Unstable sinus rhythm. What does sinus rhythm mean? Sinus rhythm according to ECG

The main organ of the human body, which supplies all its tissues with blood, is the heart. The degree of oxygen saturation of the brain and the functional activity of the whole organism depend on the systematic contractions of its muscles. To excite the muscle tissue of the heart, an impulse (electrical signal) coming from conducting cardiomyocytes is required.

Normally, these shocks are produced by the sinus node - the characteristics of the heart rhythm depend on their frequency and location. In modern medicine, diseases of the cardiovascular system are detected using a special examination method - an electrocardiogram. Practitioners prescribe it to diagnose pathologies of the heart muscle, monitor the course of existing ailments, before any surgical intervention and for preventive purposes.

ECG results provide doctors with specific information about cardiac activity. In our article we will provide information about the features and parameters of normal heart rhythm and possible deviations. We will also tell our readers what sinus rhythm is on an ECG and how to determine its pathological signs.

Heart Rate Characteristics

The occurrence of electrical phenomena in the heart is caused by the movement of sodium and potassium ions in the myocardial cells, which creates the necessary conditions for excitation, contraction and then the transition to the original state of the heart muscle. Electrical activity is characteristic of all types of myocardial cells, but only cardiomyocytes of the conduction system exhibit spontaneous depolarization.

One of the most important parameters of normal heart function is sinus rhythm, which indicates the fact that the source of muscle contractions comes from the Keith-Fluck node (or the sinus region of the heart). The regular repetition of emerging cardiac impulses is determined on the cardiogram both in healthy people and in patients with heart pathologies.

The ECG complex consists of several waves, intervals and segments, which reflect the complex mechanisms of depolarization and repolarization waves propagating through the heart muscle.

It is carried out according to the following scheme:

assessment of heart rhythm regularity;
counting the number of contractions of the heart muscle;
definition of the “pacemaker” - the source of the occurrence and conduction of excitation in the heart muscle;
study of the function of impulse conduction through the heart.

The heart rate of a healthy adult ranges from 60 to 90 beats per minute. Tachycardia indicates an increase in heart rate, bradycardia - a decrease. To determine the “pacemaker of the heart” (the area of the myocardium that generates impulses), the course of excitation in the upper sections - the atria - is assessed. This indicator is determined by the ratio of the teeth of the ventricular complex. Sinus rhythm, vertical position of the EOS (the electrical axis of the heart, which reflects the peculiarities of its structure) and a normal heart rate indicate the absence of any abnormalities in the functioning of the heart muscle in the patient’s body.

What does sinus rhythm mean?

The structure of the heart muscle consists of four chambers, which are separated by valves and septa. In the right atrium, in the zone of confluence of the superior and inferior vena cava, there is a certain center consisting of specific cells that send electrical impulses and set the rhythm for the regular repetitions of muscle contractions - the sinus node.

The cardiomyocytes that form it are grouped into bundles, they have a spindle-shaped shape and are characterized by weak contractile function. However, they are also capable of generating discharges, like the processes of neurons with glial coating. The sinus node sets the heart muscle a rhythm that ensures normal blood delivery to the tissues of the human body.

This is why maintaining a regular sinus rhythm is extremely important for assessing cardiac function. On an ECG, this indicator means that the impulse comes from the main (sinus) node - the norm is 50 beats per minute. Its change indicates the fact that the electrical energy stimulating the heart muscle comes from another part of the heart.

For further excitation and contraction of the myocardium, the sinus node sends signals to the conduction system - the Aschoff-Tawar junction (atrioventricular) and Purkinje muscle fibers (the walls of the heart located in the interventricular septum and entwining its apex)

When interpreting the final cardiogram data, special attention is paid to:

on the QRS (ventricular complex) following the P wave;
per interval (time period) PQ – normally its range is from 120 to 200 milliseconds;
on the shape of the P wave, which must be constant at each point of the electric field;
the R-R intervals are similar to the boundary of the R-R intervals;
per T segment is observed behind each P wave.

Signs of violation

Not every modern person can boast of the absence of heart problems. Very often, an ECG reveals such pathological conditions as blockade, which is provoked by a change in the transmission of impulses from the nervous system directly to the heart, arrhythmia, caused by a discrepancy in the systematicity and sequence of myocardial contractions. Irregular sinus rhythm, indicated by a change in the cardiographic indicator - the distance between the teeth of the cardiogram, may indicate dysfunction of the “pacemaker”.

The diagnosis of sick sinus syndrome is made based on clinical findings and heart rate. To determine this parameter, the doctor interpreting the ECG results uses the following calculation methods: divide the number 60 by the R-R interval expressed in seconds, multiply the number 20 by the number of teeth of the ventricular complexes performed within three seconds.

Violation of sinus rhythm on an ECG means the following deviations:

arrhythmia - differences in R-R time intervals of more than 150 milliseconds, most often this phenomenon is observed during inhalation and exhalation and is due to the fact that at this moment the number of beats fluctuates;
bradycardia – heart rate is less than 60 beats/min, the P-P interval increases to 210 ms, the correct propagation of the excitation impulse is preserved;
rigid rhythm - the disappearance of its physiological irregularity due to a violation of neurovegetative regulation, in this case there is a decrease in the R-R distance by 500 ms;
tachycardia - heart rate exceeds 90 beats/min, if the number of myocardial contractions increases to 150 beats/min, ascending ST elevation and descending depression of the PQ segment are observed, second degree atrioventricular block may occur.

To identify possible heart rhythm disturbances, a Holter ECG is performed - daily monitoring of the functional activity of the myocardium

Causes of sinus arrhythmia

The patient's anxiety can be caused by the ECG conclusion, which indicates data on irregularity and instability of sinus rhythm. The most common reasons for such deviations are:

alcohol abuse;
congenital or acquired heart defects;
smoking;
mitral valve prolapse;
acute heart failure;
poisoning of the body with toxic substances;
uncontrolled use of cardiac glycosides, diuretics and antiarrhythmics;
neurotic disorders;
increased levels of thyroid hormones.

To clinically differentiate cardiac arrhythmias, physiological tests are performed - this makes it possible to neutralize the effect of the autonomic nervous system and accurately identify the presence of morphological changes in the sinus node.

If the irregularity of sinus rhythm is not eliminated by holding the breath and drug tests, this indicates that the patient has:

cardiomyopathy;
myocarditis;
ischemic disease;
pathologies of the bronchopulmonary system;
anemia;
severe form of vegetative-vascular dystonia;
dilation of the heart cavities;
diseases of the endocrine glands;
disorders of electrolyte metabolism.

