Dynamics st t what. ECG pictures for coronary heart disease (CHD)

In the event that the myocardium experiences a significant or critical oxygen deficiency, a cascade of biochemical changes occurs, as a result of which certain changes appear on the ECG - depression of the ST segment.

Such changes in most cases should be regarded as acute until proven otherwise. But sometimes depression remains on the ECG for years, even in people who do not have problems with depression. coronary arteries. Only the clinical picture will allow you to decide on the tactics of patient management, but we will not talk about the clinic.

And so, first of all, let's see where this ST segment is located on the ECG.

On the left you see a schematic representation of a single complex and ST segment. If you draw an imaginary line (ISOLINE) from the beginning to the end of the complex, then it will just pass through the ST segment. That is, there is neither elevation nor depression here - this is the norm. If the segment were under the isoline, this would be called “depression”, if, on the contrary, above the isoline, then “elevation”.

It should be noted that elevation or depression is not always pathological, it depends on their severity.

normal at rest

in chest leads depression should be less than 0.5 mm.

in limb leads depression should be less than 0.5-1 mm.

Let's look at the ECG snippet

First you need to draw an isoline, the accuracy of the measurement depends on the correctness of this stage. Usually, with the help of a ruler, a more or less even section of the isoline is found between two complexes and a line is drawn through them. This will be the isoline. Something like that.

Now it is clearly visible that the ST segment is under the isoline. But what to do now, in what place to measure this very depression? It is clear that you need to attach the ruler vertically and measure from the isoline to the line of the segment itself, but where to do this?

Here you can see that if you choose a place arbitrarily, you can get completely different values ​​of depression. How to proceed? The answer is simple, the measurement must be carried out as follows. It is necessary to find the point (j) where the S wave ends, or if there is no S wave, then the point of intersection of the descending knee R with the isoline. Then set aside 0.08 s (4 mm) from this point and measure the depression (this will be point i) in it. Some foreign authors recommend setting aside 0.04 s. (2 mm). But if there is derpessia, then it is both at 0.04 and at 0.08

In our case, the situation will look like this

Thus, we can say that in lead V5 there is a depression of up to 0.5 mm (this is the norm), and in V6 it is about 0.8 mm, which is beyond the norm, but does not always indicate true ischemia. In such cases, such depression should be described in the conclusion. And the clinician will already be puzzled about what to do with it, a detailed clinical interpretation is beyond the scope of this course.

The next topic is the most important in the entire section "ISCHEMIA",

Evaluation of ST Elevation or Depression Normally, the ST segment is on the isoline. Segment elevation is normal:

• limb leads up to 1 mm,
• V1-V2 up to 3 mm,
• V5-V6 up to 2 mm.

• Normal in limb leads up to 0.5 mm
• V1-V2 ≥ 0.5 mm - deviation from the norm

1. Preservation of the juvenile T waveform: T wave inversion in leads V1 and V2 in a healthy adult.

1. With left ventricular hypertrophy - depression of the ST segment of a convex shape with inversion of the T wave in V4-V6, often with a horizontal position of the EOS - in leads I, aVL, and in a vertical position - II, III, aVF
2. With hypertrophy of the right ventricle - depression of the ST segment of a convex shape with inversion of the T wave in V1-V3.

1. With blockade of LBBB - depression of the ST segment and inversion of the T wave in V4-V6.
2. With the blockade of PNPG - depression of the ST segment and inversion of the T wave in V1-V3.

• mild ST segment depression, or isolated T-wave inversion, or other disorders that are not caused by a specific pathology.

1. ST depression - ischemia
2. ST elevation - fault current
3. Q wave - necrosis (heart attack)

1. Acute ST elevation MI
2. Acute MI with ST segment depression

1. Depth > 1mm.
2. Present in two or more leads.
3. Occurs in two or more consecutive QRS complexes.
4. The form is horizontal or oblique; T-wave inversion is optional.
5. Abnormal ST segment bulge in leads V1-V3 or V2-V4 associated with T-wave inversion; the terminal part of the abnormal ST segment has a typical taut appearance.

1. ST segment depression.
2. Isoline offset.
3. The presence of T-wave inversion or the absence of it.
4. Often associated with small, flat or slightly inverted T-waves.

