The electrocardiogram of the heart is the main diagnostic study that allows you to draw conclusions about the work of the organ, the presence or absence of pathologies and their severity. Decryption ECG of the heart is carried out by a cardiologist, who sees not only the curves on paper, but can also visually assess the patient's condition, analyze his complaints.

The indicators collected all together help to make the correct diagnosis. Without an accurate diagnosis, it is impossible to prescribe effective treatment Therefore, doctors carefully study the results of the patient's ECG.

Brief information about the ECG procedure

Electrocardiography examines the electrical currents that occur during the work of the human heart. This method is quite simple and affordable - these are the main advantages diagnostic procedure, which has been carried out by doctors for a long time and with regard to the interpretation of the results, doctors have accumulated sufficient practical experience.

The cardiogram of the heart was developed and implemented in its modern form at the beginning of the twentieth century by the Dutch scientist Einthoven. The terminology developed by the physiologist is still used today. This once again proves that the ECG is a relevant and in-demand study, the indicators of which are extremely important for diagnosing heart pathologies.

The value of the cardiogram

An electrocardiogram is extremely important, since its correct reading allows you to detect the most serious pathologies, the patient's life depends on the timely diagnosis of which. A cardiogram is performed in both adults and children.

Upon receipt of the results, the cardiologist can assess the heart rate, the presence of arrhythmia, metabolic pathology in the myocardium, electrical conduction disturbance, myocardial pathology, localization of the electrical axis, and the physiological state of the main human organ. In some cases, the cardiogram can confirm other somatic pathologies that are indirectly related to cardiac activity.

Important! Doctors recommend doing a cardiogram if the patient feels obvious changes in heart rhythm, suffers from sudden shortness of breath, weakness, and faints. It is necessary to do a cardiogram for primary pains in the heart, as well as for those patients who have already been diagnosed with abnormalities in the work of the organ, noises are observed.

An electrocardiogram is a standard procedure during a medical examination, in athletes during a medical examination, in pregnant women, before surgical interventions. Diagnostic value has an ECG with and without exercise. They make a cardiogram for pathologies of the endocrine and nervous systems, with an increase in lipid levels. For the purpose of prevention, it is recommended to make a heart diagnosis for all patients who have reached forty-five years of age - this will help to identify abnormal performance of the organ, diagnose pathology and begin therapy.

What are the results of the study?

The results of the study for dummies will be absolutely incomprehensible, therefore it is impossible to read the cardiogram of the heart on your own. The doctor receives from the electrocardiograph a long millimeter paper with curves printed on it. Each graph reflects an electrode attached to the patient's body at a certain point.

In addition to graphs, devices can also provide other information, for example, the main parameters, the rate of one or another indicator. A preliminary diagnosis is generated automatically, so the doctor needs to independently study the results and only take into account what the device gives out in terms of possible disease. Data can be recorded not only on paper, but also on electronic media, as well as in the memory of the device.

Interesting! Holter monitoring is a type of ECG. If the cardiogram is taken in the clinic in a few minutes while the patient is lying down, then with Holter monitoring, the patient receives a portable sensor, which he attaches to his body. It is necessary to wear the sensor for a full day, after which the doctor reads the results. The peculiarity of such monitoring is the dynamic study of cardiac activity in various states. This allows you to get a more complete picture of the patient's health status.

Deciphering the results of the study: main aspects

Curves on graph paper are represented by isolines - a straight line, which means that there are no impulses at the moment. Deviations up or down from the isoline are called teeth. In one complete cycle heart contraction six teeth are laid, which are assigned standard letters of the Latin alphabet. Such teeth on the cardiogram are either directed up or down. The upper teeth are considered to be positive, and the downward ones are considered negative. Normally, the S and Q waves dip slightly down from the isoline, and the R wave is a peak rising upward.

Each tooth is not just a drawing with a letter, behind it lies a certain phase of the heart. You can decipher the cardiogram if you know which teeth mean what. For example, the P wave demonstrates the moment when the atria are relaxed, R indicates the excitation of the ventricles, and T indicates their relaxation. Doctors take into account the distance between the teeth, which also has its own diagnostic value, and if necessary, entire groups of PQ, QRS, ST are examined. Each research value speaks about a certain characteristic of the organ.

For example, with an unequal distance between the R teeth, doctors talk about extrasystole, atrial fibrillation, weakness of the sinus node. If the P wave is elevated and thickened, then this indicates a thickening of the walls of the atria. An extended PQ interval indicates artrioventricular block, and an expansion of the QRS suggests ventricular hypertrophy, blockade of the His bundle. If there are no gaps in this segment, doctors suspect fibrillation. A prolonged QT interval indicates serious heart rhythm disturbances that can be fatal. And if this combination of QRS is presented as a flag, then doctors talk about myocardial infarction.

Table of normal values ​​\u200b\u200band other indicators

To decipher the ECG, there is a table containing the norms of values. Focusing on it, doctors can see deviations. As a rule, in the process of long work with cardiological patients, doctors no longer use the table at hand, the norm in adults is memorized by heart.

Indicator Amplitude of the norm, s QRS from 0.06 to 0.1 Rot 0.07 to 0.11 Q from 0.07 to 0.11 T from 0.12 to 0.28 PQ from 0.12 to 0.2

In addition to tabular values, doctors consider other parameters of the work of the heart:

• rhythmicity of heart contractions - in the presence of arrhythmia, i.e. failures in the rhythmicity of contractions of the heart muscle, the difference between the indicators of the teeth will be more than ten percent. In people with a healthy heart, normosistolia is noted, but pathological data make the doctor alert and look for deviations. The exception is sinus arrhythmia in combination with sinus rhythm, as often happens in adolescence, but in adults, sinus rhythm with deviations indicates the beginning of the development of pathology. A striking example of deviations is extrasystole, which manifests itself in the presence of additional contractions. It occurs with malformations of the heart, inflammation of the myocardium, ischemia,
• heart rate is the most accessible parameter, it can be assessed independently. Normally, in one minute there should be from 60 to 80 complete cycles of the heart. With a rapid cycle, more than 80 beats speak of tachycardia, but less than 60 is bradycardia. The indicator is more illustrative, since not all severe pathologies give bradycardia or tachycardia, and in single cases, the ECG of a healthy person will also show such phenomena if he is nervous during electrocardiography.

Types of heart rate

An electrocardiogram shows another important parameter - the type of heart rhythm. It means the place where the signal propagates, prompting the heart to contract.

There are several rhythms - sinus, atrial, ventricular and atrioventricular. The norm is sinus rhythm, and if the impulse occurs in other places, then this is considered a deviation.

An atrial rhythm on an ECG is a nerve impulse that occurs in the atria. Atrial cells provoke the appearance of ectopic rhythms. Such a situation arises when the sinus node malfunctions, which should produce these rhythms on its own, and now the atrial innervation centers do it for it. The immediate cause of this deviation is hypertension, weakness of the sinus node, ischemic disorders, and some endocrine pathologies. With such an ECG, nonspecific ST-T wave changes are recorded. In some cases, atrial rhythm is observed in healthy people.

The atrioventricular rhythm occurs in the node of the same name. The pulse rate with this type of rhythm falls below 60 beats / min, indicating bradycardia. Causes of atrioventricular rhythm - weak sinus node, taking certain medications, blockade of the AV node. If tachycardia occurs with atrioventricular rhythm, this is evidence of a previous heart attack, rheumatic changes, such a deviation appears after surgical interventions on the heart.

Ventricular rhythm is the most severe pathology. The impulse emanating from the ventricles is extremely weak, the contractions often fall below forty beats. Such a rhythm occurs with a heart attack, circulatory failure, cardiosclerosis, heart defects, in a preadgonal state.

Deciphering the analysis, doctors pay attention to the electrical axis. It is displayed in degrees and shows the direction of the impulses. The norm for this indicator is 30-70 degrees when tilted to the vertical. Abnormalities suggest intracardiac blockade or hypertension.

When deciphering the ECG, terminological conclusions are issued, which also demonstrate the norm or pathology. A bad ECG or a result without pathology will show in a complex all indicators of the work of the heart. Atrioventricular block will be reflected as a prolonged PQ interval. Such a deviation in the first degree does not threaten the life of the patient. But with the third degree of pathology, there is a risk of sudden cardiac arrest, since the atria and ventricles work in their own incongruous rhythm.

If the conclusion contains the word "ectopic rhythm", this means that the innervation does not come from the sinus node. The condition is both a variant of the norm and a severe deviation due to cardiac pathologies, taking medications, etc.

If the cardiogram shows nonspecific ST-T wave changes, then this situation requires additional diagnostics. The reason for the deviation may be metabolic disorders, major electrolyte imbalance or endocrine dysfunction. A high T wave may indicate hypokalemia, but is also a normal variant.

With some pathologies of the heart, the conclusion will show a low voltage - the currents emanating from the heart are so weak that they are recorded below normal. Low electrical activity is due to pericarditis or other cardiac pathologies.

Important! The borderline ECG of the heart indicates a deviation of some parameters from the norm. This conclusion is generated by the electrocardiograph system and does not mean severe violations at all. Upon receipt of such data, patients should not be upset - it is enough just to undergo an additional examination, identify the cause of the violations and treat the underlying disease.

Myocardial infarction on ECG

An ECG in myocardial infarction records extremely important diagnostic data, according to which it is possible not only to diagnose a heart attack, but also to determine the severity of the violations. The manifestation of pathology on the ECG will be noticeable already with the onset of symptoms of a crisis. There will be no R wave on the tape - this is one of the leading signs of myocardial infarction.

An electrocardiographic study is quite simple and effective method diagnostics, used by cardiologists around the world to study the activity of the heart muscle. The results of the procedure in the form of graphs and digital symbols, as a rule, are transferred to specialists for further data analysis. However, if, for example, there is no right doctor, the patient has a desire to independently decipher the indicators of his heart.

Preliminary interpretation of the ECG requires knowledge of special basic data, which, due to their specificity, are not subject to everyone. In order to make correct calculations of the ECG of the heart for a person who is not related to medicine, it is necessary to familiarize yourself with the basic principles of processing, which are combined for convenience into the appropriate blocks.

Familiarization with the basic elements of a cardiogram

You should know that the interpretation of the ECG is carried out thanks to elementary, logical rules that can be understood even by an ordinary layman. For a more pleasant and calm perception of them, it is recommended to start familiarizing yourself first with the simplest principles of decoding, gradually moving to a more complex level of knowledge.

Ribbon layout

The paper, which reflects data on the functioning of the heart muscle, is a wide ribbon of a soft pink hue with a clear “square” marking. The larger quadrilaterals are formed from 25 small cells, and each of them, in turn, equates to 1 mm. If a large cell is filled with only 16 dots, for convenience, you can draw parallel lines along them and follow similar instructions.

The horizontals of the cells indicate the duration of the heartbeat (sec), and the verticals indicate the voltage of individual ECG segments (mV). 1 mm is 1 second of time (in width) and 1 mV of voltage (in height)! This axiom must be kept in mind throughout the entire period of data analysis, later its importance will become obvious to everyone.

The paper used allows you to correctly analyze the time intervals

teeth and segments

Before moving on to the names of specific departments of the gear graph, it is worth familiarizing yourself with the activity of the heart itself. The muscular organ consists of 4 compartments: the 2 upper ones are called the atria, the 2 lower ones are called the ventricles. Between the ventricle and the atrium in each half of the heart there is a valve - a leaflet responsible for accompanying blood flow in one direction: from top to bottom.

