Sinus rhythm: essence, reflection on the ECG, norm and deviations, features

© Author: A. Olesya Valerievna, candidate of medical sciences, practicing physician, teacher at a medical university, especially for SosudInfo.ru (about the authors)

Sinus rhythm is one of the most important indicators of normal heart function, which indicates that the source of contractions comes from the main, sinus node of the organ . This parameter is one of the first in the ECG conclusion, and patients who have undergone the study are eager to find out what it means and whether they should worry.

The heart is the main organ that supplies blood to all organs and tissues; the degree of oxygenation and the function of the entire organism depend on its rhythmic and consistent work. To contract a muscle, a push is needed - an impulse emanating from special cells of the conduction system. The characteristics of the rhythm depend on where this signal comes from and what its frequency is.

the cardiac cycle is normal, the primary impulse comes from the sinus node (SU)

The sinus node (SU) is located under the inner lining of the right atrium, it is well supplied with blood, receiving blood directly from the coronary arteries, and is richly supplied with fibers of the autonomic nervous system, both parts of which influence it, contributing to both an increase and a decrease in the frequency of impulse generation.

The cells of the sinus node are grouped into bundles; they are smaller than ordinary cardiomyocytes and have a spindle-shaped shape. Their contractile function is extremely weak, but their ability to form an electrical impulse is akin to nerve fibers. The main node is connected to the atrioventricular junction, to which it transmits signals for further excitation of the myocardium.

The sinus node is called the main pacemaker, because it is the one that provides the frequency of heart contractions that gives the organs adequate blood supply, therefore maintaining a regular sinus rhythm is extremely important for assessing the work of the heart when it is damaged.

The control system generates pulses of the highest frequency compared to other parts of the conduction system, and then transmits them further at high speed. The frequency of impulse formation by the sinus node ranges from 60 to 90 per minute, which corresponds to the normal heart rate when they occur due to the main pacemaker.

Electrocardiography is the main method that allows you to quickly and painlessly determine where the heart receives impulses, what their frequency and rhythm are. ECG has become firmly established in the practice of therapists and cardiologists due to its accessibility, ease of implementation and high information content.

Having received the result of electrocardiography, everyone will look at the conclusion left there by the doctor. The first of the indicators will be the assessment of the rhythm - sinus, if it comes from the main node, or non-sinus, indicating its specific source (AV node, atrial tissue, etc.). So, for example, the result “sinus rhythm with heart rate 75” should not worry you, this is the norm, and if a specialist writes about non-sinus ectopic rhythm, increased heart rate (tachycardia) or slowdown (bradycardia), then it’s time to go for further examination.

Rhythm from the sinus node (SU) – sinus rhythm – normal (left) and pathological non-sinus rhythms. The pulse origination points are indicated

Also in conclusion, the patient can find information about the position of the EOS (electrical axis of the heart). Normally, it can be either vertical or semi-vertical, or horizontal or semi-horizontal, depending on the individual characteristics of the person. Deviations of the EOS to the left or right, in turn, usually indicate organic pathology of the heart. The EOS and its position options are described in more detail in a separate publication.

Sinus rhythm on a cardiac cardiogram - what is it?

The sinus rhythm detected on the electrocardiogram is displayed by identical teeth at equal intervals of time and indicates the correct functioning of the heart. The source of impulses is set by the natural pacemaker, the sinus (sinusoidal) node. It is localized in the angle of the right atrium and serves to generate signals that cause sections of the heart muscle to contract one by one.

A feature of the sinus node is its abundant blood supply. The number of impulses it sends is influenced by the divisions (sympathetic, parasympathetic) of the autonomic nervous system. If there is a malfunction in their balance, the rhythm is disturbed, which is manifested by an increase in heart rate (tachycardia) or slowdown (bradycardia).

Normally, the number of pulses generated should not exceed 60-80 per minute.

Maintaining sinus rhythm is important for stable circulation. Under the influence of external and internal factors, disruption of the regulation or conduction of impulses may occur, which will lead to disruptions in hemodynamics and dysfunction of internal organs. Against this background, the development of signal blockade or weakening of the sinusoidal node is possible. On the electrocardiogram, the resulting disorder is displayed as the presence of a focus of replacement (ectopic) impulses in a certain part of the heart muscle:

• atrioventricular node;
• atria;
• ventricles.

When the signal source is located anywhere other than the sinus node, we are talking about heart pathology. The patient will have to undergo a series of examinations (24-hour ECG monitoring, stress tests, ultrasound) to identify the causative factor of the disorder. Treatment will be aimed at eliminating it and restoring sinus rhythm.

Who orders the study and when?

