ECG infarction transcript. Decoding a heart attack by ecg

On an ECG with myocardial infarction (photo 1), doctors clearly see signs of cardiac tissue necrosis. A heart attack cardiogram is a reliable diagnostic method and allows you to determine the degree of heart damage.

ECG decoding for myocardial infarction

An electrocardiogram is a safe research method, and if a heart attack is suspected, it is simply irreplaceable. ECG in myocardial infarction is based on cardiac conduction disturbances, i.e. in certain areas of the cardiogram, the doctor will see abnormal changes that indicate a heart attack. To obtain reliable information, doctors use 12 electrodes when taking data. Cardiogram for myocardial infarction (photo 1) registers such changes based on two facts:

• with a heart attack in a person, the process of excitation of cardiomyocytes is disturbed, and this happens after cell death;
• in the tissues of the heart affected by a heart attack is disturbed electrolyte balance - potassium largely leaves the damaged tissue pathologies.

These changes make it possible to register lines on the electrocardiograph, which are signs of conduction disturbances. They do not develop immediately, but only after 2-4 hours, depending on the compensatory capabilities of the body. Nevertheless, a cardiogram of the heart with a heart attack shows the accompanying signs by which it is possible to determine the violation of the work of the heart. A photo with a transcript is sent by the cardiological ambulance team to the clinic where such a patient will be admitted - cardiologists will be ready in advance for a serious patient.

Myocardial infarction looks on the ECG (photo below) as follows:

• complete absence of the R wave or its significant decrease in height;
• extremely deep, sinking Q wave;
• raised S-T segment above the isoline level;
• the presence of a negative T wave

The electrocardiogram also shows the various stages of a heart attack. Heart attack on ECG (photo in gal.) can be subacute, when changes in the work of cardiomyocytes are just beginning to appear, acute, acute and at the stage of scarring.

Also, the electrocardiogram allows the doctor to evaluate the following parameters:

• diagnose the very fact of a heart attack;
• determine the area where pathological changes have occurred;
• establish the limitation of the changes that have occurred;
• decide on the tactics of treating the patient;
• predict the possibility of death.

Transmural myocardial infarction is one of the most dangerous and severe types of heart damage. It is also called macrofocal or Q-infarction. Cardiogram after myocardial infarction (photo below) with a large-focal lesion shows that the zone of death of heart cells captures the entire thickness of the heart muscle.

Myocardial infarction

Myocardial infarction is a consequence of ischemic heart disease. Most often, ischemia leads to atherosclerosis of the heart vessels, spasm or blockage. Happen heart attack (photo 2) maybe as a result surgical interventionif an artery is ligated or angioplasty is performed.

Ischemic infarction goes through four stages of the pathological process:

• ischemia, in which the cells of the heart stop receiving the required amount of oxygen. This stage can last for a long time, since the body includes all compensatory mechanisms to ensure the normal functioning of the heart. The immediate mechanism of ischemia is the narrowing of the cardiac vessels. Until a certain moment, the heart muscle copes with such a lack of blood circulation, but when thrombosis narrows the vessel to a critical size, the heart is no longer able to compensate for the shortage. This usually requires a 70 percent or more narrowing of the artery;
• damage that occurs directly in cardiomyocytes, which begins within 15 minutes after the cessation of blood circulation in the damaged area. A heart attack lasts about 4-7 hours. It is here that the patient begins the characteristic signs of a heart attack - chest pain, heaviness, arrhythmia. Extensive heart attack (photo below) - the most difficult outcome of an attack, with such damage, the zone of necrosis can reach up to 8 cm in width;
• necrosis - death of heart cells and the termination of their functions. In this case, the death of cardiomyocytes occurs, necrosis does not allow them to perform their functions;
• scarring - the replacement of dead cells by connective tissue formations that are not able to take on the function of precursors. This process begins almost immediately after necrosis and little by little for 1-2 weeks a connective tissue scar of fibrin fibers is formed at the site of injury.

Hemorrhagic cerebral infarction is a related condition in terms of mechanisms of damage, however, it is the release of blood from the cerebral vessels that interfere with the functioning of cells.

Heart after a heart attack

A heart after myocardial infarction (photo 3) undergoes the process of cardiosclerosis. Connective tissue, which replaces cardiomyocytes, turns into a rough scar - pathologists can see it when autopsy people who have had myocardial infarction.

The scar after myocardial infarction has a different thickness, length and width. All these parameters affect the further activity of the heart. Deep and large foci of sclerosis are called extensive infarction. Recovery from such a pathology is extremely difficult. With microsclerosis, the infarction, as well, can leave minimal damage. Often, patients do not even know that they have suffered such a disease, since the symptoms were minimal.

A scar on the heart after a heart attack (photo in gal.) in the future it does not hurt and does not make itself felt about 5-10 years after a heart attack, however, it provokes a redistribution of the cardiac load to healthy areas, which now have to do more work. After a certain time, the heart after a heart attack (photo below) looks worn out - the organ cannot carry out the load, ischemic disease the heart in patients is aggravated, there are pains in the heart, shortness of breath, they quickly get tired, requires constant drug support.

Myocardial infarction photo gallery

ECG for myocardial infarction displays the stages and possible complications in heart. With the help of this study, the size of ischemia, depth and location are determined. Heart attack is caused by ischemia (insufficient blood supply to the heart).

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Myocardial infarction is called the death of the heart muscle, as a result, it stops working.

ECG localization of ischemic foci

ECG diagnostics allows you to determine the localization of the ischemic focus. For example, it can manifest in the walls of the left ventricle, on the anterior walls, septa, or lateral walls.

It is least often found in the right ventricle, therefore, to determine it, experts use the chest leads in the diagnosis.

ECG localization of infarction:

• Anterior - LAP artery is affected. Indicators: V1-V4. Leads: II, III, aVF.
• Posterior - RCA artery is affected. Indicators: II, III, aVF. Leads: I, aVF.
• Lateral - the Circunflex artery is affected. Indicators: I, aVL, V5. Leads: VI.
• Basal - RCA artery is affected. Indicators: none. Leads V1, V2.
• Septal - the Septal performan artery is affected. Indicators: V1, V2, QS. Leads: absent.

What is heart ischemia

Myocardial infarction, or acute ischemia of the heart muscle, claims millions of lives every year. Ischemia occurs due to insufficient blood delivery to the heart.

Lack of blood circulation in one of the parts of the heart for more than 15 minutes leads to the death of this area.

As a result, necrosis (death) of heart cells occurs. Breaks in blood vessels triggered by blood clots - solid blood clots that clog the capillary, veins and arteries.