Features in young patients

The parameters of a child’s cardiogram differ significantly from the results of an adult’s ECG - every mother knows how often her baby’s heart beats. Physiological tachycardia is explained by the anatomical features of the child’s body:

up to 1 month, heart rate varies from 105 to 200 beats/min;
up to 1 year – from 100 to 180;
up to 2 years – from 90 to 140;
up to 5 years – from 80 to 120;
up to 11 years – from 75 to 105;
up to 15 – from 65 to 100.

A rhythm of sinus origin is recorded in children without defects of the heart muscle, its valve apparatus or blood vessels. Normally, on a graphical ECG recording, the P segments before ventricular systole should have the same shape and size, and the heart rate should not exceed age-specific indicators. Unstable heart rhythm and sinus ectopy are a signal to search for unfavorable factors that provoke a decrease in the activity of the main node of the conduction system of the heart.

Very often, the cause of sinus arrhythmia in childhood can be a breath-holding reflex associated with a change in temperature, fear or confusion of the child

Sick sinus syndrome is observed in premature babies, infants who experienced oxygen deficiency during intrauterine development, newborns with high blood pressure inside the skull, infants with vitamin D deficiency, adolescents - the processes of rhythm changes are associated with the rapid growth of the child’s body and vegetative-vascular dystonia. Physiological disorders of sinus rhythm resolve without specific treatment as heart rate regulation improves and the central nervous system matures.

Such a child needs to undergo cardiography once every six months; the state of his cardiovascular system is monitored by a qualified specialist.

Dysfunction of sinus rhythm of a pathological nature can be caused by a severe infectious and inflammatory process, genetic predisposition, congenital structural abnormalities and deformations of the heart muscle. In this case, the cardiologist prescribes therapeutic and preventive measures for the small patient under conditions of constant monitoring of the functional activity of the heart.

Summarizing the above information, I would like to add that an ECG is a simple and inexpensive diagnostic method with which dysfunctions of the heart muscle can be detected in a short period of time. However, in the presence of serious pathological changes, this technique is not enough to make a final diagnosis - the patient is prescribed echocardiography, ultrasound scanning of the heart and coronary examination of its vessels.

Some people advocate that doctors give them complete information about their health. But if you think about it, it's not such a great idea. All these medical terms can scare the layman. For example, what does “sinus heart rhythm” mean? Such words are not very clear to ordinary people, and the doctor gets another panicking patient.

Principles of the heart

Thanks to this organ, blood flows into all vessels of the body and provides every cell with nutrition and oxygen. The heart is the engine of the body, and this engine works constantly throughout human life. Its structure is very complicated, it’s even hard to believe that nature could create such a mechanism.

It all starts with the generation of an electrical impulse by the sinoarterial node. Following the stimulation of this small group of cells, the atria contract, pushing blood into the ventricles. Then they relax. On the contrary, the ventricles contract when an electrical wave reaches them, throwing blood into the arteries. Later, all four chambers relax. And everything starts in a circle. It's amazing how smoothly this mechanism works. Considering that its work does not stop for a second, it is even strange how rarely failures occur.

The generation of an electrical signal occurs at approximately equal intervals of time, although normally they can and should even vary slightly. On the contrary, if this does not happen, this may indicate depletion of reserves. This condition is called “rhythm rigidity.” It can be observed during ischemia.

Sinus rhythm

What it is? What does this entry mean in the ECG transcript? Should you panic when you see her? In fact, it's the other way around. Such a recording most often indicates normal heart function, although it may accompany some diseases. This is what sinus rhythm of the heart means, especially if there are no other words. You can calm down and visit a doctor only after a year, if no other need arises.

It’s a different matter if we are talking about sinus rhythm disturbances. This could be arrhythmia, attacks of tachycardia or bradycardia, and much more. In fact, any ECG interpretation must be interpreted by a special doctor or at least a therapist. And then it will be clear whether there are any problems or everything is fine. After all, the entry “irregular sinus rhythm” for a teenager and an elderly person will not mean the same thing.

Varieties

In addition to the entry already mentioned, it can be written “sinus rhythm vertical” or “horizontal”. What could these phrases mean? Only information about how the contraction impulse passes through the cells. The fact is that an electric wave passes through muscle tissue in a certain direction, approximately coinciding with the anatomical axis of the heart. That is, this only speaks about the peculiarities of its location.

As a rule, people with a hypersthenic physique have a horizontal sinus rhythm, while others have a vertical sinus rhythm. However, both of these options are the norm. This is just a feature.

Cardiogram

Sinus rhythm has a number of signs that are clearly visible on the ECG. Firstly, the heart rate is 60-80 beats per minute, and in newborns and children under 6 years old - up to 150. Secondly, the P wave always precedes the QRS complex. Thirdly, PQ has a constant duration within the normal range (0.12-0.20 seconds). Finally, the duration of P-P or R-R is also the same.

For non-specialists, a graphical display of the work of their hearts is not very informative. An ordinary patient may not even see serious disorders, while for cardiologists this type of research can provide a lot of valuable information. So you should not neglect the annual examination - an ECG can show problems in the functioning of the heart even when they are not yet felt or manifested.

Violations

Like even the most accurate and reliable mechanism, the functioning of the heart can go wrong. Fortunately, even the smallest problems make themselves felt almost immediately. When people talk about disorders, they usually mean that due to some reason the sinus rhythm increases, decreases, or gets disrupted. What it is? In medical terms, these conditions are called sinus tachycardia, bradycardia and arrhythmia, respectively. And they all mean that something is wrong with the node generating the electrical impulse. With tachycardia, the sequence of all phases of the heart in the cycle is maintained, but the heart rate exceeds 100 beats per minute. With bradycardia, the opposite is true - the contraction frequency decreases to values less than 60. As for arrhythmia, periods of faster and slower heart activity can alternate, and fluctuations in P-P values on the ECG can exceed 10%.

Don’t be immediately alarmed if one of these words is heard or, for example, something like “irregular sinus rhythm.” In some cases, these disorders may be of a physiological nature and do not require treatment at all, but only observation. Thus, so-called respiratory sinus arrhythmia is often observed - this term refers to alternating periods of more frequent and less frequent heartbeats, depending on inhalation and exhalation. This condition is typical for children and adolescents. Other types of sinus arrhythmia are extremely rare, more often in severe diseases, for example, in acute myocardial infarction.

Causes

Tachycardia and bradycardia can be of both pharmacological and pathological nature. What substances can increase or decrease the heart rate? The list is quite extensive.

