What does sinus arrhythmia look like on an ecg? Atrial fibrillation on the ECG: description and signs. What does sinus arrhythmia look like on an ECG?

Arrhythmia looks like this on an ECG:
- the first is characterized by a slowdown in conduction, but the complexes do not fall out and PQ remains > 0.2 sec;

Conclusions

How not to guess with a diagnosis? We perform an ECG if sinus arrhythmia is suspected

This article describes the normal heart rhythm at different ages, what methods exist for detecting sinus arrhythmia, and how to correctly read a cardiogram.

Heart rhythm and its norm

Heart rhythm shows how often and at what intervals the heart muscle contracts. This characteristic is the main indicator by which the presence of pathologies can be determined.

Each cardiac cycle, when the heart is functioning properly, contracts at regular intervals. If the duration of the cycles is not the same, then this is already a rhythm disturbance.

The normal heart rate is considered to be from 60 to 90 beats per minute, but everything depends on external and internal factors that determine the person’s condition. An excess of several indicators is not considered critical, but it is recommended to consult a doctor to determine the problem.

First of all, heart rhythm depends on a person’s age. In children, the heart beats faster than in adults - the average is 120 beats per minute. This is considered a completely normal phenomenon, since the blood volume of babies is small, and the cells need oxygen.

Normal heart rate by year:

At the age of 20 to 30, men have 60-65, and women 60-70 beats per minute;
At the age of 30 to 40, men have 65-70 beats per minute, and women have 70-75 beats per minute;
At the age of 40 to 50, men have 70-75, and women 75-80 beats per minute;
At the age of 50 to 60, men have 75-78 beats per minute, and women have 80-83 beats per minute;
At the age of 60 to 70, men have 78-80 beats per minute, and women have 83-85 beats per minute;
At the age of 70 and older, men have 80 beats per minute and women have 85 beats per minute.

Research methods and their description

Arrhythmia is considered a common disease among adolescents during puberty. The disease is defined by the following symptoms: chest pain, tachycardia, shortness of breath and others.

Sinus arrhythmia is an uneven distribution of the rhythm, in which it becomes more frequent or less frequent. To determine the cause of the disease, research is necessary.

It happens that a situation arises when an in-depth study may be needed; a person may be prescribed invasive methods - that is, with penetration into the esophagus, blood vessels or heart.

Exercise tests

In order to detect sinus arrhythmia during physical activity, it is most often used bicycle ergometry, treadmill test or tilt test.

Bicycle ergometry

As the name suggests, the procedure is carried out using a structure that resembles an exercise bike with an attached apparatus. First, the indicators before the procedure are recorded - blood pressure is measured, ECG and heart rate are recorded. The patient begins to pedal at the speed and power set by the doctor. Then the specialist increases the indicators. During the entire procedure, ECG indicators are recorded, and blood pressure is measured every 2-3 minutes. The moment when the patient stops pedaling and rests is also recorded. It is important to understand how quickly the heart returns to a normal rhythm.

Treadmill test

This procedure is also related to the simulator. The patient walks on a treadmill at different speeds. The intensity is adjusted by changing the speed and angle of inclination.

Also, all indicators are recorded while driving. There are no significant differences from bicycle ergometry. But it is believed that the treadmill is more natural and familiar to the patient.

If any discomfort occurs, the patient can stop. The doctor also closely monitors the patient's condition.

Tilt test

To perform this procedure, the patient is placed on a special table, then he is secured with straps and placed in an upright position. During the change of positions, all ECG readings, as well as blood pressure, are recorded.

Event monitoring

A special device is attached to the patient, but he turns it on only when he feels pain or any discomfort. The received recordings are transmitted to the doctor on the phone.

ECG is the most important research method through which abnormalities can be detected. This can be determined by the following indicators:

what is the heart rate per minute - bracardia is less than 60, tachycardia is more than 90, and the norm is in the range from 60 to 90;
where is the source of rhythm located? If everything is normal, then it is located in the sinus node;
where the presence and place of extraordinary excitations of the myocardium is extrasystal;
where conduction from the sinus node is impaired, inside the ventricles, or the problem lies in the atrium;
whether there are fibrillations and flutters in the ventricles or in the atrium.

During the procedure, the patient must undress to the waist, free his legs and lie down on the couch. The nurse then applies the product to the lead sites and attaches the electrodes. The wires go to the device and a cardiogram is taken.

