How to describe the rhythm ex. Permanent electrocardialism: indications, clinical aspects, ECG interpretation principles

1. Violation of the imposition of rhythm.The main reason is the exhaustion of the battery, which is within 7-10 years. The ECG has a decrease in the frequency of stimulation and the oscillation of the intervals of ST - ST and the amplitude of the spikes (Fig. 5.4.1). Showing replacement ex.

Fig. 5.4.1. ECG in disruption of the imposition of the Rhythm of the ex (different intervals of stimulation are recorded)

2. Expulsion pulse unit at the output (violation of "capture") or inefficient stimulation. At the ECG there are artifacts of stimulation, followed by the depolarization complexes of the respective cameras, although myocardium is not in the refractory stage. At the same time, the spike can be deformed, low-voltage, which indicates a malfunction of the electrode, low charge charge and sub-stimulation, insufficient to initiate the reduction of myocardium. In addition, reasons can be: displacement of the stimulating electrode, myocardial perforation, an increase in the stimulation threshold, damage to the electrode, incorrectly specified parameters of the extender.

Main reasons:

Macro. Endocardial electrode: High amplitude spikes are recorded on ECG without the subsequent excitation of the heart. In the case of displacement to another chamber, the amplitude of the spikes is significantly reduced. The displacement can be detected when comparing radiographs in a direct and left side projection with the initial and at echocardiography. The replacement of the endocardial electrode is shown.

Microsnotation of an endocardial electrode: On ECG after some high-amplitude spikes, the excitation of the heart is recorded. During echocardiographic research, hyperkinosis or disconesia is noted at the site of the implantation of the electrode head and the displacement of the electrode head by more than 3 mm in hyperkinesia. The replacement of the endocardial electrode is shown.

High stimulation threshold: reasons may be anti-game drugs, hypercalemia, aging electrode, fibrosis, reactive inflammation. At the ECG there is a decrease in the amplitude of the spike cardiogram. There is a sensitivity and synchronization function of ex. Treatment: You can try to eliminate the cause - replace antiarrhythmic, burn hyperkalemia, replace the electrode. To reduce the stimulation threshold, glucocorticosteroids are used, increasing the amplitude of the pulse using the programming or implantation of electrodes with a low stimulation threshold (iridium, platinum, carbon) or distinguishing steroids after implantation.

Fracture of an endocardial electrode: There is a complete fracture when the metal wire and insulation is damaged, and incomplete with damage only wires. In case of incomplete fracture on an ECG when changing the position of the body, the ends of the electrodes can contact and indulgent complexes appear. Periodic resumption of stimulation can be revealed at hmm. In the case of complete fractures, modified spikes are recorded without the subsequent excitation of the heart. The diagnosis of a fracture is placed during radiography. Showing the replacement of the electrode.

Coupling of the exh body in the box with the electrode spinning - Syndrome "Vertune".

3. Detection violations. Sensitivity reduction (hyposensing - Undersensing): In the event of its own depolarization of the corresponding camera, the pacemaker is not turned off and continues to work, which leads to the occurrence of incorrect rhythm (imposed rhythm is imposed on its own) (Fig. 5.4.2 and 5.4.3). Ex the "believes" that there is no sinus activity and continues to work with a given frequency. In most cases, electric incentives reaches the myocardium of ventricles in the phase of its refractoriness. In the opposite case, stimulation arrhythmia occurs. Causes: Low amplitude of the perceived signal (especially with ventricular extrasystole), incorrectly specified sensitivity of ex.

Fig. 5.4.2. ECG with ex in the Patient VVI mode with a high degree av-blockade. Expensive dysfunction, reduced sensitivity. The first 2 complexes imposed from the heart rate 61 per minute, 3, 4 and 6 are sinus (3- aberrant). Despite the sinus rhythm with sufficient heart rate, the exemplary work is not inhibited, along with sinus rhythm, imposed complexes (5 and 6) are recorded.

Fig. 5.4.3. ECG with ex in the Patient VVI mode with a high degree av-blockade. Expensive dysfunction, reduced sensitivity. The first complex imposed from the heart rate 61 per minute, then the sinus rhythm from the CSS 67-77 per minute is registered. The work of the exh at the beginning is inhibited, however, before the penultimate complex of the QRS, despite the sufficient heart rate is registered with the spike and the following QRS drain complex behind it.

To eliminate these disorders, it is sufficient to reprogram the sensitivity of the pacemaker.

