Means in ecg. Electrocardiography (ECG)

An electrocardiograph (ECG) is a device that allows you to assess cardiac activity, as well as diagnose the state of this organ. When passing the examination, the doctor receives data in the form of a curve. How to read an ECG trace? What types of teeth are there? What ECG changes are visible? Why do doctors need this diagnostic method? What does the ECG show? These are far from all the questions of interest to people who are faced with electrocardiography. First you need to find out how the heart works..

The human heart consists of two atria and two ventricles. Left-hand side the heart is more developed than the right one, since it bears a heavy load. It is this ventricle that most often suffers. Despite the difference in size, both sides of the heart should work stably and harmoniously.

Learning to read the electrocardiogram on your own

How to read the ECG correctly? This is not as difficult to do as it might seem at first glance. First, you should look at the cardiogram. It is printed on special paper with cells, and two types of cells are clearly visible: large and small.

The ECG conclusion is read from these cells. teeth, cells? These are the main parameters of the cardiogram. Let's try to learn how to read an ECG from scratch.

The value of the cells (cells)

There are two types of cells on the paper for printing the examination result: large and small. They all consist of vertical and horizontal guides. Vertical is voltage and horizontal is time.

Large squares are made up of 25 small squares. Each small cell is equal to 1 mm and corresponds to 0.04 seconds in the horizontal direction. Large squares are 5 mm and 0.2 seconds. In the vertical direction, a centimeter of the strip is equal to 1 mV of voltage.

Barbs

There are five teeth in total. Each of them on the graph displays the work of the heart.

1. P - Ideally, this wave should be positive within the range of 0.12 to two seconds.
2. Q - negative wave, shows the state of the interventricular septum.
3. R - displays the state of the ventricular myocardium.
4. S - negative wave, shows the completion of processes in the ventricles.
5. T - positive wave, shows the restoration of potential in the heart.

Everything ECG teeth have their own reading characteristics.

P wave

All the teeth of the electrocardiogram are of some importance for the correct diagnosis.

The very first wave of the graph is called P. It denotes the time between heartbeats. To measure it, it is best to select the beginning and end of the prong and then count the number of small cells. Normally, the P wave should be between 0.12 and two seconds.

However, measuring this indicator in only one area will not give accurate results. To make sure that the heartbeat is even, it is necessary to determine the interval of the P wave in all areas of the electrocardiogram.

R wave

Knowing how to read an ECG in an easy way, you can understand if there are heart pathologies. The next important prong the graph is R. It is easy to find - it is the highest peak on the graph. This will be the positive prong. Its highest part is noted on the R cardiogram, and its lower parts are Q and S.

The QRS complex is called the ventricular, or sinus, QRS complex. In a healthy person, the sinus rhythm on the ECG is narrow, high. The figure clearly shows the ECG R waves, they are the highest:

Between these peaks, the number of large squares indicates This indicator is calculated using the following formula:

300 / number of large squares = heart rate.

For example, there are four full squares between the peaks, then the calculation will look like this:

300/4 = 75 heart beats per minute.

Sometimes on the cardiogram there is an elongation of the QRS complex for more than 0.12 s, which indicates a blockade of the His bundle.

PQ spacing

PQ is the interval from the P wave to the Q wave. It corresponds to the time of conduction of excitation through the atria to the ventricular myocardium. PQ interval rate in different ages different. Usually it is 0.12-0.2 s.

The interval increases with age. So, in children under 15 years of age, PQ can reach 0.16 s. Between the ages of 15 and 18, the PQ increases to 0.18 s. In adults, this figure is equal to a fifth of a second (0.2).

With an extension of the interval to 0.22 s, one speaks of bradycardia.

QT wave spacing

If this complex is longer, then it is possible to assume ischemic heart disease, myocarditis or rheumatism. With the shortened type, hypercalcemia may be noted.

ST interval

Normally, this indicator is located at the level of the midline, but may be two cells higher than it. This segment shows the process of restoration of the depolarization of the heart muscle.

In rare cases, the indicator can rise three cells above the midline.

Norm

The decoding of the cardiogram should normally look like this:

• Segments Q and S must always be below the centerline, that is, negative.
• The R and T waves should normally be above the midline, that is, they will be positive.
• The QRS complex should be no wider than 0.12 s.
• The heart rate should be between 60 and 85 beats per minute.
• There should be sinus rhythm on the ECG.
• The R should be higher than the S wave.

ECG for pathologies: sinus arrhythmia

And how to read an ECG for various pathologies? One of the most common heart diseases is sinus rhythm disturbance. It can be pathological and physiological. The latter type is usually diagnosed in people involved in sports with neuroses.

With sinus arrhythmia, the cardiogram looks like this: sinus rhythms are preserved, fluctuations in R-R intervals are observed, but during a breath hold the graph is even.

In pathological arrhythmias, the preservation of the sinus impulse is observed constantly, regardless of the delay in breathing, while wave-like changes are observed at all intervals of the R-R.

Manifestation of a heart attack on an ECG

When myocardial infarction occurs, changes in the ECG are pronounced. Signs of pathology are:

• increase in heart rate;
• the ST segment is elevated;
• there is a fairly persistent depression in the ST leads;
• QRS complex increases.