Tachycardia:

adrenaline/norepinephrine;
caffeine;
nicotine;
alcohol;
atropine;
sympathomimetics;
aminophylline;
glucocorticosteroids;
thyroid hormones;
diuretics;
medications aimed at lowering blood pressure.

Bradycardia:

"Verapamil";
sympatholytics;
quinidine;
cardiac glycosides;
beta blockers;
morphine

It is worth noting that some of the medications mentioned in both lists are used in obstetrics, for example, to improve blood supply to the uterus and fetus and relieve edema. So, if you are taking any of these medications, there is no need to worry too much unless it causes serious inconvenience.

As for the pathological causes of disorders, they are also quite common. Tachycardia:

acute or chronic heart failure;
myocardial infarction;
severe attack of angina;
acute myocarditis;
hypoxemia;
anemia;
arterial hypotension;
high body temperature;
thyrotoxicosis;
thrombus in the pulmonary artery;
pheochromocytoma.

Bradycardia may accompany the following diseases or conditions:

myocardial infarction;
sick sinus syndrome;
cardiosclerosis;
hypothyroidism;
infections;
increased intracranial pressure;
hypothermia;
intubation;
hypercalcemia;
hypokalemia;
stomach and duodenal ulcers;
uremia;
some types of poisoning;
Meniere's syndrome.

As you can see, the list is quite extensive, so you need to make sure that sinus rhythm is not disturbed (we have already explained what this is).

Diagnostics

In addition to the already mentioned electrocardiography, a type of examination such as echography or ultrasound of the heart is very often used. It can also be informative and can reveal a lot of interesting things. However, unfortunately, it will not say almost anything about disturbances in the functioning of the sinus node, except perhaps only about concomitant diseases. In any case, the diagnosis of “sinus rhythm disturbance” is made solely on the basis of ECG data.

Treatment and control

If the nature of the conditions is pharmacological, to improve the situation, the influence of the mentioned substances on the functioning of the heart should be excluded. If we are talking about any pathological condition, tachycardia or bradycardia are only symptoms. Treatment in this case will be aimed at the underlying disease; after the situation improves, the unpleasant sensations associated with the heart rhythm will disappear.

By the way, you can check the operation of the “motor” yourself at any time, but it is better to do it in the morning. You just need to count the number of pulse beats per minute and compare it with the standard. A result between 60-80 is considered completely normal, we can say that this is sinus rhythm. What it is is now clear.

fb.ru

Definition and essence of the method

An electrocardiogram is a recording of the heart, which is presented as a curved line on paper. The cardiogram line itself is not chaotic; it has certain intervals, teeth and segments that correspond to certain stages of the heart.

To understand the essence of an electrocardiogram, you need to know what exactly is recorded by a device called an electrocardiograph. The ECG records the electrical activity of the heart, which changes cyclically in accordance with the onset of diastole and systole. The electrical activity of the human heart may seem like fiction, but this unique biological phenomenon exists in reality. In reality, the heart contains so-called cells of the conduction system, which generate electrical impulses that are transmitted to the muscles of the organ. It is these electrical impulses that cause the myocardium to contract and relax with a certain rhythm and frequency.

The electrical impulse propagates through the cells of the conduction system of the heart strictly sequentially, causing contraction and relaxation of the corresponding sections - the ventricles and atria. The electrocardiogram reflects precisely the total electrical potential difference in the heart.

decryption?

An electrocardiogram can be taken in any clinic or multidisciplinary hospital. You can contact a private medical center where there is a cardiologist or therapist. After recording the cardiogram, the tape with curves is examined by the doctor. It is he who analyzes the recording, deciphers it and writes a final report, which reflects all visible pathologies and functional deviations from the norm.

An electrocardiogram is recorded using a special device - an electrocardiograph, which can be multi-channel or single-channel. The speed of ECG recording depends on the modification and modernity of the device. Modern devices can be connected to a computer, which, with a special program, will analyze the recording and issue a final conclusion immediately after the procedure is completed.

Any cardiograph has special electrodes that are applied in a strictly defined order. There are four clothespins in red, yellow, green and black that are placed on both arms and both legs. If you go in a circle, then the clothespins are applied according to the “red-yellow-green-black” rule, from the right hand. It’s easy to remember this sequence thanks to the student saying: “Every-Woman is an Eviler Trait.” In addition to these electrodes, there are also chest electrodes, which are installed in the intercostal spaces.

As a result, the electrocardiogram consists of twelve waveforms, six of which are recorded from the chest electrodes, and are called chest leads.

The remaining six leads are recorded from electrodes attached to the arms and legs, three of which are called standard, and three more are called enhanced. The chest leads are designated V1, V2, V3, V4, V5, V6, the standard ones are simply Roman numerals - I, II, III, and the reinforced leg leads - the letters aVL, aVR, aVF. Different leads of the cardiogram are necessary to create the most complete picture of the activity of the heart, since some pathologies are visible on the chest leads, others on the standard ones, and still others on the enhanced ones.

The person lies down on the couch, the doctor attaches the electrodes and turns on the device. While the ECG is being written, the person must be absolutely calm. We must not allow the appearance of any irritants that can distort the true picture of the work of the heart.

How to correctly perform an electrocardiogram followed by
transcript - video

The principle of decoding an ECG

Since the electrocardiogram reflects the processes of contraction and relaxation of the myocardium, it is possible to trace how these processes occur and identify existing pathological processes. The elements of the electrocardiogram are closely related and reflect the duration of the phases of the cardiac cycle - systole and diastole, that is, contraction and subsequent relaxation. Decoding the electrocardiogram is based on the study of the teeth, their position relative to each other, duration, and other parameters. The following elements of the electrocardiogram are studied for analysis:
1. Teeth.
2. Intervals.
3. Segments.

All sharp and smooth convexities and concavities on the ECG line are called teeth. Each tooth is designated by a letter of the Latin alphabet. The P wave reflects contraction of the atria, the QRS complex – contraction of the ventricles of the heart, the T wave – relaxation of the ventricles. Sometimes after the T wave on the electrocardiogram there is another U wave, but it has no clinical and diagnostic role.

An ECG segment is considered to be a segment enclosed between adjacent teeth. For diagnosing heart pathology, the P – Q and S – T segments are of great importance. The interval on the electrocardiogram is a complex that includes a tooth and an interval. The P–Q and Q–T intervals are of great importance for diagnosis.