Over the sensitivity of the pacemaker (increase in sensitivity, hypersensing, oversensing): At the expected point in time (after the corresponding interval), stimulation does not occur (there is no spike). Teeth T, P (with VVI), myopotencyal, interference is interpreted as R teeth and the pacemaker time meter is reset. With erroneous detection of the Tonga, the count of the interval Va begins. This leads to inhibition of the work of the pacemaker ie. The development of a "pacemector" pause and the development of bradyrithmias (Fig. 5.4.3 and 5.4.5) or the launch of pacemener tachyarhythmias - extrasystole, circular tachycardia.

Fig. 5.4.4. ECG with ex in the Patient VVI mode with a high degree av-blockade. Exemption Dysfunction, increased sensitivity. The first 2 complexes imposed from CSS 61 per minute. Then the pause is registered with a duration of 2000 ms., Caused by AV-blockade of 2 degrees, followed by a sinus complex (3 complex). At the expected point in time (after the corresponding interval), the stimulation does not occur (there is no spike), since the tooth P is interpreted by the stimulant as the prong R (increased sensitivity) and the pacemaker time counter is reset.

Myopotencylists arising from the movement of hands can be perceived as potentials from the myocardial of ventricles, extends to inhibition mode and does not produce electrical incentives, which can lead to the occurrence of hazardous long pauses and the occurrence of spontaneous complexes. In this case, the intervals between the imposed complexes become different, and the rhythm is incorrect. This phenomenon was called myopotential inhibition.

Myopotencyals can be perceived as spontaneous atrial abbreviations and can be activated AV conduction (myopotential triggering).

Causes of increasing sensitivity: incorrect programming, damage to the electrode isolation (there is a "trigger" ex in response to the movement of the heart wall).

Fig.5.4.5. ECG with an exorment Patient VVI mode with a constant form of atrial fibrillation and a high degree of AV-blockade. Dysfunction EX, increased myopotential sensitivity. In Figure A), the first 2 complexes imposed from the CSS 61 per minute. The pause is then recorded with a duration of more than 2000 ms, followed by its own complex (3 complex), 4 complex imposed. In rice b) the first 2 complexes imposed, 3 and 4 - nodal from the heart rate 32-35 per minute. Pause originated during the patient's physical activity and the cause of their occurrence was myopotential inhibition due to the increased myopotential sensitivity of the ex. In its own complexes, there is a violation of repolarization in the ST segment (depression) and teeth T (negative) - poststimulation syndrome.

In suspected myopotential sensitivity of the extension, there should be provocative tests with a voltage of various muscle groups (bending of brushes with stubborn palms into the wall or towards each other, the establishment of the hand to the opposite shoulder in front or behind the back, lifting gravity on the elongated arm, the tension of the muscles of the press lying with bending Legs in the knees) with simultaneous registration of ECG or Hmm. The method of correction of myopotential sensitivity is to reduce the sensitivity of the EX method by reprogramming. Adextension to the correction is checked. As a rule, when re-conducting tests with previously, the previously, myopotential inhibition or triggering by manipulation of these disorders is not noted.

Table 5.4. The main signs and reasons for dysfunction ex

Problem	Possible reasons
Reducing the frequency of ex 5-7 minutes from the specified	Depletion of lithium battery
Speakers ex, do not easily wed to teeth P or QRS, although myocardium is not in the refractor stage	Displacement of the electrode, electrode breakage, contact weakening, battery discharge, increase the stimulation threshold, incorrectly specified parameters ex
The imposed rhythm is imposed on its own (incentive arrhythmia) or the availability of spikes during its own normal rhythm	Causes: Low amplitude of the perceived signal (especially with ventricular extrasystole), incorrectly specified sensitivity of the pacemaker.
Paismaker Pause (no Spikes ex)	Bad contact or rupture of wires going to the electrode; Increased sensitivity of excess (excessive perception of teeth and p, myopotencyal)
Reducing the amplitude of Spikes ex	High stimulation threshold, electrode breakdown, battery discharge

Why is it important to understand how the heart pacemaker works? The answer to the question is largely dependent on the design and mode of operation of the ex. The device works according to the following scheme (principle):

• he tracks the rhythm of the heart, and if there is a rare or incorrect rhythm with the abbreviation passage, sends a pulse through the electrode to the heart;
• if the rhythm is normal, exh is at rest - in different people, the device works in different ways: someone is constantly turned off at someone;
• Sends an impulse to the atria and the right ventricle, - the right and left ventricle, the right atrium;
• frequency adaptive stimulants (R-type) have sensory sensors that react to changes in the body (temperature rise, nervous system activity, physical activity, etc.), and according to the program, the operation mode is chosen;
• from the device and carries back information from the heart to the microchip ex.