In case of a heart attack, the main means of recognizing zones of necrosis of the heart muscle is a cardiogram. With its help, you can determine the depth of organ damage.

With a heart attack, the graph shows an increase in the ST segment, and the R wave will be lowered downward, giving the ST a shape reminiscent of a cat's back. Sometimes, with pathology, changes in the Q wave can be observed.

Ischemia

When it occurs, you can see in which part it is located.

• Location of ischemia at the anterior wall of the left ventricle. It is diagnosed with symmetrical pointed T-waves.
• Location at the epicardium of the left ventricle. The T-wave is pointed, symmetrical, and directed downward.
• Transmural type of left ventricular ischemia. T is pointed, negative, symmetrical.
• Ischemia in the left ventricular myocardium. T is smoothed, slightly raised up.
• The defeat of the heart is displayed by the state of the T wave.

Changes in the ventricles

The ECG shows changes in the ventricles. Most often they appear in the left ventricle. This type of cardiogram occurs in people with prolonged additional stress, for example, with obesity. With this pathology, the electric axis deviates to the left, against the background of which the S wave becomes higher than R.

Holter method

And how to learn to read an ECG, if it is not always clear which teeth and how they are located? In such cases, a continuous recording of the cardiogram is prescribed using a mobile device. It constantly records ECG data on a special tape.

This method of examination is necessary in cases where the classical ECG fails to identify pathologies. During Holter's diagnosis, a detailed diary must be kept, where the patient records all his actions: sleep, walks, sensations during activity, all activity, rest, symptoms of the disease.

Data registration usually takes place within 24 hours. However, there are times when it is necessary to take readings for up to three days.

ECG decoding schemes

1. Conductivity and heart rate are analyzed. For this, the regularity of heart contractions is assessed, the number of heart rates is calculated, and the conducting system is determined.
2. Axial rotations are revealed: they determine the position of the electric axis in the frontal plane; around the transverse, longitudinal axis.
3. The R wave is analyzed.
4. QRS-T is being analyzed. In this case, the state of the QRS complex, RS-T, T wave, as well as the Q-T interval is assessed.
5. A conclusion is made.

According to the duration of the R-R-cycle, they speak of the regularity and norm of the heart rate. When assessing the work of the heart, not one R-R interval is assessed, but everything. Normally, deviations within 10% of the norm are allowed. In other cases, the wrong (pathological) rhythm is determined.

To establish the pathology, the QRS complex and a certain period of time are taken. It counts how many times the segment is repeated. Then the same period of time is taken, but further on the cardiogram, it is counted again. If at equal intervals of time the number of QRS is the same, then this is the norm. At different amounts, pathology is assumed, while they are guided by the P waves. They must be positive and stand in front of the QRS complex. Throughout the graph, the P shape should be the same. This option speaks of the sinus rhythm of the heart.

With atrial rhythms, the P wave is negative. Behind it is the QRS segment. In some people, the P wave on the ECG may be absent, completely merging with the QRS, which indicates the pathology of the atria and ventricles, which the impulse reaches at the same time.

The ventricular rhythm is shown on the electrocardiogram as a deformed and dilated QRS. In this case, the connection between P and QRS is not visible. There are large distances between the R-waves.

Cardiac conduction

ECG is used to determine cardiac conduction. On the P wave, the atrial impulse is determined, normally this indicator should be 0.1 s. The P-QRS interval displays the total atrial conduction velocity. The rate of this indicator should be in the range of 0.12 to 0.2 s.

The QRS segment shows ventricular conduction, the normal range is from 0.08 to 0.09 s. With increasing intervals, cardiac conduction slows down.

What the ECG shows, patients do not need to know. A specialist should understand this. Only a doctor can correctly decipher the cardiogram and make the correct diagnosis, taking into account the degree of deformation of each individual tooth, segment.

The concept of "ECG" stands for "electrocardiogram". It is a graphical recording of the electrical impulses of the heart.

The human heart has its own pacemaker. The pacemaker is located directly in the right atrium. This place is called the sinus node. The impulse that comes from this node is called a sinus impulse (it will help to decipher what the ECG will show). It is this source of impulses that is located in the very heart and generates electrical impulses by itself. Then they are sent to the conducting system. Impulses in people who do not have cardiac pathology pass evenly along the cardiac conduction system. All these outgoing impulses are recorded and displayed on the cardiogram tape.

It follows from this that the ECG - electrocardiogram - is graphically recorded impulses of the cardiac system. Will ECG show heart problems? ? Of course it is great and quick way identify any heart disease... Moreover, the electrocardiogram is the most basic method in the diagnosis of pathology and different diseases hearts.

Created by the Englishman A. Waller in the seventies of the XIX century. Over the next 150 years, the apparatus that records the electrical activity of the heart has undergone changes and improvements. Although the principle of work has not changed.

Modern ambulance teams are necessarily supplied with portable ECG devices, with the help of which you can very quickly make an ECG, saving valuable time. An EKG can even diagnose a person. An ECG will show heart problems: from acute cardiac pathologies to In these cases, not a minute is to be lost, and therefore a cardiogram made on time can save a person's life.