A sheet with a referral for a cardiogram is issued by the attending physician or cardiologist. If you have complaints or heart problems, you should immediately go to the hospital for examination. This procedure allows you to check the condition of the heart, as well as determine the presence of abnormalities.

Using an ECG, a number of specific pathologies can be identified:

• formation of expansion in the area of ​​the heart chamber;
• changes in the size of the heart muscle;
• development of necrosis in tissues during myocardial infarction;
• ischemic lesions of the myocardial wall.

Decoding the cardiogram of the heart: sinus rhythm

Panic when a “sinus rhythm” recording is detected is typical for people unfamiliar with medical terms. Usually the cardiologist prescribes a series of examinations, so you will be able to see him again only after receiving all the results. The patient can only wait patiently and familiarize himself with publicly available sources of information.

In fact, sinus rhythm is the generally accepted norm, therefore, there is no point in worrying. Deviations are possible only in heart rate (HR). It is affected by various physiological factors, the influence of the vagus nerve and autonomic failures. The number of heart beats per minute may become higher or lower than normal for age, despite sending signals from the natural pacemaker.

A diagnosis of “tachycardia” or “bradycardia” of sinus type is made only after a comprehensive assessment of all the nuances. The doctor will pay attention to the patient’s condition and ask about the actions performed immediately before the study. If the decrease or increase in heart rate is insignificant and is associated with the influence of external factors, then the procedure will be repeated a little later or on another day.

Identification of the natural pacemaker during electrocardiography occurs according to generally accepted criteria:

• the presence of a positive P wave in the second lead;
• there is an equal interval between the P and Q waves, not exceeding 0.2 seconds;
• negative P wave in lead aVR.

If the transcript indicates that the patient has sinus rhythm and a normal position of the electrical axis of the heart (EOS), then they are afraid of nothing. The rhythm is set by its natural driver, that is, it comes from the sinus node into the atria, and then into the atrioventricular node and ventricles, causing alternate contractions.

When should you worry?

Cardiography findings indicating pathological sinus tachycardia, bradycardia or arrhythmia with instability and irregularity of rhythm should be a cause for concern.

With tachy- and bradyforms, the doctor quickly determines whether the pulse is more or less abnormal than normal, clarifies complaints and refers for additional examinations - ultrasound of the heart, Holter, blood tests for hormones, etc. Having found out the cause, you can begin treatment.

Unstable sinus rhythm on the ECG is manifested by unequal intervals between the main teeth of the ventricular complexes, the fluctuations of which exceed 150-160 ms. This is almost always a sign of pathology, so the patient is not ignored and the cause of instability in the sinus node is found out.

Electrocardiography will also indicate that the heart beats with an irregular sinus rhythm. Irregular contractions can be caused by structural changes in the myocardium - scar, inflammation, as well as heart defects, heart failure, general hypoxia, anemia, smoking, endocrine pathology, abuse of certain groups of drugs and many other reasons.

An irregular sinus rhythm comes from the main pacemaker, but the frequency of the organ’s beats either increases or decreases, losing its constancy and regularity. In this case, they talk about sinus arrhythmia.

Arrhythmia with sinus rhythm can be a variant of the norm, then it is called cyclic, and it is usually associated with breathing - respiratory arrhythmia. With this phenomenon, the heart rate increases as you inhale, and decreases as you exhale. Respiratory arrhythmia can be found in professional athletes, adolescents during periods of increased hormonal changes, and people suffering from autonomic dysfunction or neuroses.

Sinus arrhythmia associated with breathing is diagnosed on an ECG:

• The normal shape and location of the atrial waves, which precede all ventricular complexes, are preserved;
• As you inhale, the intervals between contractions decrease, and as you exhale, they become longer.

sinus rhythm and respiratory arrhythmia

Several tests can help distinguish physiological sinus arrhythmia. Many people know that during the examination they may be asked to hold their breath. This simple action helps to neutralize the effect of vegetatives and determine a regular rhythm, if it is associated with functional reasons and is not a reflection of pathology. In addition, taking a beta-blocker increases arrhythmia, and atropine relieves it, but this will not happen with morphological changes in the sinus node or heart muscle.

If the sinus rhythm is irregular and cannot be eliminated by holding your breath and pharmacological tests, then it’s time to think about the presence of pathology. It can be:

1. Myocarditis;
2. Cardiomyopathies;
3. Ischemic disease, diagnosed in most older people;
4. Heart failure with expansion of its cavities, which inevitably affects the sinus node;
5. Pulmonary pathology - asthma, chronic bronchitis, pneumoconiosis;
6. Anemia, including hereditary;
7. Neurotic reactions and severe vegetative dystonia;
8. Disorders of the internal secretion organs (diabetes, thyrotoxicosis);
9. Abuse of diuretics, cardiac glycosides, antiarrhythmics;
10. Electrolyte disturbances and intoxications.