Under the strong pressure of the incoming blood, the vessel ruptures. Statistics note that more than half of people die instantly, the remaining 30% die in hospitals. About 15-20% of those affected survive.

Changes and interpretation of results

What an ECG looks like, everyone knows how to decipher it - only a few.

The teeth on the ECG are indicated by Latin letters: P, Q, R, S, T, U:

• P - polarization of the atria;
• Q, R, S - ventricular polarization;
• T - ventricular repolarization;
• U - the functioning of the distal parts of the ventricle.

The teeth stretching upward are called "positive" by experts, and "negative" downward. In a healthy person, Q, S always have a negative result, and R - positive.

To decipher the ECG, analyze the intervals of change between the waves and their components. The analysis allows you to establish the rhythm and heart rate.

The higher the tooth, the more actively the heart works. The lower, the slower.

ECG signs a heart attack is diagnosed by Q, S, T, R. If you add their indicators together, you get something like a small hump, vaguely reminiscent of the bowed back of a cat. Left ventricular hypertrophy is defined by R and S, where R is extended and S is deflected to the left.

Right bundle branch block is diagnosed by R and S, where R decreases and S expands. In the case of a blockade of the right pedicle of His, expansion of both teeth - R and S occurs.

Video

Stages

Experts distinguish 4 stages of myocardial infarction by ECG:

1. The most acute stage. Development period: from 3 hours to 3 days. The decreasing length of the R wave speaks of the developing necrosis. The smaller its length, the greater the likelihood of necrosis of a part of the heart.

   Serious damage to the heart is indicated by a ST elevation of 5 millimeters or more. The indicators characterize cardiac ischemia. Ends in death.

2. Acute stage. Development period: 2 - 3 weeks. It is characterized by the expansion of the necrosis zone and an increase with subsequent expansion of Q. The T wave indicators tend to the level of "negative" indicators, that is, it gradually decreases.
3. Mild stage. Development period: from 3 months to six months. It is characterized by an elongated T-wave. The sharper the stage, the longer it is. At the second stage of the disease, its length stabilizes for several weeks, then "T" tends in the opposite direction, becoming positive.
4. The cicatricial stage is considered to be the final stage that results in a scar. Its presence is determined by the Q scar. The scar remains in place until the last heart beat. Scars can heal or enlarge.

   The activity of the scar is determined by the "T" wave. With an increase in the size of the scar, it moves in positive side, when decreasing - in the negative direction. If the scar does not show its activity, then the "T" indicator is gradually smoothed out.

Transmural infarction ECG

Specialists divide the stage of transmural infarction into 4 stages:

• The most acute stage, which lasts from a minute to several hours;
• Acute stage, which lasts from an hour to 2 weeks;
• Mild stage that lasts from 2 weeks to 2 months;
• The cicatricial stage that occurs after 2 months.

Transmural infarction refers to acute stage... On the ECG, it can be determined by the rising wave of "ST" to "T", which is in a negative position. On last stage it is formed Q. The "ST" segment remains on the indicators of devices from 2 days to 4 weeks.

If, during a second examination, the patient continues to rise of the "ST" segment, then he develops a left ventricular aneurysm.

With transmural infarction, a Q wave is found, "ST" moves towards the isoline, "T" expands in the negative zone.

I would like to tell you about the main diagnostic method - ECG for myocardial infarction. According to the cardiogram, you will learn to determine the degree of damage to your heart by pathologies.

Nowadays, myocardial infarction, a very common dangerous disease. Many of us can confuse the symptoms of a heart attack with acute angina pectoris, which will lead to sad consequences and death. With this diagnostic method, cardiologists can accurately determine the condition of the human heart.

If you notice the first symptoms, you urgently need to make an ECG and consult a cardiologist. In our article you can find out how to prepare yourself for this procedure and how it will be deciphered. This article will be useful to everyone, since no one is immune from this pathology.

Myocardial infarction is necrosis (tissue necrosis) of a part of the heart muscle, which occurs due to insufficient oxygen supply to the heart muscle due to circulatory failure. It is myocardial infarction that is the main cause of death, today, and disability in people all over the world.

ECG in myocardial infarction is the main tool for its diagnosis. If symptoms characteristic of the disease appear, you should immediately visit a cardiologist and undergo an ECG test, since the first hours are very important.

You should also undergo regular examinations for early diagnosis of deterioration of the heart. Main symptoms:

• dyspnea;
• chest pain;
• weakness;
• heart palpitations, interruptions in the work of the heart;
• anxiety;
• heavy sweating.

The main factors due to which oxygen does not enter the blood well and the blood flow is disrupted are:

• coronary stenosis (due to a blood clot or plaque, the opening of the artery is sharply narrowed, which causes a large-focal myocardial infarction).
• coronary thrombosis (the lumen of the artery is suddenly clogged, due to which large focal necrosis of the walls of the heart occurs).
• stenosing coronary sclerosis (narrowing of the lumen of some coronary arteries, which causes small-focal myocardial infarction).

Myocardial infarction quite often develops against the background arterial hypertension, diabetes mellitus and atherosclerosis. It can also occur due to smoking, obesity and an immobile lifestyle.

Conditions provoking myocardial infarction, due to which the supply of oxygen decreases, can be:

• constant excitement;
• nervous overstrain;
• excessive physical activity;
• surgery;
• differences in atmospheric pressure.

ECG for myocardial infarction is performed using special electrodes that are attached to the ECG machine and which record the signals sent by the heart. For a conventional ECG, six sensors are sufficient, but twelve leads are used for the most detailed analysis of heart function.

Cardiac pathology can take on various forms. Electrocardiographic diagnostics of myocardial infarction is capable of detecting the following types of disease:

• transmural;
• subendocardial;
• intramural.

Each of the diseases has a specific state of the zones of necrosis, damage, ischemia. Transmural myocardial infarction has signs of macrofocal necrosis, which affects from 50% to 70% of the walls of the left ventricle. Helps to detect signs of myocardial infarction of this type vector of depolarization of the opposite wall.

The complexity of diagnostics is that a significant part of the myocardium does not demonstrate changes occurring in it, and only vector indicators are able to indicate them. Subendocardial myocardial infarction does not belong to small focal forms of diseases.

It is almost always extensive. The greatest difficulty for doctors in the study of the condition internal organ represents the blurring of the boundaries of areas of the affected myocardium.

When traits of subendocardial damage are detected, doctors observe the time of their manifestation. Signs of myocardial infarction of the subendocardial type can be considered a full confirmation of the presence of pathology, if they do not disappear within 2 days. Intramural myocardial infarction is considered medical practice a rarity.

