The case was sent by Steffen Grautoff, an urgent care doctor and a cardiologist working at the "ambulance" in the north-west of Germany. Original - see.

Steffen wrote:

"A few weeks ago I was able to learn the IMTST because I saw such a case in your blog."

"I recorded an ECG 50-year-old man who complained about pain in the chest. I was at my workplace (in Germany, doctors work at the "ambulance). Surprisingly, the patient 2 days ago made a long cycling trip without any complaints. "

"In addition to hypertension, he had no other risk factors atherosclerosis. However, immediately I was not quite sure that his problem was coronary. "
"But when I looked at his ECG, I smiled, because I remembered the message in your blog."

In Germany, ECG is recorded at a speed of 50 mm / s:

What do you think?

Below, in the image, I squeezed them so that they look like as if recorded at a speed of 25 mm / s. I also made them side by side:

The same, but at a speed of 25 mm / s.

What do you think?

Steffen also wrote:
"I remembered the ECG from your blog under the heading:" Iptst is better visible in the extrasystole, diagnosed the paramedic, ignored the doctor" year 2013. ECG looked similarly (although it was recorded at a speed of 50 mm / s) and, which is not surprising - when angiography was found an occlusion of PMJ. "

What does Shteafene say?

Look at V2 and V3. HA has the morphology of the blockade of the right leg (QR or RSR), because it occurs in the left ventricle. ST Segments for morphology The blockade of the right leg should be shifted in the opposite direction from the terminal teeth R ". That is, there must be a small depression of the segment of ST. But there is its element, the concordant teeth R. This is a very specific feature of T1im (acute front of them due to occlusion of PMJV).

We also note that in the complex of the HE in V4-V6 there are giant coronary tons, which are much more pronounced than no more moderately acute T in sinus complexes. In fact, from normal complexes, only in V4 has obviously acute T.

The acute coronary T in the complexes of HE are visible and in leads from the limbs.
This case, Shteaffen meant: Stemi Seen Best in Pvc, Diagnosed by Medic, Ignored by Physician (text in English, Sorry, hands did not reach).

Ken Grauer

Un Grand Merci. Dr. Steffenu for the presented this case in which there is a pearl, facilitating the recognition of acute impst in the morphology of the ventricular extrasystole! Its case perfectly demonstrates how sometimes acute coronary occlusion can only be recognized in the complexes of the HE!
========================

ECG, which we are discussing ("compressed" version).

• Rhythm - stomatricular bigemia. According to Dr. Smith - an assessment of normal (sinus) complexes on this record does not give a final response to the presence of acute T1im (myocardial infarction associated with occlusion). In leads V1 and V2 there is small Element St.; and, perhaps, acute coronary T in v4 (and, probably, v3); as well as thin reciprocal changes in the lower leads - But they are not enough to confirm the diagnosis.
• But how clearly was captured by Dr. Stephen - based on the morphology of the HE appears enough ECG evidence of acute T1I!
• Most remarkable anomaly morphology HE is observed in the V2 assignment. To clarify the moments noted by Dr. Smith above, I spent vertical Red A line parallel to the vertical lines of the grid, which indicates the end of the QRS HE complex in leads V1 and V2. Intermittent red line extended to demonstrate the end of the QRS HE complex in V3-V6 leads, as well as in leads from the limbs. Short horizontal Yellow lines Indicate the position of the baseline.
• In the HE in V1 elevation of the ST segment, it is usually observed in the HE related to them. However, it should be obvious that in the complex of the HE in V2 and V3 there is a significant element of the point J, which simply should not be. In addition, there is a terminal inversion T in the Ze complexes in the V2 assignment ( Red arrow). Evaluate the entire QRST HE in the V2 assignment. Is the complex not similar to the morphology of acute impste? (Look, I broke it Blue Rectangle).
• The morphology of the ST-T wave of HE in many other leads demonstrates an increased amplitude t, which in the context of diagnostic changes in the morphology of the HE in V2 and V3 consistent with acute T. In these HEs. And in the context of the explicitly abnormal position of the point j ST in the complexes of the HE in V2 and V3, dotted red lines in leads V3-V6 suggest that in these leads there is also an abnormal element of ST for. The overall picture strongly indicates the acute occlusion of PMIV!

