EP3934528A1

EP3934528A1 - System for predicting at least one cardiological dysfunction in an individual

Info

Publication number: EP3934528A1
Application number: EP20711078.4A
Authority: EP
Inventors: Amir Jadidi; Thomas Arentz; Björn Müller-Edenborn
Original assignee: Albert Ludwigs Universitaet Freiburg
Current assignee: Albert Ludwigs Universitaet Freiburg
Priority date: 2019-03-08
Filing date: 2020-03-05
Publication date: 2022-01-12
Also published as: WO2020182609A1; DE102019203155A1; US20220175299A1

Abstract

The invention relates to a system for predicting at least one cardiological dysfunction in an individual, the system comprising: a means for providing an ECG, which has a number n of time-synchronised ECG tracings, each comprising a chronological order of time signals representing a sinus rhythm of the individual's heartbeat, to which time signals at least one P wave, a QRS complex and a T wave can be assigned in chronological order; a selection means, which selects at least two ECG tracings from the n ECG tracings; an analysis unit, which analyses the selected ECG tracings as follows: a) determination of an iso-electrical signal level, b) determination of a first point in time chronologically before the QRS complex, c) determination of a second point in time chronologically after the first point in time and chronologically before the QRS complex, d) execution of determination steps a) to c) for all selected ECG tracings, e) determination of an earliest first point in time from all the first points in time determined for the selected ECG tracings and a latest second point in time from all the second points in time determined for the selected ECG tracings, f) determination of a time frame delimited by the earliest first point in time and latest second point in time, known as the P wave duration; and a comparator, which generates a signal in the event that the determined P wave duration deviates from a reference value.

Description

System for the prediction of at least one cardiac dysfunction of a

Individual

Technical area

The invention relates to a system for predicting at least one cardiological dysfunction in an individual.

State of the art

There is a unanimous opinion among medical professionals that patients with advanced atrial cardiomyopathy are at increased risk of developing cardiovascular disease, typically in the form of

Atrial fibrillation, heart failure, or ischemic stroke can occur. The mechanical and / or electrical that develop in these cases

Functional disorders of the heart muscle in the area of the atria are based on a pathological increase in connective tissue (fibrosis) and one with it

associated local scarring of the heart muscle. In addition, a

There are accompanying enlargements (dilation) of the atria. . Common ones

Diagnostic techniques for identifying people with atrial cardiomyopathy are either based on magnetic resonance imaging

Atrial sequence image recordings or on an invasive electroanatomical mapping using a special 3D system of a cardiac electrophysiological catheter laboratory. Both diagnostic options are characterized by limited availability and high costs. In the case of magnetic resonance-supported examinations, gadolinium must also be injected as a contrast medium. For the reasons mentioned, it's on the Hand that such examinations on patients with atrial cardiomyopathy are only carried out in exceptional cases, ie not systematically.

Since the clinical picture of atrial cardiomyopathy, especially in the form of cardiac fibrosis, is closely connected with an increased risk of cardiac arrhythmias, e.g. in the form of atrial fibrillation or atrial flutter, alternative cost-effective and resource-saving diagnostic methods that are to be used as predictive low-cost screening methods are desirable.

On the basis of detailed investigations on electrocardiograms recorded on a large number of healthy people as well as those suffering from atrial cardiomyopathy, some ECG-based measurement parameters could be identified, on the basis of which a qualified risk assessment for atrial fibrillation and / or stroke appears possible.

From an article by Jane Caldwell et al, “Prolonged P-wave duration is associated with atrial fibrillation recurrence after successful pulmonary vein Isolation for paroxysmal atrial fibrillation”, Journal of Interventional Cardiac Electrophysiology, March 2014, Volume 39, Issue 2, p. 131 -138, it emerges that, in the course of postoperative studies on patients with pulmonary vein isolation, the

The finding confirmed that the P-wave of an electrocardiogram (ECG) showing the sinus rhythm of the heart function, in particular its P-wave duration, can be used as a relevant assessment parameter for a risk assessment against the occurrence of atrial fibrillation or stroke. In the context of statistical evaluations it could be concluded that

Patients with an extended P-wave duration of> 140 ms are at a significantly increased risk of atrial fibrillation and / or stroke.