The principle of operation of electrocardialism is approximately the same - and well disclosed on the following videos:

Some models of stimulants are equipped with card operating devices. Doctors can familiarize themselves with these records with the planned control of IVR settings. However, such devices, as a rule, work less on a single battery (because the charge is consumed and to ensure the energy of recording functions). The device registers ventricular and atrial violations of the rhythm of the heart: the flickering and fluttering of the atrialists, ventricular and superspostricular tachycardia, fibrillation of ventricles.

How the pacemaker works: constantly or turns off - You need to find out directly at the attending physician. In fact, at first, it will even be felt - it is especially good when lying on the left side (or on the right - if exhilant on the right side): a feeling of buzz. It goes fast enough - after a month, another will not be completely not felt (although it may appear again and again, for example, after physical activity - I had after a swim at 800 - 1000 m).

Currently, electrocardialism is used in the treatment of rhythm disorders and conductivity of various genesis. With the development of progress, implanted electrocardiosimulators (ex) are also being improved: two-chamber stimulants that ensure the necessary frequency of rhythm came to change the single-chamber mode. The latest exemplary models are complex devices with wide features of programming their functions. At the same time, with the complication of the pacemakers, it is expanding both its possibilities in the control of the rhythm of patients and difficulties in the interpretation of the functioning of permanent ex.

The interpretation of the results of daily monitoring of the electrocardiogram (see ECG) plays an important role in assessing the functioning of the implanted apparatus, which helps in competent patient's jurisdiction. We attempted an attempt to analyze the SM ECG in patients who did not find any dysfunctions with the standard registration of the cardiogram and the "interrogation) of the implanted devices.

During the SM ECG, the following parameters of the Ex: Ex:

1. Efficiency, i.e. Compliance with spikes and signs of heart cameras.
2. The absence or availability of violations of perception (detection) by any channel (hypo or hypersensing).
3. Violations of the rhythm associated with the work of the ex.
4. Changes in programmed stimulation parameters.

SM ECG was performed on the Siemens system. Surveyed 124 patients aged from 23 to 80 years, of which 69 men and 55 women. Indications for the installation of the EXC were the dysfunction of the sinus node (SUCH, transient failure of the sinus node) with the development of synicopal states, insufficiency of blood circulation - in 48 patients; Atrioventricular blocks of 2-3 degrees are congenital or acquired (including after radio frequency ablation operations AV compounds about paroxysmal supraventricular tachycardium) - in 58 patients, 16 surveyed had combined loss of sinus and AV assembly. Two patients about paroxysms of ventricular tachycardia (Zht) was implanted cardioverter-defibrillator (ICD).

In 63 surveyed there were single-chamber stimulation, while the domestic EX-300 domestic devices were implanted, ex-500, EX-501, EX-511, EX-532, EX-3000. In 60 patients - two-chamber stimulation: "Sigma", "Kappa" devices of the company Medtronic; "Pikos", "AXIOS", "Kairos", "Metros", "Ergos" of Biotronik, "Vita 2", "Selection" of Vitatron and the domestic apparatus ex-4000. At one patient was implanted by the MEDTronic Exmentan Exentrics.

All examined patients during the recording of ordinary ECG violations in the work of the exept was not detected. For cm ECG, effective stimulation was in 119 patients (96%), episodes of ineffective stimulation of ventricles (Fig. 1) - in 3 patients (2%) and episodes of inefficient atrial stimulation - in 3 patients (2%). Exactness frequency of exh various Patients differed: from isolated up to 100% imposed complexes. However, even CM ECG allows you to only state the facts of violation of stimulation, but does not indicate their reasons that can be somewhat: the dislocation of the electrode, its breakage, the exhaustion of the battery, increase the stimulation threshold, etc.

Violation of the perception of biopotentials by any channel (hypo-, hypersensing) can also be due to various reasons: inadequate bios signals, dislocation of the electrode, its breakdown, battery discharge, excessive perception of myopotencylists, detection of teeth R or T stomaching channel, detection of teeth R, T or U at the atrial canal, etc. Modern exemptions are capable of sensing atrial and / or ventricular activity. The complication of the systems is aimed at providing atrioventricular (AV) synchronization, eliminating negative electronic interactions between the channels of ex and adverse interactions of imposed and spontaneous rhythms.