Doctors of the ambulance teams themselves decipher the ECG tape and in case acute pathology, if the device shows a heart attack, then, turning on the siren, the patient is quickly taken to the clinic, where he will be immediately provided urgent help... But in case of problems, urgent hospitalization is not necessary, everything will depend on what the ECG shows.

In what cases is an electrocardiogram prescribed?

If a person has the symptoms described below, then the cardiologist sends him to an electrocardiogram:

• swelling of the legs;
• fainting;
• have shortness of breath;
• sternum pain, back pain, neck pain.

An ECG is necessarily assigned to pregnant women for examination, people in preparation for surgery, medical examination.

Also ECG results are required in case of a trip to a sanatorium or if you need permission for any sports activities.

For prevention and if a person has no complaints, doctors recommend taking an electrocardiogram once a year. This can often help diagnose asymptomatic heart disease.

What the ECG will show

On the tape itself, the cardiogram can show a set of waves, as well as decays. These teeth are designated in large Latin letters P, Q, R, S and T. When decoding, the cardiologist examines and deciphers the width, height of the teeth, their size and the intervals between them. According to these indicators, it is possible to determine general state muscles of the heart.

With the help of an electrocardiogram, various pathologies of the heart can be detected. Will an ECG show a heart attack? Of course, yes.

What determines the electrocardiogram

• Heart rate - HR.
• Rhythms of contractions of the heart.
• Heart attack.
• Arrhythmias.
• Ventricular hypertrophy.
• Ischemic and cardystrophic changes.

The most disappointing and serious diagnosis on an electrocardiogram is myocardial infarction. In diagnostics heart attacks ECG plays an important and even major role. With the help of a cardiogram, the zone of necrosis, localization and depth of lesions of the heart area are revealed. Also, when decoding the cardiogram tape, it is possible to recognize and distinguish acute myocardial infarction from aneurysm and past scars. Therefore, when undergoing a medical examination, it is imperative to do a cardiogram, because it is very important for a doctor to know what the ECG will show.

Most often, a heart attack is associated directly with the heart. But it is not so. A heart attack can occur in any organ. Happens (when the lung tissue partially or completely dies if there is a blockage of the arteries).

There is a cerebral infarction (in other words ischemic stroke) - the death of brain tissue, which can be caused by thrombosis or rupture of cerebral vessels. With a cerebral infarction, functions such as speech, physical movement, and sensitivity can be completely lost or disappear.

When a person has a heart attack, the death or necrosis of living tissue occurs in his body. The body loses tissue or part of an organ, as well as the functions performed by this organ.

Myocardial infarction is the death or ischemic necrosis of areas or areas of the heart muscle itself due to complete or partial loss of blood supply. Heart muscle cells begin to die about 20-30 minutes after blood flow stops. If a person has a myocardial infarction, blood circulation is impaired. One or more blood vessels at the same time fail. Most often, heart attacks occur due to blockage of blood vessels by blood clots (atherosclerotic plaques). The zone of spread of the infarction depends on the severity of the violation of the organ, for example, extensive myocardial infarction or microinfarction. Therefore, you should not immediately despair if the ECG shows a heart attack.

This becomes a threat to the work of the entire cardiovascular system of the body and threatens life. In the modern period, heart attacks are the main cause of death among the population of the developed countries of the world.

Heart attack symptoms

• Dizziness.
• Labored breathing.
• Pain in the neck, shoulder, which can radiate to the back, numbness.
• Cold sweat.
• Nausea, feeling of a full stomach.
• Constriction in the chest.
• Heartburn.
• Cough.
• Chronic fatigue.
• Loss of appetite.

The main signs of myocardial infarction

1. Intense pain in the region of the heart.
2. Pain that does not stop after taking nitroglycerin.
3. If the duration of the pain is more than 15 minutes.

Causes of a heart attack

1. Atherosclerosis.
2. Rheumatism.
3. Congenital heart defect.
4. Diabetes.
5. Smoking, obesity.
6. Arterial hypertension.
7. Vasculitis.
8. Increased blood viscosity (thrombosis).
9. Previously suffered heart attacks.
10. Severe coronary artery spasms (eg, with cocaine).
11. Age-related changes.

Also, the ECG allows you to identify other diseases, such as tachycardia, arrhythmia, ischemic disorders.

Arrhythmia

What to do if the ECG showed arrhythmia?

Arrhythmia can be characterized by numerous changes in the rate of heartbeat.

Arrhythmia is a condition in which there is an abnormality in the heart rhythm and heart rate. More often, this pathology is marked by a heartbeat failure; the patient has a rapid or slow heartbeat. An increase is observed during inhalation, and a decrease is observed during exhalation.

Angina pectoris

If the patient has bouts of pain under the sternum or to the left of it in the left arm, which can last for several seconds, and can last up to 20 minutes, then the ECG will show angina pectoris.

The pain is usually worse when lifting weights, heavy physical exertion, when going out into the cold, and can disappear at rest. Such pains are reduced within 3-5 minutes when taking nitroglycerin. The patient's skin turns pale and the pulse becomes uneven, which causes interruptions in the work of the heart.

Angina pectoris is one of the forms of the heart. Often it is quite difficult to diagnose angina pectoris, because such deviations can manifest themselves in other cardiac pathologies. Angina pectoris can further lead to heart attacks and strokes.