A recent review study by Yao-Sheng Wang et al., “Prolonged P-wave duration is associated with atrial fibrillation recurrence after radiofrequency catheter ablation: A systematic review and meta-analysis”, International Journal of Cardiology, Volume 227, January 15 2017, pp. 355-359, confirms this in a meta-analysis of 9 separate studies. The electrocardiograms of a cumulative over 1000 patients were analyzed with regard to an extended P-wave duration who had undergone cardiological high-frequency catheter ablation. These studies showed that patients with a P-wave duration longer than 149.5 ms are exposed to the risk of atrial fibrillation with a probability of 66%.

One in the article by Amir Jadidi et al. , “The Duration of the Amplified Sinus-P- Wave Identities Presence of Left Atrial Low Voltage Substrate and Predicts Outcome After Pulmonary Vein Isolation in Patients With Persistent Atrial Fibrillation”, JACC: Clinical Electrophysiology, Volume 4, Issue 4, April 2018, 531 - 543, presented study, which was carried out on patients with pulmonary vein isolation, confirms the connection between a prolonged P wave and the increased risk of a recurrence of cardiac arrhythmias in the form of

Atrial fibrillation and stroke. The present study shows for the first time that the strongly amplified P-wave duration, which can be derived from a digitally amplified 12-channel surface ECG within a sinus rhythm, correlates very well with the extent of the fibrotic low-voltage substrate within the left atrium. Patients with a P-wave duration of> 150 ms are at an increased risk of a recurrence of arrhythmias.

Presentation of the invention

The invention is based on the object of specifying a system for predicting at least one cardiological dysfunction, in particular in the form of atrial fibrillation and / or ischemic stroke and / or heart failure, so that the reliability and resilience of a prediction about the

The likelihood that an individual will experience cardiac dysfunction should be significantly improved. So it should be possible systemically

To be able to carry out examinations on a large number of individuals quickly and economically in order to be able to make reliable risk assessments about the occurrence of future cardiological dysfunction with a reliability for each individual of at least 80%, preferably at least 90%. The system according to the solution is specified in claim 1. Features which advantageously develop the system are the subject of the subclaims and the further description, in particular with reference to FIG

Refer to exemplary embodiments.

The invention is based on the knowledge that the reliability with which a statement can be made about a potentially existing risk to which an individual is exposed of suffering atrial fibrillation or an ischemic stroke in the future is directly correlated with the accuracy of the

Metrologically recorded P-wave duration, the "Area under the total or left atrial P-wave (AUP), the quotient of the amplitude of the total P-wave to the total P-duration and the quotient of the mean or maximum amplitude of a predetermined proportion of the P-wave for the duration of this part or for the total duration of the P-wave ”.

On the one hand, on the basis of meticulous evaluations of electrocardiograms that have been obtained from a large number of people, the

Difficulties and the associated possible errors in the

Risk assessment of cardiac arrhythmias recognized on the basis of the P-wave duration and, on the other hand, the knowledge gained that the resilience of such a risk assessment depends very sensitively on the accuracy of the measurement-technical recording of the P-wave duration. The aim is to precisely determine the P wave duration with a time error of a maximum of ± 2 ms, preferably a maximum of ± 1 ms, particularly preferably a maximum of ± 0.5 ms. With growing

Tolerance range, the reliability of information deteriorates non-linearly. The measurement quality on which the system according to the solution is based for the temporal acquisition of the P-wave duration enables person-specific predictions with regard to future cardiovascular dysfunction with a probability of at least 80% up to over 90%.

For this purpose, the system according to the solution comprises a means for providing an EKG recorded on a person, which has a number n of time-synchronous EKG leads which each comprise a time sequence of the sinus rhythm of a heartbeat of the person representing time signals. The means for providing the EKG is preferably in the form of a digital 12-channel standard EKG recording device or a body surface EKG recording system that uses multiple electrodes to record the electrical cardiac excitations.

Alternatively, the means for providing the n time-synchronous EKG leads can only be designed in the form of a storage medium on which the n-EKG leads are stored in digital form. In a simplest form, only n = 3 derivations are necessary, which are used as the basis for further evaluation.