P.S: The overwhelming majority of ECG changes due to them will be diagnosed based on changes in the morphology of ST-ST in sinus complexes. But in the last decade, experts began to pay attention to the morphological changes of ST-T in ventricular extrasystoles - And I found an amazing number of cases when acute it was obvious by morphological changes of the HE. And sometimes (as it takes place in this case) - acute T1im can only be obvious when assessing the morphology ST-T ventricular extrasystole.

• Actually PEARL: If you can without a doubt To say that in one or two leads, the morphology of ST-T in ventricular extrasystoles is not normal (as in this case in V2 and V3), then it becomes much easier to appreciate the ST-T disorders in the extrasystole complexes and in other leads.

Depression segment of St.In turn, manifests itself in the form of elevation of ST segment, since electrocardiographic recorders in clinical practice use AC amplifiers that automatically compensate for any negative shift of the TQ segment. As a result of this e-compensation, the ST segment will be proportionally raised. Consequently, according to the theory of diastolic current of damage, the rise of the ST segment is an imaginary offset.

True offset that can only be observed if ECG-amplifier DCIt is that the TQ isolate is located below the usual, taking a negative value.

This hypothesis suggests that ischemic lifting ST. (And strongly pointed teeth T) is associated with systolic damage current. Change the extracellular charge of myocardial cells in a state of acute ischemia, three factors are capable of relatively positive (compared to normal cells) during electrical systole (Qt interval).
(1) pathologically early repolarization (shortened duration of PD);
(2) Slowed speed of the ascending PD knee; (3) Reduced PD amplitude. The presence of one or more of these factors create a voltage gradient between the normal and ischemic zones during the Qt interval. Thus, the damage current vector will be directed to the zone of ischemia.

Mechanism of this systolic current Damage will result in the primary lifting ST, sometimes with high positive (sharp) teeth

When acute ischemia It is a transmural (due to diastolic and / or systolic current of damage), the total vector is usually mixed in the direction of external (epicardial) layers, and the Elevation of ST and sometimes high positive (sharp) teeth of the S.T. may appear on the zero of the ischemia. Distributions registering signals from the contralateral surface of the heart.

Sometimes recycling changes may be more explicit than the primary element of ST. When ischemia at the initial stage is limited by subendocardium, the general vector ST is usually shifted in the direction of the inner ventricular layer and the ventricle cavity, so the leads located above them (for example, the front chest) demonstrate the depression of ST segment with the ST of the ST in the AVR assignment.

Such a picture subendocardial ischemia Typical during spontaneous episodes of stress angina, symptomatic or asymptomatic (nonsense) ischemia, provoked by load or pharmacological stress studies.

On the amplitude of the changes of ST In case of acute ischemia, multiple factors can affect. Pronounced (explicit) Element or depression of ST in many leads usually indicates a very heavy ischemia. On the contrary, the rapid elimination of ST lifting during thrombolytic therapy or percutaneous coronary intervention is a specific marker of successful reperfusion.

These relationships, however, are not universalbecause Heavy ischemia or they may be accompanied by small changes in ST-T, and may not be accompanied by them. Moreover, the relative increase in the amplitude of the T (Giant Teeth T) can be combined or preceded by the late ST due to the damage current generated by myocardial ischemia with or without it.

Training video ECG during angina and types of depression segment ST

Download this video and view from another video hosting on the page :. Table of contents of the topic "Electrocardiogram for blockades and ischemia myocardium":

Cardiovascular diseases, in particular ischemic disease Hearts (IBS) are the leading cause of death in Russian Federation. In 2007, 1.2 million people died from the diseases of the circulatory system.

Currently, there are highly efficient treatment methods that allow not only to reduce mortality from myocardial infarction, but also reduce the likelihood of developing heart failure, heart rhythm violations and other complications leading to disability.

The effectiveness of treatment depends on the timeliness of the diagnosis of myocardial infarction. This article presents modern criteria Electrocardiographic diagnostics acute forms HebS. They can be used by the emergence medical careThe tasks of which include intensive therapy in patients with acute coronary syndrome (OCS) and ensuring their transportation to the hospital.

