Determination of the axis on the ecg. Normal position of EOS #8212; What is this. General information about pathology

Electrical axis of the heart is the average direction of the electromotive axis of the heart over the entire period of depolarization. The usual direction corresponds to + 59, but even in a healthy heart, a deviation in the location of the electrical axis on a scale from + 20 to + 100 is possible. Deviation of the electrical axis of the heart to the right is observed when the heart physically moves to the right and this indicates hypertrophy of the right cardiac ventricle or that the left ventricle has lost its activity.

What kind of phenomenon is this and how can you determine whether there is a deviation of the electrical axis?

The position of the axis is determined by the state of the His bundle and the cardiac ventricular muscle. This is influenced to some extent by the position of the heart. According to the correct position, the electrical axis is from the apex to the base almost parallel to the anatomical axis of the heart. The direction of the axis depends on the following factors:

Location of the heart in the chest;

The relationship between the mass of the ventricular myocardium;

Focal myocardial lesions;

Disturbances in the conduction of impulses to the ventricles.

The electrical axis of the heart moves to the right side in the following cases:

In people of asthenic type;

For thromboembolism pulmonary artery;

With hypertrophy of the right ventricular myocardium. Here the heart deviates to the right for some reason. First of all, in the hypertrophic ventricle the excitation of an additional number of fibers is very high and therefore its electrical potential has increased. It also takes longer to excite the ventricle compared to the norm. Therefore, the normal ventricle depolarizes much earlier in time than the hypertrophied ventricle, since it remains electropositive;

For congenital heart defects.

You should know these factors:

If the heart axis is deviated to the right in newborns, then there is no pathology. And this condition cannot be considered as right ventricular hypertrophy, since in newborn babies a deviation angle of +100 is a common phenomenon. Many children have this manifestation even in the first months of life, especially those who live in areas with harsh climates and in high mountains. Deviation to the right occurs in small children with blockade of the left posterior branch of the His bundle.

Projection of the average result vector QRS to the frontal plane is called average electric axle heart (AQRS). Rotations of the heart around the conventional anteroposterior axis are accompanied by a deviation of the electrical axis of the heart in the frontal plane and a significant change in the configuration of the complex QRS in standard and reinforced unipolar limb leads.

As shown in Fig. 4.10, the position of the electrical axis of the heart in the six-axis Bailey system is quantitatively expressed by the angle a, which is formed by the electrical axis of the heart and the positive half of the axis of the standard lead. The positive pole of the axis of this lead corresponds to the origin - 0 negative - ±380 The perpendicular drawn from the electrical center of the heart to the horizontal zero line coincides with the axis of lead aVF, the positive pole of which corresponds to +90°, and the negative pole corresponds to minus 90 e. The positive pole of axis II of the standard lead is located at an angle break +60 V, III standard lead - at an angle of +120%, lead aVL - at an angle -30°, and lead aVR - at an angle -150°, etc.

U healthy person The electrical axis of the heart is usually located in the sector from 0° to +90°, only occasionally going beyond these limits. Normally, the electrical axis of the heart approximately corresponds to the orientation of its anatomical axis. For example, the horizontal position of the electrical axis of the heart (angle a from 0° to 29°) is often found in healthy people with a hypersthenic body type, and the vertical position of the electrical axis is often found in people with a vertically located heart.

More significant turns of the electrical axis of the heart around the anteroposterior axis, both to the right (more than +9(G)) and to the left (less than 0°), are usually caused by pathological changes in the heart muscle - hypertrophy of the ventricular myocardium or disturbances of intraventricular conduction (see . below). However, it should be remembered that with moderate pathological changes in the heart, the position of the electrical axis of the heart may not differ in any way from that in healthy people, i.e. it can be horizontal, vertical or even normal.

Let's consider two methods for determining the position of the electrical axis of the heart.

Determination of angle a by graphical method. To accurately determine the position of the electrical axis of the heart using a graphical method, it is enough to calculate the algebraic sum of the amplitudes of the teeth of the complex QRS in any two leads from the limbs, the axes of which are located in the frontal plane. Typically, standard leads I and III are used for this purpose (Fig. 4.11). Positive or negative value of an algebraic sum

teeth QRS on an arbitrarily chosen scale is plotted on the positive or negative part of the axis of the corresponding lead in the six-axis Bailey coordinate system.

For example, on the ECG shown in Fig. 4.11, algebraic sum of the teeth of the complex QRS in standard lead I is + 12 mm (R== 12 mm, Q = 0 mm, S= Oh mm). This value is plotted on the positive part of the lead axis I. The sum of teeth in standard lead III is -12 mm (R= + 3 mm, S=- 15 mm); it is placed on the negative part of this lead.

These quantities (corresponding to the algebraic sum of ampli tud teeth) actually represent projections of the desired electrical axis of the heart on the axis I and III of standard leads. From the ends of these projections, perpendiculars to the axes of the leads are restored. The intersection point of the perpendiculars is connected to the center of the system. This line is the electrical axis of the heart (AQRS). IN in this case angle a is -30 degrees (sharp deviation to the left of the electrical axis of the heart).

Angle a can also be determined after calculating the algebraic sums of the amplitudes of the teeth of the complex QRSb two leads from the limbs various tables and diagrams given in electrocardiography manuals.

Visual determination of angle a. The graphical method described above for determining the position of the electrical axis of the heart, although it is the most accurate, in practice is rarely used in clinical electrocardiography. A simpler and more accessible method is the visual method for determining the position of the electrical axis of the heart, which allows you to quickly assess the angle a with an accuracy of ±10°. The method is based on two well-known principles.

1. Maximum positive or negative value the algebraic sum of the teeth of the complex QRS observed in that electrocardiographic lead, the axis of which approximately coincides with the location of the electrical field of the heart and is parallel to it.

2. Complex type R.S. where the algebraic sum of the teeth is zero (R = S or I = Q+ S), is recorded in the lead whose axis is perpendicular to the electrical axis of the heart.

For example, let’s try to determine the position of the electrical axis of the heart visual method according to the ECG shown in Fig. 4.12. Maximum algebraic sum of teeth of the complex QRS and the highest tooth R are observed in standard lead II, and the type complex RS(R*S)- in lead aVL. This indicates that the electrical axis of the heart is located at an angle a of about 60° (coinciding with axis II of the standard lead and perpendicular to the axis of lead aVL). This is also confirmed by the approximate equality of the amplitude of the teeth R in leads I and III, the axes of which in this case are located at some identical (!) angle to the electrical axis of the heart (R ] l > R t ~ R ul). Thus, the ECG shows a normal position of the electrical axis of the heart (angle a = 60°).

Let's consider another option for the normal position of the electrical axis of the heart (angle A= 45°), shown on rice. 4.13.a. In this case, the electrical axis of the heart is located between the axes of leads II and aVR. Maximum tooth R will be registered in the same way as in the previous example, in lead II, and

/?,>/?,> Rul*. In this case, the electrical axis is perpendicular to a hypothetical line, which seems to pass between the axes of standard lead III and lead aVL. Under certain assumptions, it can be considered that the axes of leads III and aVL are almost perpendicular to the electrical axis of the heart. Therefore, it is in these leads that the algebraic sum of the teeth approaches zero, and the complexes themselves QRS take the form R.S. where are the teeth/? w and i? aVL have a minimum amplitude, only slightly exceeding the amplitude of the corresponding teeth Sj n and S sVL .

At vertical position of the electrical axis of the heart (Fig. 4.13, b), when angle a is about +90°, the maximum algebraic sum of the teeth of the complex QRSn maximum positive wave R will be detected in lead aVF, the axis of which coincides with the direction of the electrical axis of the heart. Complex type R.S. Where R-S, is recorded in standard lead I, the axis of which is perpendicular to the direction of the electrical axis of the heart. The negative wave predominates in lead aVL S, and in lead III there is a positive wave R.

With an even more pronounced rotation of the electrical axis of the heart to the right, for example, if angle a is +120°, as shown in Fig. 4.13, in, maximum tooth R is recorded in standard lead III. A com is recorded in lead aVR.

plex QR, Where R= Q. Positive waves predominate in lead II and aVF R, and in leads I and aVL there are deep negative waves S.