The preferably n = 12 time-synchronous EKG leads include, in periodic sequence, the electrocardiographically recorded electrical activities of all heart muscle fibers, each of which is defined as a sinus rhythm, which in its chronological sequence changes into the so-called P wave, the QRS complex and the T wave is divisible. Of central importance in this case is the

Time segment of the P wave that corresponds to the atrial excitation and the beginning of which is triggered by electrical stimulation in the sinus node. The electric

Stimulus formation spreads from the sinus node in the right atrium over the left atrium in the direction of the AV node (atrioventricular node). The temporal end of the P-wave is defined by the achievement of the complete electrical excitation of the atria, which usually precedes the ventricular excitation defined in the sinus rhythm by the QRS complex.

In addition to the means for providing an EKG recorded on the individual, the system includes a selection means which selects those EKG leads from the number n provided EKG leads which are preferably suitable for a P-wave duration determination.

The EKG leads present in digital form enable the use of a program evaluating image data and / or numerical evaluation algorithms within the framework of the processor-supported selection means, which, with additional use of stored expert information, for example in the form of Reference data, as well as optional use of self-learning

Data signal evaluation routines, from the n ECG leads select those that contain characteristic and complete P-wave components. From all ECG leads, at least two or, if the selection criteria are met, preferably all ECG leads are to be selected. The selection of suitable EKG leads is thus based on a certain degree of similarity between the EKG leads present on the part of the provision means and a predetermined reference as the first decision criterion E1.

A processor-based arithmetic unit, which serves as an analysis unit and communicates with the selection means, analyzes the preselected EKG leads with respect to the beginning and end of the P-wave in at least one sinus rhythm per EKG lead.

For this purpose, it is first necessary to determine an iso-electrical signal level based on the time signals of a selected EKG lead. An iso-electrical signal level that can be assigned to the time signals of a selected EKG lead is preferably characterized in that, within a predetermined time span, the EKG time signals have no technically evaluable signal levels that are higher than the noise component. To determine the iso-electrical signal level, a time period before the P-wave within a is suitable

Sinus rhythm which is at least 10 ms, preferably at least 20 ms, particularly preferably at least 30 ms long.

For the purpose of determining the beginning of the P-wave, the analysis unit determines that first point in time which is before the QRS complex and from which the subsequent time signals of the EKG lead are one of the iso-electrical signals

Signal level have different signal levels. This signal level, which deviates from the iso-electrical signal level, preferably has at least twice the signal level compared to the iso-electrical signal level. Optionally, a further criterion can be used to determine the first point in time defining the beginning of the P-wave, according to which, within a first time period immediately following the first point in time, subsequent time signals each have a positively increasing signal level, that is, those caused by the time signals Mathematically, the P-wave defined within the second point in time has positive first derivatives.

To determine the second point in time defining the end of the P wave, which is after the first point in time and before the QRS complex, it is necessary to determine the point in time at which the time signals of the EKG lead are based on an iso-electrical signal level If the signal level deviates, assume the iso-electrical signal level again. Advantageously, the end of the P-wave, i. E. as the second point in time, that point in time whose assigned time signal corresponds to the iso-electrical signal level and which is directly related to this time signal

preceding time signal has at least twice the signal level compared to the iso-electrical signal level.

A second point in time, which determines the second point in time, can advantageously be used

Decision criterion can be used according to which the time signals lying within a second time period following the second point in time must have the isoelectric signal level or are limited by the temporal start of the temporally following QRS complex, which corresponds to the so-called chamber complex. The second time span should be at least 4 ms.

Another optional decision criterion, which can be used in combination or as an alternative to the above decision criteria to determine the respective first and second point in time, which time-limit the P-wave, uses the comparison of the EKG leads with a reference time signal pattern from a sinus rhythm -P wave. A numerical pattern recognition is carried out as part of the comparison. The analysis unit selects that first point in time that was recorded as the earliest in time from all selected EKG leads, which each comprise time-synchronized time signals. In contrast, the

selected EKG time signals selected that second point in time which has been determined chronologically as the latest second point in time. On the basis of the earliest first point in time and the latest second point in time, the analysis unit determines the actual (maximum) P-wave duration, which is necessary for further considerations of an exact measurement duration of the P-wave within the

Corresponds to the heart sine rhythm.