The decrease in sensitivity in any channel was detected in 32 patients (25.6%), including hyposensing p-waves with single-chamber atrial stimulation (Fig. 2), r-wave hyposensing with one-chamber stimulation of ventricles, hyposensing p-waves with two-chamber Stimulation (Fig. 3), hyposensing R-waves with two-chamber stimulation, hyposensing and p- and r-waves with two-chamber stimulation. The data of sensitivity disorders appeared according to our data the most common type of dysfunction of stimulating systems. In this case, the obvious becomes the limited informativeness of determining the amplitude of the endocardial signal with the standard programming of the ex (in the lying position). The casual physical activity of the patient with the ECG monitoring allows diagnosing inadequate programming of parameters and predetermines the more accurate individual selection of indicators and polarity (mono- or bipolar) sensitivity of the instruments.

Hypersensing in one of the channels was revealed in 19 patients (15.3%). This was manifested by the detection of the potentials of the breast muscles by the atrial channel of ex (Fig. 4) or the detection of myopotency with the ventricular channel, which caused the inhibition of the release of the next ventricular incentive and the appearance of the pause in the work of the ex (Fig. 5). In 12 patients (9.7%), the cause of the increased sensitivity of the ventricular channel with the development of pauses in the work of the EX was various technical disorders.

Based on the observations described above, we carry out samples with a load on the shoulder belt during the primary programming of the sensitivity parameters of the implanted ex. Being in the lying position, the patient under the monitor control of the ECG puts pressure in various directions on the hand of the doctor. In this case, the reproducibility of myopotential inhibition reaches 85% in comparison with CM ECG. It helps more adequately program the sensitivity parameters of the EX channels and, if necessary, as well as the possibility, transfer detection to bipolar regime. This technique allows to ensure the adequacy and reliability of the functioning of the EX in terms of preventing hemodynamically significant pauses and prevent possible syncopal and pressing states associated with the phenomenon of detection by the system of activity of skeletal muscles.

Speaking of excess detection, it is also necessary to take into account the possibility of perception by the atrial channel of the rhythm of ventricular activity (both stimulated and spontaneous ventricular reduction), which can lead to a "slowdown" of the device. The base interval of the atrial channel is launched from the perceived ventricular activity. This violation may be observed more often when positioning the atrial electrode of active fixation in the region of the lower third of the interpidential partition. The potentially possible opposite version of excessive sensitivity (the perception of the atrial stimulus ventricular channel (Crosstalk) with a potential development of ventricular asistolis) is never marked with the factory settings of the "blind period" and the sensitivity of the ventricular channel and is possible only with inadequate programming of these parameters.

The arrhythmias can be spontaneous or related to the work of the ex, the latter is called Pacemaker. From the Arrhythmia associated with the work of ex, in 1 patient (0.8%) was revealed by PaisMeric ventricular extrasystole. Differentiate the ventricular extrasystole caused by the main disease, from the one that is due to stimulation, the following criteria are helped: the identity of all extrasystic complexes recorded after imposed; stability of the clutch interval; Disappearance of extrasystole after shutdown ex. In 4 patients (3.2%), paroxysms of "PaceMecery" tachycardia (PMT) were revealed against the background of the preserved ventriculo-caliological (VA) conduct (Fig. 6). The presence of the conduct without the development of "echo reductions" during ventricular stimulation may not lead to any undesirable phenomena, and sometimes prevents the development of hydrodynricular arrhythmias. But with two-chamber stimulation, the preserved Va-Conduction can create the basis for the development of circular PMT.

"PaceMeker" Allritemia was successfully corrigging with a decrease in the parameters of the energy of the incentive. As for Pacemaker Mediated Tachycardia (Pacemaker Mediated "Endless Loop" TachyCardia), in most cases it is easily prevented by adequate lengthening of atrial refractoriness, which ensures that retrofitted ventricular activity in the immunity of the atrial channel. Determination of the duration of the retrograde conducting is particularly relevant in the absence of the function of automatic relief "Paismaker" tachycardia in the rhythmoditel, which makes it a hemodynamically dangerous.

In addition to the frequency that the camera stimulation was carried out, other programmed parameters were also estimated: the duration of the delay, the hysteresis function (increase the base interval of stimulation to preserve the spontaneous rhythm), response to the load of frequency-adaptive stimulants, exemplary behavior when the upper frequency of the tracking is reached (Upper Tracking Limit), automatic mode switching (MODE SWITCH).