Often in the doctor’s report you can see small Latin letters, which also indicate teeth, intervals and segments. Small letters are used if the prong is less than 5 mm long. In addition, several R waves may appear in the QRS complex, which are usually designated R’, R”, etc. Sometimes the R wave is simply missing. Then the entire complex is designated by only two letters - QS. All this has important diagnostic significance.

ECG interpretation plan - general scheme for reading results

When deciphering an electrocardiogram, the following parameters reflecting the work of the heart must be established:

position of the electrical axis of the heart;
determining the correctness of the heart rhythm and conductivity of the electrical impulse (blockades, arrhythmias are detected);
determining the regularity of contractions of the heart muscle;
determination of heart rate;
identifying the source of the electrical impulse (whether sinus rhythm is determined or not);
analysis of the duration, depth and width of the atrial P wave and the P – Q interval;
analysis of the duration, depth, width of the QRST ventricular wave complex;
analysis of parameters of the RS – T segment and T wave;
analysis of Q – T interval parameters.

Based on all the studied parameters, the doctor writes a final conclusion on the electrocardiogram. The conclusion may roughly look like this: “Sinus rhythm with heart rate 65. Normal position of the electrical axis of the heart. No pathology was detected." Or this: “Sinus tachycardia with heart rate 100. Single supraventricular extrasystole. Incomplete blockade of the right bundle branch. Moderate metabolic changes in the myocardium."

In the conclusion on the electrocardiogram, the doctor must reflect the following parameters:

sinus rhythm or not;
rhythm regularity;
heart rate (HR);
position of the electrical axis of the heart.

If any of the 4 pathological syndromes are identified, then indicate which ones - rhythm disturbance, conduction, overload of the ventricles or atria, and damage to the structure of the heart muscle (infarction, scar, dystrophy).

Example of deciphering an electrocardiogram

At the very beginning of the electrocardiogram tape there should be a calibration signal, which looks like a large letter “P” 10 mm high. If this calibration signal is not present, then the electrocardiogram is uninformative. If the height of the calibration signal is below 5 mm in standard and enhanced leads, and below 8 mm in chest leads, then there is a low voltage of the electrocardiogram, which is a sign of a number of heart pathologies. For subsequent decoding and calculation of some parameters, you need to know what period of time fits into one cell of graph paper. At a belt speed of 25 mm/s, one cell 1 mm long is equal to 0.04 seconds, and at a speed of 50 mm/s – 0.02 seconds.

Checking the regularity of heart contractions

It is assessed by the intervals R - R. If the teeth are located at the same distance from each other throughout the entire recording, then the rhythm is regular. Otherwise it is called correct. Estimating the distance between the R - R teeth is very simple: the electrocardiogram is recorded on graph paper, which makes it easy to measure any gaps in millimeters.

Heart rate (HR) calculation

It is carried out using a simple arithmetic method: count the number of large squares on graph paper that are placed between two R waves. Then the heart rate is calculated using the formula, which is determined by the speed of the tape in the cardiograph:
1. The tape speed is 50 mm/s - then the heart rate is 600 divided by the number of squares.
2. The tape speed is 25 mm/s - then the heart rate is 300 divided by the number of squares.

For example, if 4.8 large squares fit between two R teeth, then the heart rate, at a belt speed of 50 mm/s, will be equal to 600/4.8 = 125 beats per minute.

If the heart rate is abnormal, then the maximum and minimum heart rate is determined, also taking as a basis the maximum and minimum distances between the R waves.

Identifying the source of the rhythm

The doctor studies the rhythm of heart contractions and finds out which node of nerve cells causes the cyclic processes of contraction and relaxation of the heart muscle. This is very important for identifying blockages.

Decoding ECG - rhythms

Normally, the pacemaker is the sinus node. And such a normal rhythm itself is called sinus - all other options are pathological. In various pathologies, any other node of the nerve cells of the cardiac conduction system can act as a pacemaker. In this case, the cyclic electrical impulses become confused and the heart rhythm is disrupted - an arrhythmia occurs.

In sinus rhythm on the electrocardiogram in lead II there is a P wave before each QRS complex, and it is always positive. In one lead, all P waves should have the same shape, length and width.

With atrial rhythm the P wave in leads II and III is negative, but is present before each QRS complex.

Atrioventricular rhythms are characterized by the absence of P waves on cardiograms, or the appearance of this wave after the QRS complex, and not before it, as is normal. With this type of rhythm, the heart rate is low, ranging from 40 to 60 beats per minute.

Ventricular rhythm characterized by an increase in the width of the QRS complex, which becomes large and quite frightening. The P waves and the QRS complex are completely unrelated to each other. That is, there is no strict correct normal sequence - the P wave, followed by the QRS complex. Ventricular rhythm is characterized by a decrease in heart rate - less than 40 beats per minute.

Detection of pathology of electrical impulse conduction through the structures of the heart

To do this, measure the duration of the P wave, the P–Q interval and the QRS complex. The duration of these parameters is calculated from the millimeter tape on which the cardiogram is recorded. First, count how many millimeters each tooth or interval occupies, after which the resulting value is multiplied by 0.02 at a recording speed of 50 mm/s, or by 0.04 at a recording speed of 25 mm/s.

The normal duration of the P wave is up to 0.1 seconds, the P – Q interval is 0.12-0.2 seconds, the QRS complex is 0.06-0.1 seconds.

Electrical axis of the heart

Denoted as the alpha angle. It can have a normal position, horizontal or vertical. Moreover, in a thin person the axis of the heart is more vertical relative to the average values, while in a fat person it is more horizontal. The normal position of the electrical axis of the heart is 30–69 o, vertical – 70–90 o, horizontal – 0–29 o. The alpha angle, equal to 91 to ±180 o, reflects a sharp deviation of the electrical axis of the heart to the right. The alpha angle, equal to 0 to –90 o, reflects a sharp deviation of the electrical axis of the heart to the left.

The electrical axis of the heart can deviate under various pathological conditions. For example, hypertension leads to a deviation to the right; a conduction disorder (blockade) can shift it to the right or left.

Atrial P wave

The atrial P wave should be:

positive in I, II, aVF and chest leads (2, 3,4, 5, 6);
negative in aVR;
biphasic (part of the tooth lies in the positive region, and part in the negative) in III, aVL, V1.

The normal duration of P is no more than 0.1 seconds, and the amplitude is 1.5 - 2.5 mm.

Pathological forms of the P wave may indicate the following pathologies:
1. Tall and sharp teeth in leads II, III, aVF appear with hypertrophy of the right atrium (“cor pulmonale”);
2. A P wave with two peaks and a large width in leads I, aVL, V5 and V6 indicates hypertrophy of the left atrium (for example, mitral valve disease).