On the contrary, when horizontal position of the electrical axis of the heart, (angle a from +30° to 0°) maximum tooth R will be fixed in standard lead I (Fig. 4.14, a), and the type complex RS- in lead aVF. A deepened wave is recorded in lead III S y and in lead aVL there is a high tooth R.R [ > R ll > R lli< S uy

With a significant deviation of the electrical axis of the heart to the left (angle a - -30), as shown in Fig. 4.14, b, maximum positive tooth R shifts to lead aVL, and the complex QRSuxcm RS - to lead II. High prong R is also recorded in lead I, and in leads III and aVF deep negative waves predominate S. R x > R li > R m .

So for practical definition in the future, we will use the visual method of determining the angle a. We suggest that you independently complete several tasks to determine the position of the electrical axis of the heart visually(see Fig. 4.16-4.19). In this case, it is advisable to use a pre-prepared diagram of a six-axis coordinate system (see Fig. 2.6), as well as the following algorithm.

Algorithm for determining the position of the electrical axis of the heart in the frontal plane

1. Find one or two leads in which QRS approaches zero ( R S or R* Q+ L). The axis of this lead is almost perpendicular to the desired direction of the electrical axis of the heart.

2 Find one or two leads in which the algebraic sum of the teeth of the complex QRS has the maximum positive value. The axis of this lead approximately coincides with the direction of the electrical axis of the heart.

3. Adjust the two results. Determine angle a.

Usage example of this algorithm shown in Fig. 4.15. When analyzing the ECG in 6 limb leads shown in Fig. 4.15, the normal position is approximately determined

study of the electrical axis of the heart R H = A, > L,. The algebraic sum of the teeth of the complex (DO" is equal to zero in lead III (R= 5). Consequently, the electrical axis is presumably located at an angle a+30° to the horizontal, coinciding with the aVR axis. Algebraic sum of teeth QRS has a maximum value in leads I and II, with A, - Rxv This confirms the assumption made about the value of angle a (+30°), since identical projections on the lead axis (equal teeth R, and /?,) are possible only with this arrangement of the electrical axis of the heart.

Conclusion. Normal position of the electrical axis of the heart. Angle a - +30°.

Now, using the algorithm, independently determine the position of the electrical axis of the heart on the ECG shown in Fig. 4.16-4.19.

Check the correctness of your decision.

Standards of correct answers

Rice. 4.16, a. Analysis of the relationships between the teeth of the complex QRSw The presented ECG suggests that there is a normal position of the electrical axis of the heart (R il > R l > R m). Indeed, the sum of the teeth of the complex QRS equals zero in lead aVL (R ~ S). Consequently, the electrical axis of the heart is presumably located at an angle of +60° to the horizontal and coincides with axis II of the standard lead. Algebraic sum of teeth of the complex QRS has a maximum value in standard lead II. This confirms the assumption made about the value of the angle a+60". Conclusion. The normal position of the electrical axis of the heart is Angle a+60°.

Rice. 4.16, b. The ECG shows a deviation of the electrical axis of the heart to the left: high waves R registered in leads I and aVL, deep waves S- in leads III and aVF, with i ^> R II > i ^ II.

Algebraic sum of the amplitudes of the teeth of the complex QRS is equal to zero in standard lead II. Therefore, the electrical axis of the heart is perpendicular to the axis of lead II, i.e., located at an angle a = -30°. Maximum positive value sum of teeth QRS is detected in lead aVL, which confirms the assumption made. Conclusion. Deviation of the electrical axis of the heart to the left. Angle a- -30 e.

Rice. 4.17, a. The ECG shows a deviation of the electrical axis of the heart to the right: high waves Rm mVF and deep teeth 5, aVU and R in > R u > R l . Algebraic sum of the amplitudes of the teeth of the complex QRS equals zero in lead aVR. The electrical axis of the heart is located at an angle a+ 120 e and approximately coincides with axis III of the standard lead. This is confirmed by the fact that the maximum amplitude of the tooth R determined in lead Sh.

Conclusion, Deviation of the electrical axis of the heart to the right. Angle a= +120*.

Rice. 4.17, b. The ECG recorded high waves L w aVF and relatively deep waves L ", aVL, with ^ P >^ G > L^. The sum of the amplitudes of the waves QRS equal to zero in lead I. The electrical axis of the heart is located at an angle a = +90°, coinciding with the axis of lead aVR In lead aVF there is a maximum positive sum of wave amplitudes QRS which confirms this assumption. Conclusion. Vertical position of the electrical axis of the heart. Angle a - +90°.

Rice. 4.18, a. The ECG recorded high waves /?, hVL and deep waves L* H1 oVF, with /?,>/?,>/?,. In lead aVR, the algebraic sum of the teeth of the complex QRS equal to a bullet. The electrical axis of the heart most likely coincides with the negative half of the axis of standard lead III (the largest amplitude S U 1). Unlike an ECG, it depicts

Noah in Fig. 4.17, a, the electrical axis of the heart is not deviated to the right but

to the left, so angle a is approximately -60°. Conclusion. A sharp deviation of the electrical axis of the heart to the left. Angle a -60 e.

Rice. 4.18, 6. There is approximately a rotation of the heart axis to the left: high teeth I am aVL, deep serrations Sul aVF , and R J > R ll > R tll . There is no lead on the ECG in which the algebraic sum of the waves QRS is clearly equal to zero. However, the minimum algebraic sum of teeth QRS approaching zero, found in leads II and aVF , whose axes are located nearby, at an angle of 30* to each other. Moreover, the sum of the amplitudes of the teeth of the complex QRS in standard lead II it has a small positive value, and in lead aVF it has a small negative value. Consequently, a hypothetical line perpendicular to the electrical axis of the heart passes between the axes of leads II and aVF, and the electrical axis of the heart itself is accordingly located approximately at an angle a equal to - 15°, i.e., between the axes of leads I and aVL. Indeed, the maximum algebraic sum of teeth QRS found in leads I and aVL, which confirms the assumption made. Conclusion. Deviation of the electrical axis of the heart to the left. Angle a* - 15 e.

Rice. 4.19 A. There is approximately a rotation of the electrical axis of the heart to the left: high waves D, aVL, relatively deep waves S uv what does it have to do with R t > R n > R m . As in the previous example, it is impossible to identify a lead on the ECG in which the algebraic sum of the teeth QRS equal to zero. A hypothetical line perpendicular to the electrical axis of the heart probably runs between adjacent lead axes III and aVF , since the algebraic sum of the teeth QRS in these leads approaches zero, and the sum of the teeth in III lead indicates the predominance of the negative wave S, and in lead aVF - to the predominance of the wave R. Consequently, the electrical axis of the heart is most likely located at an angle a* +15°. Maximum positive algebraic sum of teeth QRS is detected in lead I, which confirms the assumption made. Conclusion. Horizontal position of the electrical axis of the heart. Angle a +15°.

Rice. 4.19, b. Approximately has a rotation of the electrical axis of the heart to the left: high teeth Rlt aVL, deep teeth 5 Ш, aVF, and R l > R ^> R Bl . In lead aVF, the algebraic sum of waves QRS equal to zero, i.e. the electrical axis is perpendicular to the axis of lead aVF. Therefore, we can assume that angle a is 0°. The maximum positive sum of waves is found in standard lead I, which confirms the assumption made. Conclusion. Horizontal position of the electrical axis of the heart. Angle ai 0°.

The electrical axis of the heart (EOS) is one of the main parameters of the electrocardiogram. This term is actively used both in cardiology and in functional diagnostics, reflecting the processes occurring in the most important organ of the human body.

The position of the electrical axis of the heart shows the specialist what exactly is happening in the heart muscle every minute. This parameter is the sum of all bioelectrical changes observed in the organ. When taking an ECG, each electrode of the system registers excitation passing at a strictly defined point. If you transfer these values to a conventional three-dimensional coordinate system, you can understand how the electrical axis of the heart is located and calculate its angle relative to the organ itself.

How is an electrocardiogram taken?

ECG recording is performed in a special room, maximally shielded from various electrical interference. The patient sits comfortably on the couch with a pillow under his head. To take an ECG, electrodes are applied (4 on the limbs and 6 on the chest). An electrocardiogram is recorded when calm breathing. In this case, the frequency and regularity of heart contractions, the position of the electrical axis of the heart and some other parameters are recorded. This simple method allows you to determine whether there are abnormalities in the functioning of the organ, and, if necessary, refer the patient for a consultation with a cardiologist.