It is quickly detected in the first hours of its onset, since the myocardial excitation vector on the ECG indicates changes in the heart metabolic processes... Potassium leaves the cells affected by necrosis. But the difficulty in detecting pathology is that potassium damage currents are not formed, because it does not reach the epicardium or endocardium.

To identify this type of myocardial infarction, even longer monitoring of the patient's condition is required. The ECG should be done regularly for 2 weeks. Deciphering the analysis results alone is not a complete confirmation or denial of the preliminary diagnosis. To clarify the presence or absence of a disease is possible only when analyzing its signs in the dynamics of their development.

Depending on the symptoms, several variants of myocardial infarction are distinguished:

• Anginal is the most common option. It manifests itself lasting more than half an hour and does not pass after taking the medicine (nitroglycerin), severe pressing or constricting pain behind the sternum. This pain can radiate to the left half chestas well as in the left arm, jaw and back. The patient may develop weakness, anxiety, fear of death, and severe sweating.
• Asthmatic - an option in which there is shortness of breath or choking, heart palpitations... Pain is usually absent, although it can be a precursor to shortness of breath. This variant of the development of the disease is typical for older age groups and for people who have previously had myocardial infarction.
• Gastralgic is a variant characterized by an unusual localization of pain that manifests itself in the upper abdomen. It can spread to the shoulder blades and back. This option is accompanied by hiccups, belching, nausea, vomiting. Bloating is possible due to intestinal obstruction.
• Cerebrovascular - symptoms are associated with cerebral ischemia: dizziness, fainting, nausea, vomiting, loss of orientation in space. The appearance of neurological symptoms complicates the diagnosis, which can absolutely correctly be made in this case only with the help of an ECG.
• Arrhythmic - an option when the main symptom is palpitations: a feeling of cardiac arrest and interruptions in its work. Pain is absent or only slightly manifested. Possibly weakness, shortness of breath, fainting, or other symptoms from a fall blood pressure.
• Malosymptomatic - an option in which the detection of a previous myocardial infarction is possible only after taking an ECG. However, such mild symptoms as causeless weakness, shortness of breath, interruptions in the work of the heart can precede a heart attack.

For any variant of myocardial infarction, an ECG must be done for accurate diagnosis.

Cardiac cardiogram

Human organs transmit a weak current. This is what makes it possible to make an accurate diagnosis with the help of a device that registers electrical impulses. The electrocardiograph consists of:

• a device that amplifies a weak current;
• a device that measures voltage;
• recording device on an automatic basis.

According to the data of the cardiogram, which is displayed on the screen or printed on paper, the specialist makes a diagnosis. There are special tissues in the human heart, otherwise they are called the conducting system, they transmit signals to the muscles indicating relaxation or contraction of the organ.

Electric current in the heart cells comes in periods, these are:

• depolarization. The negative cellular charge of the heart muscle is replaced by a positive one;
• repolarization. The negative intracellular charge is restored.

A damaged cell has a lower electrical conductivity than a healthy one. This is what the electrocardiograph records. The passage of the cardiogram allows you to record the action of the currents that arise in the work of the heart.

When there is no current, the galvanometer fixes a straight line (isoline), and if myocardial cells are excited in different phases, then the galvanometer fixes a characteristic wave, directed up or down.

An electrocardiographic test records three standard leads, reinforced three and chest leads six. If there is evidence, then more leads are added to check the posterior cardiac regions.

The electrocardiograph records each lead with a separate line, which further helps to diagnose heart lesions.
As a result, the complex cardiogram has 12 graphic lines, and each of them is studied.

On the electrocardiogram, five teeth are distinguished - P, Q, R, S, T, there are cases when U is also added. Each has its own width, height and depth, and each is directed in its own direction.

There are intervals between the teeth, they are also measured and studied. Interval deviations are also recorded. Each tooth is responsible for the function and capabilities of certain muscle regions of the heart. Experts take into account the relationship between them (it all depends on the height, depth and direction).

All these indicators help to distinguish the normal work of the myocardium from the disturbed one caused by various pathologies. The main feature of the electrocardiogram is the identification and registration of pathology symptoms important for diagnosis and further treatment.

ECG diagnosis of myocardial infarction allows you to determine the localization of ischemia. For example, it can manifest in the walls of the left ventricle, on the anterior walls, septa or lateral walls.

It is worth noting that myocardial infarction rarely occurs in the right ventricle, therefore, to determine it, experts use special chest leads in the diagnosis.

Localization of myocardial infarction by ECG:

• Anterior infarction - the LAP artery is affected. Indicators: V1-V4. Leads: II, III, aVF.
• Posterior infarction - RCA artery is affected. Indicators: II, III, aVF. Leads: I, aVF. Lateral infarction - the Circunflex artery is affected. Indicators: I, aVL, V5. Leads: VI.
• Basal infarction - RCA artery is affected. Indicators: none. Leads V1, V2.
• Septal infarction - Septal performan artery is affected. Indicators: V1, V2, QS. Leads: absent.

Preparation and procedure

Many believe that the EKG procedure does not require special preparation. However, for a more accurate diagnosis of myocardial infarction, you must adhere to the following rules:

1. Stable psycho-emotional background, the patient should be extremely calm and not nervous.
2. If the procedure takes place in the morning, you should refuse to eat.
3. If the patient smokes, it is advisable to refrain from smoking before the procedure.
4. You also need to limit your fluid intake.

Before the examination, it is necessary to remove the outer clothing and expose the shins. The specialist wipes the electrode attachment point with alcohol and applies a special gel. Electrodes are placed on the chest, ankles and arms. During the procedure, the patient is in a horizontal position. The ECG time is approximately 10 minutes.

During normal operation of the organ, the line has the same cyclicity. Cycles are characterized by sequential contraction and relaxation of the left and right atria and ventricles. In this case, in the heart muscle, complex processesaccompanied by bioelectric energy.

Formed in different parts of the heart, electrical impulses are evenly carried throughout the human body and reach skin person, which is fixed by the apparatus with the help of electrodes.

ECG decoding for myocardial infarction

Myocardial infarction is divided into 2 types - large focal and small focal. ECG allows diagnosing large focal myocardial infarction. An electrocardiogram consists of teeth (protrusions), intervals and segments.

On the cardiogram with a heart attack, the protrusions look like concave or convex lines. In medical practice, there are several types of teeth that are responsible for the processes occurring in the myocardium, they are designated by Latin letters.