P–Q interval

The P–Q interval has a normal duration of 0.12 to 0.2 seconds. An increase in the duration of the P–Q interval is a reflection of atrioventricular block. On the electrocardiogram, three degrees of atrioventricular block (AV) can be distinguished:

I degree: simple lengthening of the P–Q interval while preserving all other complexes and waves.
II degree: prolongation of the P–Q interval with partial loss of some QRS complexes.
III degree: lack of connection between the P wave and QRS complexes. In this case, the atria work in their own rhythm, and the ventricles - in their own.

Ventricular QRST complex

The ventricular QRST complex consists of the QRS complex itself and the S – T segment. The normal duration of the QRST complex does not exceed 0.1 seconds, and its increase is detected with blockades of the Hiss bundle branches.

QRS complex consists of three waves, Q, R and S, respectively. The Q wave is visible on the cardiogram in all leads except 1, 2 and 3 chest leads. A normal Q wave has an amplitude up to 25% of that of an R wave. The duration of the Q wave is 0.03 seconds. The R wave is recorded in absolutely all leads. The S wave is also visible in all leads, but its amplitude decreases from the 1st thoracic to the 4th, and in the 5th and 6th it may be completely absent. The maximum amplitude of this tooth is 20 mm.

The S–T segment is very important from a diagnostic point of view. It is by this tooth that myocardial ischemia can be detected, that is, a lack of oxygen in the heart muscle. Usually this segment runs along the isoline, in the 1st, 2nd and 3rd chest leads; it can rise up by a maximum of 2 mm. And in the 4th, 5th and 6th chest leads, the S-T segment can shift below the isoline by a maximum of half a millimeter. It is the deviation of the segment from the isoline that reflects the presence of myocardial ischemia.

T wave

The T wave is a reflection of the process of eventual relaxation in the cardiac muscle of the ventricles of the heart. Typically, when the amplitude of the R wave is large, the T wave will also be positive. A negative T wave is normally recorded only in lead aVR.

Q-T interval

The Q–T interval reflects the process of eventual contraction in the myocardium of the ventricles of the heart.

ECG interpretation - normal indicators

The transcript of the electrocardiogram is usually recorded by the doctor in conclusion. A typical example of a normal cardiac cardiogram looks like this:
1. PQ – 0.12 s.
2. QRS – 0.06 s.
3. QT – 0.31 s.
4. RR – 0.62 – 0.66 – 0.6.
5. Heart rate is 70 - 75 beats per minute.
6. sinus rhythm.
7. The electrical axis of the heart is located normally.

Normally, the rhythm should be only sinus, the heart rate of an adult is 60 - 90 beats per minute. The P wave is normally no more than 0.1 s, the P – Q interval is 0.12-0.2 seconds, the QRS complex is 0.06-0.1 seconds, Q – T is up to 0.4 s.

If the cardiogram is pathological, then it indicates specific syndromes and deviations from the norm (for example, partial blockade of the left bundle branch, myocardial ischemia, etc.). The doctor can also reflect specific violations and changes in the normal parameters of the waves, intervals and segments (for example, shortening of the P wave or Q-T interval, etc.).

Interpretation of ECG in children and pregnant women

In principle, children and pregnant women have normal heart electrocardiogram readings - the same as in healthy adults. However, there are certain physiological characteristics. For example, the heart rate of children is higher than that of an adult. The normal heart rate of a child up to 3 years of age is 100–110 beats per minute, 3–5 years old – 90–100 beats per minute. Then gradually the heart rate decreases, and in adolescence it is compared with that of an adult - 60 - 90 beats per minute.

In pregnant women, there may be a slight deviation of the electrical axis of the heart in late gestation due to compression by the growing uterus. In addition, sinus tachycardia often develops, that is, an increase in heart rate to 110 - 120 beats per minute, which is a functional condition and goes away on its own. An increase in heart rate is associated with a greater volume of circulating blood and increased workload. Due to the increased load on the heart, pregnant women may experience overload in various parts of the organ. These phenomena are not a pathology - they are associated with pregnancy and will go away on their own after childbirth.

Decoding the electrocardiogram during a heart attack

Myocardial infarction is a sudden cessation of oxygen supply to the heart muscle cells, resulting in the development of necrosis of a tissue area that is in a state of hypoxia. The reason for the disruption of oxygen supply can be different - most often it is a blockage of a blood vessel, or its rupture. A heart attack involves only part of the muscle tissue of the heart, and the extent of the damage depends on the size of the blood vessel that is blocked or ruptured. On an electrocardiogram, myocardial infarction has certain signs by which it can be diagnosed.

In the process of development of myocardial infarction, four stages are distinguished, which have different manifestations on the ECG:

acute;
acute;
subacute;
cicatricial.

The most acute stage myocardial infarction can last for 3 hours - 3 days from the moment of circulatory disturbance. At this stage, the Q wave may be absent on the electrocardiogram. If it is present, then the R wave has a low amplitude or is completely absent. In this case, there is a characteristic QS wave, reflecting a transmural infarction. The second sign of an acute infarction is an increase in the S-T segment by at least 4 mm above the isoline, with the formation of one large T wave.

Sometimes it is possible to detect the phase of myocardial ischemia preceding the acute phase, which is characterized by high T waves.

Acute stage A heart attack lasts 2–3 weeks. During this period, a wide and high-amplitude Q wave and a negative T wave are recorded on the ECG.

Subacute stage lasts up to 3 months. The ECG shows a very large negative T wave with a huge amplitude, which gradually normalizes. Sometimes a rise in the S-T segment is detected, which should have leveled off by this period. This is an alarming symptom, as it may indicate the formation of a cardiac aneurysm.

Scar stage heart attack is final, since connective tissue is formed at the damaged site, incapable of contraction. This scar is recorded on the ECG as a Q wave, which will remain for life. Often the T wave is smoothed, has a low amplitude, or is completely negative.

Interpretation of the most common ECGs

In conclusion, doctors write the result of the ECG interpretation, which is often incomprehensible because it consists of terms, syndromes and simply statements of pathophysiological processes. Let's consider the most common ECG conclusions, which are incomprehensible to a person without a medical education.

Ectopic rhythm means not sinus - which can be either a pathology or a norm. The norm is ectopic rhythm when there is a congenital malformation of the conduction system of the heart, but the person does not present any complaints and does not suffer from other cardiac pathologies. In other cases, an ectopic rhythm indicates the presence of blockades.

Changes in repolarization processes on the ECG reflects a violation of the process of relaxation of the heart muscle after contraction.