Anticipate the presence of sinus arrhythmia on the cardiogram can be done as follows:

You can see the P wave in all leads, while it is always positive in lead II, and vice versa negative in lead aVR, while the electrical axis is within age limits.
Next, you should pay attention to changes in the R-R intervals. Usually the intervals between the teeth are shortened and lengthened smoothly, but if there is a sinus arrhythmia, then abrupt changes are observed.
Again, if there is no difference when holding the breath at the R-R interval, then this indicates an arrhythmia. The exception is older people.

Holter ECG

A device is attached to the patient's body - halter, which records indicators for forty-eight hours. In this case, the person should keep a diary describing their daily activities and symptoms. After which the doctor must analyze the obtained indicators.

This diagnosis allows you to accurately identify the presence of the disease by monitoring the work of the heart over a certain period of time.

But it is worth taking into account the fact that the device may have some malfunctions, so the indicators in some places may not be accurate or may have some deviations.

Electrophysiological study

This method is used if discomfort could not be detected during other studies. One of the electrodes is inserted through the nose into the food passage or a vein is catheterized into the heart cavity. After which a small impulse is given, and the doctor monitors the change in rhythm.

Useful video

The following video lessons will help you learn how to decipher ECG results yourself:

Conclusion

Paying close attention to your heart's function can protect you from more serious illnesses. If shortness of breath or rapid heartbeat occurs, it is recommended to immediately consult a doctor. As was described in the article, an ECG is one of the most accurate ways to detect sinus arrhythmia; you can read the cardiogram yourself, but for an accurate diagnosis it is recommended to consult a specialist.

Sinus arrhythmia on ECG: detailed interpretation, all signs

The abnormal heart rhythm that characterizes sinus arrhythmia can be seen on an ECG. This condition is often diagnosed in healthy people. In this situation, it is considered as a variant of the norm that does not require medical intervention. In most cases, sinus arrhythmia is asymptomatic. Therefore, the only way to detect it is routine electrocardiography.

What does sinus arrhythmia look like on an ECG?

The main method for diagnosing cardiovascular disease is electrocardiography.

The diagnosis of “sinus arrhythmia” refers to a condition in which the heart rate increases or decreases. The disorder is caused by the uneven generation of impulses that occur in the sinus node.

The main method for diagnosing cardiovascular disease is electrocardiography. Based on the results of the diagnosis, the cardiologist can judge whether a person has abnormalities in the functioning of the heart. The pathology has a number of characteristic symptoms that make it possible to accurately determine it in the process of deciphering the cardiogram.

First signs

Sinus arrhythmia, regardless of whether it is respiratory or not, shows characteristic signs on the ECG. It is through them that the cardiologist will be able to identify the presence of a disorder in the patient that has not previously manifested itself.

The doctor will decipher the received cardiogram in accordance with the standards for taking readings after this type of diagnosis. He will do this in stages. Decoding the cardiogram of a person who has sinus arrhythmia involves studying individual parts and leads. Their change should be characteristic directly for this pathological condition.

Sinus arrhythmia is indicated by the following signs that can be found on the cardiogram:

Presence of sinus rhythm. There will be a P wave in all leads. It is positive in lead II, and negative in aVR. The electrical axis can be detected within the boundary, which corresponds to a variant of the age norm. In other leads, this wave can have different values, both positive and negative. This indicator depends on the EOS.
Periodic change of R-R intervals. It may be greater by just 0.1 seconds. As a rule, such changes are directly related to the breathing phase. Occasionally, after the shortest interval, the longest period is observed. The intervals that are present between the R waves can be shortened or lengthened if the development of a physiological form of arrhythmia is observed. Organic disorders lead to intermittent disruptions in the duration of intervals. They can exceed normal values by 0.15 seconds.
There is no difference in the duration of the R-R intervals at the moment of holding the breath during inhalation. This symptom is usually observed in children and adolescents. This symptom is not typical for elderly patients. Their disorder persists even during breathing manipulations (air retention in the lungs).

If the doctor knows these signs and can see them on the electrocardiogram, then it will not be difficult for him to give the patient the correct diagnosis.

Symptoms as the disease progresses

The heart rate as sinus arrhythmia develops reaches 71-100 beats per minute

The results of scientific research have shown that the symptoms of the disease in its various manifestations become more pronounced on the ECG with the active development of the pathological process. Signs of sinus arrhythmia become noticeable to the patient himself, since heart rhythm disturbances negatively affect his well-being.

Further development of arrhythmia leads to a greater change in the direction, shape and amplitude of the P wave. These processes directly depend on the localization of the rhythm source and the speed of the excitation wave in the atria.

In patients with sinus arrhythmia, the heart rate gradually changes, which is also displayed on the cardiogram. As the disease progresses, it reaches 71-100 beats per minute. If the rhythm is more rapid, the patient is diagnosed with sinus tachycardia.