The protrusion P - characterizes the contraction of the atria, the protrusions Q R S reflect the state of the contractile function of the ventricles, the protrusion T fixes their relaxation. The R wave is positive, the Q S waves are negative and downward. Decrease in the R wave indicates pathological changes in the heart.

Segments are straight line segments that connect the protrusions to each other. The ST segment located on the midline is considered normal. An interval is a defined area made up of projections and a segment.

Large focal myocardial infarction, the cardiogram shows a modification of the complex of protrusions Q R S. The appearance of a pathological protrusion Q indicates the development of pathology. Q is considered the most consistent sign of myocardial infarction.

An electrocardiogram does not always show signs that determine the development of pathology the first time, but only in 50% of cases. The first characteristic feature the development of pathology is the rise of the ST segment.

What does a large heart attack look like on a cardiogram? For large focal MI, the following picture is characteristic:

• r wave - completely absent;
• q wave - significantly increased in width and depth;
• segment ST - located above the isoline;
• t wave - in most cases has a negative direction.

During the study, the following features and deviations are checked:

1. Disruption of blood circulation, which leads to arrhythmias.
2. Restriction of blood flow.
3. Failure of the right ventricle.
4. Thickening of the myocardium - the development of hypertrophy.
5. Violation of the rhythm of the heart as a result of pathological electrical activity of the heart.
6. Transmural infarction of any stage.
7. Features of the location of the heart in the chest.
8. Regular heart rate and intensity of activity.
9. The presence of damage to the structure of the myocardium.

Normal indicators

All heart rate impulses are recorded in the form of a graph, where changes in the curve are marked vertically, and the time of ups and downs is calculated horizontally.

Prongs - vertical stripes are designated by letters of the Latin alphabet. The segments are measured horizontally, fixing the changes - the intervals of each cardiac process (systole and diastole).

In adults, the normal values \u200b\u200bfor a healthy heart are:

1. Before the contraction of the atria, the P wave will be indicated. It is the determinant of sinus rhythm.

It can be negative or positive, and the duration of such a marker is no more than a tenth of a second. A deviation from the norm may indicate impaired diffuse metabolic processes.

2. The PQ interval has a duration of 0.1 seconds.

It is during this time that the sinus impulse manages to pass through the artioventicular node.

3. The T wave explains the processes during repolarization of the right and left ventricles. It indicates the stage of diastole.
4. The QRS process on the graph lasts 0.3 seconds, which includes several waves. This is a normal process of depolarization at the time of ventricular contraction.

ECG indicators for myocardial infarction are very important in diagnosing the disease and identifying its features. Diagnostics should be quick in order to find out the features of the lesion of the heart muscle and understand how to resuscitate the patient.

The localization of the affected area can be different: death of tissues of the right ventricle, damage to the pericardial sac, valve death.

The lower left atrium may also be affected, preventing blood from leaving this area. Transmural infarction leads to a blockage of blood vessels in the area of \u200b\u200bthe coronary supply of the heart muscle. Defining points in the diagnosis of a heart attack:

• Exact localization of the site of muscle death.
• The period of the striking effect (how long the condition lasts).
• Depth of defeat. On the ECG, the signs of myocardial infarction are easily detected, but it is necessary to find out the stages of the lesion, which depend on the depth of the focus and the strength of its spread.
• Concomitant lesions of other areas of the heart muscles.

It is important to consider. Indicators of teeth and in the case of blockade of the His bundle in the lower part, which provokes the onset of the next stage - transmural infarction of the left ventricular septum.

In the absence of timely treatment, the disease can spread to the area of \u200b\u200bthe right ventricle, since the blood flow is impaired, and necrotic processes in the heart continue. To prevent a deterioration in health, the patient is administered metabolic and diffuse drugs.

Stages of myocardial necrosis

Between healthy and dead (necrotic) myocardium in electrocardiography, intermediate stages are distinguished:

• ischemia,
• damage.

ISCHEMIA: this is an initial lesion of the myocardium, in which there are no microscopic changes in the heart muscle, and the function is already partially impaired.

As you should remember from the first part of the cycle, two opposite processes occur sequentially on the cell membranes of nerve and muscle cells: depolarization (excitation) and repolarization (restoration of the potential difference). Depolarization is a simple process for which you only need to open ion channels in the cell membrane, through which ions will run outside and inside the cell due to the difference in concentration.

Unlike depolarization, repolarization is an energy-intensive process that requires energy in the form of ATP. For aTP synthesis oxygen is necessary, therefore, with myocardial ischemia, the repolarization process begins to suffer in the first place. Violation of repolarization is manifested by changes in the T wave.

With myocardial ischemia, the QRS complex and ST segments are normal, and the T wave is changed: it is expanded, symmetrical, equilateral, increased in amplitude (span) and has a pointed apex. In this case, the T wave can be both positive and negative - it depends on the location of the ischemic focus in the thickness of the heart wall, as well as on the direction of the selected ECG lead.

Ischemia is a reversible phenomenon, over time, metabolism (metabolism) is restored to normal or continues to deteriorate with the transition to the stage of damage.

DAMAGE: this is a deeper damage to the myocardium, in which, under a microscope, an increase in the number of vacuoles, swelling and dystrophy of muscle fibers, disruption of membrane structure, mitochondrial function, acidosis (acidification of the environment), etc. Both depolarization and repolarization suffer. The damage is thought to primarily affect the ST segment.

The ST segment can move above or below the isoline, but its arc (this is important!), When damaged, is turned by a bulge towards the displacement. Thus, in case of myocardial injury, the ST segment arc is directed towards the displacement, which distinguishes it from many other conditions in which the arc is directed towards the isoline (ventricular hypertrophy, bundle branch block, etc.).

The T wave when damaged can be of different shapes and sizes, depending on the severity of concomitant ischemia. Damage also cannot exist for a long time and turns into ischemia or necrosis.

NEKROSIS: myocardial death. The dead myocardium is not able to depolarize, therefore, dead cells cannot form an R wave in the ventricular QRS complex. For this reason, with transmural infarction (myocardial death in a certain area along the entire thickness of the heart wall), there is no R wave in this ECG lead at all, and a QS-type ventricular complex is formed.

If necrosis has affected only part of the myocardial wall, a QrS-type complex is formed, in which the R wave is reduced, and the Q wave is enlarged compared to the norm. Normally, the Q and R waves must obey a number of rules, for example:

• the Q wave must always be present in V4-V6.
• the width of the Q wave should not exceed 0.03 s, and its amplitude should NOT exceed 1/4 of the amplitude of the R wave in this lead.
• the R wave should grow in amplitude from V1 to V4 (i.e., in each successive lead from V1 to V4, the R wave should howl higher than in the previous one).
• in V1, the r wave may normally be absent, then the ventricular complex looks like QS. In people under 30, the QS complex can occasionally be found in V1-V2, and in children even in V1-V3, although this is always suspicious of an infarction of the anterior part of the interventricular septum.