Tachycardia

Many people are very worried when they find out that the ECG showed tachycardia.

Tachycardia is an increase at rest. Heart rhythms with tachycardia can reach 100-150 beats per minute. Such a pathology can also occur in people, regardless of age, when lifting weights or with increased physical exertion, as well as with strong psycho-emotional arousal.

Still, tachycardia is considered more likely not a disease, but a symptom. But this is no less dangerous. If the heart begins to beat too quickly, then it cannot have time to fill with blood, which further leads to a decrease in the release of blood and a lack of oxygen in the body, as well as the heart muscle itself. If the tachycardia lasts more than a month, it can lead to further malfunction of the heart muscle and an increase in the size of the heart.

Symptoms of tachycardia

• Dizziness, fainting.
• Weakness.
• Dyspnea.
• Increased anxiety.
• Feeling of increased heart rate.
• Heart failure.
• Pain in the chest area.

The causes of tachycardia can be: ischemic disease heart, various infections, toxic effects, ischemic changes.

Conclusion

Now there are many different heart diseases that can be accompanied by excruciating and painful symptoms. Before starting their treatment, it is necessary to diagnose, find out the cause of the problem and, if possible, eliminate it.

Today, an electrocardiogram is the only effective method in diagnosing heart pathologies, which is also completely harmless and painless. This method is suitable for everyone - both children and adults, and is also affordable, effective and highly informative, which is very important in the conditions of modern life.

Cardiovascular diseases are one of the leading causes of death among the population worldwide. Over the past decades, this indicator has significantly decreased due to the emergence of more modern methods examination, treatment, and, of course, new drugs.

Electrocardiography (ECG) is a method of recording the electrical activity of the heart, one of the first methods of research, which long time remained practically the only one in this area of ​​medicine. About a century ago, in 1924, Willem Einthoven received Nobel prize in medicine, he designed an apparatus with which the ECG was recorded, named its teeth and determined the electrocardiographic signs of some heart diseases.

With the advent of more modern developments, many research methods lose their relevance, but this does not apply to electrocardiography. Even with the advent of imaging techniques (CT, etc.), the ECG for decades continues to be the most common, very informative, and in some places the only available method for examining the heart. Moreover, over the century of its existence, neither the device itself, nor the method of its use have changed significantly.

Indications and contraindications

Electrocardiography is a unique examination method that helps to make a diagnosis or becomes a starting point for drawing up a plan for further examination of a patient. In any case, the diagnosis and treatment of any heart disease begins with an ECG.

ECG is an absolutely safe and painless method of examination for people of all ages; there are no contraindications to conventional electrocardiography. The study takes only a few minutes and does not require any special training.

But there are so many indications for electrocardiography that it is simply impossible to list them all. The main ones are as follows:

• general examination during prophylactic medical examination or medical commission;
• assessment of the state of the heart in various diseases (, atherosclerosis, lung disease, etc.);
• differential diagnosis for chest pain and (often have a non-cardiac cause);
• suspicion of, as well as control of the course of this disease;
• diagnostics of cardiac arrhythmias (daily ECG monitoring by Holter);
• violation of electrolyte metabolism (hyper- or hypokalemia, etc.);
• drug overdose (for example, cardiac glycosides or antiarrhythmic drugs);
• diagnostics of extracardiac diseases (thromboembolism pulmonary artery) and etc.

The main advantage of ECG is that the study can be performed outside the hospital; many ambulances are equipped with electrocardiographs. This enables the doctor to detect myocardial infarction at the patient's home at its very beginning, when the damage to the heart muscle is just beginning and is partially reversible. After all, treatment in such cases begins even during the transportation of the patient to the hospital.

Even in cases where the ambulance is not equipped with this device and the ambulance doctor is not able to perform a study on prehospital stage, the first diagnostic method in the emergency room medical institution there will be an ECG.

ECG interpretation in adults

In most cases, cardiologists, therapists, emergency doctors work with electrocardiograms, but a specialist in this field is a functional diagnostics doctor. Decoding an ECG is a difficult task that is beyond the power of a person who does not have the appropriate qualifications.

Usually, on the ECG of a healthy person, five waves can be distinguished, which are recorded in a certain sequence: P, Q, R, S and T, sometimes a U wave is recorded (its nature is not exactly known today). Each of them reflects the electrical activity of the myocardium in different parts of the heart.

When registering an ECG, several complexes are usually recorded, corresponding to cardiac contractions. In a healthy person, all the teeth in these complexes are located at the same distance. The difference in the intervals between the complexes is indicative of.

In this case, in order to accurately establish the shape of the arrhythmia, Holter ECG monitoring may be required. With the help of a special small portable device, the cardiogram is recorded continuously for 1-7 days, after which the resulting record is processed using a computer program.

• The first P wave reflects the process of depolarization (coverage of excitation) of the atria. By its width, amplitude and shape, the doctor may suspect hypertrophy of these heart chambers, impaired conduction of the impulse through them, suggest that the patient has organ defects and other pathologies.
• The QRS complex reflects the process of coverage of the ventricles of the heart. Deformation of the complex shape, a sharp decrease or increase in its amplitude, the disappearance of one of the teeth can indicate a variety of diseases: myocardial infarction (using an ECG, you can establish its localization and age), scars, conduction disturbances (blockade of the bundle of His bundle), etc.
• The last T wave is determined by repolarization of the ventricles (relatively speaking, by relaxation), the deformation of this element may indicate electrolyte disturbances, ischemic changes and other pathologies of the heart.