Sinus rhythm This is the normal heart rate of a healthy person.

Sinus or sinusoidal tachycardia means that a person has a correct and regular rhythm, but an increased heart rate - more than 90 beats per minute. In young people under 30 years of age, this is a variant of the norm.

Sinus bradycardia- this is a low heart rate - less than 60 beats per minute against the background of a normal, regular rhythm.

Nonspecific ST-T changes mean that there are minor deviations from the norm, but their cause may be completely unrelated to heart pathology. It is necessary to undergo a full examination. Such nonspecific ST-T changes can develop with an imbalance of potassium, sodium, chlorine, magnesium ions, or various endocrine disorders, often during menopause in women.

Biphasic R wave in combination with other signs of a heart attack indicates damage to the anterior wall of the myocardium. If no other signs of a heart attack are detected, then a biphasic R wave is not a sign of pathology.

QT prolongation may indicate hypoxia (lack of oxygen), rickets, or overexcitation of the child’s nervous system, which is a consequence of birth trauma.

Myocardial hypertrophy means that the muscular wall of the heart is thickened and works under enormous load. This can lead to the formation of:

heart defects;
heart failure;
arrhythmias.

Also, myocardial hypertrophy can be a consequence of previous heart attacks.

Moderate diffuse changes in the myocardium mean that tissue nutrition is impaired and cardiac muscle dystrophy has developed. This is a fixable condition: you need to see a doctor and undergo an adequate course of treatment, including normalizing your diet.

Deviation of the electrical axis of the heart (EOS) left or right is possible with hypertrophy of the left or right ventricle, respectively. EOS can deviate to the left in obese people, and to the right - in thin people, but in this case this is a variant of the norm.

Left type ECG– EOS deviation to the left.

NBPNG– an abbreviation for “incomplete right bundle branch block.” This condition can occur in newborns and is a normal variant. In rare cases, RBBB can cause arrhythmia, but generally does not lead to the development of negative consequences. Block of the Hiss bundle branch is quite common in people, but if there are no complaints about the heart, then it is not at all dangerous.

BPVLNPG– an abbreviation meaning “blockade of the anterior branch of the left bundle branch.” Reflects a violation of the conduction of electrical impulses in the heart, and leads to the development of arrhythmias.

Small growth of the R wave in V1-V3 may be a sign of interventricular septal infarction. To accurately determine whether this is the case, it is necessary to do another ECG study.

CLC syndrome(Klein-Levy-Kritesco syndrome) is a congenital feature of the conduction system of the heart. May cause the development of arrhythmias. This syndrome does not require treatment, but it is necessary to be regularly examined by a cardiologist.

Low voltage ECG often recorded with pericarditis (a large amount of connective tissue in the heart that has replaced muscle tissue). In addition, this sign may be a reflection of exhaustion or myxedema.

Metabolic changes are a reflection of insufficient nutrition of the heart muscle. It is necessary to be examined by a cardiologist and undergo a course of treatment.

Extrasystole is a violation of the rhythm of heart contractions, that is, arrhythmia. Serious treatment and observation by a cardiologist is required. Extrasystole can be ventricular or atrial, but the essence does not change.

Rhythm and conduction disturbances– symptoms that together indicate arrhythmia. Observation by a cardiologist and adequate therapy are necessary. It is possible to install a pacemaker.

Conduction slowdown means that the nerve impulse travels through the tissues of the heart more slowly than normal. This condition itself does not require special treatment - it may be a congenital feature of the conduction system of the heart. Regular monitoring by a cardiologist is recommended.

Blockade 2 and 3 degrees reflects a serious disturbance of cardiac conduction, which is manifested by arrhythmia. In this case, treatment is necessary.

Rotation of the heart by the right ventricle forward may be an indirect sign of the development of hypertrophy. In this case, it is necessary to find out its cause and undergo a course of treatment, or adjust your diet and lifestyle.

Price of an electrocardiogram with interpretation

The cost of an electrocardiogram with interpretation varies significantly, depending on the specific medical institution. Thus, in public hospitals and clinics the minimum price for the procedure of taking an ECG and interpreting it by a doctor is from 300 rubles. In this case, you will receive films with recorded curves and a doctor’s conclusion on them, which he will make himself, or using a computer program.

If you want to receive a thorough and detailed conclusion on the electrocardiogram, a doctor’s explanation of all the parameters and changes, it is better to contact a private clinic that provides such services. Here the doctor will be able not only to write a conclusion after deciphering the cardiogram, but also to calmly talk to you, taking his time to explain all the points of interest. However, the cost of such a cardiogram with interpretation in a private medical center ranges from 800 rubles to 3,600 rubles. You should not assume that bad specialists work in an ordinary clinic or hospital - it’s just that a doctor in a government institution, as a rule, has a very large amount of work, so he simply does not have time to talk with each patient in great detail.

When choosing a medical institution for taking a cardiogram with interpretation, first of all, pay attention to the qualifications of the doctor. It is better for this to be a specialist - a cardiologist or therapist with good experience. If a child needs a cardiogram, then it is better to contact specialists - pediatricians, since “adult” doctors do not always take into account the specifics and physiological characteristics of children.

www.tiensmed.ru

What it is?

People far from medicine do not know what sinus rhythm is. At the same time, the definition of such a concept is important to know, since the pathologies of such a condition can cause serious consequences. The sinus rhythm of the heart refers to certain oscillatory movements that provoke the formation of impulses in a special node, which are subsequently distributed in the ventricle or atrium. This is how the heart muscle contracts.

Sinus rhythm indicates the absence of pathological functioning of the heart. Electrocardiography is considered very effective in identifying it. The normal sinus rhythm of the heart in adults is considered to be the frequency when the heart contracts in the amount of 50 beats per minute. When receiving other digital values, a pulse is generated through another node, which produces a different quantitative value. Reliable results of a cardiogram are possible only if the patient is in a calm state during the procedure. Normal sinus rhythm can be indicated by the following values:

heart rate varies between 60-80 beats over a one-minute period. The average is 70 beats, the maximum is 85 beats. In newly born children, this figure is equivalent to 150 strokes;
The PQ interval is characterized by a constant duration.

The sine rhythm can be vertical or horizontal. This means the direction of passage of the contractile impulse through cellular structures. It is known that the passage of an electric wave occurs in a certain direction, which to some extent coincides with the cardiac axis, which means: deciphering the cardiogram of these indicators indicates the peculiarities of the location of the impulse. It has been noticed that for people with a hypersthenic body constitution, a sinus heart rhythm in a horizontal direction is more characteristic, for others - a vertical one. Both options are considered the norm.