What influences the location of the EOS?

Before discussing the direction of the electrical axis, you should understand what the conduction system of the heart is. It is this structure that is responsible for the passage of impulses through the myocardium. The conduction system of the heart is atypical muscle fibers, connecting different parts of the organ. It begins with the sinus node, located between the mouths of the vena cava. Next, the impulse is transmitted to the atrioventricular node, located in the lower part of the right atrium. The next to take up the baton is the His bundle, which quickly diverges into two legs - left and right. In the ventricle, the branches of the His bundle immediately become Purkinje fibers, which penetrate the entire cardiac muscle.

An impulse entering the heart cannot escape the myocardial conduction system. This is a complex structure with fine settings, sensitively responding to the slightest changes in the body. In case of any disturbances in the conduction system, the electrical axis of the heart can change its position, which will be immediately recorded on the electrocardiogram.

EOS location options

As you know, the human heart consists of two atria and two ventricles. Two circles of blood circulation (large and small) ensure the normal functioning of all organs and systems. Normally, the mass of the myocardium of the left ventricle is slightly greater than that of the right. It turns out that all impulses passing through the left ventricle will be somewhat stronger, and the electrical axis of the heart will be oriented specifically towards it.

If you mentally transfer the position of the organ to a three-dimensional coordinate system, it will become clear that the EOS will be located at an angle from +30 to +70 degrees. Most often, these are the values recorded on the ECG. The electrical axis of the heart can also be located in the range from 0 to +90 degrees, and this, too, according to cardiologists, is the norm. Why do such differences exist?

Normal location of the electrical axis of the heart

There are three main provisions of the EOS. The range from +30 to +70° is considered normal. This option occurs in the vast majority of patients who visit a cardiologist. The vertical electrical axis of the heart is found in thin, asthenic people. In this case, the angle values will range from +70 to +90°. The horizontal electrical axis of the heart is found in short, tightly built patients. On their card, the doctor will mark the EOS angle from 0 to +30°. Each of these options is normal and does not require any correction.

Pathological location of the electrical axis of the heart

A condition in which the electrical axis of the heart is deviated is not a diagnosis in itself. However, such changes in the electrocardiogram may indicate various violations in the work itself important body. TO major changes The following diseases affect the functioning of the conduction system:

Cardiac ischemia;

Chronic heart failure;

Cardiomyopathies of various origins;

Congenital defects.

Knowing about these pathologies, the cardiologist will be able to notice the problem in time and refer the patient for inpatient treatment. In some cases, when EOS deviation is registered, the patient requires emergency care in intensive care.

Deviation of the electrical axis of the heart to the left

Most often, such changes in the ECG are observed with enlargement of the left ventricle. This usually occurs with the progression of heart failure, when the organ simply cannot fully perform its function. It is possible that such a condition will develop when arterial hypertension accompanied by pathology large vessels and increased blood viscosity. In all these conditions, the left ventricle is forced to work hard. Its walls thicken, leading to inevitable disruption of the impulse through the myocardium.

Deviation of the electrical axis of the heart to the left also occurs with narrowing of the aortic mouth. In this case, stenosis of the lumen of the valve located at the exit from the left ventricle occurs. This condition is accompanied by a disruption of normal blood flow. Part of it is retained in the cavity of the left ventricle, causing it to stretch and, as a result, thickening of its walls. All this causes a natural change in EOS as a result of improper conduction of the impulse through the myocardium.

Deviation of the electrical axis of the heart to the right

This condition clearly indicates right ventricular hypertrophy. Similar changes develop in some respiratory diseases (for example, bronchial asthma or chronic obstructive pulmonary disease). Some birth defects hearts can also cause enlargement of the right ventricle. First of all, it is worth noting pulmonary artery stenosis. IN individual situations tricuspid valve insufficiency can also lead to a similar pathology.

Why is changing EOS dangerous?

Most often, deviations of the electrical axis of the heart are associated with hypertrophy of one or another ventricle. This condition is a sign of long-standing chronic process and, as a rule, does not require emergency assistance from a cardiologist. The real danger is the change in the electrical axis due to His bundle block. In this case, the conduction of impulses through the myocardium is disrupted, which means there is a risk sudden stop cardiac activity. This situation requires urgent intervention by a cardiologist and treatment in a specialized hospital.

With the development of this pathology, the EOS can be deviated both to the left and to the right, depending on the localization of the process. The blockade may be caused by myocardial infarction, infectious lesion heart muscle, as well as taking certain medications. A regular electrocardiogram allows you to quickly make a diagnosis, which means it allows the doctor to prescribe treatment taking into account all important factors. In severe cases, it may be necessary to install a pacemaker (pacemaker), which will send impulses directly to the heart muscle and thereby ensure normal functioning of the organ.

What to do if the EOS is changed?

First of all, it is worth considering that the deviation of the heart axis itself is not the basis for making a particular diagnosis. The position of the EOS can only give impetus to a more careful examination of the patient. For any changes in the electrocardiogram, you cannot do without consulting a cardiologist. An experienced doctor will be able to recognize normal and pathological conditions and, if necessary, prescribe additional examinations. This may include echocardioscopy for targeted study of the condition of the atria and ventricles, blood pressure monitoring and other techniques. In some cases, consultation with related specialists is required to decide on further management of the patient.

To summarize, several important points should be highlighted:

The normal EOS value is considered to be the range from +30 to +70°.

Horizontal (from 0 to +30°) and vertical (from +70 to +90°) positions of the heart axis are acceptable values and do not talk about the development of any pathology.

Deviations of the EOS to the left or to the right may indicate various disorders in the conduction system of the heart and require consultation with a specialist.

A change in EOS detected on a cardiogram cannot be made as a diagnosis, but is a reason to visit a cardiologist.

The heart is amazing organ, ensuring the functioning of all systems of the human body. Any changes that occur in it inevitably affect the functioning of the whole organism. Regular examinations by a therapist and an ECG will allow timely detection of serious illnesses and avoid the development of any complications in this area.

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The electrical axis of the heart is a concept that reflects the total vector of the electrodynamic force of the heart, or its electrical activity, and practically coincides with the anatomical axis. Normally, this organ has a cone-shaped shape, with its narrow end directed downwards, forward and to the left, and the electrical axis has a semi-vertical position, that is, it is also directed downwards and to the left, and when projected onto the coordinate system it can be in the range from +0 to +90 0.

An ECG conclusion is considered normal if it indicates any of the following positions of the heart axis: not deviated, semi-vertical, semi-horizontal, vertical or horizontal position. The axis is closer to the vertical position in thin people tall people asthenic physique, and to the horizontal - in strong stocky persons of hypersthenic physique.

Reasons for deviations from the norm

Axial deviation to the right or left is not considered an independent disease, but it can indicate diseases that lead to disruption of the heart.

cardiomyopathy (increase in myocardial mass or expansion of the heart chambers), caused by anemia, hormonal imbalances in the body, coronary heart disease, post-infarction cardiosclerosis. changes in myocardial structure after myocarditis ( inflammatory process in cardiac tissue);

Symptoms

Diagnostics

Ultrasound of the heart is the most informative method, allowing you to assess anatomical changes and identify ventricular hypertrophy, as well as determine the degree of disruption contractile function. This method is especially important for examining a newborn baby for congenital pathology hearts.

Treatment

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When the EOS is in a vertical position, the S wave is most pronounced in leads I and aVL. ECG in children aged 7–15 years. Characterized by respiratory arrhythmia, heart rate 65-90 per minute. The position of the EOS is normal or vertical.

Regular sinus rhythm - this phrase means absolutely normal heartbeat, which is generated in the sinus node (the main source of cardiac electrical potentials).

Left ventricular hypertrophy (LVH) is a thickening of the wall and/or enlargement of the left ventricle of the heart. All five position options (normal, horizontal, semi-horizontal, vertical and semi-vertical) occur in healthy people and are not pathological.

What does the vertical position of the heart axis on an ECG mean?