Dynamics of electrocardiographic signs of OX

The development of myocardial ischemia at ACS primarily manifests changing T. T.. With complete occlusion of the coronary arteries, a high and wide teeth of T is formed, on average 30 minutes after the development of clinical manifestations of the OX.

When analyzing the ECG patient from the OCC, it is important to take into account not only the size and the presence of inversion of the teeth T, but also its form. Variants of changing the teeth in the first hours of the penetrating myocardial infarction are presented in Fig. one.

Fig. 1. Options for changes of the tooth t as a sign of long-term myocardial ischemia characteristic of the acute phase of OUT: A- Teeth T in V4 is very high and wide, in size exceeds qRS complex; Quality V3 - depression of the ST segment at point j and a wide high tonnet; Highly high t, much more QRS complex; D- very high pointed teeth t, in shape resembling such with hypercalemia (this option is less common)

Under OIM, with the element of the ST segment, the T, on average after 72 hours from the beginning of the disease, becomes negative, but not deeper than 3-5 mm. In the future, as a rule, after a month, the shape of the Tuska T is normalized; If this happens earlier, it should be excluded by repeated OEM with "pseudonormalization" of T. T.

In case of incomplete occlusion of the coronary artery, the inversion of the teeth T, it becomes negative in those responsibilities, where it should be (or was compared with the previous ECG) positive. More criteria for changing the teeth T against the background of ischemia without lifting the ST segment are presented below.

• teeth T should be positive in leads I, II, V3-6;
• tusk T must be negative in AVR assignment;
• tusk T may be negative in III, AVL, AVF, V1, less often in V1, and with the vertical location of the electric axis of the heart in young people and in the second lead;
• when persistent juvenile ECG Teeth T may be negative in V1, V2 and V

• the depth of the negative teeth T exceeds 1 mm;
• inversion of Tissue is registered at least in two neighboring leads;
• the depth of the tissue T in V2-4 leads, exceeding 5 mm, in combination with an increase in the corrected interval Q - T to 0.425 ° C and more, in the presence of teeth R, it may be the result of spontaneous reperfusion and develop as a result of an ACS with the lift ST.

Formation pathological teeth Q. It may begin after 1 hour after the development of occlusion of the coronary vessel and end after 8-12 hours from the moment of the development of the SMX symptoms. Below are the characteristics of the pathological teeth q, depending on the lead in which the ECG is recorded:

1. in the brand V2, any q tooth is considered pathological;
2. in decomposition V3, almost any prong Q testifies to the presence of violations;
3. in the V4 brace, the Tusk Q is deeper than 1 mm or wider than 0.02 seconds, or deeper (wider) q q in the brand V5 is not registered;
4. in III, the definition q should not exceed 0.04 s in width and make up more than 25% of the value of the R;
5. in the rest of the leads, the q should not be wider than 0.03 s;
6. the exceptions are the leads of III, AVR, and V1, where nonpautological wide and deep q teeth can be recorded, as well as the AVL lead, where the q can be wider than 0.04 C or deeper than 50% of the magnitude of the Tusque R with the presence of a positive teeth. In this definition.

Lifting segment St. With complete occlusion, the coronary artery develops quickly and stabilizes to 12 hours from the beginning of the development of symptoms.

When analyzing the ECG, estimating the elevation value of the ST segment, it is important to take into account not only the degree of its lifting, but also the form of its element. In fig. 2 shows the characteristic dynamics of changes in the ST segment with the forming myocardial penetrating infarction.

Fig. 2. Dynamics of changes in repolarization on the background of an ox with the lifting of the ST segment. Initially, the normal segment of ST at 07:13 has a concave shape, at 07:26 it straightened (from point j to the top of T straight line), then acquired a convex shape, and at 07:56 the elevation of the ST segment increased, which is characteristic of the OIM segment of St.

Thus, if the ST segment acquires a convex form, and its element has not yet reached the critical level, it is necessary to regard these changes as subepicardial damage, which should be treated with reperfusion thrombolytic therapy.