Possible violations

In some cases, the sinus rhythm of the heart undergoes certain disruptions, which can manifest themselves in:

Arrhythmia and its varieties. This pathology indicates an irregular heart rhythm when there is an unstable sinus rhythm.
Sinus tachycardia. Represents an accelerated heartbeat. Tachycardia of a physiological nature occurs in athletes during training sessions. The cause of this disorder is rapid blood circulation, which occurs as a result of stress, provoking a more intense contraction of the heart. Accelerated sinus rhythm can also be caused by increased adrenaline levels due to severe emotional turmoil. The pathological form of tachycardia becomes a consequence of the use of certain substances in the form of alcohol or medications. Diseases of the blood and heart can also cause a rapid heartbeat.
Bradycardia. It is a condition when there is a disturbance in the repolarization process with a simultaneous decrease in heart rate. Most often, the causes of this pathology are infectious diseases.
Coronary sinus rhythm. It is a type of cardiac contraction of a passive nature, when the myocardial region, localized close to the coronary cardiac minus, acts as the rhythm controller. The coronary sinus rhythm is detected only by ECG.

Causes of pathologies in children

The children's population is characterized by sinus node arrhythmia, which in this case is considered a physiological manifestation related to the characteristics of growing up and thoracic motor activity caused by breathing. This condition is considered a normal variant and does not require therapeutic measures.

However, disturbed sinus rhythm in children may indicate the presence of certain pathologies:

high pressure inside the skull;
rickets.

Pathological sinus rhythm of the heart, which occurs in severe form, can be caused by childhood malformations. In this case, in order to normalize the functioning of the heart organ, long-term treatment is necessary, which allows for surgery. In most cases, impaired heart activity is asymptomatic in children, which is why it is important to carefully monitor children's health so as not to miss a dangerous disease in its development stage.

Causes of pathologies in pregnant women

During pregnancy, the heart experiences significant stress. The organ begins to function at an accelerated rate, enriching the maternal and child’s body with oxygen. As a result, arrhythmic manifestations during pregnancy are quite common conditions.

Abnormal heart rhythm can result from various diseases or high cardiac load. Pregnant women experience sinus rhythm with a heart rate that exceeds the normal values by 10 beats over a one-minute period. If sinus rhythm disturbances occur as a result of gestation, they disappear on their own at the end of the birth process.

Symptoms

Signs of sinus rhythm may include:

dizziness;
frequent loss of consciousness;
pain syndrome in the sternum area;
weakness, provoking a decrease in work activity.

Diagnostics

In addition to ultrasound and electrical cardiography, additional diagnostic methods can help to understand what it is - sinus rhythm of the heart and what pathologies are possible. Thus, Holter monitoring or a drug test can be prescribed, through which it becomes possible to determine the localization of the pathology. Such diagnostic studies become appropriate at a rate exceeding 90 heart beats per minute.

Holter monitoring refers to a conventional electrocardiogram performed over a 24-hour period. Due to the long duration of such diagnostics, it becomes possible to study the condition of the heart subjected to various loads. This examination can be carried out during physical activity.

Treatment

Often, heart rhythm disturbances do not require special treatment. In most cases, it is enough to give up bad habits, as well as emotional and physical stress. Heart problems can be prevented by eating a healthy, consistent diet. It would be useful to take vitamin and mineral complexes, the action of which is aimed at strengthening and maintaining the functioning of the heart muscle.

cardioplanet.ru

Sinus rhythm of the heart: features of anatomy and physiology

Before we start talking about the sinus rhythm of the heart, I would like to dwell on some issues of the anatomy and physiology of the cardiovascular system. Without exception, all organs and systems of the human body are constantly in need of oxygen and other useful substances supplied by the circulatory system. The human heart is a fairly simple but powerful pump that ensures constant blood circulation throughout the circulatory system.

The human heart is capable of making more than 100,000 beats per day and has a specific “pacemaker” called the sinus node and located in the right atrium. It is this node that generates impulses or electrical signals that first enter the atria, causing them to contract and push blood into the ventricles. After this, a certain pause occurs, allowing the ventricles of the heart to fill with blood, and then the impulse passes through the ventricle and blood, and is sent further through the circulatory system to all organs and tissues of the human body. This is how the heart constantly contracts at a certain frequency. Normal sinus rhythm is considered to be with a heart rate (heart rate) of 60 to 70 per minute.

On an ECG, normal sinus rhythm looks like this:

the highest wave (P wave) has a constant height;
The distance between the teeth is approximately the same.

Any deviations from the norm are a sign of an abnormal heart rate and various diseases associated with impaired sinus rhythm of the heart (arrhythmia, sinus tachycardia, sinus bradycardia, etc.).

Sinus rhythm disturbances: causes of the pathological condition

There are conditions in which the pacemaker malfunctions, then the patient’s heart begins to beat either much faster than usual or much slower. What can cause this condition:

lack of oxygen or hypoxia;
anemia;
severely increased blood pressure (arterial hypertension);
congenital anomalies of the anatomical structure of the sinus node;
congenital heart defects;
inflammatory diseases of the myocardium;
cardiac ischemia;
heart attack;
physical fatigue;
obesity of varying degrees;
smoking and alcohol abuse;
various disorders of the endocrine system;
constant stress.

There are a number of age-related reasons for changes in the sinus rhythm of the heart. In children, its disorder often develops as a consequence of:

congenital heart defects, which often occur against the background of an unfavorable course of pregnancy;
pathologies of the nervous system;
various endocrine disorders;
intoxications of various origins, including individual intolerance to certain drugs or drug overdose;

Many, even the most banal studies that are carried out in a clinic during a medical examination, help to suspect and diagnose various serious health problems. Therefore, doctors strongly recommend not to neglect annual examinations with primary specialists, as well as systematically conduct basic research. An electrocardiogram is considered to be one of the important and at the same time simple diagnostic manipulations. Having received the result of such a study in their hands, many patients pay attention to the indicated sinus rhythm of the heart. Let's talk about the term sinus rhythm of the heart, what is the norm in adults and children.

Probably every person knows that the heart is an organ that performs work rhythmically. In a healthy person, the heartbeat rhythm is determined by the sinus node. Accordingly, we can conclude that the sinus rhythm of the heart is precisely the normal heart rhythm.

The sinus node is a natural impulse generator and is located inside the right atrium. The impulse moves from bottom to top. First it reaches the right atrium, and then the left. The impulse then passes through the atrioventricular junction towards the ventricles. Its effect causes the heart to contract and relax rhythmically, thus performing its main functions - pumping blood throughout the body.