The system according to the solution also includes a comparator which determines a deviation between the determined P-wave duration and a reference value and generates a signal on the basis of a second decision criterion. The second decision criterion is a maximum

Time span Atmax is based, for which the following applies: 100 <Atmax ^ 140 ms. In the event that the determined P-wave duration is greater than Atmax, the comparator generates the signal in the form of an acoustic, visual or haptically perceptible signal.

As already mentioned, the use of a 12-lead EKG enables the acquisition of 12 leads that correspond to the 12 EKG standard deviations according to Einthoven,

Goldberger and Wilson and have the following designations: I, II, III, aVR, aVL, aVF, V1 to V6.

It has proven to be particularly advantageous to select at least two, preferably all of the following EKG leads for determining the respective first point in time: II, III, aVF, aVR, V1, V2.

At least two, preferably all of the following EKG leads are suitable for determining the respective second point in time: I, II, III, aVR, aVL, aVF, V2 to V6. It is also possible to use only at least three EKG leads according to the solution in order to determine the P-wave duration with sufficiently high reliability. In this case it is important to arrange the EKG electrodes so that the measurement of at least one inferior or one lateral or one inferolateral or one superolateral or one anterior EKG lead is possible. To derive the lateral or inferior or inferolateral or superolateral EKGs, the EKG electrodes can be attached to the right and left of the sternum or the central sagital axis of the body. To derive the anterior or posterior EKG electrodes, the EKG electrodes can be attached to the front and rear of the chest. In all cases, the EKG electrodes must be on opposite sides of the zero potential line of the Flerzfeld according to Augustus Waller (1887).

The distance between two electrodes should be greater than 1 cm in order to adequately record the cardiac signals and to make them accessible for the diagnosis of atrial cardiomypathy, e.g. right and left of the sternum or on the right and left clavicle ("collarbone") or on the right Ear and the left clavicle (each on the other side of the zero potential line) or right hand and left hand.

In order to reduce artifacts and other interfering influences, for example relating to the noise level, when evaluating the EKG leads, it is advisable to superimpose and mathematically superimpose the time signals of an EKG lead of at least two, preferably 10 to 1000, sinus rhythms of the heartbeat in the middle. The analysis unit performs the superimposition and mathematical averaging separately on all selected ECG leads. On the basis of the superimposed and averaged time signals per EKG lead, the analysis unit carries out the determination steps explained above for obtaining the first and second time.

Optionally, an integrator is also provided which, on the basis of the determined P-wave duration, generates an integral value, a so-called Area-Under-The- Curve value, created over the time sequence of the time signals within the determined P-wave duration. The existing comparator or a further, additional comparator compares the determined integral value with a

Reference value and generated on the basis of a third

Decision criterion a signal.

From the P-wave determined above, the quotient of the mean or maximum amplitude of the total P-wave to the total P-duration and the quotient of the mean or maximum amplitude of a predetermined portion of the P-wave to the duration of this portion or to the total duration of the P-wave can be determined. These parameters are compared with the existing comparator or another with a reference value, which generates a signal on the basis of a further decision criterion.

Brief description of the invention

The invention is hereinafter described without limiting the general

The concept of the invention is described by way of example using exemplary embodiments with reference to the drawings. Show it:

Fig. 1 a schematic representation of a system according to the solution for

Prediction of at least one cardiological dysfunction,

Fig. 1 b sinus rhythm of a heart beat of an individual,

2a-d EKG representations each with twelve EKG leads for four different people.

Ways to carry out the invention, commercial utility

Figure 1 a shows in a schematic compilation of components

system for predicting at least one cardiological dysfunction of a person. The means 1 for providing a person or Individual acquired ^ECG's, typically in the form of a digital n-lead ECG recording device, provides the electrical stimulus potentials at the heart of the person is who are sorted by cardiac ECG lead defined spatial areas assigned. Standard ECG recording devices have a total of n = 12 ECG leads 2, which are based on Einthoven, Goldberger and Wilson

have the following designations: I, II, III, aVR, aVL, aVF, V1 to V6.