Diagnostics in patients with bundle branch blockade

The presence of a blockade of the right leg does not prevent the identification of large focal changes. And in patients with left leg blockade, ECG diagnostics of a heart attack is very difficult. A lot of ECG signs of macrofocal changes on the background of left leg blockade have been proposed. When diagnosing acute myocardial infarction, the most informative of them are:

1. The appearance of a Q wave (especially a pathological Q wave) in at least two leads from leads aVL, I, v5, v6.
2. Reduction of the R wave from lead V1 to V4.
3. Serration of the ascending S wave knee (Cabrera sign) in at least two leads from V3 to V5.
4. Concordant ST segment displacement in two or more adjacent leads.

If any of these signs are detected, the probability of a heart attack is 90-100%, however, these changes are observed only in 20-30% of patients with myocardial infarction against the background of left leg blockade (changes in the ST segment and T wave are observed in dynamics in 50%). Therefore, the absence of any ECG changes in a patient with left leg blockade in no way excludes the possibility of a heart attack.

For an accurate diagnosis, it is necessary to determine the activity of cardiospecific enzymes or troponin T. Approximately the same principles for the diagnosis of MI in patients with ventricular preexcitation syndrome, in patients with an implanted pacemaker (constant ventricular stimulation).

In patients with blockade of the left anterior branch, signs of macrofocal changes in the lower localization are:

1. Registration in lead II of complexes of the type QS, qrS and rS (r wave
2. The R wave in lead II is smaller than in lead III.

The presence of a blockade of the left posterior branch, as a rule, does not complicate the identification of large-focal changes.

Transmural infarction ECG

Specialists divide the stage of transmural infarction into 4 stages:

• The most acute stage, which lasts from a minute to several hours;
• Acute stage that lasts from one hour to two weeks;
• A mild stage that lasts from two weeks to two months;
• The cicatricial stage, which occurs after two months.

Transmural infarction refers to the acute stage. On the ECG, it can be determined by the rising wave of "ST" to "T", which is in a negative position. At the last stage of transmural infarction, the formation of the Q wave occurs. The "ST" segment remains on the indicators of devices from two days to four weeks.

If, during a second examination, the patient continues to rise of the ST segment, then this indicates that he is developing a left ventricular aneurysm. Thus, transmural infarction is characterized by the presence of a Q wave, movement of the "ST" towards the isoline and the "T" wave, which expands in the negative zone.

Posterior ventricular infarction is difficult to diagnose with an ECG. In medical practice, about 50% of cases, the diagnosis does not show problems with the posterior regions of the ventricle. The posterior wall of the ventricle is divided into the following parts:

• The diaphragmatic section, where the posterior walls adjacent to the diaphragm are located. Ischemia in this part causes inferior infarction (posterior diaphragmatic infarction).
• Basal section (upper walls) adjacent to the heart. Ischemia in this part is called posterior basal infarction.

Inferior infarction occurs when the right coronary artery is blocked. Complications are characterized by lesions of the separation of the interventricular septum and the posterior wall.

With a lower heart attack, ECG indicators change as follows:

• The third Q wave becomes larger beyond the third R wave by 3 mm.
• The cicatricial stage of myocardial infarction is characterized by a decrease in the Q wave to half the R (VF).
• Expansion of the third Q wave to 2 mm is diagnosed.
• In posterior infarction, the second Q wave rises above the first Q (in a healthy person, these indicators are reversed).

It should be noted that the presence of a Q wave in one of the leads is not a guarantee of posterior infarction. It can disappear and appears when a person breathes intensively. Therefore, to diagnose posterior infarction, conduct an ECG several times.

The difficulty is as follows:

1. The extra weight of the patient can affect the conduction of the cardiac current.
2. It is difficult to identify new scars of myocardial infarction if there is already a scarring in the heart.
3. Impaired conductivity of complete blockade, in this case it is difficult to diagnose ischemia.
4. Frozen cardiac aneurysms do not record new dynamics.

Modern medicine and new ECG machines are able to easily perform calculations (this happens automatically). With the help of Holter monitoring, you can record the work of the heart throughout the day.

In modern wards, there is cardiac monitoring and an audible alarm, which allows doctors to notice altered heartbeats. The final diagnosis is made by a specialist based on the results of an electrocardiogram, clinical manifestations.

In this publication I would like to talk about such a necessary and effective method diagnosis, like an ECG in myocardial infarction. After reviewing the information provided, everyone will be able to determine the heart attack on the ECG, as well as its stage, the degree of damage.

Many, faced with this kind of disease, increasingly understand that myocardial infarction is one of the terrible and popular pathologies of the heart, the consequences of which can lead to great health problems in general, not excluding death.

During the onset of symptoms, many, after reading information from many sources, often confuse the symptoms of a heart attack with angina pectoris. In order not to make mistakes with your own hand, you should go to the hospital at the first symptoms, where specialists can determine the exact state of the heart with eCG.

What is a heart attack and its types

Myocardial infarction is one of the clinical types of ischemic heart disease, which proceeds with the formation of ischemic necrosis of the myocardial area, which subsequently leads to absolute or relative insufficiency of its blood supply.

Important! ECG during a heart attack is one of the main types of diagnosis and identification of signs of the disease. At the first symptoms of myocardial infarction, you must immediately contact a cardiologist for an ECG test in the first 60-120 minutes, which are very important!

The main reasons for coming to the doctor can be considered:

• Shortness of breath;
• Pain syndromes behind the breastbone;
• Malaise;
• Frequent pulse when listening, as well as possible irregular rhythms of the heart;
• Feeling of fear, with a lot of sweating.

You should know! Myocardial infarction is the first sign of development against the background of arterial hypertension, a strong decrease or increase in glucose, as well as against the background of atherosclerosis, smoking, excess weight or a sedentary lifestyle.

The following factors provoke a heart attack:

• Frequent anxiety, depression, stress, anxiety;
• Work related physical activity or sports activities (weightlifters);
• Operational interventions;
• Frequent changes in atmospheric pressure.

To ensure your health and your life, at the first sign, you should undergo a diagnosis. With the help of an ECG during the formation of a heart attack, a specialist will use special electrodes that are connected to the cardiogram apparatus, after which a certain kind of signals from the heart muscle will occur. To conduct a conventional ECG, 6 sensors should be used, in the case when it comes to determining the ECG of a heart attack - as many as 12.