However, repolarization changes are not always starting with changes in the form of the ST segment. In some cases, this segment remains concave and element is formed against the background of continuing ischemia. This embodiment of the ST segment is diagnostically more favorable, since the area of \u200b\u200bmyocardial lesion in this case is substantially less than with the convex form of ST.

Occasionally the form of the ST segment remains concave, and the rise of it is so insignificant that signs of heart attack can not be noticed, in this case, the analysis of the shape of the T. T.

In interpretation, the presence of the "ischemic" tape characteristic of the acute phase of OIM, reciprocal changes in the form of depression of ST segment, ECG in dynamics (comparison with the original and in the process of observation), form (convexity) of the ST segment, as well as the presence of pathological teeth Q.

Criteria for estimating the element of the ST segment when

1. The degree of lifting segment ST is estimated by the location of the point J (the transition site of the QRs complex to the ST segment) relative to the top level of the range of R - R. The changes should be registered at least in two consecutive leads.

1. For men, over 40 years old, the rise of ST segment for 2 mm and more in breasts V2-3 and 1 mm and more in leads I, II, III, AVR, AVL, AVF, V1 and V4-6 are considered pathological.

1. For men under 40 years old, the elevation of ST segment, exceeding 2.5 mm in leads V2-3 and 1 mm and more in leads I, II, III, AVR, AVL, AVF, V1 and V4-6 are considered pathological.

1. In women, the elevation of the ST segment exceeding 1.5 mm in V2-3 and 1 mm leads, in leads I, II, III, AVR, AVL, AVF, V1 and V4-6, is considered pathological.

1. With a low-voltage, the less pronounced rise of the ST segment (0.5 mm and more) can be considered diagnostically significant.

1. In additional leads V7-9, the lifting of 0.5 mm is diagnorated.

1. In additional leads V3-4, the rise R by 0.5 mm is considered pathological.

1. Elevation of the ST segment may be transient, in 20% of cases, spontaneous thrombolysis occurs.

1. Myocardial side infarction against the background of complete occlusion of the left envelope of the artery or the diagonal branch of the front interventication coronary artery can lead to the development of a penetrating Oim without signs of lifting ST or with a very insignificant Elevation of st only in AVL assignment. Potentials of the side wall are worse than all reflected in the standard ECG shooting.

1. The degree of depression is estimated at point J and correlates with the lower level of the range of R - R.

1. Depression is pathological only if it is registered at least in two consecutive leads.

1. The depression of the ST segment cannot be a sign of a subendocardial infarction, if it is a reciprocal.

1. The depression of ST segment, reaching 0.5 mm and more registered in leads V2-3 and (or) component of 1 mm and more in leads I, II, III, AVR, AVL, AVF, V1 and V4-6, is regarded as a sign acute subepocardial infarction (damage) of myocardium.

1. The appearance of depression with a depth of 0.5 mm, not being a sign of a subendocardial infarction, indicates an increased risk of its development. If she persists, despite the use of the entire arsenal of appropriate therapy, it is advisable to conduct a coronarylasty for 48 hours.

1. The depression of ST segment exceeding 2 mm, registered in three or more leads, indicates an unfavorable forecast. The risk of death is 35% over the next month and 47% for 4 years, if coronoplasty is not performed.

1. The depression of ST segment in eight and more leads when combined with element in AVR / V1 leads is a sign of the defeat of the main trunk of the left coronary artery or the defeat of several large coronary arteries, if it reaches 1 mm.

It must be borne in mind that the criteria ischemic changes The ECG is not used to identify myocardial infarction, if the patient has disorders of intraventricular conductivity with pronounced changes in repolarization, Wolff Syndrome - Parkinson - White, ventricular replacement rhythm, as well as an artificial rhythm driver, stimulating ventricles. In these cases, there are source violations Repolarization and changes in the ventricular complex.

Signs of ventricular hypertrophy, thromboembolism pulmonary arteriesAlso, electrolyte disorders make it difficult to diagnose the OX. In these cases, first of all, take into account clinical manifestations Diseases.

The definition of myocardial necrosis markers (troponin or MB fraction of the KFC) and ECCG, carried out in the hospital during the observation process, will help verify the diagnosis.