Sinus rhythm, when irregular, does not exclude pathology, but, on the contrary, most often indicates it. This means that in addition to “sinus”, the rhythm must also be correct.

an example of interruptions and instability in the operation of the sinus node

If the patient knows about his existing diseases, then the diagnostic process is simplified, because the doctor can act purposefully. In other cases, when an unstable sinus rhythm was found on the ECG, a complex of examinations is required - Holter (24-hour ECG), treadmill, echocardiography, etc.

Acceptable standards

Whether the cardiogram readings are normal can be determined by the position of the teeth. Heart rhythm is assessed by the interval between the RR waves. They are the highest and should normally be the same. A slight deviation is acceptable, but not more than 10%. Otherwise, we are talking about a slowdown or increase in heart rate.

The following criteria are typical for a healthy adult:

• PQ interval varies within 0.12-0.2 seconds;
• Heart rate is 60-80 beats per minute;
• the distance between the Q and S teeth remains in the range from 0.06 to 0.1 sec;
• the P wave is 0.1 sec;
• The QT interval varies from 0.4 to 0.45 seconds.

In children, the indicators are slightly different from adults, which is due to the characteristics of the child’s body:

• QRS interval does not exceed 0.1 second;
• Heart rate varies depending on age;
• the distance between the Q and T teeth is no more than 0.4 seconds;
• PQ interval 0.2 sec.
• the P wave does not exceed 0.1 sec.

In adults, as in children, in the absence of pathologies, there should be a normal position of the electrical axis of the heart and sinus rhythm. You can see the permissible frequency of reductions by age in the table:

What criteria are used to decipher the ECG result?

The results of the cardiogram are deciphered by doctors according to a special scheme. Medical specialists have a clear understanding of which marks on the cardiogram are normal and which are abnormal. The ECG conclusion will be issued only after calculating the results, which were displayed in schematic form. A doctor, when examining a patient’s cardiogram in order to correctly and accurately decipher it, will pay special attention to a number of such indicators:

You can also read: Diagnosis of myocardial infarction using ECG

• the height of the bars displaying the rhythm of heart impulses;
• the distance between the teeth on the cardiogram;
• how sharply the indicators of the schematic image fluctuate;
• what specific distance is observed between the bars displaying the pulses.

A doctor who knows what each of these schematic marks means carefully studies them and can clearly determine what kind of diagnosis needs to be made. Cardiograms of children and adults are deciphered according to the same principle, but normal indicators for people of different age categories cannot be the same.

Reasons for deviation from the norm

Heart rate varies depending on the time of day, psycho-emotional state and other external and internal factors. To obtain reliable data, you will need to take into account many nuances:

Equally important is careful preparation for the procedure:

• It is prohibited to consume alcohol and drugs a couple of days before the ECG.
• It is better to forget about smoking, coffee and energy drinks on the day of the procedure.
• Immediately a couple of hours before the examination, it is not recommended to transfer, stay in stressful situations and become overtired.

If you were unable to follow all the rules, then upon arrival at the diagnostic room you should tell the specialist about it. He will take this nuance into account and, if necessary, schedule an examination for another day.

A general list of factors that can affect the frequency and rhythm of the heart rhythm is as follows:

• mental disorders;
• overwork (psycho-emotional, physical);
• developmental defects (congenital, acquired);
• taking medications with antiarrhythmic effect;
• disruption of the valve apparatus (insufficiency, prolapse);
• dysfunction of the endocrine glands;
• advanced stage of heart failure;
• pathological changes in the myocardium;
• inflammatory heart diseases.

The use of medications, especially for stabilizing blood pressure (Mexari) and improving metabolic processes (Metonate, Adenosine), must be reported before the procedure. Many heart medications can slightly distort the results.

results

ECG results: sinus rhythm. If all the parameters reflected on the cardiogram correspond to sinus rhythm, this means that the innervation impulses correctly follow from top to bottom. Otherwise, the impulses originate from the secondary parts of the heart.

What does a vertical position mean when there is sinus rhythm on an ECG? This is the normal location of the heart in the thoracic region, on the line of the conventional location of the central axis. Since the location of the organ is permissible at different angles of inclination and in different planes, both vertical and horizontal, as well as in intermediate ones. This is not a pathology, but only indicates the distinctive characteristics of the structure of the patient’s body and is detected as a result of an ECG examination.