Areas of the ECG connecting different teeth are called "segments". Normally, they lie on the isoline, or their deviation is not significant. There are intervals between the teeth (for example, PQ or QT), which reflect the travel time of an electrical impulse through the parts of the heart; in a healthy person, they have a certain duration. The lengthening or shortening of these intervals is also a significant diagnostic sign. Only a qualified doctor can see and evaluate all changes on the ECG.

In decoding an ECG, every millimeter is important, sometimes even half a millimeter is decisive in choosing treatment tactics... Very often, an experienced doctor can make an accurate diagnosis using an electrocardiogram without using additional research methods, and in some cases its informative value is superior to the data of other types of research. In fact, this is a screening method of examination in cardiology, which allows detecting or at least suspecting heart disease in the early stages. That is why the electrocardiogram will remain one of the most popular diagnostic methods in medicine for many years to come.

Which doctor to contact

For a referral for an ECG, you need to contact a therapist or cardiologist. The analysis of the cardiogram and the conclusion on it are given by the doctor of functional diagnostics. The ECG report itself is not a diagnosis and should be considered by the clinician in conjunction with other patient data.

Fundamentals of electrocardiography in educational video:

Video course "EKG under the power of everyone", lesson 1:

Video course "EKG is within the power of everyone", lesson 2.

An electrocardiogram is a very simple and informative method that allows you to study the work of a person's heart and determine the causes of pain in the heart. With the help of an ECG, you can assess the heart rate and the condition of the heart muscle itself. The result of an electrocardiographic study looks like seemingly incomprehensible lines on a piece of paper. Moreover, they contain information about the state and functioning of the heart. Decryption ECG indicators should be done by an experienced doctor, but if you know how to decipher the ECG, you can independently assess the work of your heart.

The ECG data on the work of the heart looks like alternating waves, flat intervals and segments. These elements are located on the isoline. It is necessary to understand what these elements mean:

• EKG waves are bulges that point down (negative) or up (positive). The P wave on the ECG means the work of the cardiac atria, and the T wave on the ECG reflects the regenerative capabilities of the myocardium;
• Segments on an ECG are the distance between several teeth that are next to each other. The most important segment indicators on the ECG are ST and PQ. The duration of the ST segment on the ECG is influenced by the pulse rate. The PQ segment on the ECG reflects the penetration of the biopotential to the ventricles through the ventricular node directly to the atrium;
• An ECG interval is an interval that includes both a segment and a wave. Roughly speaking, this is 1 prong with a piece of isoline. For diagnostics great importance have PQ and QT intervals.

In total, 12 curves are recorded on the cardiogram. When decoding an ECG, it is imperative to pay attention to the heart rate, electrical axis, interval conductivity, QRS complexes, ST segments and teeth.

To decipher the ECG, you need to know how much time fits into one cell. Standard indicators are as follows: a 1 mm cage is equal to 0.04 seconds at a speed of 25 mm / s.

The intervals between the R waves should be equal, this determines the rhythm of the human heart. By counting the number of cells between the R waves and knowing the recording rate of indicators, you can also determine the heart rate (HR). The heart rate rate when decoding the ECG is from 60 to 90 heart beats per minute. It is very simple to calculate the heart rate on the ECG. If the belt speed is 50mm / s, then HR = 600 / for the number of large squares.

By evaluating the P wave, you can determine the source of excitation in the heart muscle. Shows ECG decoding sinus rhythm - the norm for a healthy person.

It is also worth paying attention to the displacement of the electrical axis of the heart. If the shift is sharp, then this indicates problems with the cardiovascular system.

On the ECG, the decoding of the norm should look like this:

• The heart rate should be sinus;
• The normal heart rate is 60-90 beats / min;
• QT intervals - 390-450 ms.
• EOS - it is always calculated from the isoline. The height of the teeth is taken as a basis. The norm assumes that R exceeds S in height. If the ratio is reversed, the likelihood of ventricular disease is high;
• QRS - when studying this complex, pay attention to its width. Normally, it can reach 120 ms. There should also be no pathological Q;
• ST - the norm assumes being on the isoline. The T wave is directed upward, characterized by asymmetry.

The lengthening of the intervals may indicate atherosclerosis, myocardial infarction, etc. And with shortened intervals, the presence of hypercalcemia can be assumed.

Reading ECG waves.

• P - reflects the excitation of the right and left atrium, this wave should be positive. It consists of half excitation of the right atrium and half of excitation of the left atrium;
• Q - is responsible for the excitation of the interventricular septum. It is always negative. Its normal indicator is ¼ R at 0.3 s. An increase in the normal indicator indicates myocardial pathology;
• R - vector of excitation of the apex of the heart. It determines the activity of the walls of the ventricles. Must be determined at each lead. Otherwise, ventricular hypertrophy is assumed;
• S - negative wave, its height should be 20 mm. It is also worth paying attention to the ST segment. Its deviations indicate myocardial ischemia;
• T - usually in the first or second leads directed upwards, on VR it has a negative value. A change in the indicator indicates the presence of hyper- or hypokalemia.