1. Mild ST segment depression ≤ 1 mm is often seen in healthy individuals.
2. Incorrect application (bad contact) of the electrodes.
3. Ischemia.
4. electrolyte disorders.
5. KMP.
6. Myocarditis.
7. Pericarditis, incl. constrictive.
8. Violation of intraventricular conduction.
9. TELA.
10. Hyperventilation.
11. Drinking cold water.
12. Arrhythmias.
13. The use of drugs (drugs).
14. Alcohol abuse.

With a serious lack of oxygen in the myocardium, cascade changes appear at the biochemical level on the electrocardiogram - elevation or depression of the st segment.

Consider such changes acute until the arguments disprove the assertion.

Somewhere in one out of five cases after the end of an attack of tachycardia, for some time (up to several weeks) there is a decrease in this segment of the art, lengthening of the Q-T interval and unmotivated T waves expressing myocardial ischemia. With prolonged changes on the electrocardiogram, a conclusion about a small-focal infarction is possible.

1. Reduced concentration and attention are manifested in the difficulty of remembering and poor academic performance. Physical activity is also significantly reduced, to the point of stupor, which can be considered lazy. Teenage and childhood depressions are often accompanied by aggressive attacks and increased conflict, which hide self-hatred.
2. The mood gets better in the evening. Loss of self-confidence and low self-esteem. Due to these feelings, the patient moves away from society and strengthens his emerging sense of inferiority. Long depressive periods in patients over 50 years of age are accompanied by deprivation and a clinical picture that is similar to dementia. Persistent gloomy thoughts, pessimistic attitude, increasing guilt, self-deprecation - a familiar state? It is he who is most often shown in all films, associating it with the depression of the art segment. And the patient, as in all such films, thinks about harming himself, and even comes to thoughts of suicide.
3. The patient begins to sleep poorly, may have nightmares, it is very difficult for him to get up in the morning. Appetite worsens, there is a frequent preference for carbohydrate food protein. The desire to eat may appear in the evening. A person in a state of depression has a distorted sense of time: for him, it lasts a very long time.
4. Another important sign is the unwillingness to take care of themselves, which leads to an extremely sloppy appearance, at least.
5. Communication with such a person often comes down to discussing his past problems. The very same speech of the patient is slowed down, and the formulation of ideas becomes a difficult task for him.
6. During the examination, patients look at the light or out the window. Gestures are directed in their direction, hands are pressed to the chest. During anxious depression, the hands are pressed to the throat, the Veragut fold is observed in facial expressions, the corners of the mouth are lowered. When manipulating objects, the actions will be fussy. The voice becomes lower and quieter, there are large pauses between each word, there is low directiveness.

Such reasons may indirectly confirm the diagnosis of st interval depression:

• Dilated pupils.
• Tachycardia.
• Constipation.
• Reduced elasticity of the skin, it becomes flabby.
• The fragility of nails and hair is greatly increased.
• The patient seems much older than his years.
• Because of cravings for foods rich in carbohydrates, weight can increase uncontrollably.
• Sexual attraction increases, because this reduces the level of anxiety.

What can cause depression?

1. At the genetic level, ST depression is caused by the pathology of the eleventh chromosome.
2. With the biochemical path of development of this diagnosis, the exchange of catecholamines and serotonin is complicated.
3. Neuroendocrine development is manifested when the rhythm of the pituitary gland, hypothalamus and limbic system, as well as the pineal gland, is destroyed, due to which the level of production of releasing hormones and melatonin is reduced. Daylight is involved in the creation of these hormones - the less it is, the worse the production.
4. Between the ages of twenty and forty, increased bursts of depressive states are observed.
5. A sharp decline in the social class of a person.
6. The presence of suicide in the family.
7. Loss of loved ones and relatives in adolescents over eleven years of age.
8. The risk group includes people with increased conscience, diligence and anxiety.
9. Naturally, stressful events, problems with the satisfaction of sexual desires also lead to depression.
10. Some doctors add here homosexuality and the period after childbirth.

How does depression develop?

