EP3606416A1

EP3606416A1 - Method for determining a plurality of action potentials in the heart

Info

Publication number: EP3606416A1
Application number: EP18714500.8A
Authority: EP
Inventors: Ovidiu Codreanu
Original assignee: Biotronik SE and Co KG
Current assignee: Biotronik SE and Co KG
Priority date: 2017-04-03
Filing date: 2018-03-29
Publication date: 2020-02-12
Also published as: US20200054233A1; WO2018184968A1; DE102017107082A1

Abstract

The invention relates to a method for determining a plurality of action potentials in the heart having the following steps: a) recording a superficial ECG signal (31) synchronously with at least 64 channels, b) recording at least one IEGM signal (30), c) processing the superficial ECG signal by means of ICA analysis and determining the sum and position of a plurality of action potentials in the heart on the basis of the ICA analysis (32) and d) comparing the at least one IEGM signal with the plurality of action potentials (33) and correcting the sum and/or the position of at least one of the plurality of action potentials in the heart (34) on the basis of this comparison. The invention further relates to a corresponding device, a corresponding computer program product and a corresponding system.

Description

Method for determining a variety of activation potentials in the heart

The present invention describes a method for determining a plurality of activation potentials in the heart, a corresponding computer program product, a corresponding device and a corresponding system.

background

One known method for the non-drug, minimally invasive treatment of idiopathic or paroxysmal arrhythmias of the heart is intracardiac ablation. In the case of atrial fibrillation, for example, a catheter with at least one electrode is introduced via the venous blood vessels into the right atrium of the heart and placed through the cardiac septum in the left atrium. Most ablation catheters have 4 electrodes, with RF energy delivered to the tissue via the electrode at the tip of the catheter. Subsequently, muscle tissue areas in the left atrium are so desolated (ablated) by means of a high-frequency current introduced through the electrode that so-called rotors (circular excitations) or ectopic activation sources are eliminated, which are the cause of the atrial fibrillation. Alternatively, a minimally invasive treatment by means of laser or cold can be carried out analogously.

The success rate of ablation can be increased if, during treatment, the efficacy of lesions induced by ablation or other minimally invasive procedures can be more reliably assessed. This is only possible to a limited extent with today's methods. In many cases, therefore, a second AF ablation is required after a first AF ablation treatment (AF = atrial fibrillation). This leads to an increased burden on the patient. The preparation of a surface electrocardiogram (ECG), ie the recording of the electrical activity of cardiac muscle fibers by means of electrodes applied to the surface of the patient's body, has for many years been one way of detecting arrhythmias of the heart. Surface ECGs are also already being used to assess the outcome of an ablation.

From the document US Pat. No. 7,123,954 B2, methods are already known which evaluate surface ECG signals and intracardiac ECG signals of an electrode arranged in the heart by means of a so-called temporospatial morphology correlation in order to be able to assess arrhythmias better, to better identify possible ablation sites and to identify them To assess the success of ablation. Intracardiac excitation (pacing) is performed to record the intracardiac ECG signals. The temporopatial morphology correlation analyzes the reproducibility of a time-dependent and electrode-specific electrogram morphology.

US Pat. No. 9,370,312 B2 describes various calculation methods for matching a surface ECG with an intracardiac ECG by means of imaging (maps) of electrical potentials of the heart. In this case, an endocardial imaging by means of a catheter and an image based on a surface ECG are generated and brought into agreement on the basis of anatomical fixed points and / or electrical properties of the images.

Document US 2012/0232417 Al discloses a method for analyzing signals for determining a condition of a heart.

Yi Zhu et al., Proceedings of Sixth IEEE Symposium on Biolnformatics and BioEngineering (2006), p. 340, describes the use of Independent Component Analysis (ICA) in its article "Noninvasive Study of the Human Heart using Independent Component Analysis." ECG data for the simulation of cardiac activity. The document "Predicting Catheter Ablation Outcome in Persistent Atrial Fibrillation Using Atrial Dominant Frequency and Related Spectral Features," M. Garibaldi et al, Engineering in Medicine and Biology Society, 34th Annual International Conference of the IEEE EMBS (2012), pages 613-616 describes a method for determining an ablation result.

The known methods described above often have the disadvantage that they are still too inaccurate and can detect in part only an interruption of the signal path in the surface of the heart muscle by ablation, but do not detect signal paths in the depth of the heart muscle. Therefore, the result of ablation is often not properly assessed.