Optimum AV delay should provide synchronization of atrial and ventricular systole alone and during exercise. With frequency adaptive two-chamber stimulation in 8 patients (6.5%), the delay changed depending on the heart rate, but within the programmed interval (dynamic AV delay). In many modern ex in DDD mode, the hysteresis of the delay is set in mode, in which the interval is automatically shortened to the programmed value when switching at sservant stimulation on the P-synchronized ventricular stimulation.

The function of hysteresis in stimulating ventricles (an increase in the base interval of stimulation to preserve spontaneous rhythm) was included in 4 surveys (3.2%). The hysteresis values \u200b\u200bidentified at the SMG also corresponded to the programmed parameters (Fig. 7).

Upon the frequency of the atrial ray of the upper limit of the frequency of the tracking, the conduct of atrial pulses on the ventricles may vary as follows: a) the division mode arises (hold 2: 1, 3: 1, etc.); b) Conducts with the periodicals of Westerbach. Such a conduct with exceeding the upper limit of the frequency of the tracking was revealed in 8 patients (6.5%), as in the "division" mode (Fig. 8) and in the mode of periodicals of Westerbach (Fig. 9).

To avoid the tracking of fast atrial rhythms, in modern devices there is a function of automatic switching mode (MODE SWITCH). When it is turned on, if the frequency of the atrial rhythm exceeds the programmed, the stimulator will automatically go into operation mode with the absence of a trigger response to atrial activity (VVI, VDI, DDI). The operation of this function at the CM ECG was detected in 3 surveys (2.4%), 2 of them were paroxysms of atrial fibrillation (Fig. 10), in 1 - atrial extrasystole and accelerated atrial rhythm (Fig. 11).

In many modern devices, there is a so-called function of preventive ventricular stimulation directed against the inhibition of the ventricular channel cross-sensing ("VENTRICULAR Safety Pacing"). When the atrial electrode is near the ventricular, the atrial stimulus can be detected by the ventricular canal, causing inhibition of the outlet of the ventricular pulse. To prevent this, a special detection window was allocated after the ventricular "blind" period. If activity is detected in such a window, it is assumed that it was an inadequate sensing of the atrial incentive, and the extent instead of the suppression launches the yield of the ventricular pulse at the end of the abbreviated car interval. At a CM ECG in one patient (the device of the company "Vitatron"), the function of the preventive ventricular stimulation function was revealed (Fig. 12).

Of the violations of the spontaneous rhythm, the following can be noted: sufficiently valuable extrasystolia - in 26 (21%), paroxysms of hydrodynricular tachycardia (SVT) - 11 (8.9%) and the constant form of SVT - in 5 patients (4%). The ventricular extrasystolism of various degrees of graduation on the lane is noted in 50 patients (40.3%), of which 6 (4.8%), sequins, registered paroxysms (Fig. 13) are registered.

IKD is implanted with ventricular tachyarhyrahythmias and are a two-chamber ex with antitachycardic functions (electrostimulation and discharge). Depending on the type of rhythm violation, the method of eliminating them is automatically changing (various types of antitachycardic stimulation, different discharge power). When analyzing the daily ECG in 2 patients with ICD (1.6%), one of them marked a single ventricular extrasystole, therefore there was no inclusions of the device, in the second - paroxysms of the railway, which are borne by electrostimulation (Fig. 14).

The permanent form of atrial fibrillation was recorded in 16 (12.9%), atrial fibrillation fibrillation paroxysms - in 12 patients (9.7%), of which 4 was implanted with a single-chamber stimulator and 8 - two-chamber. Under the atrial fibrillation, the ECG painting depends on the programmed exebility of the ex: If it exceeds the amplitude of the highest fibrillation waves, the latter are not detected and there is no atrocarditricular stimulation with the base frequency, and there is no atrium response, since They are in the refractory period.

If the sensitivity is more than the lowest, but less than the highest fibrillation waves, then, in the absence of the "Mode Switching" function, part of the waves are detected and the P (F) -Synchronized ventricular stimulation with a frequency is not higher than the upper limit, part of the waves are not detected, And then ineffective atrial stimuli is fed with a base frequency (Fig. 15). Finally, if the sensitivity is less than the lowest waves, then for the prevention of frequent ventricular stimulation, the machine works in VVI mode.