Features of deciphering an electrocardiogram

Based on the electrocardiogram, the cardiologist will be able to assess the electrical potential of the heart muscle during systole (contraction) and diastole (relaxation). Displays data in 12 curves. Each of them demonstrates the passage of an impulse through a specific part of the heart. Waveforms are recorded on 12 leads:

• 6 leads on the arms and legs designed to assess vibrations in the frontal plane.
• 6 leads in the chest area for recording potentials in the horizontal plane.

Each curve has its own elements:

• The teeth in appearance resemble bulges directed up and down. They are designated by Latin letters.
• Segments are the distance between several teeth located nearby.
• An interval is a gap consisting of several teeth or segments.

General principles of decoding

Evaluating the electrocardiogram is a complex process. The doctor carries it out step by step so as not to miss the slightest changes:

To better understand the information, it is advisable to familiarize yourself with various options for expert opinions:

• A healthy person is characterized by sinus rhythm, 60-80 heartbeats per minute, EOS in a normal position and the absence of pathologies.
• With an increased or decreased heart rate, sinus tachycardia or bradycardia is indicated in conclusion. The patient will be advised to undergo several more examinations or repeat the procedure on another day if the result was influenced by external factors.
• In elderly patients and people who do not lead a healthy lifestyle, pathological changes in the myocardium of a diffuse or metabolic nature are often detected.
• A record of the presence of nonspecific changes in the ST-T interval indicates the need for additional examinations. In this case, it is not possible to find out the true cause only with the help of electrocardiography.
• The detected repolarization disorder indicates incomplete recovery of the ventricles after contraction. Usually, various pathologies and hormonal imbalances affect the process. To detect them, several more examinations will be required.

For the most part, the conclusions are positive. Changes can be overcome with lifestyle changes and medications. An unfavorable prognosis is usually when coronary artery disease, proliferation (hypertrophy) of the chambers of the heart muscle, arrhythmia and failures in the conduction of impulses are detected.

Conduction disorders

Normally, having formed in the sinus node, electrical excitation travels through the conduction system, experiencing a physiological delay of a split second in the atrioventricular node. On its way, the impulse stimulates the atria and ventricles, which pump blood, to contract. If in any part of the conduction system the impulse is delayed longer than the prescribed time, then excitation to the underlying sections will come later, and, therefore, the normal pumping work of the heart muscle will be disrupted. Conduction disturbances are called blockades. They can occur as functional disorders, but more often they are the result of drug or alcohol intoxication and organic heart disease. Depending on the level at which they arise, several types are distinguished.

Sinoatrial blockade

When the exit of an impulse from the sinus node is difficult. In essence, this leads to sick sinus syndrome, slowing of contractions to severe bradycardia, impaired blood supply to the periphery, shortness of breath, weakness, dizziness and loss of consciousness. The second degree of this blockade is called Samoilov-Wenckebach syndrome.

Atrioventricular block (AV block)

This is a delay of excitation in the atrioventricular node longer than the prescribed 0.09 seconds. There are three degrees of this type of blockade. The higher the degree, the less often the ventricles contract, the more severe the circulatory disorders.

• In the first, the delay allows each atrial contraction to maintain an adequate number of ventricular contractions.
• The second degree leaves some of the atrial contractions without ventricular contractions. It is described, depending on the prolongation of the PQ interval and the loss of ventricular complexes, as Mobitz 1, 2 or 3.
• The third degree is also called complete transverse blockade. The atria and ventricles begin to contract without interconnection.

In this case, the ventricles do not stop because they obey the pacemakers from the underlying parts of the heart. If the first degree of blockade may not manifest itself in any way and can be detected only with an ECG, then the second is already characterized by sensations of periodic cardiac arrest, weakness, and fatigue. With complete blockades, brain symptoms are added to the manifestations (dizziness, spots in the eyes). Morgagni-Adams-Stokes attacks may develop (when the ventricles escape from all pacemakers) with loss of consciousness and even convulsions.

Impaired conduction within the ventricles

In the ventricles, the electrical signal propagates to the muscle cells through such elements of the conduction system as the trunk of the His bundle, its legs (left and right) and branches of the legs. Blockades can occur at any of these levels, which is also reflected in the ECG. In this case, instead of being simultaneously covered by excitation, one of the ventricles is delayed, since the signal to it bypasses the blocked area.

In addition to the place of origin, a distinction is made between complete or incomplete blockade, as well as permanent and non-permanent blockade. The causes of intraventricular blocks are similar to other conduction disorders (ischemic heart disease, myocarditis and endocarditis, cardiomyopathies, heart defects, arterial hypertension, fibrosis, heart tumors). Also affected are the use of antiarthmic drugs, an increase in potassium in the blood plasma, acidosis, and oxygen starvation.