Summary

The object can be seen to provide a method that allows a more accurate assessment of the ablation, including lower-lying areas. The object is also to provide a corresponding device.

There are provided a method having the features of claim 1, a computer program product according to claim 8, an apparatus according to claim 9 and a system according to claim 15. Further embodiments are the subject of dependent claims.

In particular, the size and location of a variety of activation potentials in the heart can be determined by the following steps:

a) taking at least one surface ECG signal in synchronism with a plurality of channels,

b) recording at least one IEGM signal,

c) processing the surface ECG signal by ICA analysis and determining the amount and location of a variety of activation potentials in the heart based on the ICA analysis as well as d) comparing the at least one IEGM signal with the plurality of activation potentials and correcting the magnitude and / or location of at least one of the plurality of activation potentials in the heart based on the comparison.

It can be provided that the recording of the surface ECG signal takes place synchronously for all channels (eg 64 channels). Furthermore, the synchronous recording of the surface ECG signal can be synchronized with the recording of the IEGM signal. The synchronicity of the surface ECG signal with the IEGM signal can improve the evaluation of the signals.

In one example of the method, the 64-channel surface ECG is recorded. For the purposes of the present disclosure and for all embodiments described herein, fewer or more channels for recording are conceivable, such. 6, 32, 128, etc. The use of a larger number of channels increases the accuracy of the signal analysis and is associated with a higher computational effort.

ICA analysis (ICA = Independent Component Analysis) is a well-known analysis method of signal processing technology that can reconstruct statistically independent signal sources present in a linearly mixed signal. See, for example, the publication "Independent Component Analysis" by A. Hyvärinen, J. Karhunen, and E. Oja, John Wiley & Sons, Inc., 2001, which describes the operation of the ICA using their basic mathematical algorithms.

In the present case, the ICA analysis is applied to the data set of a multichannel surface ECG, preferably with 64 channels, and the data set is processed to determine a variety of cardiac activation potentials, including their magnitude and location. In the context of the present disclosure, "amount" of the activation potential is understood to mean the time-dependent course of the respective potential.

The ICA analysis can be used because the measuring points (electrodes / channels of the ECG) are spatially distributed. They are at predetermined locations on the surface attached to the patient's body. Furthermore, it is assumed that the number of measurement points (channels) is greater than the number of statistically independent signal sources (here: activation potentials in the heart). In addition, in the present case, the detected mixed signals (channels of the surface ECG) are a linear combination of the native signal sources (activation potentials of the heart) or, for the later calculations, a sufficiently accurate linear combination. Furthermore, the activation potentials have no Gaussian distribution and are statistically independent.

It is further provided to record at least one intracardiac (preferably unipolar) ECG signal (hereinafter referred to as the IEGM signal), which is detected by means of at least one electrode arranged inside the heart. For this purpose, a catheter, at the tip of which the electrode is arranged, is advanced via the venous system into the heart of the patient and guided transseptally into the left atrium. The catheter is moved along the inner wall of the chamber to selectively measure the electrical potential on the inner wall by means of the electrode. The at least one electrode can additionally be used for ablation.

In one embodiment, ICA analysis may also be applied to the IEGM signal. The IEGM signal is a composite signal that is composed of individual signals generated by different electrical action potentials. The ICA allows extraction and isolation of the single signals from the IEGM. For this purpose, the typical ICA calculation steps are applied to the IEGM signal.

The IEGM signal is then compared with the plurality of activation potentials determined by ICA analysis from the surface ECG data set or combinations of these activation potentials and thus analyzed in combination. Based on this comparison, the amount and / or location of at least one of the plurality of activation potentials in the heart is corrected. By comparison, an activation potential from the surface ECG evaluated by means of ICA analysis or a combination of such activation potentials can be assigned to the activation potential determined by means of the IEGM signal. Since the location of the associated activation potential is much more accurately known with the detected IEGM signal, this allows IEGM signal correction of the variety of activation potentials determined by ICA analysis.

The solution has the advantage that areas lying deeper in the heart muscle can also be examined. The combination of surface ECG signal and IEGM signal not only captures superficial signal paths. Activation potentials from deeper areas of the heart muscle flow into the signal of the surface ECG and are worked out by the decomposition into signal sources by means of the ICA analysis. For example, if after ablation only the preferably unipolar IEGM signal for the site in question is greatly altered or disappears, it is very likely that in a deeper area of the myocardium there is still a conductive path that still needs to be treated by ablation. Ablation can be more accurately assessed by the procedure.