The teeth of a normal human ECG: indicators in the table

Video

ECG interpretation - rhythms.

The rhythm in decoding the ECG is of great importance. The normal rhythm when decoding an ECG is sinus. And all the rest are pathological.

With sinus rhythm on the electrocardiogram in lead II, there is a P wave in front of each QRS complex, and it is always positive. In one lead, all P waves should be the same shape, length, and width.

With atrial rhythm, the P wave in the II and III leads is negative, but is present in front of each QRS complex.

Atrioventricular rhythms are characterized by the absence of P waves on cardiograms, or the appearance of this wave after the QRS complex, and not in front of it, as is normal. With this type of rhythm, the heart rate is low, ranging from 40 to 60 beats per minute.

The ventricular rhythm is characterized by an increase in the width of the QRS complex, which becomes large and rather intimidating. The P waves and the QRS complex are completely unrelated to each other. That is, there is no strict correct normal sequence - the P wave, followed by the QRS complex. The ventricular rate is characterized by a decrease in heart rate - less than 40 beats per minute.

ECG decoding in adults: the norm in the table

Analysis of the position of the teeth on the ECG and measuring the distance between the high R and R waves are cardiogram indicators that may indicate a normal ECG in adults.

The maximum difference between tall R and R waves can be 10%, ideally they should be equal. If the sinus rhythm is slow, then this indicates bradycardia, and if it is frequent, then the patient has tachycardia.

Table of indicators of the norm of the cardiogram in adults

In the cardiogram, deviations from the norm and specific syndromes can be indicated separately. This is indicated if the cardiogram is pathological. Violations and changes in the parameters of segments, intervals and teeth are also noted separately.

ECG norm in children.

ECG norm in a child it is quite different from the testimony of an adult and looks like this:

• The baby's heart rate is quite high. Up to 110 blows for children under 3 years old, up to 100 blows for children from 3 to 5 years old. 60 to 90 strokes for teens;
• The rhythm must be sinus;
• The normal indicator of the P wave in children is up to 0.1 s;
• the QRS complex can have values ​​of 0.6-0.1 s;
• PQ - may fluctuate within 0.2 s;
• QT up to 0.4 s;

ECG decoding is performed qualified specialist... This functional diagnostic method checks:

1. Heart rate: what is the state of the generators of electrical impulses and the cardiac systems conducting these impulses.
2. Heart muscle: its condition and performance, damage, inflammation and other pathological processes that could affect the condition of the heart.

Show all

Heartbeat

Patients collect the electrocardiogram along with its results. It is impossible to decipher it on your own. To read the diagram, you need a special medical education... No need to be nervous before meeting a functional diagnostician. At the reception, he will tell you all the risks of the diagnosis, appointing effective treatment... But if the patient is diagnosed serious illness, then you will need to consult a cardiologist.

When the ECG decoding has not given clear results, the doctor may prescribe additional studies:

• ECG control;
• Holter (monitoring the work of the heart throughout the day);
• Ultrasound of the heart muscle;
• Treadmill (test for heart performance during exercise).

The results of measurements using these studies are an accurate indicator of the work of the heart. If there are no malfunctions in the myocardium, the tests will have good performance.

On the ECG of a healthy person, there is an inscription "Sinus rhythm". If the frequency of beats per minute up to 90 is added to this inscription, the results are good, the heart works without interruption. Sinus rhythm is a measure of the rhythm of the sinus node, which is the main rhythm producer for regulating and generating electrical impulses with which the heart muscle contracts. The description of the electrocardiogram, which includes sinus rhythm, is a norm indicating the health of the sinus node and the heart muscle itself.



If the cardiogram has no other markings in its description, it indicates complete heart health. Sinus rhythm can be replaced by atrial, atrioventricular, or ventricular. These types of rhythms indicate that the contractions are carried out precisely by these parts of the heart, which is considered a pathology.



What is lipid profile and blood lipid spectrum - analysis decoding

What is sinus arrhythmia?

Sinus arrhythmia - frequent diagnosis in childhood and adolescence. It is characterized by different time intervals between the sinus contractions of the heart muscle. Experts say that this pathology can be caused by changes at the physiological level. Up to 40% of sinus arrhythmias should be monitored by a cardiologist. Patients should be examined and re-examined every 3-4 months. Such precautions will protect you as much as possible from the development of more serious heart diseases.



Sinus bradycardia is the rhythm of heart contractions up to 50 times per minute. This phenomenon is also possible in healthy people during sleep or in professional athletes. Bradycardia of a pathological nature can be a sign of sick sinus syndrome. This case implies severe bradycardia, reaching 35 heartbeats per minute. You can observe such a pathology all the time, and not just at night.

If the bradycardia consists of pauses between contractions of up to 3 seconds during the day and up to 5 seconds at night, oxygen supply to the tissues may be disrupted, which usually leads to fainting. Only a pacemaker of electrical origin, which is placed directly on the heart during surgery, will help to get rid of this problem. The installation takes place in place of the sinus node, which further allows the heart to work without interruption.