Each of the individual EKG leads 2 is made up of digitally recorded

Time signals together that reflect the sinus rhythm 3 of the heart activity. FIG. 1 b shows the classic morphology of a sinus rhythm 3 which, in chronological order, is composed of at least the P wave, a subsequent QRS complex and a concluding T wave. The system according to the solution determines the P-wave duration PWD of the person with a high-precision quality, whereby for the first time reliable statements about the stroke risk of a person can be made with a reliability of at least 80%. For this purpose, the time beginning ti and the time end t2 of the P wave must be determined with high precision and without errors. This assumes that the means 1 for providing the on

S the n-ECG leads 2, preferably provides individual acquired ECG ^'at a sampling rate of at least 500 Hz of at least 1000 Hz. In the case of a sampling rate of 1000 Hz, a time signal can be recorded per millisecond. If a finer time resolution is to be achieved, the digital one would have to be

electrocardiographic recording take place at a correspondingly higher sampling rate. Sampling rates of 2000 Hz or 5000 Hz are particularly desirable.

Moreover, it is advantageous that the means ECG leads n-2 provides for the provision of a person recorded ^ECG's 1 in amplified form in which the n-ECG leads 2 on the assignable the timing signals with respect

Signal levels are amplified with a gain factor of at least 4, preferably of at least 8, both in the time axis (x-axis) and in the voltage amplitude (Y-axis). Likewise is the gain of the time axis of

Significance to enable accurate measurement. The time axis should be displayed with at least 100mm / sec and preferably 200mm / sec. The n-EKG leads 2 recorded digitally in the above manner and optionally processed using signal technology are fed to a computer-based selection means 4 in the form of a digital data record, which, on the basis of a first decision criterion E1, selects those EKG leads 2 from the number of n-EKG leads 2 ^' , on the basis of which the most precise possible time determination of the respective first point in time ti and second point in time t2 is possible.

To determine the first point in time ti, which defines the beginning of the P-wave, it is first necessary to determine the iso-electrical signal level ISO. In one

The time range that precedes the QRS complex corresponds to the start of the P wave at the point in time ti at which the signal level of the time signals from the ISO electrical signal level is characterized by a technically verifiable signal level that is positively different from the electrical ISO signal level. This technically verifiable signal level is preferably doubled

Signal level amount compared to the iso-electrical signal level. Immediately at this technically verifiable signal level, which contrasts with the iso-electrical signal level, the temporally following time signals within a first time period Ati immediately following the first point in time ti must have signal levels that increase positively or decrease negatively in the case of an inverse curve shape. The first time period typically corresponds to a maximum of half the P-wave duration in which the P-wave rises positively.

The first time span should therefore preferably be between 40 and 80 ms.

For the determination of the second point in time t2, the time signals lying within a second time period following the second point in time t2 should again have the isoelectric time signal level ISO. The isoelectric time interval At2 following the second point in time t2 should be at least 4 ms.

In addition, the comparison of the metrologically detected sinus rhythm with a reference time signal pattern or a set of reference time signal patterns is advantageous Framework of a software-based pattern recognition. Such a pattern recognition enables the typical morphology of a sinus rhythm P wave within the respective metrologically recorded EKG leads. However, should the pattern recognition lead to a negative result, the corresponding EKG lead is not suitable for determining exactly the beginning and the end of the P-wave. The following characteristics are currently regarded as morphologically relevant criteria:

1. Does the P-wave have a monophasic negative or negative-positive

If there is a rash in lead I, there is no sinus rhythm and the analysis cannot be performed.

2. If the P wave has a monophasic positive deflection in the lead aVR, there is no sinus rhythm and the analysis cannot be carried out.

3. If the signal-to-noise ratio is greater than 0.2 in one of the 12 leads, even after averaging at least 2,000 beats, no analysis can be carried out in this lead.

4. The P-wave morphology is compared within each of the 12 ECG leads among the 10 (up to 1000) consecutively recorded P-waves. The most common, i.e. dominantly recurring, P-wave morphology is determined. If the P-wave morphology deviates by more than 15% from the “dominant” P-wave morphology in at least one derivative, these deviating morphologies are not used for the analysis.

The above cases specify criteria for performing the analysis, in each case in the absence of the criteria listed under 1 and 2, and for excluding derivations from the analysis which are not suitable for determining the P-wave duration.