This activity is achieved due to electrical impulses that move through the heart according to the "biological timetable". They are sent to specific segments of the hollow organ using a system of bundles and nodes, which are miniature muscle fibers.

The birth of the impulse occurs in the upper part of the right ventricle - the sinus node. Further, the signal passes into the left ventricle and excitation of the upper parts of the heart is observed, which is recorded by the P wave on the ECG: it looks like a gentle inverted cup.

After the electric charge reaches the atrioventricular node (or AV node), which is located almost at the junction of all 4 pockets of the heart muscle, a small “point” appears on the cardiogram, pointing down - this is the Q wave. Just below the AV node there is the following item the purpose of the impulse is the bundle of His, which is fixed by the highest tooth R among others, which can be represented as a peak or mountain.

Having overcome half of the way, an important signal rushes to the lower part of the heart, through the so-called legs of the bundle of His, outwardly resembling the long tentacles of an octopus that hug the ventricles. The conduction of the impulse along the branched processes of the bundle is reflected in the S wave - a shallow groove at the right foot of R. When the impulse spreads to the ventricles along the legs of the bundle of His, they contract. The last bumpy T wave marks the recovery (rest) of the heart before the next cycle.

Not only cardiologists, but also other specialists can decipher diagnostic indicators.

In front of the 5 main teeth on the ECG, you can see a rectangular ledge, you should not be afraid of it, since it is a calibration or control signal. Between the teeth there are horizontally directed sections - segments, for example, S-T (from S to T) or P-Q (from P to Q). To independently make an indicative diagnosis, you will need to remember such a concept as the QRS complex - the combination of the Q, R and S teeth, which registers the work of the ventricles.

The teeth that rise above the isometric line are called positive, and those that are located below them are called negative. Therefore, all 5 teeth alternate one after the other: P (positive), Q (negative), R (positive), S (negative) and T (positive).

Leads

Often you can hear the question from people: why are all the ECG graphs different from each other? The answer is relatively simple. Each of the curved lines on the tape reflects the heart readings obtained from 10-12 colored electrodes, which are installed on the limbs and in the chest area. They read data on the heart impulse, located at different distances from the muscle pump, because the graphics on the thermal tape are often different from each other.

Only an experienced specialist can competently write an ECG conclusion, while the patient has the opportunity to consider general information about your health.

Normal indicators of the cardiogram

Now that it has become clear how to decipher the cardiogram of the heart, one should proceed to the direct diagnosis of normal indications. But before getting acquainted with them, it is necessary to evaluate the ECG recording speed (50 mm / s or 25 mm / s), which, as a rule, is automatically printed on paper tape. Then, starting from the result, you can view the norms for the duration of the teeth and segments that are listed in the table (calculations can be carried out using a ruler or checkered markings on the tape):

Among the most significant provisions of the interpretation of the ECG, the following can be mentioned:

• S-T segments and P-Q should "merge" with the isometric line, without going beyond it.
• The depth of the Q wave cannot exceed ¼ of the height of the most slender tooth - R.
• The exact measurements of the S wave have not been confirmed, but it is known that it sometimes reaches a depth of 18–20 mm.
• The T wave should not be higher than R: its maximum value is ½ of the height of R.

Heart rate control is also important. It is necessary to pick up a ruler and measure the length of the segments enclosed between the vertices of R: the results obtained must coincide with each other. To calculate the heart rate (or heart rate), it is worth calculating total small cells between 3 vertices R and divide the digital value by 2. Next, you need to apply one of the 2 formulas:

• 60/X*0.02 (at 50mm/s write speed).
• 60/X*0.04 (at 25mm/s write speed).

If the figure is in the range from 59-60 to 90 beats / min, then the heart rate is normal. An increase in this index implies tachycardia, and a clear decrease implies bradycardia. If for a well-formed person a heart rate of more than 95–100 beats per minute is a rather dubious sign, then for children under 5–6 years old this is one of the varieties of the norm.

Each of the teeth and intervals indicates a certain period of time for the work of the heart muscle.

What pathologies can be identified when deciphering the data?

Although the ECG is one of the extremely simple studies in terms of structure, there are still no analogues of such a diagnosis of cardiac abnormalities. The most "popular" diseases recognized by ECG can be found by examining both the description of their characteristic indicators and detailed graphic examples.

This ailment is often recorded in adults during the implementation of the ECG, but in children it is extremely rare. Among the most common "catalysts" of the disease are the use of drugs and alcohol, chronic stress, hyperthyroidism, etc. PT is distinguished, first of all, by a frequent heartbeat, the indicators of which range from 138-140 to 240-250 beats / min.

Due to the manifestation of such attacks (or paroxysm), both ventricles of the heart do not have the opportunity to fill with blood in time, which weakens the overall blood flow and slows down the delivery of the next portion of oxygen to all parts of the body, including the brain. Tachycardia is characterized by the presence of a modified QRS complex, a mild T wave, and, most importantly, the absence of a distance between T and P. In other words, the groups of teeth on the electrocardiogram are "glued" to each other.

The disease is one of the "invisible killers" and requires immediate contact with a number of specialists, since if it is extremely neglected, it can lead to the death of a person.

Bradycardia

If the previous anomaly implied the absence segment T-P, then bradycardia is its antagonist. This ailment produces precisely a significant lengthening of T-P, indicating a weak conduction of the impulse or its incorrect accompaniment through the heart muscle. In patients with bradycardia, an extremely low heart rate index is observed - less than 40-60 bpm. If people who prefer regular physical activity, slight manifestation disease is the norm, then in the vast majority of other cases we can talk about the emergence of an extremely serious disease.

If obvious signs of bradycardia are found, it is necessary to undergo an examination as soon as possible. comprehensive examination.

Ischemia

Ischemia is called a harbinger of myocardial infarction, for this reason early detection anomalies contributes to the relief of fatal ailments and, as a result, a favorable outcome. It was previously mentioned that the S-T interval should “comfortably lie” on the isoline, however, its omission in the 1st and AVL leads (up to 2.5 mm) signals precisely about IHD. Sometimes coronary heart disease gives out only the T wave. Normally, it should not exceed ½ of the R height, however, in this case it can either “grow” to the older element or fall below the midline. The remaining teeth are not subject to significant changes.

Flutter and atrial fibrillation

Atrial fibrillation is an abnormal condition of the heart, expressed in a disorderly, chaotic manifestation of electrical impulses in the upper pockets of the heart. It is sometimes not possible to make a qualitative surface analysis in such a case. But knowing what you should pay attention to first of all, you can safely decipher the ECG indicators. QRS complexes are not of fundamental importance, since they are often stable, but the gaps between them are key indicators: when they flicker, they look like a series of notches on a hand saw.

Pathologies are clearly distinguishable on the cardiogram

Not so chaotic, large-sized waves between the QRS already indicate atrial flutter, which, unlike flicker, is characterized by a slightly more pronounced heartbeat (up to 400 beats / min). Contractions and excitations of the atria are subject to control to a small extent.

Thickening of the atrial myocardium

Suspicious thickening and stretching of the muscle layer of the myocardium is accompanied by a significant problem with the internal blood flow. At the same time, the atria perform their main function with constant interruptions: the thickened left chamber “pushes” blood into the ventricle with greater force. When trying to read an ECG graph at home, you should focus on the P wave, which reflects the state of the upper heart.

If it is a kind of dome with two bulges, most likely the patient is suffering from the disease in question. Since thickening of the myocardium in the long-term absence of qualified medical intervention provokes a stroke or heart attack, it is necessary to sign up for a consultation with a cardiologist as soon as possible with the provision detailed description uncomfortable symptoms, if any.

Extrasystole

It is possible to decipher the ECG with the "first signs" of extrasystole if there is knowledge about the special indicators of a special manifestation of arrhythmia. By carefully examining such a graph, the patient can detect unusual abnormal jumps that vaguely resemble QRS complexes - extrasystoles. They occur in any area of ​​the ECG, they are often followed by a compensatory pause, allowing the heart muscle to “rest” before starting a new cycle of excitations and contractions.

Extrasystole in medical practice is often diagnosed in healthy people. In the vast majority of cases, it does not affect the usual course of life and is not associated with serious illnesses. However, when establishing an arrhythmia, you should play it safe by contacting specialists.

With atrioventricular heart block, an expansion of the gap between the P waves of the same name is observed, in addition, they can occur at the time of analyzing the ECG conclusion much more often than QRS complexes. The registration of such a pattern indicates a low conductivity of the impulse from the upper chambers of the heart to the ventricles.

If the disease progresses, the electrocardiogram changes: now the QRS “drops out” from the general row of P waves in some intervals

Blockade of the legs of the bundle of His

The failure of such an element of the conduction system as the bundle of His should in no case be ignored, since it is located in close proximity to the Myocardium. The pathological focus in advanced cases tends to "transfer" to one of the most important parts of the heart. It is quite possible to decipher the ECG yourself in the presence of an extremely unpleasant disease, you just have to carefully examine the highest tooth on the thermal tape. If it forms not a “slender” letter L, but a deformed M, this means that the bundle of His has been attacked.

The defeat of its left leg, which passes the impulse into the left ventricle, entails the complete disappearance of the S wave. And the place of contact of the two vertices of the split R will be located above the isoline. Cardio graphic image weakening of the right leg of the bundle is similar to the previous one, only the junction point of the already indicated peaks of the R wave is under the midline. T is negative in both cases.

myocardial infarction

The myocardium is a fragment of the densest and thickest layer of the heart muscle, which in recent years has been subjected to various ailments. The most dangerous among them is necrosis or myocardial infarction. When deciphering electrocardiography, it is quite distinguishable from other types of diseases. If the P wave, which registers the good condition of the 2 atria, is not deformed, then the remaining segments of the ECG have undergone significant changes. So, a pointed Q wave can “pierce” the isoline plane, and T can be transformed into a negative tooth.

The most telling sign of a heart attack is an unnatural R-T elevation. There is a mnemonic rule that allows you to remember its exact appearance. If, when examining this area, one can imagine the left, ascending side of R in the form of a rack tilted to the right, on which a flag flies, then we are really talking about myocardial necrosis.

The disease is diagnosed both in the acute phase and after the attack subsides.

ventricular fibrillation

Otherwise, an extremely serious illness is called atrial fibrillation. hallmark This pathological phenomenon is considered to be the destructive activity of the conductive bundles and nodes, indicating an uncontrolled contraction of all 4 chambers of the muscle pump. Reading the results of an ECG and recognizing ventricular fibrillation is not at all difficult: on a checkered tape, it appears as a series of chaotic waves and hollows, the parameters of which cannot be correlated with classical indicators. In none of the segments can you see at least one familiar complex.

If a patient with atrial fibrillation is not given premature medical care he will soon die.

WPW syndrome

When, in the complex of classical pathways for conducting an electrical impulse, an abnormal Kent bundle is unexpectedly formed, located in the “comfortable cradle” of the left or right atrium, we can confidently speak of such a pathology as WPW syndrome. As soon as the impulses begin to move along the unnatural cardiac highway, the rhythm of the muscle goes astray. The "correct" conducting fibers cannot fully supply the atria with blood, because the impulses preferred a shorter path to complete the functional cycle.