• The most common is blockade of the anterosuperior branch of the left bundle branch (ALBBB).
• In second place is right leg block (RBBB). This blockade is usually not accompanied by heart disease.
• Left bundle branch block is more typical for myocardial lesions. In this case, complete blockade (PBBB) is worse than incomplete blockade (LBBB). It sometimes has to be distinguished from WPW syndrome.
• Blockade of the posteroinferior branch of the left bundle branch can occur in individuals with a narrow and elongated or deformed chest. Among pathological conditions, it is more typical for overload of the right ventricle (with pulmonary embolism or heart defects).

The clinical picture of blockades at the levels of the His bundle is not expressed. The picture of the underlying cardiac pathology comes first.

• Bailey's syndrome is a two-bundle block (of the right bundle branch and the posterior branch of the left bundle branch).

Causes of deviations in sinus rhythm

Abnormal sinus rhythm appears under the influence of pathologies or physiological factors. The forms of failure differ depending on the frequency and rhythm of contractions:

• sinus arrhythmia;
• sinus bradycardia;
• sinus tachycardia.

Despite the correct source of signals, the problem that has arisen must be dealt with. If no action is taken, a more severe form of arrhythmia may develop and dangerous symptoms of hemodynamic disturbances may appear.

Sinus tachycardia

The sinus form of tachycardia can be pathological or physiological. In the first case, it occurs due to other diseases, and in the second, after stress and overwork. The electrocardiogram usually reveals an increased frequency of contractions from 100 to 220 per minute and a short P-P interval.

The following symptoms are characteristic of an attack of sinus tachycardia:

• feeling of heartbeat;
• lack of air;
• general weakness;
• dizziness;
• sleep disturbance;
• chest pain;
• noise in ears.

Sinus bradycardia

Attacks of sinus bradycardia, like tachycardia, occur as a symptom of other diseases or as a reaction to physiological factors. They are characterized by a decrease in heart rate to 60 beats per minute or less. The electrocardiogram shows a noticeable increase in the distance between the P-P waves.

In addition to a slow heartbeat, during an attack of bradycardia the following symptoms appear:

• dizziness;
• fainting state;
• pain in the heart area;
• pale skin;
• tinnitus;
• fast fatiguability.

Sinus arrhythmia

The sinus variety of arrhythmia usually results in an irregular rhythm. The heart rate can increase or decrease sharply under the influence of various stimuli. The length of the P-P interval varies.

An attack of sinus arrhythmia is characterized by the following symptoms:

• feeling of fading and heart failure;
• change in skin color (blueness, redness);
• feeling of lack of air;
• panic attacks;
• pain in the heart area;
• tremor of the limbs;
• faintness or loss of consciousness.

Violations and criteria for their determination

If the description contains the phrase: sinus rhythm disturbances, then a blockade or arrhythmia . An arrhythmia is any disruption in the rhythm sequence and its frequency.

Blockades can be caused if the transmission of excitation from the nerve centers to the heart muscle is disrupted. For example, rhythm acceleration shows that during a standard sequence of contractions, the heart rhythms are accelerated.

If the conclusion contains a phrase about an unstable rhythm, this means a manifestation of a low heart rate or the presence of sinus bradycardia . Bradycardia has a detrimental effect on a person’s condition, since the organs do not receive the amount of oxygen required for normal activity.

Unpleasant symptoms of this disease can be dizziness, pressure changes, discomfort and even chest pain and shortness of breath.

If an accelerated sinus rhythm is recorded, then most likely this is a manifestation of tachycardia . This diagnosis is made when the number of heart beats exceeds 110 beats.

Features of ECG interpretation in children

Electrocardiography is performed in children in the same way as in adults. Problems can only arise with hyperactive kids. They must first be reassured and the importance of the procedure explained. The results obtained differ only in heart rate. During active growth, the heart has to work harder to supply all tissues of the body in full. As the child develops, the heartbeat gradually returns to normal.

Signs of sinus rhythm in children are similar to adults. The increase in heart rate must be within the acceptable age limit. If a focus of ectopic impulses is detected, then we can talk about a congenital malformation of the heart. It can only be completely removed through surgery.

Cases of mild sinus arrhythmia are most often associated with the respiratory system. During inhalation, the heart rate increases and stabilizes as you exhale. Such failures are typical for children and go away over time. When conducting an ECG, respiratory arrhythmia must be taken into account, since a cold couch, fear and other factors provoke its aggravation.