The causes of a poor cardiogram can be associated with sinus tachycardia, which is a heart rate that beats more than 90 times per minute. It is divided into physiological and pathological tachycardia. Healthy people may experience sinus tachycardia during physical and emotional stress, taking coffee or strong tea, alcoholic beverages and energy drinks. Sinus tachycardia after an active pastime is a brief manifestation. After the manifestation of an increased number of beats, the rhythm returns to its normal state for enough a short time after reducing the intensity of physical activity.



With tachycardia of a pathological nature, a rapid heartbeat worries the patient all the time. Heart palpitations can be caused by: fever, infection, blood loss, dehydration, anemia, and more. You need to treat the root cause causing tachycardia. Relief of sinus tachycardia occurs only in the case of myocardial infarction or acute coronary syndrome.



How is extrasystole manifested?

A specialist can determine this pathology immediately, since this is a change in rhythm, the nature of which is the foci behind the sinus rhythm. They give extra contractions of the heart muscle. After this process, a pause doubled in time appears, the name of which is compensatory. Patients believe that such a change in heartbeat occurs due to nervous stress. The rhythm can be both quickened and slowed down, sometimes chaotic. The patient himself may notice the dips arising in the rhythm of the heartbeat.

An example of decoding an ECG with extrasystole is an example with a pathology that is visible even to non-specialists. Some patients complain not only of changes in the rhythm, but also of unpleasant and pain in the chest area. They experience tremors, tingling sensations, a tight feeling of fear that rises in the abdomen.



Such manifestations are not always pathological and life-threatening.

Many types of extrasystoles do not inhibit blood circulation and do not reduce the efficiency of the heart.

Extrasystoles are divided into 2 types:

• functional (manifested against the background of panic and nerves);
• organic (if a person has heart defects, myocarditis and congenital problems with the cardiovascular system).

In 20% of cases, the cause of the disease is intoxication or surgery in the area of ​​the heart. A single manifestation of extrasystole occurs rarely (up to 5 times in 1 hour). Such dips are of a functional nature and are not an obstacle to normal blood supply. There are times when paired extrasystoles occur. They appear after a series of normal contractions. It is this rhythm that is an obstacle to the normal functioning of the heart muscle. For an accurate diagnosis of this manifestation, an additional ECG and Holter analysis is prescribed with a setting for a day.



The main classes of pathology

Extrasystoles also have the form of an allorhythmy. When an extrasystole appears on every second contraction, specialists diagnose bigeminia, on every third - trigeminia, on every fourth - quadrigeminia. According to Laum's classification, extrasystoles of a ventricular nature are divided into 5 classes, depending on the daily examination indicators:

1. 1. Isolated cases of manifestation of the disease up to 60 times every hour, united by one focus (monotopic).
2. 2. Permanent monotopic changes, manifested in more than 5-6 times every minute.
3. 3. Permanent polymorphic (have a different shape) and polytopic (have a different focus of origin) changes.
4. 4. Paired or group, accompanied by episodic attacks of paroxysmal tachycardia.
5. 5. Early manifestation of extrasystoles.

For treatment medications are not assigned. If the disease manifests itself less than 200 times a day (Holter monitoring will help to establish the exact number), extrasystoles are considered safe, so you should not worry about their manifestations. Regular examinations by a cardiologist are required every 3 months.

If the patient's electrocardiogram revealed pathological contractions more than 200 times every day, then additional examinations are prescribed. Specialists prescribe an ultrasound of the heart and magnetic resonance imaging (MRI) of the heart muscle. Treatment of the manifestation is specific and requires a special approach, since the therapy is not performed for extrasystoles, but for the root causes of their occurrence.



Paroxysmal tachycardia

Paroxysm is a manifestation of an attack. A similar process of increased heart rate can last for several hours or several days. An electrocardiogram displays the same intervals between muscle contractions. But the rhythm changes and can reach more than 100 beats in 1 minute (the average is 120-250 times).



Doctors distinguish supraventricular and ventricular types of tachycardia. The basis of this pathology lies in the abnormal circulation of an electrical impulse in cardiovascular system... You can get rid of this manifestation at home, but for a while: you need to hold your breath, start coughing hysterically, or dip your face in cold water... But such methods are ineffective. Therefore there is medical method for the treatment of paroxysmal tachycardia.

One of the varieties of supraventricular tachycardia is Wolff-Parkinson-White syndrome. The title includes the names of all the doctors who described it. The reason for this type of tachycardia is the appearance between the atria and the ventricles of an extra bundle of nerves, which conducts the rhythm faster than the main driver. As a result - the occurrence of one extra time of heart contraction. This pathology can be cured conservatively or surgically. The operation is prescribed only in case of low efficiency or allergy in the patient to the active components of the treatment, with atrial fibrillation or heart defects of a different nature.

Clerk-Levi-Christesco syndrome is a manifestation similar to the previous pathology, but it is characterized by earlier than normal stimulation of the ventricles with the help of an additional bundle through which a nerve impulse passes. The syndrome is a congenital pathology. If you decipher the cardiogram of the heart, its manifestation can be seen immediately by attacks of rapid heartbeat.