The ECG in SVC syndrome is distinguished by the appearance of a microwave at the left foot of the R wave, a slight widening of the QRS complex, and, of course, a significant reduction in the P-Q interval. Since the decoding of the cardiogram of a heart that has undergone WPW is not always effective, HM comes to the aid of medical personnel - the Holter method for diagnosing an ailment. It involves wearing around the clock on the body of a compact device with sensors attached to the skin.

Long-term monitoring provides a better result with a reliable diagnosis. In order to “catch” the anomaly localized in the heart in a timely manner, it is recommended to visit the ECG room at least once a year. If regular medical monitoring of the treatment of cardiovascular disease is necessary, more frequent measurements of cardiac activity may be required.

The heart is the most important human organ. With its dysfunction, the whole body suffers. Electrocardiography is used to detect various cardiovascular pathologies. It uses a device that captures the electrical impulses of the heart - an electrocardiograph. ECG interpretation allows you to see the main deviations in the work of the organ on the graphic curve, which in most cases helps to make a diagnosis without additional studies, prescribe the necessary treatment.

What concepts are used in deciphering

Deciphering an ECG is a rather complicated process that requires deep knowledge from a specialist. During the assessment of the state of the heart, cardiogram indicators are measured mathematically. In this case, concepts such as sinus rhythm, heart rate, electrical conductivity and electrical axis, pacemakers and some others are used. By evaluating these indicators, the doctor can clearly determine some parameters of the functioning of the heart.

Heart rate

Heart rate is the specific number of heartbeats in a given period of time. Usually an interval of 60 seconds is taken. On the cardiogram, heart rate is determined by measuring the distance between the highest teeth (R - R). The recording speed of the graphic curve is typically 100 mm/s. By multiplying the recording length of one mm by the duration of the segment R - R, the heart rate is calculated. In a healthy person, the number of heartbeats should be 60 - 80 beats per minute.

Sinus rhythm

Another concept included in the decoding of the ECG is the sinus rhythm of the heart. During the normal functioning of the heart muscle, electrical impulses arise in a special node, then propagate to the region of the ventricle and atrium. The presence of sinus rhythm indicates the normal functioning of the heart.

The cardiogram of a healthy person should show the same distance between the R waves throughout the recording. A deviation of 10% is allowed. Such indicators indicate the absence of arrhythmia in humans.

Conduction paths

This concept defines such a process as the propagation of electrical impulses through the tissues of the heart muscle. Normally, impulses are transmitted in a certain sequence. Violation of the order of their transfer from one pacemaker to another indicates dysfunction of the organ, the development of various blockades. These include sinoatrial, intraatrial, atrioventricular, intraventricular blockade, as well as Wolff-Parkinson-White syndrome.

On an ECG, a specialist can see a violation of cardiac conduction

Electrical axis of the heart

When deciphering the cardiogram of the heart, the concept is taken into account - the electrical axis of the heart. This term is widely used in cardiology practice. When deciphering an ECG, this concept allows a specialist to see what is happening in the heart. In other words, the electrical axis is the totality of all biological and electrical changes within an organ.

An electrocardiogram allows you to visualize what is happening in a specific area of ​​\u200b\u200bthe heart muscle using a graphic image obtained by transmitting impulses from electrodes to a special device.

The position of the electrical axis is determined by the doctor using special diagrams and tables or by comparing the QRS complexes that are responsible for the process of excitation and contraction of the heart ventricles.

If the ECG indicators indicate that the R wave in lead III has a lower amplitude than in lead I, we are talking about a deviation of the cardiac axis to the left. In the event that in the III lead the R wave has a greater amplitude than in the I lead, it is customary to speak of a deviation of the axis to the right. Normal values ​​in the cardiogram table - the R wave is the highest in lead II.

Prongs and intervals

On the cardiogram itself, obtained during the study, the teeth and intervals are not indicated. They are needed only for a specialist doing decryption.

Teeth:

• P - determines the beginning of the contraction of the atrial region;
• Q, R, S - belong to the same species, coincide with the contraction of the ventricles;
• T - the time of inactivity of the ventricles of the heart, that is, their relaxation;
• U - rarely noted on the cardiogram, there is no consensus about its origin.

For ease of interpretation, the cardiogram is divided into intervals. On the tape, you can see straight lines that run clearly in the middle of the tooth. They are called isolines or segments. When making a diagnosis, the indicators of the P-Q and S-T segments are usually taken into account.

In turn, one interval consists of segments and teeth. The length of the interval also helps to assess the overall picture of the functioning of the heart. Intervals - P - Q and Q - T have diagnostic significance.

Reading a cardiogram

How to decipher the cardiogram of the heart? This question is asked by many patients who had to deal with the procedure of electrocardiography. It is very difficult to do it yourself, because decrypting data has a lot of nuances. And if in your cardiogram you read certain violations of the activity of the heart, this does not at all mean the presence of a particular disease.

A cardiologist is reading a cardiogram

teeth

In addition to taking into account intervals and segments, it is important to monitor the height and duration of all teeth. If their fluctuation does not deviate from the norm, this indicates a healthy functioning of the heart. If the amplitude is rejected, we are talking about pathological conditions.

The norm of the teeth on the ECG:

• R - should have a duration of no more than 0.11 s., height within 2 mm. If these indicators are violated, the doctor can make a conclusion about the deviation from the norm;
• Q - should not be higher than a quarter of the R wave, wider than 0.04 s. Special attention should be paid to this tooth, its deepening often indicates the development of a myocardial infarction in a person. In some cases, tooth distortion occurs in people with severe obesity;
• R - when deciphered, it can be traced in leads V5 and V6, its height should not exceed 2.6 mV;
• S is a special tooth for which there are no clear requirements. Its depth depends on many factors, for example, weight, sex, age, position of the patient's body, but when the tooth is too deep, we can talk about ventricular hypertrophy;
• T - must be at least a seventh of the R wave.

In some patients, after the T wave, a U wave appears on the cardiogram. This indicator is rarely taken into account when making a diagnosis; it does not have any clear norms.

Intervals and segments also have their normal rates. If these values ​​are violated, a specialist usually gives a referral to a person for further research.

Normal indicators:

• the ST segment should normally be located directly on the isoline;
• the QRS complex should not have a duration of more than 0.07 - 0.11 s. If these indicators are violated, various pathologies of the heart are usually diagnosed;
• the PQ interval should last from 0.12 milliseconds to 0.21 seconds;
• The QT interval is calculated taking into account the heart rate of a particular patient.

Important! The ST segment in leads V1 and V2 sometimes runs slightly above the isoline. The specialist must take into account this feature when deciphering the ECG.

Decryption features

To record a cardiogram, a person is attached to the body with special sensors that transmit electrical impulses to an electrocardiograph. In medical practice, these impulses and their paths are called leads. Basically, during the study, 6 main leads are used. They are denoted by the letters V from 1 to 6.

We can distinguish the following rules for decoding a cardiogram:

• In lead I, II, or III, you need to determine the location of the highest region of the R wave, and then measure the gap between the next two teeth. This number should be divided by two. This will help determine the regularity of the heart rate. If the gap between the R waves is the same, this indicates a normal contraction of the heart.
• After that, you need to make a measurement of each tooth and interval. Their rules are described in the article above.

Most modern devices automatically measure heart rate. With older models, this has to be done manually. It is important to consider that the ECG recording speed is usually 25-50 mm/s.

Heart rate is calculated using a special formula. At a cardiogram recording speed of 25 mm per second, the interval distance R - R should be multiplied by 0.04. In this case, the interval is indicated in millimeters.

At a speed of 50 mm per second, the interval R - R must be multiplied by 0.02.

For ECG analysis, 6 out of 12 leads are usually used, since the next 6 duplicate the previous ones.

Normal values ​​in children and adults

In medical practice, there is the concept of the norm of the electrocardiogram, which is characteristic of each age group. Due to the anatomical features of the body in newborns, children and adults, the study indicators are somewhat different. Let's consider them in more detail.

The ECG norms in adults can be seen in the figure.

A child's body is different from an adult's. Due to the fact that the organs and systems of the newborn are not fully formed, electrocardiography data may differ.

In children, the mass of the right ventricle of the heart prevails over the left ventricle. Newborns often have a high R wave in lead III and a deep S wave in lead I.

The ratio of the P wave to the R wave in adults is normally 1:8, in children the P wave is high, often more pointed, in relation to R is 1:3.

Due to the fact that the height of the R wave is directly related to the volume of the ventricles of the heart, its height is lower than in adults.

In newborns, the T wave is sometimes negative, it may be lower.

The PQ interval appears to be shortened, as in children the speed of impulse conduction along the conduction system of the heart is higher. This also explains the shorter QRS complex.

At preschool age, electrocardiogram parameters change. During this period, there is still a deviation of the electrical axis of the heart to the left. The mass of the ventricles increases, respectively, the ratio of the P wave to the R wave decreases. The contraction force of the ventricles increases, the R wave becomes higher, the rate of impulse transmission through the conduction system decreases, which leads to an increase in the QRS complex and the PQ interval.

In children, the following indicators should normally be observed:

Important! Only after 6 - 7 years, complexes, teeth and intervals acquire a value that is inherent in an adult.

What affects the accuracy of indicators

Sometimes the results of the cardiogram may be erroneous, differ from previous studies. Errors in results are often associated with many factors. These include:

• improperly attached electrodes. If the transducers are loose or move during an ECG, this can seriously affect the results of the exam. That is why the patient is recommended to lie still for the duration of the entire period of taking the electrocardiogram;
• foreign background. The accuracy of the results is often affected by extraneous devices in the room, especially when ECG is performed at home using mobile equipment;
• smoking, drinking alcohol. These factors affect blood circulation, thereby changing the parameters of the cardiogram;
• food intake. Another reason that affects blood circulation, respectively, on the correctness of the indicators;
• emotional experiences. If during the study the patient is worried, this may affect the heart rate and other indicators;
• Times of Day. When conducting a study at different times of the day, the indicators may also differ.

The specialist must necessarily take into account the above nuances when deciphering the ECG, if possible, they should be excluded.

Dangerous diagnoses

Diagnosis using electrical cardiography helps to identify many heart pathologies in a patient. Among them are arrhythmia, bradycardia, tachycardia and others.

Cardiac conduction disorder

Normally, the electrical impulse of the heart passes through the sinus node, but sometimes other pacemakers are also noted in a person. In this case, symptoms may be completely absent. Sometimes conduction disturbance is accompanied by fatigue, dizziness, weakness, jumps blood pressure and other signs.

With an asymptomatic course, special therapy is often not required, but the patient should undergo regular examinations. Many factors can negatively affect the work of the heart, which entails a violation of depolarization processes, a decrease in myocardial nutrition, the development of tumors and other complications.

Bradycardia

A common type of arrhythmia is bradycardia. The condition is accompanied by a decrease in heart rate below normal (less than 60 beats per minute). Sometimes such a rhythm is considered normal, depending on individual features organism, but more often bradycardia indicates the development of a particular pathology of the heart.

Features of the ECG in a patient with bradycardia can be seen in the figure.

There are several types of disease. With a latent course of bradycardia without obvious clinical signs therapy is usually not required. In patients with severe symptoms, the underlying pathology is treated, violating heart rate.

Extrasystole

Extrasystole is a condition accompanied by an untimely contraction of the cardiac departments. In a patient, extrasystole causes a feeling of a strong cardiac impulse, a feeling of cardiac arrest. In this case, the patient experiences fear, anxiety, panic. The prolonged course of this condition often leads to impaired blood flow, entails angina pectoris, fainting, paresis and other dangerous symptoms.