The situation should be alarming when, with a pre-existing position of the EOS, its sharp deviation on the ECG occurs. In this case, the deviation most likely indicates the occurrence of a blockade. 6.1. P wave. Analysis of the P wave involves determining its amplitude, width (duration), shape, direction and degree of severity in various leads.

The always negative wave vector P is projected onto the positive parts of most leads (but not all!).

6.4.2. The degree of severity of the Q wave in various leads.

Methods for determining the position of the EOS.

To put it simply, an ECG is a dynamic recording electric charge, thanks to which our heart works (that is, contracts). The designations of these graphs (they are also called leads) - I, II, III, aVR, aVL, aVF, V1-V6 - can be seen on the electrocardiogram.

ECG is a completely painless and safe research, it is performed on adults, children and even pregnant women.

Heart rate is not a disease or a diagnosis, but just an abbreviation for “heart rate,” which refers to the number of contractions of the heart muscle per minute. When the heart rate increases above 91 beats/min, they speak of tachycardia; if the heart rate is 59 beats/min or less, this is a sign of bradycardia.

Electrical axis of the heart (EOS): essence, norm of position and violations

Thin people usually have a vertical position of the EOS, while thick people and obese people have a horizontal position. Respiratory arrhythmia is associated with the act of breathing, is normal and does not require treatment.

Requires compulsory treatment. Atrial flutter - this type of arrhythmia is very similar to atrial fibrillation. Sometimes polytopic extrasystoles occur - that is, the impulses that cause them come from various parts of the heart.

Extrasystoles can be called the most common ECG finding; moreover, not all extrasystoles are a sign of the disease. In this case, treatment is necessary. Atrioventricular block, A-V (A-V) block - a violation of the conduction of impulses from the atria to the ventricles of the heart.

Block of the branches (left, right, left and right) of the His bundle (RBBB, LBBB), complete, incomplete, is a violation of the conduction of an impulse through the conduction system in the thickness of the ventricular myocardium.

The most common reasons hypertrophies are arterial hypertension, heart defects and hypertrophic cardiomyopathy. In some cases, next to the conclusion about the presence of hypertrophy, the doctor indicates “with overload” or “with signs of overload.”

Cicatricial changes, scars are signs of a myocardial infarction once suffered. In such a situation, the doctor prescribes treatment aimed at preventing a recurrent heart attack and eliminating the cause of circulatory problems in the heart muscle (atherosclerosis).

Timely detection and treatment of this pathology is necessary. Normal ECG in children aged 1 – 12 months. Typically, heart rate fluctuations depend on the child’s behavior (increased frequency when crying, restlessness). At the same time, over the past 20 years there has been a clear trend towards an increase in the prevalence of this pathology.

The direction of the electrical axis of the heart shows the total magnitude of bioelectric changes occurring in the heart muscle with each contraction. The heart is a three-dimensional organ, and in order to calculate the direction of the EOS, cardiologists represent the chest as a coordinate system.

If you project the electrodes onto a conventional coordinate system, you can also calculate the angle of the electrical axis, which will be located where the electrical processes are strongest. The conduction system of the heart consists of sections of the heart muscle consisting of so-called atypical muscle fibers.

Normal ECG readings

Myocardial contraction begins with the appearance of an electrical impulse in the sinus node (which is why the correct rhythm of a healthy heart is called sinus). The myocardial conduction system is a powerful source of electrical impulses, which means that electrical changes that precede cardiac contraction occur in it first of all in the heart.

Rotations of the heart around the longitudinal axis help determine the position of the organ in space and, in some cases, are an additional parameter in diagnosing diseases. The position of the EOS itself is not a diagnosis.

These defects can be either congenital or acquired. The most common acquired heart defects are a consequence of rheumatic fever.

In this case, a consultation with a highly qualified sports doctor is necessary to decide on the possibility of continuing to play sports.

A shift in the electrical axis of the heart to the right may indicate right ventricular hypertrophy (RVH). Blood from the right ventricle enters the lungs, where it is enriched with oxygen.

As in the case of the left ventricle, RVH is caused by coronary heart disease, chronic heart failure and cardiomyopathies.

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Conducting system of the heart and why is it important for determining EOS?

The conduction system of the heart consists of sections of the heart muscle consisting of so-called atypical muscle fibers. These fibers are well innervated and provide synchronous contraction of the organ.

Myocardial contraction begins with the appearance of an electrical impulse in the sinus node (which is why the correct rhythm of a healthy heart is called sinus). From the sinus node, the electrical impulse travels to the atrioventricular node and further along the His bundle. This bundle passes through the interventricular septum, where it divides into the right, heading towards the right ventricle, and the left legs. Left leg The bundle of His is divided into two branches, anterior and posterior. The anterior branch is located in the anterior sections interventricular septum, in the anterolateral wall of the left ventricle. The posterior branch of the left bundle branch is located in the middle and lower third of the interventricular septum, the posterolateral and inferior wall of the left ventricle. We can say that the posterior branch is located slightly to the left of the anterior one.

The myocardial conduction system is a powerful source of electrical impulses, which means that electrical changes that precede cardiac contraction occur in it first of all in the heart. If there are disturbances in this system, the electrical axis of the heart can significantly change its position, which will be discussed below.

Variants of the position of the electrical axis of the heart in healthy people

The mass of the cardiac muscle of the left ventricle is normally much greater than the mass of the right ventricle. Thus, the electrical processes occurring in the left ventricle are overall stronger, and EOS will be directed specifically at it. If we project the position of the heart on the coordinate system, the left ventricle will be in the area +30 + 70 degrees. This will be the normal position of the axis. However, depending on individual anatomical features and physique the position of the EOS in healthy people ranges from 0 to +90 degrees:

So, vertical position EOS will be considered in the range from + 70 to +90 degrees. This position of the heart axis is found in tall, thin people - asthenics.
Horizontal position of the EOS It is more common in short, stocky people with a wide chest - hypersthenics, and its value ranges from 0 to + 30 degrees.

The structural features for each person are very individual; there are practically no pure asthenics or hypersthenics; more often they are intermediate body types, therefore the electrical axis can have an intermediate value (semi-horizontal and semi-vertical).

All five position options (normal, horizontal, semi-horizontal, vertical and semi-vertical) occur in healthy people and are not pathological.

So, in the conclusion of an ECG in an absolutely healthy person it can be said: “EOS is vertical, sinus rhythm, heart rate – 78 per minute,” which is a variant of the norm.

Rotations of the heart around the longitudinal axis help determine the position of the organ in space and, in some cases, are an additional parameter in diagnosing diseases.

The definition of “rotation of the electrical axis of the heart around an axis” may well be found in descriptions of electrocardiograms and is not something dangerous.

When can the position of the EOS indicate heart disease?

The position of the EOS itself is not a diagnosis. However There are a number of diseases in which there is a displacement of the heart axis. Significant changes in the position of the EOS result from:

Cardiac ischemia.
Cardiomyopathies of various origins (especially dilated cardiomyopathy).
Chronic heart failure.
Congenital anomalies of the heart structure.

EOS deviations to the left

Thus, deviation of the electrical axis of the heart to the left may indicate left ventricular hypertrophy (LVH), i.e. increasing it in size, which is also not independent disease, but may indicate left ventricular overload. This condition often occurs with long-term arterial hypertension and is associated with significant vascular resistance to blood flow, as a result of which the left ventricle must contract with greater force, the mass of the ventricular muscles increases, which leads to its hypertrophy. Ischemic disease, chronic heart failure, and cardiomyopathies also cause left ventricular hypertrophy.

In addition, LVH develops when there is damage valve apparatus left ventricle. This condition is caused by stenosis of the aortic mouth, in which the ejection of blood from the left ventricle is difficult, and aortic valve insufficiency, when part of the blood returns to the left ventricle, overloading it with volume.

These defects can be either congenital or acquired. The most common acquired heart defects are a consequence of rheumatic fever. Left ventricular hypertrophy is found in professional athletes. In this case, a consultation with a highly qualified sports doctor is necessary to decide on the possibility of continuing to play sports.

Also, the EOS can be deviated to the left in cases of intraventricular conduction disorders and various heart blocks. Deviation el. the axis of the heart to the left, together with a number of other ECG signs, is one of the indicators of blockade of the anterior branch of the left bundle branch.