The following P-wave characteristics are associated with the presence or absence of left atrial fibrosis (left atrial cardiomyopathy):

1. There is no suspicion of fibrosis in the left atrium (LA) if the sinus P-wave morphology in the inferior leads II, III, aVF is monophasic is positive and the P-wave duration is less than 143 ms for women and less than 154 ms for men.

2. Fibrosis in the left atrium (LA) is present if the total duration of the sinus P wave from the selected leads is greater than 143 ms in women and greater than 153 ms in men.

3. LA fibrosis is present if the sinus P-wave morphology is positive-negative in two of three leads II, III, aVF, regardless of the P-wave duration.

4. Pronounced LA fibrosis is present if the sinus P wave morphology has a late P component. In these cases there is a

monophasic positive P-wave in leads II, III, AVF, which is followed by an isoelectric interval, which in turn is temporal

separated P component is followed in two of the following derivatives: I, aVL, aVR, V1 -V6. The entire P-wave duration including the late

Component is usually greater than 170 ms.

The EKG leads 2 ^' selected with the aid of the selection means 4, which can include at least two EKG leads but at most all n-EKG leads, are fed to a processor-based analysis unit 5, which uses the EKG leads 2 ^' for the exact determination of the first and second times ti, t2 analyzed. The beginning and the end of the P-wave are determined exactly for all selected EKG leads 2 ^' . Due to the

The time synchronicity of all EKG leads is determined in each case by the earliest first point in time from all of the first points in time determined for the respectively selected EKG leads and a latest second point in time from all of the second times determined for the respectively selected EKG leads. The earliest first as well as the latest second point in time define the actual start and end of the P-wave and thus determine the exact P-wave duration PWD. The exact P-wave duration PWD determined in the context of the analysis unit 5 is fed to a comparator 6, which determines a deviation between the determined P-wave duration PWD and a reference value and is based on this a second decision criterion E2 generates a signal 7. In the event that the P-wave duration PWD determined is greater than a maximum predetermined time period At _max , the comparator 6 generates the signal 7. The maximum time period Atmax is typically in a range between 100 and 140 ms.

FIGS. 2a to d each show images of twelve-channel electrocardiograms which are affected by people with differently pronounced atrial cardiomyopathies. The individual ECG leads correspond to the following standard ECG leads: I, II, III, aVR, aVL, aVF, V1 to V6.

As part of investigations carried out by the applicant on patients with pulmonary vein isolation (PVI), in which PVI nonetheless persisted

If atrial fibrillation (AF) occurs, the well-founded assumption emerges that there are arrhythmogenic slower conduction points within and on the

Train or develop border areas of the left atrial low-voltage substrate

have trained. This is how an advanced left atrial correlates

Low voltage substrate with a reduced rate of activation of the left atrium, i.e. H. the electrical stimulus signal propagation, which is initiated at the sinus node and spreads over the right and left atrium in the direction of the AV node, is reflected in a longer duration of the P-wave duration recorded with the help of a 12-channel EKG.

FIGS. 2 a to d each show 12-channel surface EGKs from patients that are representative of different degrees of severity with regard to the formation of arrhythmogenic, fibrosis-rich, slower conduction points within the left atrial low-voltage substrate. In addition, the signal levels of two intracardiac signals are at the top in FIGS. 2 a-d

Catheter leads are shown which, as reference signals, mark the actual end of the P wave.

2a shows the EKG of a non-critical patient with a heart without

Significant stimulus signal propagation delays in the left atrium without scarring / Fibrosis areas. The P-wave can be seen in the EKG leads II, III, aVF, V2-V6 as a P-wave with normal morphology, in the form of a positive P-wave. For an exact determination of the P wave duration of, in this case, 133 ms, the EKG lead II is used to determine the start of the P wave, ie the first point in time t1 and the EKG lead V4 to determine the end of the P - wave, ie the second point in time.

Fig. 2b shows an EKG of a patient with incipient fibrotic

Tissue changes in the left atrium, which on the one hand lead to a change in the developing P-wave morphology, in the sense of a multi-peak wave course, see ECG leads II, III, aVF as well as an extension of the P-wave duration, in this case from 174 ms. For an exact determination of the P-wave duration, the EKG lead I & V2 is used to determine the temporal start of the P-wave, i.e. the first point in time t1 as well as the EKG lead V5 to determine the end of the P-wave, i.e. the second point in time.