It is believed that with extrasystole no more than 5 times per hour there is no health hazard, but if attacks occur more often, appropriate treatment should be carried out.

sinus arrhythmia

The peculiarity of this violation lies in the fact that when the heart rate changes, the work of the organ remains coordinated, the sequence of contraction of the heart departments is normal. Sometimes in a healthy person on the ECG, sinus arrhythmia can be observed under the influence of factors such as food intake, excitement, physical activity. In this case, the patient does not have any symptoms. Arrhythmia is considered physiological.

In other situations, this violation may indicate pathologies such as coronary heart disease, myocardial infarction, myocarditis, cardiomyopathy, heart failure.

Patients may experience symptoms in the form of headaches, dizziness, nausea, heart rhythm disturbances, shortness of breath, chronic fatigue. Treatment of sinus arrhythmia involves getting rid of the underlying pathology.

The norm and signs of arrhythmia on the cardiogram

Important! In children, sinus arrhythmia often occurs during adolescence, may be associated with hormonal disorders.

Tachycardia

With tachycardia, the patient has an increase in heart rate, that is, more than 90 beats per minute. Normally, tachycardia develops in people after strong physical exertion, sometimes stress can become the cause of a heartbeat. AT normal condition the rhythm returns to normal without health consequences.

It is important to note that tachycardia is not an independent disease and does not occur on its own. This violation always acts as a secondary symptom of some pathology. This means that treatment should be directed at the disease that caused the increase in heart rate.

One of the forms coronary disease occurring in the acute stage - myocardial infarction. The condition is accompanied by the death of myocardial tissue, often leading to irreversible consequences.

The course of a heart attack usually takes place in several stages, each of which is characterized by a change in ECG parameters:

• the early stage lasts 6-7 days. In the first few hours, the cardiogram shows a high T wave. Over the next three days, the ST interval increases, the T wave descends. With timely treatment at this stage, it is possible to completely restore myocardial function;
• appearance of dead areas. The cardiogram shows an increase and expansion of the Q wave. Medical therapy here involves the restoration of areas with tissue necrosis;
• subacute period. This stage lasts from 10 to 30 days. Here the cardiogram begins to return to normal. In place of the affected areas of the myocardium, scars appear;
• scarring stage. Its duration takes from 30 days or more, accompanied by complete scarring of tissues. Sometimes patients have cardiosclerosis and other changes.

In the picture you can see the change in ECG parameters during the disease.

Cardiogram indicators in myocardial infarction at different stages

Electrocardiography is a complex, but at the same time very informative diagnostic method that has been used in medical practice for decades. It is quite difficult to independently decipher the graphic image obtained during the study. The interpretation of the data should be handled by a qualified physician. This will help to accurately diagnose, prescribe the appropriate treatment.

Electrocardiography (ECG) is an instrumental diagnostic method that allows you to evaluate the work of the heart and displays the quality of electrical impulses. The result is displayed on paper. This method has been used for a long time and remains the main one in diagnosing heart diseases. Its popularity lies in the fact that it is absolutely harmless, there are no contraindications to its use, and it also takes only a few minutes to carry it out.

Everyone needs to undergo a cardiogram, regardless of whether there are complaints or not. That is, an ECG is performed during a regular preventive examination once a year, also with certain complaints and symptoms in patients.

For example, one might note:

Also, when contacting specialists, patients over 40 years of age must be sent for an ECG. It should be noted that it is important to frequently undergo this study for patients with diabetes mellitus and rheumatism, quite often an ECG is performed during pregnancy and childbirth, and the work of the heart is also examined before various surgical operations.

If a heart attack or stroke has been previously transferred, then the ECG should be done frequently to monitor the performance of the heart.

ECG indicators

The cardiogram of a healthy person consists of such elements as:

• The teeth are a convex or concave element;
• A segment is a part of a line that is located between two teeth;
• An interval is an element consisting of a tooth and a segment.

ECG interpretation

teeth	Characteristic	Amplitude in mm	Duration
			seconds	millimeters
R	this tooth normally has a positive appearance. It shows excitation (depolarization) of the atria	1,5 – 2,5	0,1	5
P-Q interval (R)	This segment represents the spread of depolarization from the atria to the ventricles.	—	0,12 – 0,20	6-10
Q	Normally, this tooth looks like a negative one. Indicates the beginning of the process of excitation of the ventricles	—	0,03	1,5
R	Normally, the tooth looks positive. It is the main element of ventricular depolarization	VFI - up to 20 V 1-6 - up to 25	—	—
S	This is a negative prong. It shows the final stage of depolarization	no more than 20	—	—
QRS	This is a ventricular complex, it reflects the entire process of RV and LV depolarization.	—	up to 0.12	until 6
T	This wave is positive in I, II, III, aVL, aVF and negative in aVR. It shows the process of repolarization, that is, the fading	VF1 - up to 6 V 1-6 - up to 17	0,16 — 0,24	8 – 12

ECG interpretation plan

There is a certain scheme by which the doctor deciphers the results of the ECG. Namely, the analysis of 4 main indicators is carried out:

Regularity and heart rate

In order to assess the regularity, that is, the correctness of the rhythm, the doctor evaluates R-R duration, which should be between successive cycles. Namely, in a healthy person, the duration should be the same, the difference can be within 10%. All situations that go beyond this rule are diagnosed as an abnormal or irregular heart rhythm.

With the correct rhythm, to calculate the heart rate, you need to divide the duration of the R-R interval by 60 (seconds).

If the rhythm is incorrect, then the doctor considers how many ventricular complexes have appeared in a certain amount of time. And thus calculates the frequency of the rhythm.

Source of rhythm

When analyzing the excitation source, it is estimated how the pulse propagates along the PP and LP. This is established by the appearance of the P wave. In the normal state, it is positive, rounded, located in front of the QRS. In pathological conditions, this tooth has a pointed shape, and it can also be forked.

In atrial rhythm, P may be negative (II, III), and QRS is unchanged. If the rhythms originate from the AV node, then the P wave may not appear, that is, merge with the ventricular complex. And also, if the impulse first reaches the ventricles and then to the atria, then the P wave is negative after the QRS complex. The complex is not changed.

If a ventricular rhythm is manifested, then P with QRS has no connection, while the complex is expanded and deformed.

In order to evaluate the conduction system, the doctor must calculate:

If the indicators of the duration of the teeth and intervals increase, it means that the passage of the impulse is slowed down in the lead.

Electrical axis of the heart

You can calculate the position of the EOS graphically. For this, the algebraic sum of the amplitudes of all elements of the QRS complex in leads I and III is calculated. These leads are located in the frontal plane. The resulting indicator is plotted on the corresponding axis (positive or negative) and in the corresponding assignment on the conditional coordinate system.

Electrical axis of the heart

You can also use another method. This determines the angle. These measurements are carried out according to 2 principles. The first is that the maximum value of the algebraic sum of the QRS complex is recorded in the lead, which corresponds to the location of the EOS. The mean value is plotted in the same lead. The second principle is that RS with zero algebraic sum is recorded in a lead that is perpendicular to the EOS.

Determination of the rotation of the heart around the longitudinal axis, which conditionally passes through the upper part of the heart and its base, consists in determining the configuration of the ventricular complex in the chest leads. This is because these axes are horizontal. The QRS complex in lead V6 is assessed to determine rotation.

Conduction disorder

Conduction disorders are blockades that can manifest themselves at different stages of the conduction system. This violation can manifest itself in 3 degrees. 1 - this is when the impulses pass, but with a delay. 2 - at this stage, only a part of the impulses is carried out. 3 is complete blockade, while the impulse does not pass at all.

On the electrocardiogram, grade 1 rarely manifests itself.

heart block

With sinoauricular blockade of the 2nd degree, after a contraction, a pause may occur, which takes 2 cycles in duration. That is, the full PQRST complex falls out.

Atrioventricular block. At grade 1, PQ slows down, the duration of this interval can increase up to 0.2 seconds. And the ventricular QRS complex does not change at the same time, it can be deformed if the conductivity slows down in all the legs of the His at the same time.

In grade 2 AV block, the P wave appears regularly, but there is no QRS complex behind it (the PQ interval is also absent). The ventricular complex appears with regularity once, after 2-3 P waves. This means that the number of atrial contractions is much greater than the ventricular contractions.

Heart block on EKG

3 degree AV blockade on the ECG looks like a separation of the P wave and the QRS complex, that is, there is no PQ interval.

If the proximal form is manifested, then the QRS is not changed, and in the distal form, its expansion and deformation appear.

reading teeth

Prong P - this element indicates the depolarization of PP and LP. Normally R is positive.

The Q wave reflects depolarization of the interventricular septum. This element is negative. Its normal size is considered to be ¼ of the R wave, its duration is 0.3 seconds. If it is increased, then this may indicate diseases of the myocardium.

R wave - this element shows the depolarization of the apex of the heart. Reading this wave provides information about the activity of the ventricular walls. The R wave should be the same in all leads, if this is not the case, then this may mean the presence of RV or LV hypertrophy.

The S wave is negative. Its size is about 2 mm. The S wave shows the final process of RV and LV depolarization.

The T wave reflects the repolarization of the ventricles, that is, the process of their extinction. It has a positive appearance, but in the VR lead it is negative. If this tooth is changed, then this may indicate the presence of hyperkalemia or hypokalemia.

The PQ interval is an element that consists of the end of P and the beginning of Q. It shows the complete process of atrial depolarization and the propagation of the impulse to the AV node and along the bundle of His. PQ duration is 0.12-0.18 seconds.

The QT interval is estimated by calculating it according to the formula, that is, a fixed coefficient is multiplied by the duration of the R-R interval. For men, the coefficient becomes 0.37, and for women - 0.40.

ECG norm in adults

It should be noted that during an ECG, the heart rate becomes 60-90 beats per minute. The duration of the R-R intervals is the same, the deviation can be within 10%. Norms for adults:

An electrocardiogram is the first indicator of the state of the heart. It reflects all the problems of the human cardiovascular system, makes it possible to identify ailments at an early stage in order to take the necessary treatment. But in order to correctly diagnose, the cardiogram must be correctly interpreted.

What is a cardiogram

Deciphering an ECG requires a clear understanding of what this test is all about. An electrocardiogram schematically displays the electrical activity of the heart muscle on paper or electronic media. It is recorded on special calibrated paper. The length of the horizontal axis of the square (the smallest division) is 1 mm, in time it is 0.04 seconds, respectively, large blocks of 5 mm are equal to 0.2 seconds. The black marks at the top represent intervals of three seconds. A vertical line consisting of two blocks is equal to one millivolt - this is a unit of electrical voltage, a thousandth of a volt. To understand what is at stake, it is worth looking at the photo of the ECG transcript.

The cardiogram displays 12 leads: the first half comes from the limbs, and the second - chest. They depend on the location of the electrodes on the human body, so it is very important to place them correctly. These leads reflect the activity of different parts of the myocardium. The electrodes on the body are placed accordingly.

The propagation of an impulse through the heart on the cardiogram is displayed by intervals, segments and teeth. The latter are denoted in Latin letters: P, Q, R, S, T, U. The R wave is always negative, it displays indicators for the myocardium, Q and S are positive, they show the propagation of the impulse along the interventricular septum. As for the interpretation of the T and U waves, everything depends on their shape, amplitude and sign. The first reflects myocardial repolarization, and the value of the second for diagnosing does not play a special role. The normal interpretation of the ECG provides that all indicators must be calculated to a hundredth of a second, otherwise they can be misinterpreted.