EOS deviations to the right

A shift in the electrical axis of the heart to the right may indicate right ventricular hypertrophy (RVH). Blood from the right ventricle enters the lungs, where it is enriched with oxygen. Chronic diseases respiratory organs, accompanied by pulmonary hypertension, such as bronchial asthma, chronic obstructive pulmonary disease over a long period of time cause hypertrophy. Pulmonary stenosis and tricuspid valve insufficiency lead to right ventricular hypertrophy. As in the case of the left ventricle, RVH is caused by coronary heart disease, chronic heart failure and cardiomyopathies. Deviation of the EOS to the right occurs with complete blockade of the posterior branch of the left bundle branch.

What to do if EOS displacement is found on the cardiogram?

None of the above diagnoses can be made on the basis of EOS displacement alone. The position of the axis serves only as an additional indicator in diagnosing a particular disease. If the deviation of the heart axis is outside the normal range (from 0 to +90 degrees), consultation with a cardiologist and a series of studies are necessary.

But still the main cause of EOS displacement is myocardial hypertrophy. The diagnosis of hypertrophy of a particular part of the heart can be made based on ultrasound results. Any disease leading to a displacement of the heart axis is accompanied by a number of clinical signs and requires additional examination. The situation should be alarming when, with a pre-existing position of the EOS, its sharp deviation on the ECG occurs. In this case, the deviation most likely indicates the occurrence of a blockade.

The displacement of the electrical axis of the heart itself does not require treatment, refers to electrocardiological signs and requires, first of all, to determine the cause of its occurrence. Only a cardiologist can determine the need for treatment.

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Medical indicators

Using the electrical axis of the heart, cardiologists evaluate the electrical processes that move the heart muscles. The direction of EOS depends on different anatomical and physiological factors. Average rate indicator is +590. Normally, the EOS value fluctuates between +200…+1000.

The patient is examined in a specialized room, which is shielded from various electrical noise. The patient takes a supine position with a pillow placed under his head. To take an ECG, electrodes are applied. Data is recorded during quiet breathing. At the same time, the device records the frequency and regularity of heartbeats, including the position of the EOS and other parameters.

In a healthy person, deviation of the electrical axis of the heart to the left is allowed when:

deep exhalation;
changing body position;
body features (hypersthenic).

The EOS shifts to the right in a healthy person when:

the end of a deep breath;
body features (asthenic).

The location of the EOS is determined by the mass of the 2 parts of the ventricle. The indicator under consideration is determined using 2 methods.

In the first case, the specialist identifies a displacement in the alpha angle. The value of the main indicator is calculated using a special table according to Diede.

In the second case, the specialist compares the R and S waves in leads 1 and 3. A sharp deviation of the EOS in any direction is not an independent pathology.

An electrical axis shifted to the left indicates the following problems:

left ventricular hypertrophy;
impaired functioning of the left ventricular valve;
cardiac blockade.

The above phenomena lead to incorrect functioning of the left ventricle. Any deviation of EOS indicates pathologies such as ischemia, CHF, congenital heart disease, and heart attack. Blockade of the conduction system of the main organ is associated with taking certain medications.

Additional diagnostic techniques

If a deviation of the electrical axis to the left is recorded on the cardiogram, additional instrumental examination patient. It is recommended to have an electrocardiogram while walking on a treadmill or exercise bike. Using ultrasound, the degree of ventricular hypertrophy is assessed.

If violated sinus rhythm, rejected by EOS, carried out daily monitoring Holter ECG. Data is recorded throughout the day. If the myocardial tissue is significantly hypertrophied, an x-ray is performed chest. Using angiography coronary arteries The degree of vascular damage during current ischemia is determined. Echocardioscopy allows you to determine the condition of the atria and ventricles of the heart.

Therapy for the phenomenon under consideration is aimed at eliminating the underlying disease. Some heart pathologies are treated medical supplies. Additionally, it is recommended to eat right and lead a healthy lifestyle.

At severe course illness required surgical intervention. If the conduction system is seriously impaired, a pacemaker transplant is performed. This device sends signals to the myocardium, causing it to contract.

Most often, the phenomenon in question does not threaten human life. But, if a sharp change in the position of the axis is diagnosed (value greater than +900), this can lead to cardiac arrest. Such a patient must be urgently hospitalized in intensive care. For warning similar condition annual scheduled examinations with a cardiologist are indicated.

Changes to the right

Deviation of the axis to the right is not an independent pathology, but is a diagnostic symptom of a disorder in the functioning of the main organ. Most often, such a clinic indicates an abnormal enlargement of the right atrium or ventricle. After finding out the exact cause of the development of this anomaly, the doctor makes a diagnosis.

If necessary, the patient is prescribed additional diagnostics:

1. Ultrasound - provides information about changes in the anatomy of the main organ.
2. Chest X-ray - reveals myocardial hypertrophy.
3. Daily ECG - performed for concomitant rhythm disturbances.
4. ECG during exercise - helps to detect myocardial ischemia.
5. CAG - performed to diagnose lesions of the coronary artery.

Deviation of the axis to the right can be caused by the following pathologies:

1. Ischemia is an incurable pathology in which there is blockage of the coronary arteries. If left untreated, the disease can lead to myocardial infarction.
2. Acquired or congenital stenosis of the pulmonary artery - due to the narrowing of the vessel, the normal flow of blood from the right ventricle stops, which provokes an increase in blood pressure.
3. Atrial fibrillation - can provoke a cerebral stroke.
4. Chronic cor pulmonale - observed with impaired lung function and chest pathology. Under such conditions, hypertrophy may develop.
5. The presence of a hole in the septum between the atria, through which blood is ejected from left to right. This provokes the development of heart failure.
6. Valve stenosis - manifests itself as a narrowing of the opening between the left ventricle and the corresponding atrium, which impedes the diastolic movement of blood. This pathology is acquired.
7. Pulmonary embolism - provoked by blood clots that occur in large vessels. They then move through the system, clogging the artery and its branches.
8. Primary pulmonary hypertension, which is accompanied high pressure blood caused by various reasons.

Risk factors

Axial tilt to the right is a consequence of tricyclic antidepressant poisoning. The somatotropic effect of these drugs is observed due to the presence of substances in them that affect the conduction system of the heart. If the ECG has diagnosed an axis deviation to the right side, a more in-depth diagnosis of the patient is required.

There is a direct relationship between the anatomical position of the main organ and the EOS of the QRS complex. This relationship is confirmed by the effect of breathing. When inhaling, the diaphragm lowers, the heart changes its position, which provokes a shift of the EOS to the right. In patients with pulmonary emphysema, the anatomical position of the main organ is observed. On the contrary, when you exhale, the diaphragm rises, the heart takes a horizontal position, shifting the axis to the left.

There is also a direct influence of the direction of ventricular depolarization on the EOS value. This phenomenon is confirmed with partial blockade of LBP. In this case, the impulses propagate along the upper left parts of the ventricle, which provokes an axis deviation to the left.

If the value of the parameter in question in a newborn baby is deviated from the norm to the right, there is no pathology.

Doctors do not consider this condition as right ventricular hypertrophy. This is explained by the fact that the deviation angle is +100 - normal phenomenon observed in many newborns. This is especially true for those who live in harsh climatic conditions and in the mountains.

But a deviation of the axis to the right in a baby may be associated with a blockade of the LBP. Therefore, when identifying the issue in question diagnostic symptom held full examination little patient.

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Electric axis position range is normal

For example, in the conclusion of an ECG, the patient may see the following phrase: “sinus rhythm, EOS is not deviated...”, or “the axis of the heart is in a vertical position,” this means that the heart is working correctly.

In the case of heart disease, the electrical axis of the heart, along with the heart rhythm, is one of the first ECG criteria that the doctor pays attention to, and in case of ECG decoding The attending physician must determine the direction of the electrical axis.

Deviations from the norm are deviation of the axis to the left and sharply to the left, to the right and sharply to the right, as well as the presence of a non-sinus heart rhythm.

How to determine the position of the electrical axis

Determination of the position of the heart axis is carried out by a doctor functional diagnostics, deciphering the ECG, using special tables and diagrams, according to the angle α (“alpha”).