In another embodiment, the comparison in step d) is performed by means of correlation calculation. This makes a particularly fast and easy to implement comparison of the data possible. See the definition of correlation in signal processing: Daniel Ch. Von Grünigen - "Digital Signal Processing", Carl Hanser Verlag GmbH & Co. KG, 2nd edition, 2002, especially page 51. See also the correlation calculation from a more general perspective Statistics: A. Papoulis - "Probability, Random Variables, and Stochastic Processes", McGrawHill, 3rd edition, 1991.

In a further exemplary embodiment, the amount and the position of the multiplicity of activation potentials determined according to steps a) to d) are preferably represented by means of a two-dimensional or a three-dimensional model of the heart in a two-dimensional or three-dimensional map. As a result, the distribution of the activation potentials can be assessed particularly effectively.

In this method, voltage maps (voltage maps) of the heart are calculated on the basis of electrical potentials measured in and at the heart, ie the measured ECG signals. In connection with the present Revelation ECG components, which were determined according to the method, can be used for the calculation of a voltage map.

It is also advantageous if, based on the plurality of activation potentials determined according to steps a) to d), a rotor and / or an ectopic activation potential is automatically identified. Such a pathological activation potential can, for example, in a two-dimensional or three-dimensional mapping z. B. be shown highlighted accordingly. Additionally or alternatively, other anatomical fixed points and areas such as sinus node, atrial muscle, AV node, bundle branches, ventricular muscle can be automatically identified and particularly preferably in a two-dimensional or three-dimensional image z. B. be highlighted. For example, individual signal components may have specific properties for identifying abnormal stimulus transmission or stimulus generation. For example, individual signal components are recorded as a function of time and place during the cardiac cycle and analyzed with known data via the normal cardiac conduction. Such an analysis may be a comparison of certain characteristic features of the signal component with the known data, such as a threshold comparison of the signal amplitude. Also, analysis from a morphology comparison may represent the signal component having a known signal pattern. The known signal pattern represents a normal cardiac conduction and can be generated patient-specific, eg by taking signals during normal intrinsic cardiac activity and averaging them into a pattern signal. The signal pattern may also represent a pre-stored pattern. If the analysis reveals that the signal components deviate from the properties of a normal cardiac conduction, rotors or ectopic activation potentials could be the cause. Such signal components can be graphically highlighted when creating and displaying a map. If there is a rotor, the temporal and spatial analysis of the amplitude of the corresponding signal component will have a circular signal path. Such a component can then be highlighted, this can, for. B. methods of morphological image processing can be used. In one embodiment, the magnitude and location of a plurality of activation potentials in the heart is determined by steps a) through d), respectively, in a first time period and a second time period, wherein the second time period is different from the first time period. For example, the first period is before ablation and the second period is after ablation. In the next step, the change of some of the activation potentials of the second period to the first period in terms of amount and / or location is determined. The determination of the change can be carried out by means of a data processing device (eg personal computer, notebook, tablet or smartphone). The data processing device may include a processor and a memory.

In one embodiment, in step c) the detected multichannel surface ECG is decomposed by ICA into several components, some of which represent activation potentials of the heart or combinations thereof. Other components correspond to z. As artifacts of muscle movements, respiratory movements or signal interference from external sources such. B mains humming. Parallel to the surface ECG, an IEGM signal is also detected at the ablation site. At the ablation site, it is intended to interrupt the signal conduction of the heart or to prevent an unwanted activation potential. The detected simultaneously with the surface ECG IEGM signal is then z. B. compared by cross-correlation with the ICA components and the component that gives the largest correlation factor is assigned to the point at which the heart tissue must be ablated. The ablation is then performed and steps a to d are repeated. If the signal is then re-measured at the ablated site and the ICA component that was assigned by cross-correlation to the same site in the first step is still present, then most likely, the ablation was unsuccessful. It is conceivable to apply the method not just for one but for several IEGM measurement points before and after ablation.

In this case, it is particularly preferable if a corresponding acoustic and / or visual value changes by more than a predetermined threshold value when the amount of an activation potential between the first period and the second period changes and / or tactile indication. In this case, after ablation, it is assumed that the ablation was successful at the site in question.