Fig. 2c shows an EKG of a patient with advanced fibrotic

Tissue changes in the left atrium leading to diminishing

Stimulus signal propagation and, above all, signal detection that is difficult to detect using measurement technology, so that in many ECG recordings the expression of the P-wave in the left atrium cannot be detected, or only very poorly. An exact analysis of the EKG leads reveals terminal P-wave components in leads I, aVL, V3-V6, which can only be visually recognized by means of strong amplification. For an exact determination of the P-wave duration, the EKG lead V4 is used here to determine the start of the P-wave, i.e. the first point in time h as well as the EKG lead I to determine the end of the P-wave, i.e. the second point in time. The P-wave duration in this case is 172 ms.

Fig. 2d shows an EKG of a patient with very advanced fibrotic

Tissue changes in the left atrium. This leads to a greatly reduced and weakly reproduced stimulus spread. An exact analysis of the ECG leads can still detect P-wave components in leads I, V5, which only get in the way a strong amplification are visually recognizable. For an exact determination of the P-wave duration, the EKG lead V5 is used to determine the beginning of the P-wave, i.e. the first point in time ti and the EKG lead I, V4 - V6 to determine the end of the P-wave, ie the second point in time. The P-wave duration in this case is 160 ms.

The above examples illustrate the difficulty and the necessity of determining the P-wave duration exactly. For example, in the case of a patient with an EKG according to FIGS. 2c and 2d, setting the temporal end t2 of the P-wave too early would lead to a serious misdiagnosis, especially since in these cases the P-wave that follows in time after the monophasic P-wave and deal with a minor

Time signals characterizing signal levels are not taken into account in a superficial analysis, so that the P-wave duration would be defined as too short. In such a case, the diagnosis would completely wrongly assess the patient as not at risk for health.

By way of digital signal evaluation, based on the analysis unit according to the solution, which exactly determines the signal level of the time signals

When evaluating signal level fluctuations in the range of twice the signal level compared to the iso-electrical signal level, atrial heart activities associated with the P-wave can be precisely recorded and used to determine the end of the P-wave.

List of reference symbols

1 means for providing a detected at individual ^ECG's

2 ECG lead

3 Sinus rhythm of a heartbeat

4 means of selection

5 analysis unit

6 comparator

7 signal

2 ^' selected ECG leads

E1 first decision criterion

E2 second decision criterion

PWD pulse wave duration

ISO isoelectric signal level

t1 first point in time

t2 second point in time

Ati first period

At2 second time span

Claims

1. System for predicting at least one cardiac dysfunction of a

Individual with

a means (1) for providing an EKG recorded on the individual, which has a number n of time-synchronous EKG leads (2), each of which comprises a time sequence of time signals representing a sinus rhythm (3) of a heartbeat of the individual, which in time sequence at least a P-wave, a QRS-complex and a T-wave can be assigned,

a selection means (4) which selects at least two ECG leads from the number n provided EKG leads on the basis of a first decision criterion,

an analysis unit (5) which analyzes the selected ECG leads in the following way:

a) Determining an iso-electrical signal level based on the time signals of one of the selected EKG leads,

b) determining a first point in time before the QRS complex from which the time signals of the selected EKG lead have a signal level that deviates from the iso-electrical signal level,

c) Determining a second time following the first time and before the QRS complex at which the time signals of the selected EKG lead are based on one of the iso-electrical

Signal level deviating from the signal level assume the iso-electrical signal level again,

d) Carrying out the determination steps a) to c) for all selected ECG leads,

e) determining an earliest first point in time from all the first points in time determined for the respectively selected EKG leads and a latest second point in time from all second points in time determined for the respectively selected EKG leads,

f) determining a period of time which is limited by the earliest first and latest second point in time and which corresponds to the so-called P-wave duration (PWD), and a comparator (6) which determines a deviation between the determined P-wave duration (PWD) and a reference value and generates a signal on the basis of a second decision criterion.