Recent studies in the field of ST-segment depression have helped to link three options for the development of anxiety and hypertension:

• Due to somatovegetative disorders, depression begins and hypertension additionally develops. Due to increased nerve impulses, pressure increases in the smooth muscles of the vessels of the periphery. In this variant, neurocircular dystonia or hypertension is treated, but the initial disturbing factor remains unknown.
• Arterial hypertension develops, and after that anxious depression is added. Such an ailment is considered a more dangerous form for treatment. With the help of electrocardiography, a brain component can be detected, which will allow diagnosing the disease.
• In the third and last variant, depression is manifested as a complication of arterial hypertension. Due to exacerbated symptoms, hypertension and depression, unique clinical pathologies arise, which allows for an accurate diagnosis.

The National Cardiology Center conducted a number of studies. In patients with arterial hypertension, an increased degree of anxiety was observed and there was a high risk of depression when the patient changed his group from the first to the third.

After analyzing the case histories of inpatients, it was found that doctors could make mistakes when prescribing treatment for patients with hypertension. Due to the fact that attention to the patient's anxiety was rarely paid attention to, the ability of antihypertensive drugs to resist the disease fell more and more. While taking medication to suppress the excited state of the brain, which rarely consulted with doctors, blood pressure returned to normal. Naturally, as soon as the medicine was stopped taking, the disease returned.

When establishing a diagnosis, the doctor is based on the reasons that the patient calls. But you should always check for possible mental disorders. With such violations, the clinical picture will be violated.

In the current realities, st depression and arterial hypertension should be observed by both a psychiatrist and a cardiologist. Naturally, it is important that the patient himself participate in the course of treatment, because it is he who uses the drugs and follows the regimen prescribed by the doctor.

How to analyze the causes of depression?

First, let's recap the possible symptoms of ST segment depression:

1. Too much oxygen in the lungs.
2. Decreased potassium levels.
3. Long-term use of antiarrhythmic drugs.
4. Increased concentration of adrenal hormones due to frequent stress.
5. Fibrosis, subendocardial ischemia.

How is st displayed on ekg?

Potassium deficiency is detected on the cardiogram as a pronounced U wave with depression of the ST segment.

Atrial repolarization is noted in leads avf, 3, 2 with a decrease in art. The same situation can be seen with emphysema.

Let's explain the rules that doctors use when observing the electrocardiogram of a patient suffering from coronary disease:

• The traditional way is to consider the offset of the st in the QRS cycles that are above the isoline.
• The bias level itself is found by comparing it with PQ. If you forget about this point, then you can mistakenly set the elevation of the segment.
• The starting point of measurement is after the end of the QRS for sixty to seventy seconds. This is the general standard. In case of ventricular repolarization or suspicion of this, the PQ level is taken as a point.
• Leads AVR and V1 do not make it possible to understand whether the segment has increased or not.
• With a heart rate exceeding one hundred and thirty beats per minute, pathologies can be seen, which incorrectly signals false elevation due to the hard work of the myocardium.

What are the symptoms of ischemic segment depression?

Such a disease is not always realistic to see by clinical symptoms. Rarely, pathology can be detected during the passage of a medical examination. A symptom can be called pain, the source of which is behind the sternum.

If it is present, the doctor carefully examines the source of pain, using the Metelitsa classification:

1. No pain in the pit of the stomach.
2. Physical activity is accompanied by chest pain.
3. Pain in the pit of the stomach, due to which physical activity is impossible.
4. Pain, dissipated by the use of "Nitroglycerin".

Additional visual characteristics of the diagnosis are cold sweat and skin, its blue color, rapid breathing, fatigue in the muscles.

To assess the ability of the heart muscle to respond to an increase in the frequency of contractions, analyzes using physical activity should be carried out.

A healthy person has no pathologies, because his heart adequately responds to increased stress. With exercise, arterial hypertension decreases, in rare cases, increasing systolic pressure.

In the presence of a previous myocardial infarction, myocardial ischemia is an important reason for reduced blood pressure. With pathologically frequent contraction of the heart, reduced functional cardiac capabilities indicate ventricular dysfunction. This situation occurs with the use of cardiotropic drugs.

Evaluation of ST Elevation or Depression Normally, the ST segment is on the isoline. Segment elevation is normal:

• limb leads up to 1 mm,
• V1-V2 up to 3 mm,
• V5-V6 up to 2 mm.