The second way to determine the position of the electrical axis is to compare the QRS complexes responsible for the excitation and contraction of the ventricles. So, if the R wave has a greater amplitude in the I chest lead than in the III, then there is a levogram, or deviation of the axis to the left. If there is more in III than in I, then it is a legal grammar. Normally, the R wave is higher in lead II.

Reasons for deviations from the norm

Axial deviation to the right or left is not considered an independent disease, but it can indicate diseases that lead to disruption of the heart.

Deviation of the heart axis to the left often develops with left ventricular hypertrophy

Deviation of the heart axis to the left can occur normally in healthy individuals who are professionally involved in sports, but more often develops with left ventricular hypertrophy. This is an increase in the mass of the heart muscle with a violation of its contraction and relaxation, necessary for the normal functioning of the entire heart. Hypertrophy can be caused by the following diseases:

cardiomyopathy (increase in myocardial mass or expansion of the heart chambers), caused by anemia, hormonal imbalances in the body, coronary heart disease, post-infarction cardiosclerosis, changes in the structure of the myocardium after myocarditis (inflammatory process in cardiac tissue);
long-standing arterial hypertension, especially with constantly high blood pressure numbers;
acquired heart defects, in particular stenosis (narrowing) or insufficiency (incomplete closure) of the aortic valve, leading to disruption of intracardiac blood flow, and, consequently, increased load to the left ventricle;
congenital heart defects often cause a deviation of the electrical axis to the left in a child;
conduction disturbance along the left bundle branch - complete or not complete blockade, leading to impaired contractility of the left ventricle, while the axis is deviated, and the rhythm remains sinus;
atrial fibrillation, then the ECG is characterized not only by axis deviation, but also by the presence of non-sinus rhythm.

Deviation of the heart axis to the right is a normal variant when conducting an ECG in a newborn child, and in this case a sharp deviation of the axis may occur.

In adults, such a deviation is usually a sign of right ventricular hypertrophy, which develops in the following diseases:

diseases of the bronchopulmonary system - long-term bronchial asthma, severe obstructive bronchitis, emphysema, leading to increased blood pressure in the pulmonary capillaries and increasing the load on the right ventricle;
heart defects with damage to the tricuspid (three-leaf) valve and the valve of the pulmonary artery, which arises from the right ventricle.

The greater the degree of ventricular hypertrophy, the more the electrical axis is deflected, respectively, sharply to the left and sharply to the right.

Symptoms

The electrical axis of the heart itself does not cause any symptoms in the patient. Impaired health appears in the patient if myocardial hypertrophy leads to severe hemodynamic disturbances and heart failure.

The disease is characterized by pain in the heart area

Signs of diseases accompanied by deviation of the heart axis to the left or right include headaches, pain in the heart area, swelling lower limbs and on the face, shortness of breath, asthma attacks, etc.

If any unpleasant cardiac symptoms appear, you should consult a doctor for conducting an ECG, and if an abnormal position of the electrical axis is detected on the cardiogram, it is necessary to perform further examination to establish the cause of this condition, especially if it is detected in a child.

Diagnostics

To determine the reason for deviation according to ECG axis heart left or right, a cardiologist or therapist may prescribe additional research methods:

Ultrasound of the heart is the most informative method that allows you to assess anatomical changes and identify ventricular hypertrophy, as well as determine the degree of impairment of their contractile function. This method is especially important for examining a newborn child for congenital heart pathology.
ECG with exercise (walking on a treadmill - treadmill test, bicycle ergometry) can detect myocardial ischemia, which may be the cause of deviations in the electrical axis.
Daily ECG monitoring in the event that not only an axis deviation is detected, but also the presence of a rhythm not from the sinus node, that is, rhythm disturbances occur.
Chest X-ray - with severe myocardial hypertrophy, an expansion of the cardiac shadow is characteristic.
Coronary angiography (CAG) - performed to clarify the nature of lesions of the coronary arteries during coronary disease A.

Treatment

Direct deviation of the electrical axis does not require treatment, since it is not a disease, but a criterion by which it can be assumed that the patient has one or another cardiac pathology. If, after further examination, some disease is identified, it is necessary to begin treatment as soon as possible.

In conclusion, it should be noted that if the patient sees in the ECG conclusion a phrase that the electrical axis of the heart is not in a normal position, this should alert him and prompt him to consult a doctor to find out the cause of such an ECG sign, even if there are no symptoms does not arise.

DlyaSerdca → Diagnostics → Positions of the electrical axis of the heart: norm and pathology

The electrical axis of the heart is a term that means the electrical activity of the organ, that is, the total indicator of its average vector during depolarization. This is an indicator of the electrical processes of the heart.

This concept is used in cardiology and in functional diagnostics. Determination of the direction of EOS is carried out using an ECG.

In the direction of the axis, the doctor determines the bioelectrical changes that occur in the myocardium during contraction.

To determine the direction of the EOS, there is a coordinate system that is located throughout the chest.

With electrocardiography, the doctor can install the electrodes according to the coordinate system, and it will be clear where the axis angle is located, that is, the places where the electrical impulses are strongest.

Impulses travel through the conduction system of the heart. It consists of atypical fibers that are located in certain areas of the organ.

This system begins in the sinus node. The impulse then passes to the atria and ventricles and to the bundle of His.

When any disturbances occur in the conduction system, the EOS changes its direction.

Axis location

In a healthy person, the left ventricle has a larger mass than the right.

This means that stronger electrical processes occur in the left ventricle, and accordingly the electrical axis is directed there.

If we denote this in degrees, then the LV is in the region of 30-700 with a value of +. This is considered the standard, but it should be said that not everyone has this axis arrangement.

There may be a deviation greater than 0-900 with a value of +, since it is necessary to take into account the individual characteristics of each person’s body.

The doctor may make the following conclusion:

no deviations;
semi-vertical position;
semi-horizontal position.

All these conclusions are the norm.

Concerning individual characteristics, then they note that in people who are tall and have a thin build, the EOS is in a semi-vertical position, and in people who are shorter and have a stocky build, the EOS is in a semi-horizontal position.

The pathological condition looks like a sharp deviation to the left or right.

Reasons for rejection

When the EOS deviates sharply to the left, this may mean that there are certain diseases, namely LV hypertrophy.

In this condition, the cavity stretches and increases in size. Sometimes this occurs due to overload, but it can also be a consequence of a disease.

Diseases that cause hypertrophy are:

In addition to hypertrophy, the main causes of axis deviation to the left are conduction disorders inside the ventricles and during blockades of various types.

Quite often, with such a deviation, blockade of the left leg of His, namely its anterior branch, is diagnosed.

As for the pathological deviation of the heart axis sharply to the right, this may mean that there is RV hypertrophy.

This pathology can be caused by the following diseases:

As well as diseases characteristic of LV hypertrophy:

cardiac ischemia;
chronic heart failure;
cardiomyopathy;
complete blockade of the left leg of His (posterior branch).

When the electrical axis of the heart is sharply deviated to the right in a newborn, this is considered normal.

We can conclude that the main cause of pathological displacement to the left or right is ventricular hypertrophy.

And the greater the degree of this pathology, the more EOS is rejected. A change in the axis is simply an ECG sign of some disease.

It is important to carry out timely identification of these indications and diseases.

Deviation of the heart axis does not cause any symptoms; symptoms manifest themselves from hypertrophy, which disrupts the hemodynamics of the heart. The main symptoms are headaches, chest pain, swelling of the limbs and face, suffocation and shortness of breath.

If cardiac symptoms occur, you should immediately undergo electrocardiography.

Determination of ECG signs

Legal form. This is the position at which the axis is within the range of 70-900.

On the ECG this is expressed as tall R waves in the QRS complex. In this case, the R wave in lead III exceeds the wave in lead II. In lead I there is an RS complex, in which S has a greater depth than the height of R.

Levogram. In this case, the position of the alpha angle is within the range of 0-500. The ECG shows that in standard lead I the QRS complex is expressed as R-type, and in lead III its form is S-type. The S wave has a depth greater than the height R.

With blockade of the posterior branch of the left leg of His, the alpha angle has a value greater than 900. On the ECG, the duration of the QRS complex may be slightly increased. There is a deep S wave (aVL, V6) and a high R wave (III, aVF).