Many patients have met a combination of various rhythm disorders. 19 patients (15.3%) with impaired disorders in the operation of the EX after reprogramming, the replacement of the ex (electrode) was carried out by a control cm ECG. Thus, see ECG plays an important role in identifying various violations of the exemplary work, as well as accompanying spontaneous arrhythmias, helping clinicians to eliminate them in a timely manner, thereby improve the quality of life of patients.

LITERATURE

1. Botonow S.V., Borisova I.M. The role of Holter monitoring of the ECG in identifying violations of the pacemakers in the early postoperative period. Herald of arrhythmology. 2003, 32, p. 32-33.
2. Grigorov S.S. V. V. B., Kostyleva O.V. Electrocardiogram with artificial heart rhythm driver. M .. Medicine, 1990.
3. Egorov D.F., Gordeev O.L. Dynamic observation of adult patients with implanted electrocardiosimulators. Guide for doctors. C-PB., 2004.
4. Kushakovsky M.S. Heart arrhythmias. C-p., Foliant, 1998, p.111-123.
5. Muzhik J., Egorov D.F., Serzh Barold. New perspectives in electrocardiality. C-PB., Silvan, 1995.
6. Treshkar E.V., Polyadina I.I., Yuzvinkevich S.A. and others. Difficulties of interpretation of ECG changes arising during physical exertion in patients with electrocardiosimulators .Progress in Biomedical Research. 1998, February, Volume 3, p.67-73.
7. Treshkar T.V., Kamshilova E.A. Gordeev O.L. Electrocardialism in clinical practice. C-p., Inkart, 2002.
8. Yuzvinkevich S.A., Hirmanov V.N. Programming an atri-ventricular delay as an intake of electrocardiotherapy. Progress in Biomedical Research. 1998, February, Volume 3, p.48-55.

People with an implanted pacemaker are often wondering if various medical procedures can do with a pacemaker. Today it will be discussed on the record of the electrocardiogram (ECG). First, I have a hurry to assure that you can do an ECG with a pacemaker. Moreover, in some cases it is even necessary. In particular, in the diagnosis of violations of the operation of the ECG pacemaker is the main method. ECG record does not represent any danger to the pacemaker. The whole procedure lies in the fact that the patient takes the so-called electrodes in arms and legs. After that, they will record electrical potentials from these electrodes. The fact is that the heart when working leads to the emergence of electricity. And this is electricity and will be recorded when removing the ECG. The daily monitoring is when the patient hang a special device that records the cardiogram during the day.
So, again, people with a pacemaker will perform an ECG record!

For what people with a pacemaker need to do ECG.

As mentioned above, ECG is a diagnostic technique that serves to diagnose the heart of the heart. Thus, with the help of ECG, you can identify certain violations of the heart. First, you can diagnose ischemic heart disease. Here people with a pacemaker have a significant feature. The fact is that in the diagnosis of coronary heart disease, the doctor estimates the so-called QRS complex, which reflects the reduction of ventricles, as well as the Tusk T and the ST segment. And with a pacemaker, ventricles can be reduced as a result of an electric stimulus from ex. This leads to the fact that the QRS complex is changed, as well as the TUB and the ST segment. As a result, it does not always have the opportunity to assess the presence of coronary heart disease in people with a pacemaker.

However, in some people with a pacemaker, it is still possible to estimate the availability of ischemia. First of all, this refers to people who have no ventricular stimulation. For example, people with the weakness syndrome of the sinus node have no stimulation of ventricles and only atrium is stimulated. In this case, it is possible to fully appreciate ischemia in a person or not.
In addition to ischemic heart disease, ECG allows you to estimate the presence of various heart rate disorders, in particular atrial or ventricular tachycardia, atrial or ventricular extrasystolia. Well, finally, the ECG allows you to identify violations in the work of the cardiomimulator, such as the fracture of the electrodes, the dislocation of the electrodes, the full discharge of the EXT battery.

A pacemaker on an ECG, or an ECG description with a pacemaker.

So, dear friends. Next, the information is intended for medical workers: cardiologists, specialists of functional diagnostics. And it will be about the features of the assessment and description of the ECG of a person with a pacemaker. Information is posted for educational purposes, because very often the specialized centers receive calls and questions from doctors from hospitals and a clinic that experience difficulties in the interpretation of the ECG of a person with a pacemaker.

What to evaluate when analyzing an ECG person with a pacemaker.