• Normal in limb leads up to 0.5 mm
• V1-V2 ≥ 0.5 mm - deviation from the norm

1. Preservation of the juvenile T waveform: T wave inversion in leads V1 and V2 in a healthy adult.

1. With left ventricular hypertrophy - depression of the ST segment of a convex shape with inversion of the T wave in V4-V6, often with a horizontal position of the EOS - in leads I, aVL, and in a vertical position - II, III, aVF
2. With hypertrophy of the right ventricle - depression of the ST segment of a convex shape with inversion of the T wave in V1-V3.

1. With blockade of LBBB - depression of the ST segment and inversion of the T wave in V4-V6.
2. With the blockade of PNPG - depression of the ST segment and inversion of the T wave in V1-V3.

• mild ST segment depression, or isolated T-wave inversion, or other disorders that are not caused by a specific pathology.

1. ST depression - ischemia
2. ST elevation - fault current
3. Q wave - necrosis (heart attack)

1. Acute ST elevation MI
2. Acute MI with ST segment depression

1. Depth > 1mm.
2. Present in two or more leads.
3. Occurs in two or more consecutive QRS complexes.
4. The form is horizontal or oblique; T-wave inversion is optional.
5. Abnormal ST segment bulge in leads V1-V3 or V2-V4 associated with T-wave inversion; the terminal part of the abnormal ST segment has a typical taut appearance.

1. ST segment depression.
2. Isoline offset.
3. The presence of T-wave inversion or the absence of it.
4. Often associated with small, flat or slightly inverted T-waves.

1. Mild ST segment depression ≤ 1 mm is often seen in healthy individuals.
2. Incorrect application (bad contact) of the electrodes.
3. Ischemia.
4. electrolyte disorders.
5. KMP.
6. Myocarditis.
7. Pericarditis, incl. constrictive.
8. Violation of intraventricular conduction.
9. TELA.
10. Hyperventilation.
11. Drinking cold water.
12. Arrhythmias.
13. The use of drugs (drugs).
14. Alcohol abuse.

ST interval depression is distinguished as reflected (reciprocal, discordant) changes in myocardial damage in opposite departments. For example: ST depression in standard I, aVL, V2, V4 in case of left ventricular posterior wall infarction and left ventricular hypertrophy in hypertensive disease. In the first case, the depression will be horizontally directed parallel to the isoline. With hypertrophy, the depression of the segment will be oblique, less pronounced starting from the S wave and more pronounced as it approaches the T wave. As a result of such depression, together with the first (negative) phase of the T wave, it (segment) forms an isosceles triangle, the shape of which resembles the blockade of the left leg bundle of His. The difference is that with blockade, the QRS complex will be widened (> 0.10 sec). Another difference between depression in hypertrophy and reciprocal depression is that it is persistent and does not change in the near future under the influence of medications: therapy with anticoagulants, thrombolytics, nitroglycerin tests, after stopping an attack of angina pectoris, etc.

Many years of experience in cardiology (turned 50 in 2010) convinced us that if there are even minor changes, in particular, in the ST segment, on the image taken against the background of a pain attack or immediately after it, then they deserve the most serious attention, even even these displacements are 1 - 2 mm, although this contradicts the statements of the authors of many ECG manuals. The remark concerns, first of all, the disposition of the ST segment, when there is still no classical rise, but it is no longer horizontal. The initial part of the segment is a point J is located on or almost on the isoline, but the final part tends to merge with the T wave, due to which the T wave is not so clearly visible, the depression between it and the final part of the segment appears to be smoothed. As confirmed by our long-term observations (V.A. Fialko, V.I. Belokrinitsky), continued later by our interns, these changes should be considered as the earliest manifestations of myocardial ischemia, which can be transient (Fig. 19). We have named this phenomenon "slant-rise ST". Under the influence of adequate therapy, such a shift may reverse, i.e., the ST segment will become isoelectric, in those cases when the pathological process cannot be prevented, we will get a classic picture of myocardial infarction with elevation, reciprocal changes, etc. Therefore, ignoring the described changes in the so-called "small signs" can lead to a catastrophe.

