim 1.

9. 2. The control system (3) of claim 1, wherein in the analysis routine (11), the control system (3) determines the electrical state and / or the classification of an activation candidate (16) based on changes in the activation or activation candidate (16) over its spatial propagation, whereby the spatial propagation is determined based on the spatial information and the timing of the activation or activation candidate (16).

10. 2. The control system (3) of claim 1, wherein in a quality estimation routine, the control system (3) estimates a quality indicator of the channel (10) based on the spatial information.

11. 6. The control system (3) of claim 5, wherein in the analysis routine (11) the control system (3) analyzes the local activation morphology to determine the electrical isolation state of the target area (4).

12. A control system (3) as described in claim 11, wherein in the analysis routine (11), the control system (3) classifies the local activation into morphological groups and determines the electrical isolation state based on the distribution of local activation across the groups.

13. 13. The control system (3) of claim 12, wherein in the analysis routine (11), the control system (3) classifies the local activations into the morphological groups based on the number of characteristic peaks of the local activations.

14. 13. A control system (3) as claimed in claim 12, wherein the morphological groups comprise a group for local activation having one characteristic peak and / or a group for local activation having exactly two characteristic peaks and / or a group for local activation having exactly three characteristic peaks and / or a group for local activation having more than three characteristic peaks and / or a group for local activation having at least two characteristic peaks separated by a predetermined time.

15. 15. The control system (3) according to any one of the preceding claims, wherein the control system (3) is configured to receive and / or measure intracardiac electrograms (1).

16. A control system (3) as described in claim 5, wherein the target area (4) is located within a pulmonary vein (2) and the electrical isolation state is an electrical isolation state of the pulmonary vein (2).

17. A control system (3) as described in claim 8, wherein in the classification routine (17), the local activation times are measured in relation to coronary activation and / or atrial activation.

18. A control system (3) as described in claim 10, wherein in a quality estimation routine, the control system (3) estimates a quality indicator based on a comparison of adjacent channels (10), and / or wherein in the analysis routine (11), the control system (3) uses only a subset of the channels (10) selected based on the quality indicator to determine the electrical condition of the target area (4).

19. A control system (3) as described in claim 13, wherein in the analysis routine (11), the control system (3) classifies peaks as characteristic peaks using at least a predetermined amplitude, and / or using at least a predetermined slope, and / or using a maximum predetermined slope, and / or using at least a predetermined minimum peak distance, and / or using a maximum predetermined maximum peak distance, and / or based on peak morphology.

20. A control system (3) as described in claim 15, wherein the control system (3) is connectable to a catheter (5).

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