1. All the same as a person without a pacemaker (when it is possible to evaluate): sinus rhythm or not, is there ischemic changes or not, the frequency of heart rate, the presence of extrasystole (atrial or ventricular), the presence of tachycardia and its kind.
2. Are artifacts (stimuli) from the pacemaker. If there is, that is, whether the capture (that is, there is a QRS complex or prog r) after the incentives. Based on this information, it is possible to conclude that the single-chamber or duchkarm ex. If there is a single-chamber ex: can be understood in atrium or in the ventricle electrode. You can also determine the disorders of the exemplary ex, such as hypersensing, hyposensing, no capture (which may be as a result of an increase in the stimulation threshold, or electrode dislocation).

Now let's walk in order for all stages of the ECG estimate with a pacemaker.

What rhythm: sinusov or not.

Let's understand what options may be and when is it important? First, if a pacemaker is worth it, it does not mean that it constantly and continuously works. So, in the intervals, when exes does not work, we can evaluate sinus rhythm or not. For example, the illustration below shows a normal sinus rhythm, when R. teeth are present.

Another option is to fibrillation or atrial trembles - when instead of tools p we see or waves of fibrillation or waves of atrium flutter. In addition, there may be rhythm from ex with atrial stimulation, ventricular stimulation or and atrial and ventricular stimulation. In these cases, we will see the pacemaker spikes in front of the teeth P or in front of the QRS complexes, respectively. In the illustration below - ECG with an example of two-chamber heart stimulation.

Frequency of heart rate, ischemic changes, extrasystole, tachycardia.

The heart rate is measured at the RR intervals in the same way as on an ECG of an ordinary person. It can be measured and by the distance between adjacent spikes from the pacemaker to the ECG.
Ischemic modified is evaluated only if there is no ventricular stimulation, otherwise they are simply not possible.
The presence of extrasystolia of atrial and ventricular and tachycardia is also estimated similar to the human ECG without a pacemaker.

Determination of violations in the work of ex.

There are many violations in the pacemaker. But for most cases, three of them have values. If you are therapist, or a cardiologist, then these good knowledge of these three violations will be enough for you. For a functional diagnostics, I can advise you to find the book Ardasheva A.V. Clinical arrhythmology.

Loss of capture.

The loss of capture is when there is an incentive ex but is there no answer to it. That is, after the artifact from the exh is neither the Tonga R nor the QRS complex. This may be when the dislocation of the electrode occurred. In this case, the loss of capture can be periodic, that is, the capture that is, it is not. This seeks because the electrode is hanging inside the heart chamber, and if during stimulation from contact with the wall of the heart, then we will see an effective grip, if you leave the wall - the capture will not be. Other cases of capturing loss - a fracture of the electrode, an increase in the stimulation threshold, hitting the stimulus for the refractory period, for example, if the ventricular stimulus falls on the tv, then the capture will not happen, because the ventricles are in the refractory period.
The illustration below is an example of inefficient capture of ventricles. It is possible a dislocation or fracture of the ventricular electrode.

Hypersensing.

With hypersensing, the pacemaker feels any artifact and interprets it as a reduction in the heart. For example, the patient strained the muscles of the breast, the cardiac behavior thought that this was reduced by the heart and did not inflict the stimulus. That is, the ex feel something that should not feel. The example above is the myopotential inhibition. In this case, the problem is solved by simply resulted in the bipolar mode of sensitivity of ex (so that two poles of sensitivity were inside the heart). Reprogramming the problem will not be able to decide if the electrode is unipolar. In modern arrhythmology, there are practically no such electrodes. Old bipolar electrode can be changed. Another example of hypersensing is hypersinsing with a fracture of the electrode. When broken ends come into contact with each other, there are nozzles that exemplable can take for the electrical activity of the heart.
The illustration below is an example of the hypersensing of the atrial electrode.

As you noticed when hypersensing, the main sign on the ECG is the lack of spikes where they should be. In this case, hypersensing may be associated with myopotential inhibition or a fracture of an electrode. This will be found out when programming is used.

Hyposensing.

Hyposenssing is the opposite situation of the previous one. Execution does not feel the reduction in the heart. At the same time, he sends incentives even when they are unnecessary. A part of these incentives leads to the capture of the cavities of the heart, part is not accompanied by the capture as it gets during the refractoring period.

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Electrophic cardiomulation with hypertrophic cardiomyopathy (GKMP). It is shown that two-chamber stimulation with a short av-delay reduces the symptoms and pressure gradient in the LV tract in a part of patients with GKMP, having a significant gradient value.