What indicators are considered optimal

To effectively decipher the ECG, you need to study the indicators of the norm. First of all, you should pay attention to the heart rate. Normally, it should be sinus. This implies that the P waves must have a constant shape, the distance between R-R indicators and R-R - be the same, and the number of contractions - 60-80 per minute.

The electrical axis of the heart is a display of the ventricular excitation vector from an impulse, it is considered according to special medical tables, so deciphering an ECG for beginners may seem very difficult. EOS deviations are determined by the alpha angle. If the axis is in the normal position, the angle value is 50-70 degrees. It is worth paying attention: the R wave should be higher than the S. The intervals of the teeth show how the electrical impulse passes between the compartments of the heart. Each of them has specific indicators of the norm.

1. Group Width Q-R-S teeth under normal conditions is 60-100 ms.
2. The Q-T wave group displays the duration of the ventricular contraction. The norm is 390-450 ms.
3. For the Q wave, the optimal length is 0.04 s, and the depth is no more than 3 mm.
4. The S-tooth must not exceed a height of 20 mm.
5. The norm for the T wave is that in leads I and II it should go up, and in lead aVR it should have a negative indicator.

Identification of abnormalities and diseases

If you deal with the indicators of the norm, when deciphering the ECG, any pathology can be detected independently. Let's start with heart rate. If the electrical excitation does not start from the sinus node, this is an indicator of an arrhythmia. Depending on the branch of the heart in which depolarization begins, tachycardia (acceleration of the rhythm) or bradycardia (deceleration) is diagnosed. Another important indicator deviations - abnormal teeth and intervals.

1. Prolongation of the interval between the Q and T waves indicates myocarditis, rheumatism, sclerosis, or coronary disease. When Q values ​​do not meet the norm, this signals myocardial pathologies.


2. If the R wave is not displayed in all leads, this indicates that ventricular hypertrophy is possible.
3. Deviations in the ST segment indicate myocardial ischemia.
4. A T wave that is out of range may indicate hypokalemia or hyperkalemia.
5. The expansion of the P wave, especially twice, indicates an atrioventricular block.
6. A sharp rise in the ST segment means that the patient is at risk of acute heart attack or pericarditis, and its descent indicates myocardial ischemia or that the person is taking cardiac glycosides.

This or that position of the electrical axis of the heart may indicate various diseases. When the EOS is horizontal or tilted to the left, we can talk about hypertension in the patient. If the axis deviates to the right, it is possible that the person has chronic lung disease. The doctor should be concerned if, within a short time, the electrical axis suddenly changed position. The peculiarity of the EOS is that its performance may depend on various factors. For example, the vertical position is often found in thin people, and the horizontal position is common in full people.

A cardiogram can indicate a number of diseases. But do not rush to diagnose yourself. It is very difficult to interpret the ECG for beginners, because not all indicators can be calculated independently. It is better to contact a professional who will interpret the cardiogram correctly and be able to make accurate diagnoses.

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Basic Rules

When examining the results of the examination of the patient, doctors pay attention to such components of the ECG as:

• teeth;
• intervals;
• Segments.

There are strict normal parameters for each line on the ECG tape, the slightest deviation from which may indicate violations in the work of the heart.

ECG analysis

The entire set of ECG lines is examined and measured mathematically, after which the doctor can determine some parameters of the heart muscle and its conduction system: heart rate, heart rate, pacemaker, conduction, electrical axis of the heart.

To date, all these indicators are investigated by high-precision electrocardiographs.

Sinus rhythm of the heart

This is a parameter that reflects the rhythm of heart contractions that occur under the influence of the sinus node (normal). It shows the coherence of the work of all parts of the heart, the sequence of processes of tension and relaxation of the heart muscle.

The rhythm is very easy to identify by the tallest R waves: if the distance between them is the same throughout the entire recording or deviates by no more than 10%, then the patient does not suffer from arrhythmia.

heart rate

The number of beats per minute can be determined not only by counting the pulse, but also by the ECG. To do this, you need to know the speed at which the ECG was recorded (usually 25, 50 or 100mm / s), as well as the distance between the highest teeth (from one peak to another).

By multiplying the recording time of one mm by length of segment R-R you can get your heart rate. Normally, its performance ranges from 60 to 80 beats per minute.

Source of excitation

The autonomic nervous system of the heart is designed in such a way that the process of contraction depends on the accumulation of nerve cells in one of the zones of the heart. Normally, this is the sinus node, the impulses from which diverge throughout nervous system hearts.

In some cases, other nodes (atrial, ventricular, atrioventricular) can take on the role of the pacemaker. This can be determined by examining the P wave is inconspicuous, located just above the isoline.

Conductivity

This is a criterion showing the process of momentum transfer. Normally, impulses are transmitted sequentially from one pacemaker to another, without changing the order.

Electric axis

An indicator based on the process of excitation of the ventricles. Mathematical analysis of Q, R, S waves in leads I and III allows you to calculate a certain resulting vector of their excitation. This is necessary to establish the functioning of the branches of the His bundle.

The obtained angle of inclination of the axis of the heart is estimated by the value: 50-70° normal, 70-90° deviation to the right, 50-0° deviation to the left.

Teeth, segments and intervals

Teeth - ECG sections lying above the isoline, their meaning is as follows:

• P- reflects the processes of contraction and relaxation of the atria.
• Q, S- reflect the processes of excitation of the interventricular septum.
• R- the process of excitation of the ventricles.
• T- the process of relaxation of the ventricles.

Intervals are sections of the ECG lying on the isoline.

• PQ- reflects the propagation time of the impulse from the atria to the ventricles.

Segments - sections of the ECG, including an interval and a wave.

• QRST- the duration of the contraction of the ventricles.
• ST- the time of complete excitation of the ventricles.
• TP is the time of electrical diastole of the heart.

Norm in men and women

The decoding of the ECG of the heart and the norms of indicators in adults are presented in this table:

Healthy Childhood Outcomes

Deciphering the results of ECG measurements in children and their norm in this table:

Dangerous diagnoses

What dangerous conditions can be determined by the ECG readings during decoding?

Extrasystole

This phenomenon characterized by irregular heartbeat. A person feels a temporary increase in the frequency of contractions, followed by a pause. It is associated with the activation of other pacemakers, sending along with the sinus node an additional burst of impulses, which leads to an extraordinary contraction.

Arrhythmia

Characterized change in the frequency of sinus rhythm when pulses arrive at different frequencies. Only 30% of these arrhythmias require treatment, because can lead to more serious illnesses.

In other cases, this may be a manifestation of physical activity, a change in hormonal levels, the result of a fever and does not threaten health.

Bradycardia

It occurs when the sinus node is weakened, unable to generate impulses with the proper frequency, as a result of which the heart rate also slows down, up to 30-45 beats per minute.

Tachycardia

The opposite phenomenon, characterized by an increase in heart rate over 90 beats per minute. In some cases, temporary tachycardia occurs under the influence of strong physical exertion and emotional stress, as well as during illnesses associated with fever.

Conduction disorder

In addition to the sinus node, there are other underlying pacemakers of the second and third orders. Normally, they conduct impulses from the first-order pacemaker. But if their functions weaken, a person may feel weakness, dizziness caused by depression of the heart.

It is also possible to lower blood pressure, because. the ventricles will contract less frequently or arrhythmically.

Why there might be differences in performance

In some cases, when re-analyzing the ECG, deviations from previously obtained results are revealed. With what it can be connected?

• different time of day. Usually, an ECG is recommended to be done in the morning or afternoon, when the body has not yet had time to be influenced by stress factors.
• Loads. It is very important that the patient is calm while recording the ECG. The release of hormones can increase heart rate and distort performance. In addition, before the examination, it is also not recommended to engage in heavy physical labor.
• meal. Digestive processes affect blood circulation, and alcohol, tobacco and caffeine can affect heart rate and pressure.
• electrodes. Improper overlap or accidental shifting can seriously change the performance. Therefore, it is important not to move during the recording and degrease the skin in the area where the electrodes are applied (the use of creams and other skin products before the examination is highly undesirable).
• Background. Sometimes other devices can interfere with the operation of the electrocardiograph.

Additional examination methods

Halter

Method long-term study of the work of the heart, made possible by a portable compact tape recorder that is capable of recording results on magnetic tape. The method is especially good when it is necessary to investigate recurrent pathologies, their frequency and time of occurrence.

Treadmill

Unlike a conventional ECG recorded at rest, this method is based on the analysis of the results after physical activity . Most often, this is used to assess the risk of possible pathologies not detected on a standard ECG, as well as when prescribing a course of rehabilitation for patients who have had a heart attack.

Phonocardiography

Allows analyze heart sounds and murmurs. Their duration, frequency and time of occurrence correlate with the phases of cardiac activity, which makes it possible to assess the functioning of the valves, the risks of developing endocarditis and rheumatic heart disease.

A standard ECG is a graphic representation of the work of all parts of the heart. Its accuracy can be affected by many factors, so doctor's advice should be followed.

The examination reveals most of the pathologies of the cardiovascular system, however, additional tests may be required for an accurate diagnosis.

Finally, we suggest watching a video course on decoding “ECG for everyone”:

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What is an ECG, how is the procedure

The principle of obtaining an ECG is very simple. We are talking about the fact that sensors are attached to the skin of the patient, which record the electrical impulses that accompany the beating of the heart. Recording is done on a piece of paper. A competent doctor can tell a lot about the patient's health from this diagram.

It depicts cyclical changes in the corresponding electrical impulses. It is important to note that this diagnostic method is not absolutely accurate and exhaustive. It can be considered, rather, as a basis for the main conclusions.

What exactly is shown in the ECG?

Suppose you need to take an electrocardiogram. How to do it right? Do I need to be a specialist in order to carry out this procedure, or if all the necessary rules are carefully followed, even a non-specialist can carry out the procedure? Let's try to answer these questions.

Interestingly, the electrocardiogram is used not only in the treatment of cardiac patients, but also in a number of other cases:

• This takes place not only during various medical examinations, but also for the diagnosis of those diseases that are not directly related to the heart, but can create complications in it.
• Also, when using medical preparations, which have a strong effect on the body, often check the health of the cardiovascular system in this way to prevent possible consequences taking such medications.
  In such cases, it is customary to check not only before, but also after the therapeutic course is completed.

The procedure itself is not very complicated. Its total duration does not exceed ten minutes. The room temperature must not be too low. At the same time, the room must be ventilated. Compliance with this and similar rules is very important for such a procedure. This is due to the fact that any change in the patient's physical condition will be reflected in the electrocardiogram.

Here are some other requirements:

1. Before starting the procedure, the patient must be given rest. Its duration should be at least a quarter of an hour.
2. During the reading procedure, the patient should lie on his back.
3. During work, he should have even breathing.
4. You also need to take into account the time of eating. Everything should be done either on an empty stomach or not earlier than two hours after the last meal. This reception should not be plentiful.
5. Of course, on the day of the procedure, it is not allowed to take any sedative or tonic drugs. Also, do not drink coffee or tea or other similar drinks. If the patient smokes, then he should refrain from this habit for at least an hour before the procedure.