Varieties of MI

The pathology of myocardial infarction is possible in most forms, but the ECG when examining this organ can reveal only the following:

• Transmural infarction (has indicators of macrofocal necrosis of the walls of the left ventricle of the heart, which can reach up to 55-70% of the lesion);
• Subendocardial (in 90% of cases it proceeds extensively, with an ECG, blurred edges of the affected area of \u200b\u200bthe myocardium often appear, which makes it difficult for an ultrasound specialist to see this problem);
• Intramural (considered one of the small focal types of pathologies).

According to the identified symptoms, the following forms of MI can be distinguished:

1. Anginous is one of the most common types of infarction. It manifests itself as severe pain behind the chest, which often radiates to the left upper part body (face, hand, hypochondrium). The patient feels unwell, lethargy, a sharp deterioration general condition, sweating.
2. Asthmatic - manifests itself as shortness of breath, lack of oxygen for inhalation. With these symptoms in adults and the elderly, this suggests that an MI has already been transferred;
3. Gastralgic - unpleasant localization of pain in the upper abdomen. There may also be an unpleasant feeling of constriction in the shoulder blades, back. All this causes hiccups, a feeling of nausea, "bloating" of the abdomen, pain in some areas of the intestines.
4. Cerebrovascular - manifests itself as dizziness, severe pain in the temples and the back of the head, nausea, vomiting. The diagnosis of this type can only be determined using an ECG.
5. Arrhythmic - a constant feeling that the pulse disappears, or is temporarily absent. May be light-headed, severe headache, a sharp decrease in blood pressure.
6. Malosymptomatic - the localization of the heart attack is concluded in a sharp weakness and shortness of breath.

Remember! For better recognition of these symptoms, an ECG should be taken immediately.

Rody ECG in the study of myocardial infarction

The ECG is an integral part of the recognition of a particular symptom of myocardial infarction, and its diagnostic technique is simple and explains a lot, both for cardiologists and doctors. Thanks to the latest technologies, everyone has a chance to quickly and effectively diagnose the heart and identify pathologies of a heart attack, both at home and in specially designated institutions.

Any ECG performed is direct evidence of the existence of a particular disease in humans for doctors. It is easy to confuse MI with pancreatitis, cholecystitis, so an electrocardiogram should be performed immediately.

Although the following fact should be noted - in almost 8-9% of this diagnosis, there may be incorrect data. Therefore, for a more accurate identification of a particular pathology, the ECG should be performed several times, as well as decoding.

Heart attack ECG overview

Conducting an ECG in the development of an acute disturbance of blood flow in the myocardium is the very integral part of the study of the organ. The decoding of the diagnosis increases several times during the first few hours of the formation of myocardial infarction, because it is at this time that the symptoms of this disease begin to manifest themselves.

On the film, at the first stages of the development of the disease, one can observe only the initial disturbances in the blood supply, and then only if these disturbances were revealed during the production of an electrocardiogram. In the photo this is expressed as changes in the S - T segment.

Let us present you with visual indicators of changes in ECG waves:

This kind of deviations on the electrocardiogram are associated with 3 factors occurring in the infarcted area, thereby dividing into certain zones:

1. Death of tissues - but only with the development of Q-infarction;
2. Violation of the integrity of cells, which subsequently threatens with necrosis;
3. Insufficient amount of blood flow, which is quite recoverable.

There are certain signs that the development of myocardial infarction was revealed in the description of the ECG:

• The R-wave (ЗR) is small or completely absent;
• q wave (ЗQ) deep;
• wave T (3T) is negative;
• the S - T segment is lower than the isoline.

Time stages of development of a heart attack on the cardiogram

Table of stages of MI formation

ECG signs depending on the size of the lesion

ECG changes during different MI positions

In order to accurately establish the diagnosis, the specialist must use all twelve electrodes for the ECG. Let's imagine this in the form of a photo:

And depending on the position of the lesion, the disease is displayed on the film in different ways. Consider the types of heart attacks.

Anterior septal Q-infarction

Lateral MI

Lead - standard. III from the left arm, right leg and chest V-VI

Signs of pathologies - ЗQ - deep, widened, the S - T segment slowly rises above the isoline.

Anterior-posterior Q-infarction

Lead - standard. III from the left arm, right leg and chest III - VI

Signs of pathologies - ЗQ - deep, widened, the S - T segment rises significantly above the isoline, while the ЗТ is positive, merging with the segment.

Posterior diaphragmatic

Q-infarction anterior subendocardial

Posterior subendocardial non-Q infarction

Lead standard. II, III, from the right leg, chest V-VI.

Signs of pathologies - z R - decreased, zT - positive, then there is a slight decrease in the segment, without the Q wave.

Difficulties in conducting an ECG

The location of the teeth and gaps can provoke the following factors:

• at overweight the patient can change the electrical position of the heart;
• scars on the heart with a previously transferred MI, do not allow revealing new changes;
• it is almost impossible to identify IHD in case of conduction disturbances in the form of a blockade along the left bundle branch;
• "Frozen" ECG with aneurysm will not reveal new changes in the work of the heart.

With the help of an ECG, there is a chance to determine the localization of ischemia. Let's give you a table:

In conclusion, I would like to remind you that in modern world, thanks to innovative technologies, it is quite easy and quick to identify a heart attack on an ECG. It is also effectively possible to decipher all the indicators identified on the electrical tape, I record the work of the heart muscle for 24 hours or more. Improved wards have cardiac monitoring, as well as audible alarms, which allows doctors in case of serious changes to immediately respond to the situation, providing quickly necessary assistance.

ECG in infarction is of great importance for its diagnosis, in particular for the diagnosis of localization, the magnitude of necrosis, for differential diagnosis with an unclear picture, pain of a different nature and for prognosis.

Typical ECG changes in heart attack are:

• a sharp shift of the RS-T interval (discordant) up and down in I and III standard leads;
• a rapid decrease in the amplitude of the QRS complex or the formation of Q, QS waves;
• rapid development of inversion and deformity (discordant in leads) of the T wave.

Changes in the QRS complex on the ECG with a heart attack

According to relatively recent studies, the positive QRS complex recorded in standard leads is a mirror image of the normally occurring negative potential of the inner layers of the myocardium (i.e., its intracavitary surface). If during this movement of excitation between the inner and outer layers a non-functioning, "dead" tissue appears that loses the property of polarization, negative deviations of the electrocardiogram are perceived from the outer layers of the heart. The intracavitary negative potential is transmitted either unchanged (negative QRS complex) or in the form of a positive, but reduced or deformed QRS complex (due to the partial loss of the depolarization function by the myocardium). The localization and size of the inactive, damaged ("dead") area, respectively, affect the ECG in heart attack. This theory explains the main deviations from the ECG in heart attack.