The above object is further achieved by a computer program product for determining the size and arrangement of a plurality of activation potentials in the heart with program code means for executing a computer program after its implementation in a data processing device, the program code means being provided after implementation in the data processing device as described above Perform procedure. The computer program product has the advantages explained above for the method.

The above problem is further solved by a device comprising the following elements:

receiving means for receiving a record of a surface ECG signal recorded in synchronism with a plurality of channels, and data of at least one IEGM signal of the associated heart received during the same period;

a data processing device, which is set up for this purpose

to process the data set of the surface ECG signal by means of ICA analysis and to determine the amount and position of a multiplicity of activation potentials in the heart based on the ICA analysis and

compare the data of the at least one IEGM signal with the plurality of activation potentials and correct the magnitude and / or location of at least one activation potential of the plurality of activation potentials in the heart based on the comparison.

As a data processing device is for example a microprocessor, such as a personal computer with multi-core processor.

In one embodiment of the device, the 64-channel surface ECG can be recorded. However, ECG recordings with fewer or more channels than 64 are also possible. Analogous to the method, the device is designed such that the success of an ablation can be assessed more accurately, because deeper areas of the myocardium are also included in the analysis.

In a preferred embodiment, the data processing device is set up to carry out the comparison by means of correlation calculation. As already explained above, a correlation of the data is possible by means of the correlation calculation.

In a further embodiment, the device further comprises a display device (for example in the form of a screen with a suitable resolution, for example 1920 × 1080 pixels), which is set up, preferably by means of an amount and location of the determined plurality of activation potentials two-dimensional or three-dimensional model of the heart in a two-dimensional or three-dimensional image.

In a further exemplary embodiment, the data processing device is set up to automatically identify a rotor and / or an ectopic activation potential based on the determined multiplicity of activation potentials. This simplifies the analysis of the data by the attending person.

In particular for the evaluation of the effectiveness of an ablation treatment, it is advantageous if the data processing device is set up for the amount and location of a multiplicity of activation potentials in the heart in each case in a first period (eg before the ablation) and in a second period (eg, after ablation), wherein the second period is different from the first period, and the change in the plurality of activation potentials of the second period to the first period in terms of amount and / or location to determine.

Further simplified is the interpretation of the measurement results and the assessment of the ablation, if the data processing device is set up, with a change in the amount of an activation potential between the first period and the second period by more than a predetermined threshold value to generate an indication signal which causes an output of an audible and / or visual and / or tactile indication on a display device (eg a screen, a loudspeaker or the like).

The above object is also achieved for the same reasons by a system comprising a device as described above and a recording device for a surface ECG signal in synchronism with a plurality of channels, for example with 32 or 64 channels, and / or a recording device for at least one IEGM. Signal solved, wherein the device and the receiving device for a surface ECG signal and / or the receiving device for at least one IEGM signal are connected such that the receiving device for a surface ECG signal the respectively determined surface ECG signal to the Device transmitted and the receiving device for at least one IEGM signal transmitted the respectively determined at least one IEGM signal to the device.

Description of embodiments

The invention will be explained below with reference to embodiments and with reference to the figures. All described and / or illustrated features alone or in any combination form the subject matter of the invention, regardless of their summary in the claims or their back references.

It shows schematically: the arrangement of the electrodes of the receiving device on the body of

patients;

Fig. 2 is a schematic enlarged view of an 8-fold electrode;

Fig. 3 shows an embodiment of a method. Fig. 4 is a schematic arrangement of the system for measuring the Ablationserfolgs

The system includes a data processing device (eg, a processor of a computer), a catheter having one or more electrodes on the distal catheter tip, and means for detecting a surface ECG. Here, the surface ECG is detected unipolar against a reference electrode by means of special electrodes via a plurality of channels (see step 31 in FIG. 3). An example of the arrangement of 8-fold electrodes 11 and reference electrodes 12 on the body of the patient 13 is shown in FIG. The reference electrodes for surface ECG and for unipolar IEGM are z. B. frontally attached to the legs (as shown in Fig. 1). In a preferred embodiment, 8 patch electrodes each with 8 individual electrodes are used, so that the total ECG is measured over 64 channels. The channels for surface ECG and the IEGM channels are z. B. sampled synchronously with 24-bit resolution.