Diagnostic technique including
It includes the attachment of four electrodes to the hands and ankles and the installation of six suction cups on the patient's chest.

Do it in the following order. Each electrode has a specific color. Put a damp cloth under them. This is done both to increase conductivity and to improve the adhesion of the electrode to the skin surface.

When installing suction cups on the chest, the skin is usually decontaminated with alcohol solution. The diagram will display several types of teeth that have a different shape.

To carry out diagnostics, it is enough to record data for no longer than four consecutive cycles.

So, in what cases does it make sense to go to the doctor and do a cardiogram?

There are several main options:

• This should be done if you clearly feel discomfort in the chest.
• With shortness of breath, although it may look familiar, it makes sense to see a doctor for an ECG.
• If you are overweight, then you are undoubtedly at risk for heart disease. It is recommended to do an electrocardiogram regularly.
• The presence of chronic and severe stress in your life is a danger not only to your heart, but also to other systems of the human body. An ECG in such a case is a matter of vital importance.
• There is such chronic illness like tachycardia. If you suffer from it, then the ECG should be done regularly.
• Hypertension is considered by many as a possible step towards a heart attack. If at this stage you regularly diagnose using an ECG, then your chances of recovering will increase dramatically.
• Before surgical operation It is important for the doctor to be sure. That your heart can handle it. An ECG may be done to check.

How often is it necessary to resort to such a procedure? This is usually determined by the attending physician. However, if you are over forty, then it makes sense to carry out this procedure annually. If you are much older, then you should do an ECG at least once a quarter.

What does the ECG show

Let's see what we can see on the electrocardiogram:

1. First of all, she will tell in detail about all the features of the rhythm of the heartbeat. In particular, this will allow you to track the increase in heart rate or weak heartbeat. The diagram shows in what rhythm and with what force the patient's heart beats.
2. Another important advantage is that the ECG is able to show various pathologies that are inherent in the heart. This is due to the fact that any, say, tissue necrosis will conduct electrical impulses differently than healthy tissue. Such features will also help to identify those who are not yet sick, but have a tendency to do so.
3. There is an ECG under stress. This is useful in cases where a relatively healthy person wants to assess the health of their heart.

Principles for decoding indicators

A cardiogram is not one, but several different graphs. Since several electrodes are attached to the patient, electrical impulses can in principle be measured between each pair of them. In practice, the ECG contains twelve graphs. The doctor evaluates the shape and frequency of the teeth, and also considers the ratio of electrical signals on various graphs.

Each disease corresponds to specific signs on the ECG graphs. If they are determined, then this makes it possible to make the correct diagnosis to the patient. The norm and violations in the interpretation of the ECG are very important. Each indicator requires the most careful attention. A reliable result occurs when the analysis is carried out accurately and reliably.

reading teeth

There are five different types of waveforms on an ECG. They are designated in Latin letters: S, P, T, Q and R. Each of them characterizes the work of one of the sections of the heart.

Different types of intervals and segments are also taken into account. They represent the distance between certain types of teeth and also have their own letter designations.

Also, the analysis considers the QRS complex (it is also called the QRS interval).

In more detail, the elements of the ECG are shown in the figure given here. This is a kind of ECG decoding table.
First, the heart rate is assessed. As you know, it is usually 60-80 cuts per second.

How the doctor analyzes the results

The study of the electrocardiogram occurs in several successive stages:

1. At this stage, the doctor must calculate and analyze the intervals. The doctor examines the QT - interval. If there is an elongation of this segment, then this indicates, in particular, coronary heart disease, if we are talking about shortening, then we can talk about hypercalcemia.
2. After that, an indicator such as the electrical axis of the heart (EOS) is determined. This is done using a height-based calculation. various types teeth on an electrocardiogram.
3. After that, the complex is considered. We are talking about a tooth of the R type and its nearest sections of the graph on both sides.
4. Next is the interval. It is believed that for a normal heart, it should be in the midline.
5. After that, based on the studied data, a final cardiological conclusion is given.

• P - normally should be positive, shows the presence of bioelectricity in the atria;
• The Q wave is normally negative, it refers to the interventricular septum;
• R - characterizes the electrical potential in the ventricular myocardium;
• The S wave - in a normal situation, it is negative, shows the final process of electricity in the ventricles, normally such a tooth will be lower than the R wave;
• T - must be positive, here we are talking about the recovery process of biopotential in the heart.
• The heart rate should be between 60 and 80 per minute. If it goes beyond these boundaries, then this indicates violations in the work of the heart.
• QT - the interval is normal for an adult is 390-450 milliseconds.
• The width of the QRS interval should be approximately 120 milliseconds.

Possible errors in the result

Despite its obvious advantages, this procedure also has certain disadvantages:

Pathologies in the interpretation of the ECG can be determined according to the available descriptions of various variants of cardiograms. There are detailed tables that will help determine the type of pathology detected. To increase the reliability of the result, the cardiogram should be combined with other diagnostic methods.

Cost of the procedure

If we talk about prices in Moscow, then they are approximately in the range from 650 to 2300 rubles. Let's not forget that, when receiving a cardiogram, its analysis by a qualified doctor and the quality of the medical equipment itself are of great importance.

In St. Petersburg, the average price is about the same as in Moscow. ECG price with decoding is approximately 1500 rubles for this procedure.

There is also a service to call such a specialist at home. In Moscow, this service can be provided for 1500 rubles, in Khabarovsk - for 900 rubles, and in Saratov it can be done for 750 rubles.

Conclusion

An ECG is an important means of diagnosing your cardiovascular system. She has a lot to say about her. It makes sense to regularly, at least once every two years, seek an ECG from a doctor.

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ECG interpretation

Any electrocardiogram displays the work of the heart (its electrical potential during contractions and relaxations) in 12 curves recorded in 12 leads. These curves differ from each other, as they show the passage of an electrical impulse through different parts of the heart, for example, the first is the anterior surface of the heart, the third is the back. To record an ECG in 12 leads, special electrodes are attached to the patient's body in specific places and in a certain sequence.

How to decipher the cardiogram of the heart: general principles

The main elements of the electrocardiographic curve are:

ECG analysis

Having received an electrocardiogram in his hands, the doctor begins to evaluate it in the following sequence:

1. It determines whether the heart beats rhythmically, that is, whether the rhythm is correct. To do this, he measures the intervals between the R waves, they should be the same everywhere, if not, this is already the wrong rhythm.
2. Calculates the rate at which the heart beats (HR). This is easy to do, knowing the ECG recording speed and counting the number of millimeter cells between adjacent R waves. Normally, the heart rate should not go beyond 60-90 beats. per minute.
3. According to specific features (mainly by the P wave), it determines the source of excitation in the heart. Normally, this is the sinus node, that is, in a healthy person, sinus rhythm is considered normal. Atrial, atrioventricular and ventricular rhythms indicate pathology.
4. Assesses the conduction of the heart by the duration of the teeth and segments. For each of them there are indicators of the norm.
5. Determines the electrical axis of the heart (EOS). For very thin people, a more vertical position of the EOS is characteristic, for full people it is more horizontal. With pathology, the axis shifts sharply to the right or left.
6. Analyzes teeth, segments and intervals in detail. The doctor writes down their duration on the cardiogram by hand in seconds (this is an incomprehensible set of Latin letters and numbers on the ECG). Modern electrocardiographs automatically analyze these indicators and immediately provide measurement results, which simplifies the work of the doctor.
7. Gives a conclusion. It necessarily indicates the correctness of the rhythm, the source of excitation, heart rate, characterizes the EOS, and also highlights specific pathological syndromes (rhythm disturbance, conduction disturbance, the presence of overload of individual parts of the heart and myocardial damage), if any.

Examples of electrocardiographic findings

In a healthy person, the ECG conclusion may look like this: sinus rhythm with a heart rate of 70 beats. in min. EOS in the normal position, no pathological changes were detected.

Also, for some people, a variant of the norm can be considered sinus tachycardia(acceleration of heart rate) or bradycardia (slow heart rate). In elderly people, quite often, the conclusion may indicate the presence of moderate diffuse or metabolic changes in the myocardium. These conditions are not critical and after receiving appropriate treatment and correction of the patient's nutrition, they mostly always disappear.

In addition, in conclusion, we can talk about a non-specific change in the ST-T interval. This means that the changes are not indicative and it is impossible to determine their cause only by the ECG. Another fairly common condition that can be diagnosed by a cardiogram is a violation of repolarization processes, that is, a violation of the recovery of the ventricular myocardium after excitation. This change can be caused by serious illnesses heart, as well as chronic infections, hormonal imbalance and other causes that the doctor will subsequently look for.

Prognostically unfavorable conclusions are considered, in which there is data on the presence of myocardial ischemia, hypertrophy of the heart, rhythm and conduction disturbances.

Deciphering the ECG in children

The whole principle of deciphering cardiograms is the same as in adults, but due to the physiological and anatomical features of the child's heart, there are differences in the interpretation normal indicators. This applies primarily to heart rate, since up to 5 years in children it can exceed 100 beats. per minute.

Also, sinus or respiratory arrhythmia (increased heart rate on inspiration and decrease on expiration) can be recorded in babies without any pathology. In addition, the characteristics of some teeth and intervals differ from those of adults. For example, a child may have an incomplete blockade of part of the conduction system of the heart - the right leg of the bundle of His. All these features are taken into account by pediatric cardiologists when they make a conclusion on the ECG.

Features of the ECG during pregnancy

The body of a pregnant woman goes through various processes of adaptation to a new situation. Certain changes are also taking place cardiovascular system therefore, the ECG of expectant mothers may differ slightly from the results of a study of the heart of a healthy adult. First of all, in the later stages there is a slight horizontal deviation of the EOS, caused by a change in the relative placement of the internal organs and the growing uterus.

In addition, expectant mothers may have a slight sinus tachycardia and signs of overload of individual parts of the heart. These changes are associated with an increase in blood volume in the body and usually disappear after childbirth. However, their discovery cannot be left without detailed consideration and a more in-depth examination of the woman.

Deciphering the ECG, the norm of indicators

Deciphering the ECG - business knowledgeable doctor. With this method of functional diagnostics, the following is evaluated:

• heart rhythm - the state of the generators of electrical impulses and the state of the heart system that conducts these impulses
• the state of the heart muscle itself (myocardium). the presence or absence of its inflammation, damage, thickening, oxygen starvation, electrolyte imbalance

However, modern patients often have access to their medical documents, in particular, to electrocardiography films on which medical reports are written. With their diversity, these records can bring to panic disorder even the most balanced, but ignorant person. Indeed, often the patient does not know for certain how dangerous for life and health what is written on the back of the ECG film by the hand of a functional diagnostician, and there are still a few days before an appointment with a therapist or cardiologist.

To reduce the intensity of passions, we immediately warn readers that with no serious diagnosis (myocardial infarction, acute rhythm disturbances), the functional diagnostician of the patient will not let the patient out of the office, but at least send him for a consultation with a specialist colleague right there. About the rest of the "secrets of the Open" in this article. In all unclear cases of pathological changes on the ECG, ECG control, daily monitoring (Holter), ECHO cardioscopy (ultrasound of the heart) and stress tests (treadmill, bicycle ergometry) are prescribed.

Numbers and Latin letters in ECG decoding

PQ- (0.12-0.2 s) - time of atrioventricular conduction. Most often, it lengthens against the background of AV blockade. Shortened in CLC and WPW syndromes.