The sinus form of arrhythmia can be provoked by more dangerous causes:

• hypoxia that occurred in the womb;
• high pressure inside the skull, detected immediately after birth;
• rheumatism;
• myocarditis;
• infectious diseases;
• heart defects.

Due to the voiced pathological processes, the likelihood of developing complications that can lead to death and disability increases. Less severe causes include active growth, rickets and vegetative-vascular dystonia. In most cases, they go away on their own. It is enough for parents to give their child vitamin complexes and diversify his diet.

Additional Research

If the doctor, when examining the results, sees that the length of the area between the P waves, as well as their height, are unequal, it means that the sinus rhythm is weak .

To determine the cause, the patient may be recommended to undergo additional diagnostics: the pathology of the node itself or problems of the nodal autonomic system may be identified.

Additional examination is prescribed when the rhythm is lower than 50 and stronger than 90.

Then Holter monitoring is prescribed or a drug test is performed, which makes it possible to find out whether there is a pathology of the node itself or whether the regulation of the autonomic system of the node is disrupted.

For more details about weak node syndrome, watch the video conference:

If it turns out that the arrhythmia was the result of disturbances in the node itself, then corrective measurements of the vegetative status . If for other reasons, then other methods are used, for example, implantation of a stimulator.

Holter monitoring is a regular electrocardiogram that is performed throughout the day . Due to the duration of this examination, specialists can study the condition of the heart at different degrees of stress. When conducting a regular ECG, the patient lies on the couch, and when conducting Holter monitoring, it is possible to study the state of the body during physical activity.

Decoding the electrocardiogram during pregnancy

During pregnancy, significant changes occur in a woman’s body that affect the results of electrocardiography:

• An increase in circulating blood volume contributes to the development of tachycardia and the manifestation of signs of overload in certain parts of the heart muscle.
• The growing uterus provokes displacement of internal organs, which is manifested by a change in the location of the electrical axis of the heart.
• Hormonal surges affect all systems in the body, especially the nervous and cardiovascular systems. A woman experiences attacks of tachycardia after any physical exertion. Heart rate usually increases by no more than 10-20 beats per minute from normal.

The changes that occur go away on their own after the birth of the child, but in some cases they develop into a full-fledged pathological process. To prevent it, it is necessary to be observed by a doctor throughout the entire pregnancy.

Electric axis positions

The axis position is determined by:

1. Speed ​​and quality indicators of impulse passage through the myocardial conduction system.
2. The ability of the muscle layer to contract.
3. Changes in the body that affect both the functioning of the heart in general and its conduction system in particular.

In a healthy person, the electrical axis can occupy several positions.

So, the normal position of the axis is considered to be in the range from 0 to 90, while it can be directed either down or to the left. The direction of the electrical axis directly depends on the individual characteristics in the anatomical structure of a person and happens:

1. Vertical. Characteristic of thin, tall people with a small chest.
2. Horizontal. It is typical for people who are short, overweight and have a wide chest. The axis position, in this case, fluctuates between 15 and -30

Axis deviations

As a rule, the anatomical structure of a person is a mixed type, which is why the electrical axis can deviate from the vertical or horizontal and have an intermediate position. EOS displacement is not a diagnosis, but a consequence of individual structural characteristics or diseases occurring in the body. Thus, the axis of the heart can be deviated:

Left

The location of the electrical axis of the heart from -30 to -90 is considered abnormal and may indicate an increase in the size of the left ventricle (hypertrophy). LVH is also not a diagnosis, but indicates diseases such as:

• Hypertension is the resistance of blood vessels to blood flow.
• Left ventricular infarction.
• Congenital or acquired heart defects.
• Cardiomyopathy is a disorder of muscle contraction.
• Myocarditis.
• Excess and deposition of calcium in the heart muscle.

In addition to the above, the cause of axis deviation to the left side may be a disturbance in the functioning of the LV valve, its insufficiency, blockade of the heart muscle, or conduction disturbances in the LV. People who have had rheumatic fever are susceptible to such diseases; in addition, athletes are at risk.

Right

The location of the electrical axis of the heart from +90 to +180 is considered pathological and may indicate an enlargement of the right ventricle. Since it is from it that blood enters the lungs, the cause of RPG can be:

• Diseases of the respiratory system causing hypertrophy.
• Right ventricular infarction.
• Violation of the conductivity of the pancreas.
• Pulmonary artery deformation.
• Hypertension.
• Obstruction of blood flow in the PA, as a result of the formation of blood clots.
• Heart defects leading to pulmonary congestion.
• Emphysema.

The cause of axis deviation to the right side can be coronary disease, heart failure and cardiomyopathy.