In Fig. 2 shows an enlarged view of the 8-fold electrode 11 of FIG. 1. To see are individual electrodes 21 which are arranged on a surface 20, wherein the electrodes are connected via conductors 22 to the ECG measuring system. Preferably, the 8-fold electrode is a patch electrode for receiving ECGs that are adhered to the patient's chest. In this case, a smaller or higher number of electrodes is conceivable. The electrodes 21 are arranged offset to one another, so that the largest possible proportion of the surface 20 is provided with electrodes. In this way, an electrical mapping of the surface potentials with high spatial resolution can be generated during the ECG measurement. However, other arrangements of the electrodes 21 are also suitable, if arranged so that cardiac signals can be received via them in a suitable manner.

The thus determined surface ECG data set is then forwarded to the data processing device and processed there by means of ICA analysis (see step 32 in FIG. 3). For example, ICA algorithms such as infomax, fastICA, Moedey-Schuster IC A or JADE are used for this purpose (see In A. Hyvärinen, J. Karhunen and E. Oja, "Independent Component Analysis," John Wiley & Sons, Inc., 2001 for several FastICA variants, as well as Infomax-based ICA; Jean-Francois Cardoso "High-Order Contrasts for Independent Component Analysis," Neural Computation 11, 157-192 (1999) for JADE; Molgedey L, Schuster H. "Physiological Revelation of Physiology", Phys Rev Lett., 1994; 72: 3634-3637 for Molgedey-Schuster ICA.) ICA analysis of the surface ECG signal data set The maximum number of activation potentials is 64 in this embodiment.

Preferably, simultaneously with the detection of the surface ECG, an IEGM signal is recorded by means of a catheter previously arranged in the heart, in particular by means of its electrode or its electrodes (step 30 in FIG. 3). If multiple electrodes are used, the IEGM signal can be multi-channeled. Now, the IEGM signal is preferably compared by cross-correlation with the plurality of signal sources representing signal components determined by the surface ECG and the subsequent ICA analysis (step 33 in Fig. 3). Optionally, a correction of the activation potentials ascertained by means of surface ECG with respect to their magnitude and position takes place (step 34 in FIG. 3). An optionally existing time offset between the surface ECG signal and the IEGM signal is neglected here. In cross-correlation, a cross-correlation factor is preferably determined.

To monitor the progress of treatment during ablation, the method discussed above is performed in a first period of time prior to ablation (eg, a few seconds to several minutes prior to ablation, depending on the cardiac cycle and repetition period of the atypical cardiac signal sought ) and a plurality of activation potentials including magnitude and location, and optionally corrected based on the IEGM signal. In addition, after the ablation, a second plurality of activation potentials including magnitude and location is again determined by the above method. Subsequently, the multiplicity of the determined activation potentials before the ablation is compared with the multiplicity of the determined activation potentials after the ablation. Is after ablation Activation potential that corresponds to the ablation site is still negotiating, most likely the ablation-derived lesion has not yet fully reached the signal path or ectopic source in the depth of the myocardium. The ablation must be continued in this case.

In addition, the ICA analysis can non-invasively reconstruct the local activation potentials of the rotor, ectopic, sinus, atrial, AF node, HIS bundle, bundle branches, ventricular muscle. Here, the regular heart signals are detected by registration algorithms. A database of regular heart signals is needed for this. The components can provide information about possible pathological changes in cardiac activity. Such an analysis may also be done without the use of a catheter (i.e., without the combination of an IEGM signal).

4 shows a schematic arrangement 40 of the essential components of the system for measuring the ablation success in ablation in the left atrium. The surface and intracardiac electrodes on the patient 41, including the reference electrodes, enable measurement of the surface ECG and the IEGM and are associated with multiple unipolar measurement channels 42; Data is recorded synchronously and signal conditioning is performed. The acquired data are forwarded to the data processing device 43, where they are evaluated and evaluated by means of ICA and the correlation calculation, the evaluation result in the sense of the disclosure being indicative of the success of the AF ablation. For this purpose, the data processing unit processes at least one data set of the surface ECG signal by means of ICA analysis, wherein the amount and the position of a multiplicity of activation potentials in the heart are determined based on the ICA analysis. Furthermore, the data of the at least one IEGM signal is compared with a plurality of activation potentials. Based on the comparison, the magnitude and / or location of at least one activation potential is corrected from the plurality of activation potentials in the heart. Data processing device 43 is connected to a display device 44, on which the evaluation result for the success of the AF ablation can be displayed to a user. As a means of indication of the Ablation success on the display 44 is, for example, graphic concepts such as the display of a color gamut or percentage scale. Also, a calculated structure of the cardiac chambers ('map') may be displayed on the display together with the position of the catheter as well as the indication of ablation success at the respective ablated site.