P - (0.1s) height 0.25-2.5 mm describes atrial contractions. Can talk about their hypertrophy.

QRS - (0.06-0.1s) - ventricular complex

QT - (no more than 0.45 s) lengthens with oxygen starvation (myocardial ischemia, infarction) and the threat of rhythm disturbances.

RR - the distance between the apexes of the ventricular complexes reflects the regularity of heart contractions and makes it possible to calculate the heart rate.

The decoding of the ECG in children is shown in Fig. 3

Options for describing the heart rate

Sinus rhythm

This is the most common inscription found on the ECG. And, if nothing else is added and the frequency (HR) is indicated from 60 to 90 beats per minute (for example, heart rate 68`) - this is the most successful option, indicating that the heart works like a clock. This is the rhythm set by the sinus node (the main pacemaker that generates electrical impulses that cause the heart to contract). At the same time, sinus rhythm implies well-being, both in the state of this node, and the health of the conduction system of the heart. The absence of other records denies pathological changes in the heart muscle and means that the ECG is normal. In addition to sinus rhythm, it can be atrial, atrioventricular or ventricular, indicating that the rhythm is set by the cells in these parts of the heart and is considered pathological.

This is a variant of the norm in young people and children. This is a rhythm in which impulses exit the sinus node, but the intervals between heartbeats are different. This may be due to physiological changes (respiratory arrhythmia, when heart contractions slow down on exhalation). Approximately 30% of sinus arrhythmias require observation by a cardiologist, as they are threatened by the development of more serious rhythm disturbances. These are arrhythmias after rheumatic fever. Against the background of myocarditis or after it, against the background of infectious diseases, heart defects and in persons with a burdened heredity for arrhythmias.

These are rhythmic contractions of the heart with a frequency of less than 50 per minute. In healthy people, bradycardia occurs, for example, during sleep. Also, bradycardia is often seen in professional athletes. Pathological bradycardia may indicate sick sinus syndrome. At the same time, bradycardia is more pronounced (heart rate from 45 to 35 beats per minute on average) and is observed at any time of the day. When bradycardia causes pauses in heart contractions of up to 3 seconds during the day and about 5 seconds at night, leads to disruptions in the supply of oxygen to tissues and manifests itself, for example, by fainting, an operation is indicated to install a heart pacemaker, which replaces the sinus node, imposing a normal rhythm of contractions on the heart.

Sinus tachycardia

Heart rate more than 90 per minute - is divided into physiological and pathological. In healthy people, sinus tachycardia is accompanied by physical and emotional stress, drinking coffee, sometimes strong tea or alcohol (especially energy drinks). It is short-lived and after an episode of tachycardia, the heart rate returns to normal in a short period of time after the cessation of the load. With pathological tachycardia, palpitations disturb the patient at rest. Its causes are temperature rises, infections, blood loss, dehydration, thyrotoxicosis, anemia, cardiomyopathy. Treat the underlying disease. Sinus tachycardia is stopped only with a heart attack or acute coronary syndrome.

Extrasystole

These are rhythm disturbances, in which foci outside the sinus rhythm give extraordinary heart contractions, after which there is a pause doubled in length, called a compensatory one. In general, heartbeats are perceived by the patient as uneven, rapid or slow, sometimes chaotic. Most of all, failures in the heart rhythm are disturbing. There may be discomfort in the chest in the form of jolts, tingling, feelings of fear and emptiness in the abdomen.

Not all extrasystoles are dangerous to health. Most of them do not lead to significant circulatory disorders and do not threaten either life or health. They can be functional (against the background of panic attacks, cardioneurosis, hormonal disruptions), organic (with IHD, heart defects, myocardial dystrophy or cardiopathy, myocarditis). They can also lead to intoxication and heart surgery. Depending on the place of occurrence, extrasystoles are divided into atrial, ventricular and antrioventricular (arising in a node on the border between the atria and ventricles).

• Single extrasystoles are most often rare (less than 5 per hour). They are usually functional and do not interfere with the normal blood supply.
• Paired extrasystoles of two accompany a certain number of normal contractions. Such a rhythm disturbance often indicates pathology and requires additional examination (Holter monitoring).
• Allorhythmias are more complex types of extrasystoles. If every second contraction is an extrasystole, it is bigymenia, if every third is trigynemia, and every fourth is quadrihymenia.

It is customary to divide ventricular extrasystoles into five classes (according to Laun). They are evaluated during daily ECG monitoring, since the indicators of a conventional ECG in a few minutes may not show anything.

• Class 1 - single rare extrasystoles with a frequency of up to 60 per hour, emanating from one focus (monotopic)
• 2 - frequent monotopic more than 5 per minute
• 3 - frequent polymorphic (of different shapes) polytopic (from different foci)
• 4a - paired, 4b - group (trigymenia), episodes of paroxysmal tachycardia
• 5 - early extrasystoles

The higher the class, the more serious the violations, although today even grades 3 and 4 do not always require drug treatment. In general, if there are less than 200 ventricular extrasystoles per day, they should be classified as functional and not worry about them. With more frequent, ECHO of the COP is indicated, sometimes - MRI of the heart. They do not treat extrasystole, but the disease that leads to it.

Paroxysmal tachycardia

In general, paroxysm is an attack. Paroxysmal acceleration of the rhythm can last from several minutes to several days. In this case, the intervals between heartbeats will be the same, and the rhythm will increase over 100 per minute (on average from 120 to 250). There are supraventricular and ventricular forms of tachycardia. The basis of this pathology is the abnormal circulation of an electrical impulse in the conduction system of the heart. Such a pathology is subject to treatment. From home remedies to eliminate an attack:

• breath holding
• increased forced cough
• face immersion in cold water

WPW syndrome

Wolff-Parkinson-White syndrome is a type of paroxysmal supraventricular tachycardia. Named after the names of the authors who described it. At the heart of the appearance of tachycardia is the presence between the atria and ventricles of an additional nerve bundle, through which a faster impulse passes than from the main pacemaker.

As a result, an extraordinary contraction of the heart muscle occurs. The syndrome requires conservative or surgical treatment(with ineffectiveness or intolerance of antiarrhythmic tablets, with episodes of atrial fibrillation, with concomitant heart defects).

CLC - Syndrome (Clerk-Levy-Christesco)

It is similar in mechanism to WPW and is characterized by an earlier excitation of the ventricles compared to the norm due to an additional bundle along which the nerve impulse travels. The congenital syndrome is manifested by attacks of rapid heartbeats.

Atrial fibrillation

It can be in the form of an attack or a permanent form. It manifests itself in the form of flutter or atrial fibrillation.

Atrial fibrillation

Atrial fibrillation

When the heart flickers, it contracts completely irregularly (intervals between contractions of very different durations). This is due to the fact that the rhythm is not set by the sinus node, but by other atrial cells.

It turns out a frequency of 350 to 700 beats per minute. There is simply no full-fledged atrial contraction; the contracting muscle fibers do not provide effective filling of the ventricles with blood.

As a result, the release of blood by the heart worsens and organs and tissues suffer from oxygen starvation. Another name for atrial fibrillation is atrial fibrillation. Not all atrial contractions reach the ventricles of the heart, so the heart rate (and pulse) will either be below normal (bradysystole with a frequency of less than 60), or normal (normosystole from 60 to 90), or above normal (tachysystole more than 90 beats per minute). ).

An attack of atrial fibrillation is difficult to miss.

• It usually starts with a strong heartbeat.
• It develops as a series of absolutely non-rhythmic heartbeats with a high or normal frequency.
• The condition is accompanied by weakness, sweating, dizziness.
• The fear of death is very pronounced.
• There may be shortness of breath, general arousal.
• Sometimes there is a loss of consciousness.
• The attack ends with the normalization of the rhythm and the urge to urinate, in which a large amount of urine leaves.

To stop the attack, they use reflex methods, drugs in the form of tablets or injections, or resort to cardioversion (stimulation of the heart with an electric defibrillator). If an attack of atrial fibrillation is not eliminated within two days, the risks of thrombotic complications (thromboembolism) increase pulmonary artery, stroke).

With a constant form of heartbeat flicker (when the rhythm is not restored either against the background of drugs or against the background of electrical stimulation of the heart), they become a more familiar companion of patients and are felt only with tachysystole (rapid irregular heartbeats). The main task in detecting ECG signs tachysystole of a permanent form of atrial fibrillation is a decrease in the rhythm to normosystole without trying to make it rhythmic.

Examples of recordings on ECG films:

• atrial fibrillation, tachysystolic variant, heart rate 160 in '.
• Atrial fibrillation, normosystolic variant, heart rate 64 in '.

Atrial fibrillation can develop in the program of coronary heart disease, against the background of thyrotoxicosis, organic heart defects, with diabetes, syndrome of weakness of the sinus node, with intoxication (most often with alcohol).

atrial flutter

These are frequent (more than 200 per minute) regular atrial contractions and the same regular, but more rare ventricular contractions. In general, flutter is more common in acute form and is better tolerated than flicker, since circulatory disorders are less pronounced. Trembling develops when:

• organic heart disease (cardiomyopathies, heart failure)
• after heart surgery
• on the background of obstructive pulmonary disease
• it almost never occurs in healthy people.

Clinically, flutter is manifested by rapid rhythmic heartbeat and pulse, swelling of the jugular veins, shortness of breath, sweating and weakness.

Conduction disorders

Normally, having formed in the sinus node, electrical excitation goes through the conduction system, experiencing a physiological delay of a fraction of a second in the atrioventricular node. On its way, the impulse stimulates the atria and ventricles, which pump blood, to contract. If in some part of the conduction system the impulse lingers longer than the prescribed time, then the excitation to the underlying sections will come later, which means that the normal pumping work of the heart muscle will be disrupted. Conduction disorders are called blockades. They may occur as functional disorders, but are more often the result of drugs or alcohol intoxication and organic heart disease. Depending on the level at which they arise, there are several types of them.

Sinoatrial blockade

When the exit of the impulse from the sinus node is difficult. In fact, this leads to a syndrome of weakness of the sinus node, a decrease in contractions to severe bradycardia, impaired blood supply to the periphery, shortness of breath, weakness, dizziness and loss of consciousness. The second degree of this blockade is called the Samoilov-Wenckebach syndrome.

Atrioventricular block (AV block)

This is a delay in excitation in the atrioventricular node of more than the prescribed 0.09 seconds. There are three degrees of this type of blockade. The higher the degree, the less often the ventricles contract, the more severe the circulatory disorders.

• At the first delay allows each atrial contraction to maintain an adequate number of ventricular contractions.
• The second degree leaves part of the atrial contractions without ventricular contractions. It is described in terms of PQ prolongation and ventricular beat prolapse as Mobitz 1, 2, or 3.
• The third degree is also called a complete transverse block. The atria and ventricles begin to contract without interrelation.

In this case, the ventricles do not stop, because they obey the pacemakers from the underlying parts of the heart. If the first degree of blockade may not manifest itself in any way and be detected only with an ECG, then the second is already characterized by sensations of periodic cardiac arrest, weakness, fatigue. With complete blockades, manifestations are added brain symptoms(dizziness, flies in the eyes). Morgagni-Adams-Stokes attacks may develop (when the ventricles escape from all pacemakers) with loss of consciousness and even convulsions.