Nonetheless. V.V. Murashko, A.V. Strutynsky give this small feature as a variant of the norm [12]. The obliquely ascending ST segment leads to and . Plots [24], but his point J is above the isoline therefore, it is more correct to consider this form as a kind of ST segment elevation. V. N. Orlov [8] also gives a skew-ascending segment, however, in his illustration, the point J is below the isoline. (Fig. 20 a, b, c). Some authors allow a small (1 - 2 mm) segment lifting(including the point J, as a variant of the norm). In fact, we are talking about the classic ST segment elevation, which is a manifestation of acute ischemia, and the difference, according to these authors, is only in the height of the elevation. Maybe for the conditions of the hospital stage, such a point of view is not essential (the patient is still in the hospital), but not for the ambulance or clinic! After all, here it is necessary to decide whether these changes are acute or not. Therefore, having met with such a patient and such an electrocardiogram, the doctor of the first contact should внимание!} first of all, to complaints, to compare this attack with those that took place earlier, that is, to what is called the history of an attack, and not to focus on counting millimeters of elevation, whether it exceeds the notorious limits of the norm or not. One student in the ambulance cycle test said that she witnessed how a young doctor on duty at one of the city’s clinical hospitals refused to admit a patient to an ambulance team (the student was on duty as part of this team), arguing her refusal by the fact that ST segment elevation was not exceeded 2 mm!. "Reverence" for the notorious millimeters leads to errors that at the pre-hospital stage are sometimes quite costly for patients. And the doctor, who made a diagnostic, and possibly, after it, a tactical mistake, when parsing for LEC, in his defense declares that it is written in the manuals. This is what happens when, instead of an in-depth analysis, a logical understanding of all the data obtained, including ECG data, with the leading role of the clinical picture, they are taught to count millimeters.

Such statements of the doctor need comments. Of course, it is good that doctors are reading monographs, which are now not lacking. But they are written by different authors, whose views may not coincide. The same situation occurs when doctors undergo advanced training at various GIDUV: different schools, different views.

Therefore, you need to be guided in your work not by the information that you received from monographs or lectures - today one, tomorrow another, but by those principles that are accepted in your institution and approved by standards (protocols).

We think that the thesis about the permissible limit of ST segment elevation would be correct to state in the following edition:

“If the patient has no complaints, we emphasize - without any complaints, during an ECG examination, like a random find a small ST segment elevation with or without J-point elevation, only in this case such a picture may not cause alarm. But if an emergency doctor, polyclinic, hospital emergency department, when examining a patient about complaints of pain in the chest, epigastrium, back, in the heart, against the background of a hypertensive crisis with or without shortness of breath, with differential diagnosis with radiculalgia, will find even a slight elevation, or so-called. the “oblique-ascending ST” phenomenon, with or without J-point shift, especially if these signs were not present on previous electrocardiograms - the data obtained in combination with the clinical manifestation should be considered as the earliest manifestations of OCP with the adoption of appropriate measures - reliable pain relief, antiplatelet therapy , anticoagulants, hospitalization.

If, during examination in a hospital, the initial Diagnosis, -a; m. A brief medical report on the disease and the patient's condition, made on the basis of an anamnesis and a comprehensive examination. From Greek. — recognition, diagnostics, and; and. 1. A set of techniques and methods, including instrumental and laboratory ones, that allow to recognize the disease and establish a diagnosis. From Greek. - able to recognize. 2. Diagnosis, dialysis, -a; m. peritoneal dialysis. A method for correcting water-electrolyte and acid-base balance and removing toxic substances from the body with the introduction of a dialyzing solution into the abdominal cavity.

We will try to illustrate what has been said with examples taken from many years of experience in the cardiological ambulance service of our city.

Figure 21 "A" shows the ECG of patient O., 56 years old, recorded by the cardiology team at the first visit.

In the chest leads, the described phenomenon is clearly visible, when there is still no pronounced elevation of the ST segment, but it is not isoelectric either, its final part, as it were, tends to merge with the T wave (See above). For clarity, a figure from the monograph by V.V. Murashko and A.V. Strutynsky [12], which is interpreted as a variant of the norm, is shown in the box. This ECG, combined with clinical picture was interpreted as a manifestation of acute coronary pathology. The patient was given Heparin. 1. Polysaccharide formed by residues of glucuronic acid and glucosamine; contained in the extracellular substance of the liver, lungs, arterial walls; direct-acting anticoagulant, blocks thrombin biosynthesis, reduces platelet adhesion, increases vascular permeability; stimulates collateral ("bypass") blood circulation, has an antispasmodic effect; so-called component against the blood coagulation system.