When the entire thickness of the myocardial wall is damaged (necrotic), QS waves appear on the ECG with the disappearance of the P wave, which means the transition of negative potential through the "hole" (ie, a piece of dead tissue) to the epicardium. With this "end-to-end" necrosis, complexes of the "cavity type" are transmitted, emanating directly from the genetic system (as is known, it is located in the form of branches of the His fascicle and Purkinje fibers subendocardially). In case of partial damage to the myocardium with the preservation of a part of the living muscle tissue in the damaged area (in the form of "inclusions"), the negative potential of QS will be conducted to the outer layers, but at the same time, changes in the ECG during infarction occur due to depolarization manifested by the preserved areas of the myocardium.

Changes in the ST segment and the T wave on the ECG with a heart attack

Electrocardiograms acquire the so-called mural type with a sharp shift segment S-T... The shift down and up from the isoline depends on whether this zone passes closer to the endocardium or epicardium.

It is clinically accepted that the displacement of the ST line in coronary atherosclerosis is also a reflection of the degree of ischemia of the corresponding part of the myocardium.

The T wave was previously considered an indicator of the process of restoring the bioelectric capacity of the heart after systole. It is widely believed that this tooth reflects the state of myocardial metabolism associated with the expenditure and replenishment of myocardial energy resources caused by its contraction. The metabolic and functional basis of this electrocardiographic indicator did not raise doubts among clinicians due to the fact that changes in the T wave were characteristic of a very wide range of physiological and pathological conditions (the tooth becomes changed not only with necrotic, inflammatory or sclerotic changes in the heart, but also when the mixture is inhaled , poor oxygen, during hard work). In the experiment, the inversion of the T wave was obtained when the heart was exposed to heat and cold. Of all the changes that are observed in coronary atherosclerosis and other myocardial lesions, changes in direction and T wave are the most frequent on the ECG with a heart attack, found already with weak degrees lesions and most reversible. The dynamic, temporary nature of the changes in this wave is one of the proofs of the metabolic nature of the changes that underlie it.

The question arises, what are the chemical changes in the myocardium, leading to a disruption in the course of electrical potentials and pathological ECG during a heart attack? An important prerequisite for the clarification of this question was the experience of M. G. Udelnov, consisting in the following. A piece of dead muscle tissue (taken from any animal) was applied to the heart of a cold-blooded (frog) or warm-blooded (rabbit) in situ (in vivo). As soon as a piece of dead tissue is applied to the heart, the electrocardiogram changes from normal to monophasic. As soon as a piece of tissue is removed from the surface of the heart, the electrocardiogram becomes normal. This experience has shown that there is no need to ligate the coronary artery to obtain a monophasic electrocardiogram. Obviously, changes in the electrocardiogram under these conditions are due to some chemical products that pass from a piece of dead tissue attached to the heart into the heart muscle.

Some clinical data also speak in favor of the significance of changes in the composition of electrolytes in the myocardium during a heart attack (in terms of the electrocardiographic picture). Thus, during cardiac catheterization in patients with heart attack, an increase in the content of potassium was noted in the blood of the coronary sinus. In the acute phase of the disease, hyperkalemia is observed (with a simultaneous decrease in the content of other electrolytes, in particular sodium). An excess of potassium in the blood is the result of its transfer from the left ventricular heart attack.

In severe heart attacks, the entire electrocardiographic triad is usually observed on the ECG (change in the ST segment, QRS complex, T wave); with limited necrosis that does not cover the entire thickness of the heart wall, the monophasic curve on the ECG with a heart attack is not observed, but there is only a decrease interval S-T and inversion (or other changes) of the T wave.

Changes in standard leads I and II on the ECG during heart attack indicate lesions localized in the anterior wall of the heart, and changes in standard leads III and II of the electrocardiogram indicate a lesion localized in the posterior wall of the heart.

Changes in chest leads

With the introduction of ECG into practice for infarction of chest leads, the boundaries of topical diagnosis of foci of myocardial lesion (along with that, of course, the diagnostic capabilities in general) have significantly expanded. Usually use six chest leads, but their number can be increased if necessary; in fact, every point on the surface of the chest wall can serve to lead one of the electrodes. It is possible to draw up, using multiple chest leads, a kind of topographic map of the location of changes in the myocardium and at the same time assess the degree of their massiveness (size). Of course, chest leads are suitable for recognizing focal lesions of the anterior and partly lateral walls of the heart. With extensive lesions of the anterior and anterolateral walls of the heart, changes in the electrocardiogram are noted both in I and II standard, and in all chest leads.

Undoubted advantages for topical and early diagnosis using ECG in heart attack are provided by unipolar leads according to Wilson or Goldberger. ECG changes in leads V1-V2 during infarction indicate the localization of the lesion in the anterior part of the interventricular septum. Changes in the ECG with a heart attack in leads V5-V6 are characteristic of lesions in the outer (lateral) part of the left ventricle. Isolated changes indicate the defeat of the anterior wall in the area adjacent to the interventricular septum (with its partial involvement), and the apex.

As you know, changes in the T wave in lead III are sometimes found in healthy individuals, but at the same time they can indicate the presence of foci of necrosis in the posterior wall. To differentiate the negative T wave, caused by organic changes, from similar changes of this wave, not associated with myocardial diseases (but depending on the position of the heart, high standing of the diaphragm, cardiac hypertrophy), the unipolar lead aVF can be used. With a lesion of the posterior wall (usually on the basis of coronary atherosclerosis, especially with infarctions of this localization), a deep Q wave is observed, a negative T wave as in III standard lead, so in lead aVF, whereas in people without myocardial damage, in whom these changes are found in standard lead III, in aVF the magnitude of the Q wave is normal, and the T wave is positive.

ECG with a heart attack allows you to determine atrial necrosis (although they are rarely isolated); in these cases, the atrial P waves change and the P-Q interval is shifted. With left atrial infarction, the P wave changes in the form of widening, splitting or inversion in lead I, and the P-Q interval is shifted downward; with right atrial infarction, changes in the P wave and downward displacement are noted interval P-Q... Electrocardiographic signs of atrioventricular block, atrial paroxysmal tachycardia, atrial extrasystole and atrial fibrillation are important for the diagnosis of atrial infarction.