In some cases, the rise of the ST segment is detected in patients without acute coronary syndrome; So, in young men, the elevation of the ST segment can reach 3 mm in right-wing infants. In addition, in the early repolarization syndrome, the rise of ST segment is recorded, which has a concave form and is maximally expressed in the V4 assignment; Examples of such changes are presented in Fig. 3.

Fig. 3. Variants of the lifting of the ST segment normally: A- characterized for male people, is more often registered with young people; early repolarization b-syndrome; Non-specific changes of repolarization, manifest themselves to the concave lifting of the ST segment, the inversion of the teeth T, the characteristic feature - the short interval Q- T

Features of changes to the ECG depending on the localization of them

When analyzing the ECG, it is important to take into account the features of changes characteristic of various options for localization of ischemic damage.

Acute myocardial infarction with the lifting of ST segment can manifest itself a reciprocal depression in certain leads. In some cases, when registering an ECG in 12 standard leads Reciprocal changes are expressed more distinctly than direct signs of myocardial damage. Sometimes on the basis of the presence of reciprocal depression in order to identify direct signs of myocardial infarction, it is required to remove additional leads to diagnose OX with the lifting of the ST segment.

Much depends on the variant of occlusion of the coronary arteries (the anatomical location of the coronary arteries is represented in Fig.).

When persistent occlusion the main trunk of the left coronary arteryusually develops cardiogenic shock fatal. The ECG detect signs of an extensive front-part-based infarction with a side wall capture.

With subtotal occlusion of the main trunk of the left coronary artery, the ECG is detected by the depression of the ST segment over 1 mm in 8 or more leads in combination with the element of the ST segment in the leads of AVR and (or) V1.

If occlusion front interventricular artery There was a distal to death of the diagonal branch, the forehead of myocardial is developing, which is manifested by the formation of infarctional changes in V2-4 leads, with such localization of OIM reciprocal changes are usually not detected.

Violation of blood flow on the anterior interventricular coronary artery (grid) is proximal than the disheaval of the diagonal branch leads to the development of an advanced oim. The presence of signs of the forefish is combined with the lift ST in the AVL assignment, the rise of 0.5 mm is a highly sensitive feature of OIM, and 1 mm is a highly specific feature of the proximal occlusion spacing. With this variant of occlusion, reciprocal changes in the III assignment are recorded.

With the complete absence of blood flow to the mump (occlusion proximal than the disheaval of the partition branch), changes are appear not only in V2-4, but also in leads AVR, AVL and V1.

Elevation of the ST segment in V1 is not a specific feature of the OIM and is often found in the norm, however, the element of the ST segment exceeding 2.5 mm is a reliable criterion for damage to the partition and (or) of the front basal departments, which was established when comparing ECOG data with electrocardiography data .

Reciprocal changes in the form of depression of ST segment are recorded in leads II, III, AVF and V5. ST of the ST segment in AVR, excess the amplitude of the reciprocal depression of the ST segment in III assignment over the lifting of the ST segment in AVL, the depression of ST in V5, as well as the blockade of the right leg of the Gis beam belongs to the conclusions of occlusion sprinkle branch.

At occlusion lateral branch of the left envelope coronary artery or diagonal branch MPThe sidewall heart attack develops. Such an infarction approximately in 36% of cases is manifested by the Lift ST in the AVL assignment, as a rule that does not exceed 1 mm. Only in 5% of cases, the rise of ST reaches 2 mm. In 1/3 patients with lateral oim, there are no changes to the ECG, in 2/3 cases there are some lifting or some depression of the ST segment.

The most reliable sign of OIM with the lifting ST is reciprocal changes in the form of depression of ST segment in leads II, III and AVF. In case of occlusion, the magnifier or PKA side infarction is manifested by the Limit of ST significantly more often - in 70-92% of cases. In case of occlusion, the olter of the side wall is often combined with rear oim.

Approximately 3.3-8.5% of cases of myocardial infarction confirmed by results biochemical analysis (MV-KFK and Triponin Test), has rear localization. Since the ECG registered in 12 standard leads, changes in the form of a lifting of ST segment are not detected, the insulated Oim rear wall can remain not diagnosed.