Conduction disturbance within the ventricles

In the ventricles to the muscle cells, the electrical signal propagates through such elements of the conduction system as the trunk of the bundle of His, its legs (left and right) and the branches of the legs. Blockades can occur at any of these levels, which is also reflected in the ECG. In this case, instead of being covered by excitation at the same time, one of the ventricles is delayed, since the signal to it goes around the blocked area.

In addition to the place of origin, a complete or incomplete blockade is distinguished, as well as permanent and non-permanent. The causes of intraventricular blockades are similar to other conduction disorders (IHD, myo- and endocarditis, cardiomyopathies, heart defects, arterial hypertension, fibrosis, heart tumors). Also, the intake of antiarthmic drugs, an increase in potassium in the blood plasma, acidosis, and oxygen starvation also affect.

• The most common is the blockade of the anteroposterior branch of the left leg of the bundle of His (BPVLNPG).
• In second place is the blockade of the right leg (RBNB). This blockade is usually not accompanied by heart disease.
• Blockade of the left leg of the His bundle is more typical for myocardial lesions. At the same time, complete blockade (PBBBB) is worse than incomplete blockade (NBLBBB). It sometimes has to be distinguished from the WPW syndrome.
• The blockade of the posterior inferior branch of the left leg of the bundle of His can be in persons with a narrow and elongated or deformed chest. From pathological conditions it is more characteristic of overloads of the right ventricle (with pulmonary embolism or heart defects).

The clinic of blockades at the levels of the bundle of His is not expressed. The picture of the main cardiac pathology comes first.

• Bailey's syndrome - two-beam blockade (of the right leg and posterior branch of the left leg of the bundle of His).

Myocardial hypertrophy

With chronic overloads (pressure, volume), the heart muscle in some areas begins to thicken, and the heart chambers stretch. On the ECG, such changes are usually described as hypertrophy.

• Left ventricular hypertrophy (LVH) is typical for arterial hypertension, cardiomyopathy, and a number of heart defects. But even in normal athletes, obese patients and people engaged in heavy physical labor, there may be signs of LVH.
• Right ventricular hypertrophy is an undoubted sign of increased pressure in the pulmonary circulation system. Chronic cor pulmonale, obstructive pulmonary disease, cardiac defects (pulmonary stenosis, Fallot's tetralogy, ventricular septal defect) lead to HPZh.
• Left atrial hypertrophy (HLH) - with mitral and aortic stenosis or insufficiency, hypertension, cardiomyopathy, after myocarditis.
• Right atrial hypertrophy (RAH) - with cor pulmonale, tricuspid valve defects, chest deformities, pulmonary pathologies and pulmonary embolism.
• Indirect signs of ventricular hypertrophy are the deviation of the electrical axis of the heart (EOC) to the right or left. The left type of EOS is its deviation to the left, that is, LVH, the right type is LVH.
• Systolic overload is also evidence of hypertrophy of the heart. Less commonly, this is evidence of ischemia (in the presence of angina pain).

Changes in myocardial contractility and nutrition

Syndrome of early repolarization of the ventricles

Most often, it is a variant of the norm, especially for athletes and people with congenitally high body weight. Sometimes associated with myocardial hypertrophy. Refers to the peculiarities of the passage of electrolytes (potassium) through the membranes of cardiocytes and the characteristics of the proteins from which the membranes are built. It is considered a risk factor for sudden cardiac arrest, but it does not give a clinic and most often remains without consequences.

Moderate or severe diffuse changes in the myocardium

This is evidence of myocardial malnutrition as a result of dystrophy, inflammation (myocarditis) or cardiosclerosis. Also, reversible diffuse changes accompany disturbances in the water and electrolyte balance (with vomiting or diarrhea), taking medications (diuretics), and heavy physical exertion.

This is a sign of deterioration in myocardial nutrition without pronounced oxygen starvation, for example, in violation of the balance of electrolytes or against the background of dyshormonal conditions.

Acute ischemia, ischemic changes, T wave changes, ST depression, low T

This describes the reversible changes associated with oxygen starvation of the myocardium (ischemia). It can be either stable angina or unstable, acute coronary syndrome. In addition to the presence of the changes themselves, their location is also described (for example, subendocardial ischemia). A distinctive feature of such changes is their reversibility. In any case, such changes require comparison of this ECG with old films, and if a heart attack is suspected, rapid troponin tests for myocardial damage or coronary angiography should be performed. Depending on the variant of coronary heart disease, anti-ischemic treatment is selected.

Developed heart attack

It is usually described as:

• by stages. acute (up to 3 days), acute (up to 3 weeks), subacute (up to 3 months), cicatricial (lifelong after a heart attack)
• by volume. transmural (large focal), subendocardial (small focal)
• according to the location of the infarction. are anterior and anterior-septal, basal, lateral, inferior (posterior diaphragmatic), circular apical, posterior basal and right ventricular.

All the variety of syndromes and specific ECG changes, the difference in indicators for adults and children, the abundance of causes leading to the same type ECG changes, do not allow a non-specialist to interpret even the ready-made conclusion of a functional diagnostician. It is much more reasonable, having an ECG result in hand, to visit a cardiologist in a timely manner and receive competent recommendations for further diagnosis or treatment of your problem, significantly reducing the risks of emergency cardiac conditions.

How to decipher the ECG of the heart?

An electrocardiographic study is the simplest, but very informative method for studying the work of a patient's heart. The result of this procedure is an ECG. Incomprehensible lines on a piece of paper contain a lot of information about the state and functioning of the main organ in the human body. Deciphering ECG indicators is quite simple. The main thing is to know some of the secrets and features of this procedure, as well as the norms of all indicators.

Exactly 12 curves are recorded on the ECG. Each of them tells about the work of each specific part of the heart. So, the first curve is the anterior surface of the heart muscle, and the third line is its posterior surface. To record the cardiogram of all 12 leads, electrodes are attached to the patient's body. The specialist does this sequentially, installing them in specific places.

Decryption principles

Each curve on the cardiogram graph has its own elements:

• Teeth, which are bulges directed down or up. All of them are denoted by Latin capital letters. "P" shows the work of the heart atria. "T" is the restorative capacity of the myocardium.
• Segments are the distance between several ascending or descending teeth in the neighborhood. Doctors are especially interested in indicators of such segments as ST, as well as PQ.
• An interval is a gap that includes both a segment and a tooth.

Each specific ECG element shows a certain process that occurs directly in the heart. According to their width, height and other parameters, the doctor has the ability to correctly decipher the data received.

How are the results analyzed?

As soon as the specialist receives the electrocardiogram in his hands, its decoding begins. This is done in a certain strict sequence:

1. The correct rhythm is determined by the intervals between the "R"-teeth. They must be equal. Otherwise, it can be concluded that the heart rhythm is incorrect.
2. With the help of an ECG, you can determine the heart rate. To do this, you need to know the speed at which the indicators were recorded. Additionally, you will also need to count the number of cells between the two R waves. The norm is from 60 to 90 beats per minute.
3. The source of excitation in the heart muscle is determined by a number of specific features. This will be told, among other things, by the evaluation of the parameters of the “P” wave. The norm implies that the source is the sinus node. Therefore, a healthy person always has a sinus rhythm. If there is a ventricular, atrial or any other rhythm, then this indicates the presence of pathology.
4. The specialist evaluates the conduction of the heart. This happens according to the duration of each segment and tooth.
5. The electrical axis of the heart, if it shifts to the left or right sharply enough, may also indicate problems with the cardiovascular system.
6. Each tooth, interval and segment is analyzed individually and in detail. Modern ECG devices immediately automatically issue indicators of all measurements. This greatly simplifies the work of the doctor.
7. Finally, the specialist makes a conclusion. It indicates the decoding of the cardiogram. If any pathological syndromes were found, they must be indicated there.

Normal indicators of adults

The norm of all indicators of the cardiogram is determined by analyzing the position of the teeth. But the rhythm of the heart is always measured by the distance between the highest teeth "R" - "R". Normally they should be equal. The maximum difference can be no more than 10%. Otherwise, it will no longer be the norm, which should be within 60-80 pulsations per minute. If sinus rhythm is more frequent, then the patient has tachycardia. On the contrary, a slow sinus rhythm indicates a disease called bradycardia.

The P-QRS-T intervals will tell you about the passage of the impulse directly through all the cardiac departments. The norm is an indicator from 120 to 200 ms. On the graph, it looks like 3-5 squares.

By measuring the width from the Q wave to the S wave, one can get an idea of ​​the excitation of the ventricles of the heart. If this is the norm, then the width will be 60-100 ms.

The duration of ventricular contraction can be determined by measuring the Q-T interval. The norm is 390-450 ms. If it is somewhat longer, a diagnosis can be made: rheumatism, ischemia, atherosclerosis. If the interval is shortened, we can talk about hypercalcemia.

What do teeth mean?

Without fail, when deciphering the ECG, it is necessary to monitor the height of all teeth. It can indicate the presence of serious pathologies of the heart:

• The Q wave is an indicator of excitation of the left cardiac septum. The norm is a quarter of the length of the R wave. If it is exceeded, there is a possibility of necrotic pathology of the myocardium;
• The S wave is an indicator of the excitation of those partitions that are in the basal layers of the ventricles. The norm in this case is 20 mm in height. If there are deviations, then this indicates coronary disease.
• The R wave in the ECG tells about the activity of the walls of all the ventricles of the heart. It is fixed in all ECG curves. If there is no activity somewhere, then it makes sense to suspect ventricular hypertrophy.
• The T wave appears in the I and II lines, as directed upwards. But in the VR curve it is always negative. When the T wave on the ECG is too high and sharp, the doctor suspects hyperkalemia. If it is long and flat, then there is a possibility of developing hypokalemia.

Normal pediatric electrocardiogram readings

AT childhood the norm of ECG indicators may differ slightly than the characteristics of an adult:

1. The heart rate of babies under 3 years old is about 110 pulsations per minute, and at the age of 3-5 years - 100 beats. This indicator in adolescents is already lower - 60-90 pulsations.
2. The norm of QRS readings is 0.6-0.1 s.
3. The P wave should normally not be higher than 0.1 s.
4. The electrical axis of the heart in children should remain unchanged.
5. The rhythm is only sinus.
6. On the ECG, the Q-T interval e can exceed 0.4 s, and P-Q should be 0.2 s.

Sinus heart rate in the decoding of the cardiogram is expressed as a function of heart rate on respiration. This means that the heart muscle is contracting normally. In this case, the pulsation is 60-80 beats per minute.

Why are the scores different?

Often, patients are faced with a situation where their ECG readings are different. What is it connected with? To get the most accurate results, there are many factors to consider:

1. Distortions in recording an ECG may be due to technical problems. For example, with incorrect gluing of results. And many Roman numerals look the same both upside down and upside down. It happens that the graph is cut incorrectly or the first or last tooth is lost.
2. Preliminary preparation for the procedure is important. On the day of the ECG, you should not have a hearty breakfast, it is even advisable to completely refuse it. You will have to stop drinking liquids, including coffee and tea. After all, they stimulate the heart rate. As a result, the results are skewed. It is best to take a shower beforehand, but you do not need to apply any body products. Finally, during the procedure you need to relax as much as possible.
3. The incorrect position of the electrodes cannot be ruled out.

It is best to check your heart on an electrocardiograph. He will help to carry out the procedure as accurately and accurately as possible. And in order to confirm the diagnosis indicated by the results of the ECG, the doctor will always prescribe additional studies.