Atrial fibrillation

During fibrillation, irregular contractions of the heart muscle are observed with intervals of different length between contractions. This is explained by the fact that the rhythm is set not by the sinus node, but by other atrial cells. The frequency of contractions can even reach 700 beats in 1 minute. There is simply no full atrial contraction, it falls on the muscle fibers, which do not completely fill the ventricles with blood. The consequence of this process is the deterioration of the release of blood by the heart, which leads to oxygen starvation of organs and tissues of all body systems.

Atrial fibrillation has another name: atrial fibrillation. In fact, not all atrial contractions go directly to the ventricles. This leads to a decrease in the normal heart rate (bradystole, which has a frequency of less than 60 beats per minute). But the contraction of the heart can be normal (normosystole, 60-90 times per minute) and increased (tachysystole, more than 90 times per minute).



Determining atrial fibrillation on an electrocardiogram is easy, as attacks are hard to miss. The onset of an attack in 90% of cases is a strong push of the heart muscle. Further, a series of irregular heart oscillations develops with an increased or normal frequency. The patient's condition also worsens: he becomes weak, sweaty, dizzy. The patient wakes up with a pronounced fear of death. Shortness of breath and restlessness are possible. Loss of consciousness sometimes occurs. Reading the cardiogram at the end of the attack is also easy: the rhythm is normalized. But the patient has a strong urge to urinate, during which there is enough a large number of liquids.

The relief of the disease is carried out using reflex methods, drugs in the form of pills or injections. Less commonly, experts perform cardioversion - stimulation of the heart muscle with an electric defibrillator. If the attacks of ventricular fibrillation are not resolved within 2 days, complications may occur. Pulmonary embolism, stroke may occur.

A constant form of flicker that neither helps medications, nor electrostimulation of the heart, becomes commonplace in the patient's life and is felt only during tachysystole (increased heart rate). If the electrocardiogram revealed tachysystole and atrial fibrillation, then it is necessary to reduce the number of heart contractions to normal without trying to make them rhythmic. Atrial fibrillation can appear against the background of coronary heart disease, thyrotoxicosis, heart defects of different nature, diabetes mellitus, sick sinus syndrome, intoxication after alcohol poisoning.



Atrial flutter

Atrial flutter - constant and frequent contractions of the atria (more than 200 times per minute) and ventricles (less than 200 times). Flutter in 90% of cases has acute form, but it is much better and easier tolerated than fibrillation, since changes in blood circulation are less pronounced. The development of flutter is possible against the background of heart disease (cardiomyopathy, heart failure), after undergoing operations on the heart muscle. With obstructive pulmonary disease, it practically does not appear. It is easy to read an ECG for this disease, as it is manifested by frequent rhythmic heartbeats, swollen veins in the neck, shortness of breath, increased sweating and weakness.



In a normal state, electrical excitation is formed in the sinus node, which passes through the conductive system. It experiences a physiological delay for literally a split second in the area of ​​the atrioventricular node. The atria and ventricles, which pump blood, are stimulated by this impulse. When the impulse is delayed in some part of the system, it reaches later to other areas of the heart, which leads to disturbances in the normal operation of the pumping system. Changes in conductivity are called blockade.

The occurrence of blockages is a functional disorder. But the reason for their occurrence in 75% of cases is alcohol or drug intoxication and organic diseases of the heart muscle. There are several types of blockades:

1. 1. Sinoatrial block: it is difficult for the impulse to pass directly from the sinus node. Then this blockade develops into a syndrome of weakness of the sinus node, leads to a decrease in the number of contractions until the moment of a new blockade, a violation of the peripheral blood supply, shortness of breath, weakness, dizziness and loss of consciousness.
2. 2. The Samoilov-Wenckebach blockade is the second degree of sinoatrial blockade.
3. 3. Atrioventricular block is delayed excitation of the atrioventricular node for more than 0.09 seconds. There are 3 degrees of this type of blockade. With the most high degree diseases are often contracted ventricles. Therefore, at the highest stages, blood circulation disorders become more severe.

Violation of conduction in the ventricles

The electrical signal travels inside the ventricles to special cells from the muscle tissue. The propagation of this signal is carried out through such systems as the bundle of His, its legs and their branches. The cause of a bad cardiogram is the occurrence of disturbances in the conduction of the electrical signal. Experts easily diagnose this deviation from the norm on the ECG. At the same time, the diagram clearly shows that one of the ventricles is stimulated later than the second, because the signaling is made with a delay, passing along bypass paths due to blockade of the desired site.



The blockade is classified not only by the place of origin, but also by the type. There are complete and incomplete blockades, permanent and non-permanent. The root causes of blockages inside the ventricles are the same as in other diseases with poor conduction: coronary artery disease, cardiomyopathy, defects of a different nature, fibrosis, cancers on the heart. Consumption of antiarrhythmic drugs, an increase in the level of potassium in the blood, oxygen starvation, and more can affect the occurrence of the disease.

Most often, there is a blockage of the upper branch on the left pedicle of the bundle of His. The second place is taken by the blockade of the entire area of ​​the right leg. It does not arise from other heart diseases. Left leg blockade occurs when the myocardium is damaged by a number of diseases. The lower branch of the left leg suffers from pathological changes in the structure chest person. It can also occur with overloads of the right ventricle.