Sinus rhythm of the heart - what does it mean on the cardiogram?

With normal sinus rhythm on the cardiogram, all P waves have a constant shape, and the distance P-P or R-R is the same. The heart rate ranges from sixty to eighty beats per minute. Accordingly, with such indicators, the heart is in order and functions with stability and clarity.

If the sinus rhythm is unstable, then the cardiogram shows that the height of the P waves, as well as the distance between them, are not the same. Observing such a picture, the doctor can conclude that the sinus node is weak or that another heart node has become the pacemaker. In this case, the patient is indicated for special diagnostics. Such studies will already help to find out what exactly caused the sinus rhythm disturbance: pathology of the sinus node itself or problems in its autonomic system.

Thus, if the doctor wrote in the cardiogram that sinus rhythm is normal, we can conclude that the patient’s heart is functioning normally. Violation of this indicator often indicates heart block or arrhythmias. In general, all violations of systematicity, consistency or heart rate can be called arrhythmias. Heart blocks develop when there is a disruption in the transmission of impulses from the nerve center to the heart muscle. An acceleration of the rhythm indicates the development of tachycardia, and a slowdown indicates bradycardia. A decrease in heart rate to fifty or less, or an increase in this indicator to ninety or more is a serious reason for immediately contacting a doctor. And the editors of the site www.!

What is the normal sinus rhythm in adults and children?

Normal sinus rhythm in an adult is characterized by a frequency of sixty to eighty beats per minute, as well as a regular rhythm and a constant interval between beats, which is 0.12-0.22 seconds.

Children's hearts beat completely differently depending on their age. So in the very first month of life, the sinus rhythm should be approximately one hundred and forty beats per minute, and from the age of one month of life to one year - one hundred and thirty-two beats per minute. Then the sinus rhythm gradually becomes slower. So, from the age of one to two, this figure is equal to one hundred and twenty-four beats per minute, and from two to six – one hundred and fifteen beats. In schoolchildren from six to eight years of age, sinus rhythm decreases to one hundred and six beats per minute, and from eight to ten years of age - to eighty-eight beats per minute. Over the next two years (from ten to twelve years) the indicators decrease to eighty beats per minute. For children between the ages of twelve and fifteen, a sinus rhythm of seventy-five beats per minute is considered normal.

Are all sinus rhythm disorders dangerous to health?

In fact, in some cases, sinus rhythm disturbances should not be considered a symptom. So sometimes this phenomenon is associated with breathing - immaturity of the respiratory system, banal jogging or fast walking before the study, excessive body weight, a period of active growth in children, ICP, prematurity, etc.

What else can cause sinus rhythm disturbances?

Sometimes such a problem indicates the presence of heart defects, cardiomyopathy and infective endocarditis. In children, it can also be provoked by congenital defects that are associated with an insufficiently favorable course of pregnancy or childbirth, and various ailments of the nervous and endocrine systems. In some cases, sinus rhythm disturbances are a consequence of intoxication (even the result of an overdose of medications or their individual intolerance) and deficiency of microelements, most often magnesium and selenium.

Quite often, sinus rhythm disturbances do not make themselves felt and are diagnosed only during the next examination. Therefore, it is extremely important to regularly visit a cardiologist for preventive ECGs.

Thank you

Electrocardiogram is a widely used method of objective diagnostics various pathologies of the human heart, which is used almost everywhere today. An electrocardiogram (ECG) is taken in a clinic, in an ambulance, or in a hospital department. ECG is a very important recording that reflects the condition of the heart. That is why the reflection of various types of cardiac pathology on the ECG is described by a separate science - electrocardiography. Electrocardiography also deals with the problems of correct ECG recording, decoding issues, interpretation of controversial and unclear points, etc.

Definition and essence of the method

decryption?

An electrocardiogram can be taken in any clinic or multidisciplinary hospital. You can contact a private medical center where there is a specialist cardiologist or therapist. After recording the cardiogram, the tape with curves is examined by the doctor. It is he who analyzes the recording, deciphers it and writes a final report, which reflects all visible pathologies and functional deviations from the norm.

Any cardiograph has special electrodes that are applied in a strictly defined order. There are four clothespins in red, yellow, green and black that are placed on both arms and both legs. If you go in a circle, then the clothespins are applied according to the rule “red-yellow-green-black”, from the right hand. It's easy to remember this sequence thanks to the student saying: "Every-Woman is an Eviler Trait." In addition to these electrodes, there are also chest electrodes, which are installed in the intercostal spaces.

As a result, the electrocardiogram consists of twelve waveforms, six of which are recorded from the chest electrodes, and are called chest leads. The remaining six leads are recorded from electrodes attached to the arms and legs, with three of them called standard and three more called enhanced. The chest leads are designated V1, V2, V3, V4, V5, V6, the standard ones are simply Roman numerals - I, II, III, and the reinforced leg leads - the letters aVL, aVR, aVF. Different leads of the cardiogram are necessary to create the most complete picture of the activity of the heart, since some pathologies are visible on the chest leads, others on the standard ones, and still others on the enhanced ones.

How to correctly perform an electrocardiogram followed by
transcript - video

The principle of decoding an ECG

ECG interpretation plan - general scheme for reading results

When deciphering an electrocardiogram, the following parameters reflecting the work of the heart must be established:

position of the electrical axis of the heart;
determining the correctness of the heart rhythm and conductivity of the electrical impulse (blockades, arrhythmias are detected);
determining the regularity of contractions of the heart muscle;
determination of heart rate;
identifying the source of the electrical impulse (whether sinus rhythm is determined or not);
analysis of the duration, depth and width of the atrial P wave and the P – Q interval;
analysis of the duration, depth, width of the QRST ventricular wave complex;
analysis of parameters of the RS – T segment and T wave;
analysis of Q – T interval parameters.

Based on all the studied parameters, the doctor writes a final conclusion on the electrocardiogram. The conclusion may roughly look like this: “Sinus rhythm with heart rate 65. Normal position of the electrical axis of the heart. No pathology identified.” Or this: “Sinus tachycardia with heart rate 100. Single supraventricular extrasystole. Incomplete blockade of the right bundle branch. Moderate metabolic changes in the myocardium.”

In the conclusion on the electrocardiogram, the doctor must reflect the following parameters:

sinus rhythm or not;
rhythm regularity;
heart rate (HR);
position of the electrical axis of the heart.

Example of deciphering an electrocardiogram