ECG for myocardial infarction

One of the key topics in electrocardiography is the diagnosis of myocardial infarction. Let's look at this critical topic in the following order:

Information relevant to "ECG in myocardial infarction"

Introduction Causes of myocardial infarction Symptoms of myocardial infarction Forms of infarction Factors of development of myocardial infarction Prevention of myocardial infarction Probability of complications of myocardial infarction Complications of myocardial infarction Diagnostics acute heart attack myocardium Emergency care for myocardial infarction Help before the arrival of an ambulance for myocardial infarction Must be able to resuscitate

Figure: 99. Intramural myocardial infarction With this type of infarction, the vector of myocardial excitation does not change significantly, potassium emitted from necrotic cells does not reach the endocardium or epicardium and does not form damage currents that can be displayed on the ECG tape by displacement of the ST segment. Therefore, from the ECG signs of myocardial infarction known to us,

The above listing of the ECG signs of myocardial infarction allows us to understand the principle of determining its localization. So, myocardial infarction is localized in those anatomical regions of the heart, in the leads from which signs 1, 2, 3 and 5 are recorded; 4th sign plays a role

Sequential changes in the ECG in myocardial infarction, depending on the stage of this disease, is strictly logical (see Chapter VII.3). However, in practice, situations sometimes arise when ECG signs of an acute or subacute stage of myocardial infarction persist long time and do not go into the stage of scarring. In other words, on the ECG, the elevation of the S-T segment above

Figure: 98. Subendocardial myocardial infarction In this infarction, the magnitude of the myocardial excitation vector does not change, since it originates from the conduction system of the ventricles embedded under the endocardium and reaches the intact epicardium. Therefore, the first and second ECG signs of a heart attack are absent. Potassium ions with necrosis of myocardiocytes are poured out under the endocardium, forming

Figure: 97. Large-focal myocardial infarctions The figure shows that the recording electrode A, located above the area of \u200b\u200bthe transmural infarction, will not record the R wave, since the entire thickness of the myocardium has died and there is no excitation vector here. Electrode A will register only pathological Q wave (display of the vector of the opposite wall). In the case of subepicardial

In fig. 89 schematically shows the ventricular myocardium. Figure: 89. Excitation of normal myocardium The vectors of excitation of the ventricular myocardium extend from the endocardium to the epicardium, ie. they are directed to the recording electrodes and will be graphically displayed on the ECG tape as R waves (vectors between the ventricular septum are not considered for ease of understanding). When there is

At their core, myocardial infarctions are divided into two large groups: large focal and small focal. This division is focused not only on the volume of necrotic muscle mass, but also on the features of the blood supply to the myocardium. Figure: 96. Features of myocardial blood supply The heart muscle is fed through the coronary arteries, anatomically located under the epicardium. By

Myocardial infarction is dangerous in many ways, because of its unpredictability and complications. The development of complications of myocardial infarction depends on several important factors: 1. the magnitude of the damage to the heart muscle, the more the area of \u200b\u200bthe myocardium is affected, the more pronounced the complications; 2. localization of the zone of myocardial damage (anterior, posterior, lateral wall of the left ventricle, etc.), in most cases occurs

Sometimes, when registering an ECG in patients during an anginal attack or immediately after it, the electrocardiogram identifies signs characteristic of the acute or subacute stage of myocardial infarction, namely, the horizontal rise of the ST segment above the isoline. However, this rise in the segment persists for seconds or minutes, the electrocardiogram quickly returns to normal, in contrast to a heart attack

Clinic of myocardial infarction. ECG for myocardial infarction

The condition determining the results of myocardial infarction therapy... is his early diagnosis and an adequate assessment of the patient's condition for timely interventions, since all etiopathogenetic therapy gives the main results within a "time window" of up to 6 hours.

Generally accepted criteria diagnosis of myocardial infarction are the nature of the pain syndrome, eCG changes, enzyme disorders. Consequences appear later than 6 hours, and therefore they do not play a special role for early intervention.

For early ECG diagnosis of myocardial infarction it is necessary to dwell on the modern data on the ECG picture of myocardial infarction in the acute phase. The most common classification of myocardial infarction has been based on the identification of electrocardiographic and anatomical features. So, MI is divided into transmural and nontransmural, large and small focal. It has now been established that ECG signs and morphology are not identical, that is, MI with a pathological Q wave will not necessarily be through and vice versa. A new classification of myocardial infarction by ECG signs was adopted based on their comparison with the clinic, course and prognosis. According to her, MI is divided into an infarction with a Qr wave on the ECG (the presence of pathological Q in at least 2 leads) and a heart attack without a Q wave with changes only in the terminal part of the ventricular complex of the ST segment elevation, the presence of an "ischemic" T wave.

From the analysis of clinical data it follows that an infarction with a Q-wave on an ECG has a more severe prognosis in the acute period, however, heart attacks without a Q-wave on an ECG, in turn, give a number of adverse consequences in the first year after their development.

The difference in early and long-term forecasts is associated with morphological and functional characteristics of myocardial infarction with and without pathological Q-wave on the ECG. Q-wave MI usually results from rapid complete occlusion of a relatively large coronary artery (CA). The infarction process ends quickly. The prognosis is determined by the magnitude of the MI and the state of the myocardium. MI without a Q-wave is the result of incomplete closure of the coronary artery, usually smaller. A significant number of patients have a previous CA lesion with the development of collaterals. All this determines the best prognosis for the acute period. However, partial thrombosis can later turn into complete, and the presence of previous atherosclerotic changes in the coronary artery creates conditions for progression in some patients. Hence - the deterioration of the late prognosis in MI without pathological Q-wave.

The ECG also does not provide an opportunity to isolate from the group of patients with MI without Q-wave on the ECG of persons with "small focal" MI. This purely anatomical representation cannot be accurately verified either from the ECG or from the clinic.

It is well known that more severe are anterior myocardial infarction... However, among the diaphragmatic (posterior) MI, severe forms are also distinguished. These include those in which the septal zone is involved with the development of severe arrhythmias and blockades, the involvement of the right ventricle, as well as diaphragmatic MI with the appearance of a ST decrease in the chest leads V1-3 and an increase in these positions of the R wave, which is associated with the involvement of the posterior - high zones of the myocardium. The prognosis in such patients is relatively difficult. Leads VR2-4 are used to diagnose right ventricular infarction.

Availability clinical and electrocardiographic syndrome The start of the development of myocardial infarction allows in the first hours to make the correct diagnosis and begin intensive causal therapy.

To resolve the issue about volume treatment measures it is also necessary, especially if several hours have passed since the beginning pain attack, to determine the severity of the patient's condition, his immediate prognosis.