With blockade of the anterior branch of the left leg of His, the values will be from -300 or more. On the ECG, signs of this are a late R wave (lead aVR). Leads V1 and V2 may have a small r wave. In this case, the QRS complex is not expanded, and the amplitude of its waves is not changed.

Blockade of the anterior and posterior branches of the left leg of His (complete block) - in this case, the electrical axis is sharply deviated to the left and can be located horizontally. On the ECG in the QRS complex (leads I, aVL, V5, V6), the R wave is widened and its apex is jagged. Near the high R wave there is a negative T wave.

It should be concluded that the electrical axis of the heart can be moderately deviated. If the deviation is sharp, then this may mean the presence of serious cardiac diseases.

Determination of these diseases begins with an ECG, and then methods such as echocardiography, radiography, and coronary angiography are prescribed. ECG can also be performed with stress and daily monitoring according to Holter.

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Electric axis position range is normal

In the case of heart disease, the electrical axis of the heart, along with the heart rhythm, is one of the first ECG criteria that the doctor pays attention to, and when interpreting the ECG, the attending physician must determine the direction of the electrical axis.

How to determine the position of the electrical axis

Determination of the position of the heart axis is carried out by a functional diagnostics doctor who deciphers the ECG using special tables and diagrams using the angle α (“alpha”).

Reasons for deviations from the norm

Axial deviation to the right or left is not considered an independent disease, but it can indicate diseases that lead to disruption of the heart.

Deviation of the heart axis to the left often develops with left ventricular hypertrophy

cardiomyopathy (increase in myocardial mass or expansion of the heart chambers), caused by anemia, hormonal imbalances in the body, coronary heart disease, post-infarction cardiosclerosis, changes in the structure of the myocardium after myocarditis (inflammatory process in cardiac tissue);
long-term arterial hypertension, especially with constantly high blood pressure numbers;
acquired heart defects, in particular stenosis (narrowing) or insufficiency (incomplete closure) of the aortic valve, leading to disruption of intracardiac blood flow and, consequently, increased load on the left ventricle;
congenital heart defects often cause a deviation of the electrical axis to the left in a child;
conduction disturbance along the left bundle branch – complete or incomplete blockade, leading to impaired contractility of the left ventricle, while the axis is deviated, and the rhythm remains sinus;
atrial fibrillation, then the ECG is characterized not only by axis deviation, but also by the presence of non-sinus rhythm.

In adults, such a deviation is usually a sign of right ventricular hypertrophy, which develops in the following diseases:

diseases of the bronchopulmonary system - long-term bronchial asthma, severe obstructive bronchitis, emphysema, leading to increased blood pressure in the pulmonary capillaries and increasing the load on the right ventricle;
heart defects with damage to the tricuspid (three-leaf) valve and the valve of the pulmonary artery, which arises from the right ventricle.

The greater the degree of ventricular hypertrophy, the more the electrical axis is deflected, respectively, sharply to the left and sharply to the right.

Symptoms

The disease is characterized by pain in the heart area

Signs of diseases accompanied by deviation of the heart axis to the left or right include headaches, pain in the heart area, swelling of the lower extremities and face, shortness of breath, asthma attacks, etc.

If any unpleasant cardiac symptoms appear, you should consult a doctor for an ECG, and if an abnormal position of the electrical axis is detected on the cardiogram, further examination must be performed to determine the cause of this condition, especially if it is detected in a child.

Diagnostics

To determine the cause of an ECG deviation of the heart axis to the left or right, a cardiologist or therapist may prescribe additional research methods:

Ultrasound of the heart is the most informative method that allows you to assess anatomical changes and identify ventricular hypertrophy, as well as determine the degree of impairment of their contractile function. This method is especially important for examining a newborn child for congenital heart pathology.
ECG with exercise (walking on a treadmill - treadmill test, bicycle ergometry) can detect myocardial ischemia, which may be the cause of deviations in the electrical axis.
Daily ECG monitoring in the event that not only an axis deviation is detected, but also the presence of a rhythm not from the sinus node, that is, rhythm disturbances occur.
Chest X-ray - with severe myocardial hypertrophy, an expansion of the cardiac shadow is characteristic.
Coronary angiography (CAG) is performed to clarify the nature of lesions of the coronary arteries in coronary artery disease.

Treatment

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The location of the electrical axis is normal

In healthy people, the electrical axis of the heart coincides with the anatomical axis of this organ. The heart is located semi-vertically - its lower end is directed down and to the left. And the electrical axis, like the anatomical one, is in a semi-vertical position and tends down and to the left.

The standard alpha angle is from 0 to +90 degrees.

Norm of angle alpha EOS

The location of the anatomical and electrical axes depends to some extent on body type. Asthenics (thin people with tall and long limbs), the heart (and, accordingly, its axes) is located more vertically, and in hypersthenics (short people with a stocky build) - more horizontally.

Normal alpha angle depending on body type:

A significant displacement of the electrical axis to the left or right is a sign of pathologies of the conduction system of the heart or other diseases.

A deviation to the left is indicated by a minus alpha angle: from -90 to 0 degrees. About its deviation to the right - values from +90 to +180 degrees.

However, it is not at all necessary to know these numbers, since in case of violations in the ECG interpretation you can find the phrase “EOS is deviated to the left (or right).”

Reasons for shift to the left

Deviation of the electrical axis of the heart to the left is a typical symptom of problems with the left side of this organ. It could be:

hypertrophy (enlargement, proliferation) of the left ventricle (LVH);
blockade of the anterior branch of the left bundle branch - a violation of impulse conduction in the anterior part of the left ventricle.

Causes of these pathologies:

Symptoms

EOS displacement itself does not have characteristic symptoms.

The diseases that accompany it can also be asymptomatic. This is why it is important to undergo an ECG for preventive purposes– if the disease is not accompanied unpleasant signs, you can find out about it and start treatment only after deciphering the cardiogram.

However, sometimes these diseases still make themselves felt.

Symptoms of diseases that are accompanied by a displacement of the electrical axis:

But let us repeat once again - symptoms do not always appear; they usually develop in the later stages of the disease.

Additional diagnostics

To find out the reasons for the EOS deviation, the ECG is analyzed in detail. They may also assign:

After a detailed examination, appropriate therapy is prescribed.

Treatment

The deviation of the electrical axis of the heart to the left in itself does not require specific treatment because it is just a symptom of another disease.

All measures are aimed at eliminating the underlying disease, which is manifested by displacement of the EOS.

Treatment for LVH depends on what caused the myocardial growth

Treatment for blockade of the anterior branch of the left bundle branch is installation of a pacemaker. If it occurs as a result of a heart attack, surgical restoration of blood circulation in the coronary vessels is required.

The electrical axis of the heart returns to normal only if the size of the left ventricle is returned to normal or the conduction of impulses through the left ventricle is restored.

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How is an electrocardiogram taken?

ECG recording is performed in a special room, maximally shielded from various electrical interference. The patient sits comfortably on the couch with a pillow under his head. To take an ECG, electrodes are applied (4 on the limbs and 6 on the chest). An electrocardiogram is recorded during quiet breathing. In this case, the frequency and regularity of heart contractions, the position of the electrical axis of the heart and some other parameters are recorded. This simple method allows you to determine whether there are abnormalities in the functioning of the organ, and, if necessary, refer the patient for a consultation with a cardiologist.

What influences the location of the EOS?

Before discussing the direction of the electrical axis, you should understand what the conduction system of the heart is. It is this structure that is responsible for the passage of impulses through the myocardium. The conduction system of the heart is atypical muscle fibers that connect different parts of the organ. It begins with the sinus node, located between the mouths of the vena cava. Next, the impulse is transmitted to the atrioventricular node, located in the lower part of the right atrium. The next to take the baton is the His bundle, which quickly diverges into two legs - left and right. In the ventricle, the branches of the His bundle immediately become Purkinje fibers, which penetrate the entire cardiac muscle.

EOS location options

Normal location of the electrical axis of the heart

Pathological location of the electrical axis of the heart

A condition in which the electrical axis of the heart is deviated is not a diagnosis in itself. However, such changes in the electrocardiogram may indicate various disorders in the functioning of the most important organ. The following diseases lead to serious changes in the functioning of the conduction system:

Cardiac ischemia;

Chronic heart failure;

Cardiomyopathies of various origins;

Congenital defects.