Cardiac resinchronizing therapy. Biventricular stimulation can improve symptoms and forecast in patients with heart failure, LV systolic dysfunction, which have a significant increase in the duration of QRS complexes. RESOINCHRONIZATION of the ventricles is achieved by almost simultaneous application of incentives for the right, and left-handhold electrodes, which usually leads to a significant decrease in the duration of QRS complexes.

Stimulation of the left ventricle (LV) is carried out through an electrode that is injected into the lateral branch of the coronary sine. Technically, it is very difficult to introduce an electrode into a suitable branch of the coronary sinus, to achieve a satisfactory stimulation threshold and avoid stimulation of the diaphragm. Biventricular stimulation is intended primarily to combat heart failure, and not with heart arrhythmias, therefore it is not discussed in the details in detail.

Cardiomimulators The first generation was functional in constant asynchronous mode, carrying out the stimulation of ventricles with a fixed frequency (usually 70 imp. / min) regardless of any spontaneous electrical activity of the heart. Competition with spontaneous heart rhythm often caused a feeling of neurotic heartbeat, and the incentive in the period of repolarization of ventricles could provoke FJ.

In the future, a system was developed that recognizes its own electrical activity of the heart through a stimulating electrode, which allowed In the "on demand" mode. The electrical event perceived by the stimulant (myocardial depolarization) leads to zeroing the time counter before applying the following incentive, which avoids rhythm competition.

With the advent of reliable atrial transgeneous electrodes, the implementation of the functions of stimulation and sensitivity in the atrias became the same simple as in the ventricles. This allowed to spend "Single-chamber" atrial stimulation, as well as "two-chamber" stimulation, when the function of stimulation and / or sensitivity can be carried out both at the level of atrium and ventricles. These achievements contributed to the development of the physiological approach to heart stimulation.

Coding of the cardiovulation system

- The first letter denotes the camera or camera heartwhich are stimulated: a - atrium, V - ventricles, D (dual - double) -for two-chamber systems, if it can be stimulated as atrium and ventricles.

- Second letter Indicates a camera or chamber whose electrical activity is analyzed by the device (sensitivity function). In addition to the letters A, V and D, the letter O denotes that the pacemaker does not have a sensitivity function.

- Third letter Indicates the nature of the response of the implanted device for perceived information about the spontaneous activity of the heart chamber. The letter I (inhibition is inhibiting.) Indicates that the cardiac pulse generation is inhibited by a perceived event, T (trigger-launch.) - indicates that the generation of the stimulator pulse is launched by a perceived event, D indicates that the perceived ventricular activity inhibits the pulse Stimulator, and atrial activity launches ventricular incentive generation. The letter O is denoted by the absence of an answer to perceived events (asynchronous stimulation with a fixed frequency.).

- Fourth letter - R (Rate Response - frequency response, frequency adaptation.) - Used if the stimulator has the function of adapting the frequency of stimulation to the physiological needs of the body. To do this, in a number of devices there are sensors registering physiological parameters, such as physical activity or breathing.

- Fifth letter It is relaxing only to the multifoxy heart stimulation: o indicates the absence of such a function, while A, V and D indicate the presence of a second atrial electrode, a second ventricular electrode, additional electrodes and atrial rates, and in the ventricles, respectively.

a - asynchronous stimulation of ventricles with a fixed frequency (leads I, II, III).
High-amplitude incentives are preceded by each ventricular complex.
You can see the teeth P, dissociate with ventricular complexes.
b - asynchronous stimulation of ventricles with a fixed frequency in a patient with AV-blockade I degree.
The first 3 stimulus fall into the refractory period and are ineffective, the 4th stimulus causes premature depolarization.
Examples of violation of sensitivity function: A - violation of the sensitivity function in a pacemaker running on the "on demand" mode.
1, 3, 5 and 7th incentives "capture" ventricles, while 2, 4, 6 and 8th incentives enter the teeth of spontaneous ventricular complexes;
b is a violation of the sensitivity function, leading to the fact that in the 6th ventricular complex, the stimulus coincides with the time of Tung T and causes FZH.
Stimulation of ventricles in "on demand" mode. Stimulation is inhibited by sinus complexes (2nd and 4th complexes), the 6th complex is drained.
Immediately before the incentive, you can see the provence R. It turned out that the sinus knot worked at the moment when the stimulator had already received the command to generate their own incentive, and the ventricles were activated by both pulses - from the sinus node and from the stimulator.
Drain complexes should not be confused with signs of violation of the stimulation function.

Academic video decoding ECG with a pacemifier (artificial rhythm driver)