Symptoms

A horizontal deviation of the electrical axis may not be accompanied by severe symptoms and may not manifest itself for a long time. As a rule, the patient’s well-being worsens with the onset of complications of cardiac muscle hypertrophy.

Signs of EOS deviation from the norm may include headaches, shortness of breath, suffocation, and swelling of the extremities. The manifestation of any of the above signs is the basis for contacting a cardiologist and a complete examination of the body.

Treatment

It is important to understand that the above diseases cannot be diagnosed solely by the fact of displacement of the horizontal electrical axis. The location of the EOS outside the boundaries from 0 to +900 is an indication for consultation with a cardiologist and further examinations

The most common cause of cardiac axis deviation is hypertrophy. The symptoms accompanying the disease will make it possible to make a preliminary diagnosis, which can later be confirmed or refuted by ultrasound. In the case when previously taken ECGs did not record pathology, and deviations appeared in a fairly short period of time, the cause of EOS displacements may be a blockade.

IMPORTANT! The displacement itself does not require treatment; the prescribed therapy is aimed at eliminating the causes of the pathology. Video:

Video:

The meaning of letters and numbers on an electrocardiogram

The definitions of the Latin letters that label the teeth will help you understand what is being said in the electrocardiogram:

It is equally important to find out the meaning of certain segments and intervals:

• The PQ interval shows how long it takes for an electrical impulse to travel through the heart muscle (from the atria to the ventricles). In the absence of irritating factors, the length does not exceed 0.2 seconds. Based on this indicator, the doctor will assess the general condition of the conduction system. If there is a lengthening of the distance between the P and Q waves, then the problem may be the development of heart block.
• Based on the space between the RR teeth, the doctor will determine the regularity of contractions and count them.
• The QRS complex helps you see how the signal is conducted through the ventricles.
• The segment between the S and T waves shows the moment the excitation wave passes through the ventricles. Its permissible length is 0.1-0.2 seconds. The segment is located on an isoline. If it is slightly displaced, then certain pathological processes can be suspected: higher by 1 mm or more – myocardial infarction;
• lower by 0.5 or more – ischemic disease;
• saddle-shaped segment – ​​pericarditis.

It will not be easy for an ordinary person to decipher an electrocardiogram. First, you will have to familiarize yourself with the definition of the Latin symbols that indicate the teeth, and the features of the intervals between them. Then you need to study the types of heart rhythm and generally accepted heart rate norms. Finally, it is advisable to review the options for expert opinions and the general principles of decoding. Based on the information studied, even a person far from medicine will be able to understand the cardiogram.

Why do an ECG test?

A referral for a cardiogram is issued in the following cases:

1. Pain in the heart, shortness of breath while walking.
2. If there are signs of arrhythmia, coronary artery disease, myocardial infarction.
3. Before performing a series of operations, not only on the heart, but also on other important organs.
4. In the presence of third-party diseases (ear, nose, throat) that cause complications on the heart.

5. During the medical examination of pilots, athletes and drivers.
6. To record heart activity.
7. To diagnose diseases with symptoms of irregular heartbeat, dizziness, fainting.
8. To regulate the operation of pacemakers and implants.
9. A cardiogram is recommended annually for men and women after 45 years of age.
10. During pregnancy.

Pathologies

Not everyone can boast of perfect health. Tests of the heart muscle may reveal some abnormalities.

Interpretation of ECG sinus rhythm. Inconsistency of heart activity with sinus rhythm indicates arrhythmia or blockade. The blockade occurs as a result of the transmission of impulses by the central nervous system to the heart. An increased heart rate means that the vibrations are faster. If we talk about rhythm disturbances, then in total there is a discrepancy between the frequency of contractions of the heart muscle and the sequence.

Incorrect cyclicity of sinus rhythm can be observed on the ECG by the difference in the distances between the peaks. This basically indicates a weak node. To verify arrhythmia, it is necessary to conduct Holter monitoring and a drug test. This way it is possible to identify disturbances in the self-regulation of the autonomic system and the source of oscillations.

What does an electrocardiogram consist of?

An ECG study consists of the following indicators:

1. Wave R. Responsible for contractions of the left and right atria.
2. PQ (R) interval is the distance between the R wave and the QRS complex (the beginning of the Q or R wave). Shows the duration of impulse travel through the ventricles, His bundle and atrioventricular node back to the ventricles.
3. The QRST complex is equal to the systole (moment of muscle contraction) of the ventricles. The excitation wave propagates at different intervals in different directions, forming Q, R, S waves.
4. Wave Q. Shows the beginning of the propagation of the impulse along the interventricular septum.
5. Wave S. Reflects the end of the distribution of excitation through the interventricular septum.
6. Wave R. Corresponds to the distribution of impulses along the right and left ventricular myocardium.
7. Segment (R) ST. This is the path of the impulse from the end point of the S wave (in its absence, the R wave) to the beginning of the T.
8. Wave T. Shows the process of repolarization of the ventricular myocardium (raising the gastric complex in the ST segment).