Deviation of the electrical axis of the heart to the left

Most often, such changes in the ECG are observed with enlargement of the left ventricle. This usually occurs with the progression of heart failure, when the organ simply cannot fully perform its function. It is possible that this condition may develop in arterial hypertension, which is accompanied by pathology of large vessels and increased blood viscosity. In all these conditions, the left ventricle is forced to work hard. Its walls thicken, leading to inevitable disruption of the impulse through the myocardium.

Deviation of the electrical axis of the heart to the right

This condition clearly indicates right ventricular hypertrophy. Similar changes develop in certain respiratory diseases (for example, bronchial asthma or chronic obstructive pulmonary disease). Some congenital heart defects can also cause the right ventricle to become enlarged. First of all, it is worth noting pulmonary artery stenosis. In some situations, tricuspid valve insufficiency can also lead to a similar pathology.

Why is changing EOS dangerous?

Most often, deviations of the electrical axis of the heart are associated with hypertrophy of one or another ventricle. This condition is a sign of a long-standing chronic process and, as a rule, does not require emergency care from a cardiologist. The real danger is the change in the electrical axis due to His bundle block. In this case, the conduction of impulses through the myocardium is disrupted, which means there is a risk of sudden cardiac arrest. This situation requires urgent intervention by a cardiologist and treatment in a specialized hospital.

With the development of this pathology, the EOS can be deviated both to the left and to the right, depending on the localization of the process. The blockade can be caused by myocardial infarction, infection of the heart muscle, as well as taking certain medications. A regular electrocardiogram allows you to quickly make a diagnosis, which means it allows the doctor to prescribe treatment taking into account all important factors. In severe cases, it may be necessary to install a pacemaker (pacemaker), which will send impulses directly to the heart muscle and thereby ensure normal functioning of the organ.

What to do if the EOS is changed?

To summarize, several important points should be highlighted:

The normal EOS value is considered to be the range from +30 to +70°.

Horizontal (from 0 to +30°) and vertical (from +70 to +90°) positions of the heart axis are acceptable values and do not indicate the development of any pathology.

Deviations of the EOS to the left or to the right may indicate various disorders in the conduction system of the heart and require consultation with a specialist.

A change in EOS detected on a cardiogram cannot be made as a diagnosis, but is a reason to visit a cardiologist.

The heart is an amazing organ that ensures the functioning of all systems of the human body. Any changes that occur in it inevitably affect the functioning of the whole organism. Regular examinations by a therapist and an ECG will allow timely detection of serious diseases and avoid the development of any complications in this area.

The deviation of the EOS to the right is recorded if it is in the range from +90 to +180 degrees.

Let's take a closer look at why this happens and what the normal numbers are.

When decoding an electrocardiogram, one of the parameters is the EOS - the electrical axis of the heart. This indicator indirectly reflects the position of this organ in the chest.

The atria and ventricles of the heart are controlled by impulses that travel through the conduction system. When taking a cardiogram, electrical signals passing inside the heart muscle are recorded.

For ease of measurement, the heart is schematically represented as a three-dimensional coordinate axis.

When added together, the pulses form a directed electric vector. It is projected onto the frontal vertical plane. This is EOS. Usually the electrical axis coincides with the anatomical one.

What should its normal position be?

The anatomical structure of the heart is such that its left ventricle weighs more than the right. That's why electrical excitation on the left side of the organ it is stronger.

Graphically, this is expressed in the fact that the axis is directed diagonally to the left and down. If you look at the vector projection, the left side of the heart is located in the area from +30 to +70 degrees. This is the normal value for an adult.

The position of the axis also depends on the individual characteristics of physiology.

The direction of EOS is influenced by the following factors:

Pulse speed.
The ability of the heart muscle to contract.
Features of the structure of the spine, chest, internal organs that interact with the heart.

Taking these factors into account, normal value axis varies from 0 to +90 degrees.

In a healthy person, the EOS can be in one of the following positions:

Normal - the angle of deviation from the coordinate axis is from +30 to +70 degrees.
Intermediate - from +15 to +60.
Vertical - between +70 and +90. This is typical for thin people with a narrow chest.
Horizontal - from 0 to + 30 degrees. It occurs in people with a wide chest and short stature.

In newborns, deviation of the EOS to the right is often observed. By one or two years, she moves to a vertical position. After children reach three years old the axis usually assumes its normal position.

This is due to the growth of the heart, in particular, with an increase in the mass of the left ventricle.

What could cause it to shift to the right?

A sharp deviation of the electrical vector from its axis is sometimes caused by processes occurring inside the body (pregnancy, development of tumors, etc.).

However, most often this means the presence of disturbances in the functioning of the heart muscle.

An axis shift can occur for the following pathological reasons:

Ischemic disease. Blockage of the arteries that provide blood supply to the myocardium develops.
Impaired blood flow in the branches of the pulmonary artery. Occurs as a result of vasoconstriction, which causes pressure in the right side of the heart to increase.
Myocardial infarction. Against the background of ischemic disease, tissue necrosis develops due to insufficient blood supply.
The opening between the left atrium and the ventricle narrows (stenosis), which leads to significant tension in the right side of the organ and its subsequent hypertrophy.
Blockage of the pulmonary artery (thrombosis).
Arrhythmia is a heartbeat disorder accompanied by chaotic excitation of the atria.
The occurrence of chronic pulmonary pathology in which the ventricle is also observed. In medicine, this disease is called “cor pulmonale.”
Abnormal development of the myocardium, in which there is a displacement of the organ to the right side. At the same time, the electrical axis also deviates.

A shift of the axis to the right is also observed due to long-term use of tricyclic antidepressants, resulting in severe intoxication of the body. This negatively affects the functioning of the heart.

When the EOS is deviated to the right side in newborns, this is considered normal.

However, if the shift is associated with (impaired passage of electrical impulses through the bundles of heart cells), then an additional examination of the baby is carried out.

Cardiac pathologies can be congenital or acquired during life, which develop as a result of previously suffered serious illnesses or due to increased physical activity.

For example, professional athletes are often diagnosed with an increase in the mass and volume of the left ventricle (hypertrophy).

Signs of displacement on the ECG

The angle of the electrical axis and its direction are the main characteristics when deciphering the ECG.

The interpretation of the cardiogram is given by a cardiologist. To do this, he uses special diagrams and tables designed to determine the displacement of the EOS.

The diagnostician examines the QRS waves on the electrocardiogram. This is a set of symbols that shows and displays the polarization of the ventricles.

QRS waves characterize their contraction or relaxation. R – tooth directed upward (positive), Q, S – negative, or directed downward. Q is before R and S is after it. Based on these signs, the cardiologist judges how the axis is shifting.

Deviation of the electrical axis of the heart to the right occurs if R is greater in the third lead than in the first. If the highest R amplitude is in the second lead, the EOS corresponds to the normal position.

Additional diagnostic methods

If the patient's ECG shows a tendency for the EOS to shift to the right, additional examination is carried out in order to make an accurate diagnosis.

Basically, this indicator indicates an increase in the mass of the right side of the heart.

Apply following methods diagnostics:

Chest X-ray. The pictures show an enlargement of the heart muscle, if any.
. The method allows you to obtain a complete visual picture of the state of the myocardium.
. Used if the patient has tachycardia.
Electronic cardiogram with additional load (for example,) - to determine coronary artery disease.
Angiography - reveals disturbances in the functioning of the coronary vessels.

Should I be worried and what should I do?

In itself, displacement of the electrical axis of the heart is not a disease; it only indicates the possible presence of pathologies. Cardiologists believe that one of the main reasons for deviation of the cardiac axis to the right is hypertrophy of the heart muscle.

If a shift to the right side is detected, additional examinations must be immediately performed. Based on their results, the doctor will prescribe treatment if any disorder is detected.

Usually, a sharp deviation of EOS on the electrocardiogram does not signal a threat to life. The doctor can only be alarmed strong change vector angle (up to +900). With this indicator, cardiac arrest may occur. The patient is immediately transferred to the intensive care unit.

To avoid serious consequences, if there is a displacement of the EOS, it is recommended to be examined by a cardiologist every year.