Claims

claims

A method for determining a variety of activation potentials in the heart, comprising the steps of:

a) Synchronous recording of surface ECG signals (31) with a plurality of channels,

b) recording at least one IEGM signal (30),

c) Processing the surface ECG signal by ICA analysis and determining the amount and location of a variety of activation potentials in the heart based on the ICA analysis (30) as well as

d) comparing the at least one IEGM signal to the plurality of activation potentials (33) and correcting the magnitude and / or location of at least one of the plurality of activation potentials in the heart (34) based on the comparison (30).

2. The method according to claim 1, characterized in that the surface ECG is recorded synchronously with a plurality of channels, preferably 32 or 64 channels.

3. The method according to at least one of the preceding claims 1 or 2, characterized in that the comparison (33) in step d) is carried out by means of correlation calculation.

4. The method according to at least one of the preceding claims, characterized in that the amount and the position of the determined according to steps a) to d) plurality of activation potentials preferably by means of a two-dimensional or a three-dimensional model of the heart in a two-dimensional or three-dimensional map (Map ) is pictured.

5. The method according to at least one of the preceding claims, characterized in that based on the determined according to steps a) to d) plurality of activation potentials, the identification of a rotor and / or an ectopic activation potential.

6. The method according to at least one of the preceding claims, characterized in that the amount and the position of a plurality of activation potentials in the heart with the steps a) to d) in each case in a first period and in a second period is determined, wherein the second period is different from the first period, and that the change of the plurality of activation potentials of the second period to the first period in terms of amount and / or location is determined.

7. The method according to claim 6, characterized in that when changing the amount of an activation potential between the first period and the second period by more than a predetermined threshold, a corresponding acoustic and / or visual and / or tactile indication.

8. Computer program product for determining a plurality of activation potentials in the heart with program code means for executing a computer program after its implementation in a data processing device, characterized in that the program code means are provided to carry out the method according to one of claims 1 to 6 after implementation in the data processing device ,

9. Device for determining a variety of activation potentials in the heart comprising

receiving means for receiving a record of a surface ECG signal recorded in synchronism with a plurality of channels (42), preferably 32 or 64 channels, and data at least one recorded during the same period IEGM signal of the associated heart, as well

a data processing device (43) which is adapted to process the data set of the surface ECG signal by means of ICA analysis and the amount and location of a plurality of

To identify activation potentials in the heart based on the ICA analysis as well

10. The device according to claim 9, characterized in that the data processing device is arranged to carry out the comparison by means of correlation calculation.

11. Device according to at least one of claims 9 to 10, characterized in that the device further comprises a display device which is adapted to the amount and location of the determined plurality of activation potentials preferably by means of a two-dimensional or a three-dimensional model of the heart in one to represent two-dimensional or three-dimensional image.

12. The device according to at least one of claims 9 to 11, characterized in that the data processing device is adapted to identify a rotor and / or an ectopic activation potential based on the determined plurality of activation potentials.

13. Device according to at least one of claims 9 to 12, characterized in that the data processing device is adapted to determine the amount and location of a plurality of activation potentials in the heart in each case in a first period and in a second period, wherein the second Period of the first period is different, and to determine the change in the plurality of activation potentials of the second period to the first period in terms of amount and / or location.

14. The device according to claim 13, characterized in that the data processing device is adapted to generate at a change in the amount of an activation potential between the first period and the second period by more than a predetermined threshold value, a notification signal, which on a display device an output an acoustic and / or visual and / or tactile indication causes.

15. System comprising a device (40) according to any one of claims 9 to 14 and a recording device for a surface ECG signal in synchronism with a plurality of channels (42), preferably with 32 or 64 channels, and / or a receiving device for at least an IEGM signal, wherein the device and the recording device for a surface ECG signal and / or the recording device for at least one IEGM signal are connected in such a way that the recording device for a surface ECG signal determines the respective surface ECG signal transmitted to the device and the receiving device for at least one IEGM signal transmits the respectively determined at least one IEGM signal to the device.