The video discusses the main elements that make up an electrocardiogram. Taken from the MEDFORS channel.

I 48 - Atrial fibrillation - example of writing a call card

Patient, 64 years old
Reason for calling – Arrhythmia

Complaints, medical history

Complaints of general weakness, palpitations, a feeling of interruptions in the functioning of the heart.

The attack lasted about 40 minutes, occurred at rest, took cordarone 200 mg, metoprolol 50 mg without effect. Previously, there were similar conditions, they were associated with cardiac arrhythmias, he repeatedly contacted 03, the rhythm was restored with novocainamide, cordarone.

Anamnesis of life

Hypertension stage III. IBS. Paroxysmal form of atrial fibrillation. Regularly takes enalapril 10 mg/day, betaloc 50 mg/day, cordarone 200 mg/day.

Comfortable blood pressure – 130/80

Physical examination

Condition: moderate;

Consciousness – clear, Glasgow scale – 15 points, behavior – calm;

Pupils – normal, D = S, reaction to light – lively, no gaze paresis, no nystagmus;

Skin – physiological color, dry, clean;

Heart sounds are muffled, arrhythmic, frequent, no murmurs. Pulse in the peripheral arteries is of satisfactory quality, arrhythmic, frequent;

Nervous system – without pathology, no meningeal symptoms;

The pharynx is calm, the tonsils are normal;

Excursion of the chest - normal, type of breathing - normal, percussion - pulmonary sound, auscultation - vesicular breathing, no shortness of breath;

There is no peripheral edema;

The tongue is clean and moist. The abdomen is soft, painless, participates in the act of breathing, there are no symptoms of peritoneal irritation, the liver is not enlarged, stool is formed, 1 time per day;

Urine output is normal, SSPO is negative.

Main pathology

Consciousness preserved and adequate. The skin is physiologically colored, dry. Heart sounds are muffled, arrhythmic, frequent. The pulse in the peripheral arteries is of satisfactory quality, arrhythmic, frequent.

Electrocardiography

15-35 – Atrial fibrillation. Signs of left ventricular hypertrophy. Signs of systolic myocardial overload.

16-30 – Sinus rhythm with heart rate 72 beats. per minute Signs of left ventricular hypertrophy. There are no ischemic changes. There are no dynamics with the previous ECG.

Diagnosis by the EMS team

IBS. Paroxysmal form of atrial fibrillation, paroxysm, tachysystole.

Therapeutic measures

• 15-37 – Sol. Cordaroni 450 mg IV drip
• 15-37 – Sol. Glucosae 5% 250 ml IV drip
• ECG monitoring
• It is recommended to contact your local physician (the asset has been transferred to the clinic).

Treatment result

Improvement. Restoration of sinus rhythm. Subjective improvement in well-being.

Treatment methods

Treatment tactics directly depend on what kind of deviation was identified. Most often, experts advise spending time in the fresh air more often, leading a healthy lifestyle and giving up bad habits.

To improve the ability to transmit electrical charge, it is recommended to use sedative medications and vitamin complexes. Magnesium or motherwort is prescribed for nervousness or frequent stressful situations. It is preferable to consume foods with increased vitamin D and calcium content. Thanks to this, the elasticity of the walls of blood vessels will be maintained. If the deviations are serious, the patient is referred to inpatient therapy. The department will conduct the necessary examinations to determine the cause of the failure.

ECG indicators

The main indicators of the electrocardiogram characterizing the work of the myocardium are waves, segments and intervals.

Serrations are all sharp and rounded bumps written along the vertical Y axis, which can be positive (upward), negative (downward), or biphasic. There are five main waves that are necessarily present on the ECG graph:

• P – recorded after the occurrence of an impulse in the sinus node and sequential contraction of the right and left atria;
• Q – recorded when an impulse appears from the interventricular septum;
• R, S – characterize ventricular contractions;
• T - indicates the process of relaxation of the ventricles.

Segments are areas with straight lines, indicating the time of tension or relaxation of the ventricles. There are two main segments in the electrocardiogram:

• PQ – duration of ventricular excitation;
• ST – relaxation time.

An interval is a section of an electrocardiogram consisting of a wave and a segment. When studying the PQ, ST, QT intervals, the time of propagation of excitation in each atrium, in the left and right ventricles is taken into account.