2. System according to claim 1,

characterized in that the means for providing the EKG recorded on the individual is in the form of a) digital n-channel EKG recording device, or b) a storage medium on which the n EKG leads are stored in digital form, or c ) a body surface EKG recording system that uses n multiple electrodes to record the electrical stimuli.

3. System according to claim 1 or 2,

characterized in that the means for providing the EKG recorded on the individual provides the n EKG leads with a sampling rate of at least 500 Hz, preferably of at least 1000 Hz.

4. System according to one of claims 1 to 3,

characterized in that the means for providing the EKG recorded on the individual provides the n EKG leads in amplified form, in which the n EKG leads recorded on the individual with a gain factor of at least 4, preferably of, in relation to the signal level that can be assigned to the time signals at least 8 reinforced

5. System according to one of claims 1 to 4,

characterized in that the analysis unit, prior to the determination step a), superimposes the time signals of a sequence of at least two, preferably 10 to 1000 sinus rhythms of the heartbeat of the individual and averages them to obtain time-synchronous time signals for each selected EKG lead, which correspond to the

Represent the sinus rhythm of the heartbeat of the individual and on which the determination steps a) to f) are based.

6. System according to one of claims 1 to 5,

characterized in that the first decision criterion implemented in the selection means is based on a reference time signal pattern from a sinus rhythm P-wave, which is compared with the EKG leads within the framework of a pattern recognition, and that the selection means based on a

given degree of similarity selects suitable EKG leads.

7. System according to one of claims 1 to 6,

characterized in that the analysis unit (5) evaluates the selected EKG leads to determine the respective first and second point in time as follows:

- To determine the first point in time at which the signal level of the time signal deviates from the iso-electrical signal level to a positively greater signal level, the within one point at the first point in time

immediately following the first time period, subsequent time signals each have a positively increasing signal level, and

- To determine the second point in time, the point within a second time period following the second point in time

Time signals have the iso-electrical signal level or are limited by the beginning of the ventricular complex (QRS).

8. System according to claim 7,

characterized in that the first time period is between 40 ms and 80 ms, and

that the second time span measures at least 4 ms in the presence of an isoelectric signal.

9. System according to one of claims 1 to 8,

characterized in that the means for providing the EKG recorded on the individual comprises n = 12 EKG leads which correspond to the following 12 standard EKG standard leads according to Einthoven, Goldberger and Wilson: I, II, III, aVR, aVL, aVF, V1 - V6.

10. System according to claim 9,

characterized in that the second implemented in the selection means

The decision criterion is the selection from the n-ECG leads based on at least one of the following criteria:

- At least two of the

the following ECG leads are used:

II, III, aVF, aVR, V1, V2

- To determine the second point in time, at least two of the

the following ECG leads are used:

II, III, aVR, aVL, aVF, V2 to V6

11. System according to one of claims 1 to 8,

characterized in that the means for providing the EKG recorded on the individual comprises at least n = 3 EKG leads, and

that the second decision criterion implemented in the selection means the

Selection from the n-ECG leads based on at least one of the following criteria:

- At least two of the following ECG leads are used to determine the first and second point in time:

Inferior, lateral, inferolateral, superolateral or anterior EKG lead, with the associated EKG electrodes being attached to opposite sides of the zero potential line of the Flerzfeld.

12. System according to one of claims 1 to 11,

characterized in that the second decision _{criterion is} based on a maximum time period At _max , for which the following applies: 100 <At _max ^ 140 ms, and

that in the event that the determined P-wave duration (PWD) is greater than Atmax, the comparator generates the signal.

13. System according to one of claims 1 to 12,

characterized in that an integrator is provided under

Based on the first and second points in time that limit the P-wave duration, an integral value (AUC) is created over the time sequence of the time signals within the P-wave duration,

and that the comparator or a further comparator compares the integral value with a reference value and on the basis of a third

Decision criterion generates the signal.

14. System according to one of claims 1 to 13,

characterized in that an integrator is provided under

that a divider is provided which divides the maximum or mean P-wave amplitude from the total P-waves or a selected portion thereof by the determined total P-wave duration or the selected P-wave portion and determines a ratio, and

that the comparator or another comparator compares the ratio value with a reference value and on the basis of a third

Decision criterion generates the signal.