It is possible to reveal the OIM rear wall by reciprocal changes in right-wing infants. Changes will be manifested by the depression of the ST segment in leads V1-4 (sometimes only in V2-4, if a small election was initially in the limits of normal values \u200b\u200bin the V1 assignment, and sometimes only in v1).

In addition, high reciprocal teeth R are often recorded in right-wing briefs as a result of the formation of q in leads characterizing the potentials of the rear wall. In some cases, to identify the reciprocal depression in the right-wing infants is not easy, since many patients have a small lift of ST in V2-3 and reciprocal depression will be less distinct, therefore ECG score is important.

To confirm the rear OEM, it should be removed the ECG in additional leads V7-9 (the fifth intercosta, the rear axillary line - V7, the vertical line from the angle of the left blade - V8, the left paravertebral line - V9). Routine analysis of additional assignments in all patients with pain in chest It does not apply, since the presence of reciprocal changes in the right precartial leads is a fairly sensitive sign of the rear OEM.

Blood supply bottom wall left ventricle in 80% of cases right coronary artery (PKA), in 20% - rising branch (OB) LKA.

Occlusion of PKA is the most frequent cause Development of the Lower Myocardial Infarction. With proximal occlusion of PKA, above the removal of the branch of the right ventricle, the development of the lower infarction is combined with the formation of the infarction of the right ventricle.

On the ECG infarction The lower wall is manifested by the formation of the element of the ST segment in leads II, III and AVF and is almost always accompanied by the presence of reciprocal depression in the AVL assignment.

If the cause of the development of the lower infarction is occlusion envelope branch of LKAThe ECG there are signs of damage not only lower, but also the rear, as well as the side walls of the left ventricle.

Since, with a combination of lower and lateral infarction, reciprocal depression in AVL, which is a consequence of the lower infarction, is levied by the lifting of the ST segment, which is a sign of a side infarction, in the AVL assignment is not recorded. However, in leads V5-6, the rise of the ST segment, as a sign of myocardial lateral infarction, should be detected. If there is no reciprocal depression in the ST segment and the signs of lateral infarction in V5-6 are absent, then the lifting of ST in leads II, III and AVF can be considered as a pseudo-infarction.

The proximal occlusion of PKA leads to the development of Oim right ventricle (PJ) against the background of Lower Oim. Clinically, such a heart attack is manifested by the development of hypotension, deterioration of well-being from the use of nitrates and improved well-being against the background intravenous administration solutions. The short-term forecast is characterized by a high probability of developing complications with fatal outcomes.

The ECG OIM PJ is manifested by the lifting of ST segment in V1-3 leads and simulates the head-and-part-based myocardial infarction. Characteristic feature The infarction of the right ventricle is the severity of the lifting of the ST segment in v1-2, unlike the OIM front-partitioning localization, at which the maximum element of the ST segment is observed in the V2-3 leads.

To verify the infarction of the right ventricle, it is necessary to remove additional right-wing infants: V4R (the electrode for registration of breasts should be positioned at the point in the fifth intercostriety on the middle-heartless line of the right) and V3R (registered on the site located between the location of the electrodes for the recording of V1 and V4R).

The rise of the ST segment in the V3-4R leads by 0.5 mm and more is considered to be diagnostically significant. ECG in additional leads V3-4R should be removed in cases where changes are recorded characteristic of the lower myocardial infarction.

When combined with pronounced hypertrophy of the right ventricle, the rise of ST in breast leads can be essential and resembles an front heart attack even with lifting in leads II, III and AVF.

In conclusion, it is important to note that in general, the sensitivity of the ECG diagnosis of myocardial infarction, according to foreign cardiologists and emergency medical specialists, is only 56%, therefore, 44% of patients with acute infarction Electrocardiographic signs of the disease are absent.

In this regard, with symptoms characteristic of acute coronary syndrome, hospitalization and hospital observation is shown, the diagnosis will be established on the basis of other methods of examination.

At the same time, the ECG is the method that allows you to determine the presence of indications for thrombolytic therapy. According to the recommendations of the All-Russian Scientific Society of Cardiologists, with complete occlusion of the coronary artery, it is advisable to conduct thrombolysis in order to restore the blood supply to myocardium.

In this regard, when identifying the element of the ST segment to the ECG in a patient with clinical signs Acute coronary syndrome shows emergency hospitalization in that hospital, in which thrombolytic therapy is possible. In other cases, hospitalization is recommended with a diagnosis: "OX without lifting ST" in any hospital, where there is a resuscitation separation.

O. Yu. Kuznetsova, T. A. Dubikaitis

Reflects the spread of the excitation wave into the basal departments of the interventricular partition, the right and left ventricles.

1. Optional negative prong, next to the prong r, may be absent in leads from the limbs andV5-6.

2. In the presence of several teeth, respectively s,

S`, s``, s``, etc.

3. Duration less than 0.04 seconds, amplitude in chest

the highest leads in the V1-2 leads and gradually decreases to V5-6.

Segment St.

Corresponds to the period when both ventricles are completely covered by excitation, is measured from the end S to the beginning of T (or on the end R in the absence of teeth S).

1. The duration of ST depends on the pulse frequency.

2. Normally, the ST segment is located on the isolated, depression of ST

not more than 0.5 mm (0.05 mV) in V2-3 leads and not more than 1 mm (0.1 mV) in other leads.

3. Its lift should not exceed 1 mm in all leads exceptV2-3.

4. In the leads V2-3 pathological leads should be considered the rise of the ST segment ≥2 mm (0.2 mV) in persons over 40 years old, in persons younger than 40

years ≥2.5 mm (0.25 mV) in men and ≥1.5 (0.15 mV) in women, respectively.

Teeth T.

Reflects the processes of ventricular repolarization. This is the most labilecloth.

1. In the norm, the Tusk is positive in those responsibilities where the QRS complex is presented mainly by the R.

2. With a normal arrangement of the heart, the Tusk T is positive in leads I, II, III, AVL and AVF, negative in the AVR assignment.

3. T III can be reduced, isoelectric, weakly negative with the deviation of the electrical axis of the heart to the left.

4. In definition V 1, the Tusk with the same frequency may be negative, isoelectric, positive or

two-phase, in the V2 assignment more often positive, in leads V3-6 is always positive.

With a qualitative description, a low tooth should be released if its amplitude is less than 10% of the amplitude of the R teeth R in this assignment; bleached with amplitude from -0.1 to 0.1 mV; invertedteeth T in leads I, II, AVL, V2 -V6, if its amplitude is from -0.1 to -0.5 mV; Negative with amplitude from -0.5 mV and more.

Qt interval (QRST)

Reflects electrical systole heart. It is measured from the beginning of the q (or r if q is missing) to the end of the T. T.

1. Duration depends on gender, age, rhythm frequency. Normal QT value (corrected Qt; QTC)

2. Normal QT values \u200b\u200bfluctuate within0.39-0.45 seconds.

3. If the measurements are made in different leads, as a basis

the greatest importance is taken (usually in the V2 - V3 is assigned).

4. The lengthening of the Qt interval is considered to be 0.46 seconds and more, in men 0.45 seconds and more, shortening - 0.39 seconds and less.

Tusk U.

A non-permanent, small amplitude (1-3 mm or up to 11% of the amplitude of the Tusque T), the teeth, the concordant (unidirectional) teeth T, the next after it is 0.02-0.04 seconds. The most pronounced in leads v2 -v3, more often in bradycardia. Clinical significance is not clear.

Segment Tr.

Reflects the diastole phase of the heart. It is measured from the end of the teeth T (U) to the start of the Tian R.

1. Located on an isolated, the duration depends on the frequency of the rhythm.

2. With tachycardia, the duration of the TP segment decreases, in bradycardia - increases.

RR interval

It characterizes the duration of the full cardiac cycle - systole and diastoles.

1. To determine the heart rate, it is necessary to divide 60 to RR, expressed in seconds.

IN cases where the rhythm frequency in one patient differs in a short period of time (for example, when atrial fibrillation),

maximum and minimum rhythm frequencies should be determined for the largest and smallest RR value or calculate the average rhythm frequency of 10 consecutive RR.