It is better to trust a specialist doctor to take an electrocardiogram and interpret it

People who are predisposed to developing cardiovascular diseases should periodically have an ECG to monitor the functioning of the heart and the entire system. They should visit a cardiologist at least once every 3 months and undergo all the necessary tests that will help identify even a slight disturbance in heart rhythm.

An unscheduled visit to a cardiologist and an ECG will be required for a person who suddenly develops symptoms of sinus arrhythmia. Timely consultation with a doctor will prevent the progression of the disease and the development of complications.

Repeated electrocardiography is required for a patient who periodically experiences surges in blood pressure, fainting, shortness of breath and toxicosis. Frequent diagnosis using the ECG method does not cause any harm to a person’s health, since the procedure is completely safe for his body.

An ECG does not always allow a cardiologist to obtain enough information to diagnose a patient and prescribe appropriate treatment. If controversial issues arise, he directs the person to undergo a number of additional studies, including:

Electrophysiological diagnostics.
Orthostatic test.
Echocardiogram.
Holter monitoring.
Load test.

In addition to electrocardiographic examination, differential diagnosis is also required. With its help, a cardiologist can distinguish sinus arrhythmia from another pathological condition that has a similar clinical picture. By performing only electrocardiography, a specialist cannot always obtain this information, even understanding what the ECG result means.

A differential method for diagnosing sinus arrhythmia is required in order to promptly recognize an acute form of myocardial infarction in a patient. It can develop against the background of paroxysmal tachycardia. Therefore, an ECG is required to identify this disorder.

The patient himself can decipher the ECG readings. To do this, you need to know which leads and intervals to pay attention to. Some patients try to conduct a cardiogram analysis on their own because they want to save on a specialist consultation, which is not always free. But you need to understand that a person who does not have experience in deciphering an ECG can make a serious mistake. As a result, an incorrect diagnosis will be made and inappropriate treatment will be selected.

If the patient is concerned about his own health, then he should entrust a competent doctor with both the removal of the cardiogram and its interpretation. This will prevent serious mistakes that can negatively affect the patient’s future behavior and provoke the active development of cardiovascular disease.

Signs of arrhythmia on an ECG: transcript of films

Arrhythmia is a condition in which the strength and frequency of heart contractions, their rhythm or sequence changes. Occurs as a result of disturbances in the cardiac conduction system, deterioration of excitability or automatic functions. It is not a sinus rhythm. Some episodes occur without symptoms, while others are severe and lead to dangerous consequences. In this regard, arrhythmia requires a different approach to the treatment of each specific case.

Signs of heart rhythm disturbances on the ECG

With arrhythmia, the rhythm and frequency of the heartbeat changes, becoming more or less than normal. Irregular contractions and disturbances in the conduction of electrical impulses along the myocardial conduction system are recorded. A combination of more than two signs is possible. The localization of the pacemaker may migrate, causing it to become non-sinus.

One of the criteria for arrhythmia is the frequency of contractions and its form, constant or intermittent paroxysmal. The department in which the violation occurs is also taken into account. Pathological heart rhythm is divided into atrial and ventricular.

Sinus arrhythmia when the intracardiac impulse is disrupted in the focus of the sinus node is manifested by tachycardia or bradycardia:

Tachycardia is characterized by an increase in contraction frequency to 90-100 per minute, while the rhythm remains correct. It occurs with increased automatism in the sinus node (SU), against the background of endocrine, cardiac and combined psychosomatic pathology. It can be respiratory, disappearing on inspiration. Tachycardia on the cardiogram - P waves precede each ventricular complex, equal R - R intervals are maintained, the contraction frequency increases from the age norm of an adult or child (more than 80-100 per minute). Arrhythmia looks like this on an ECG:
Bradycardia is characterized by a decrease in beat rate to less than 60 beats per minute while maintaining the rhythm. Occurs when automatism in the nervous system decreases; the provoking factors are neuroendocrine diseases and infectious agents:
- on the ECG there is a sinus rhythm with preserved P, equal intervals R - R, while the heart rate decreases to less than 60 beats per minute or from the age norm.
The sinus type of arrhythmia occurs when the transmission of impulses is disrupted, which is manifested by an irregular rhythm, more frequent or rare. It happens spontaneously in the form of paroxysm. When the atrial sinus is weakened in the focus, sick sinus syndrome develops:
- rhythm disturbance on the ECG manifests itself in the form of irregular sinus rhythm with a difference between the R - R intervals of no more than 10-15%. Heart rate decreases or increases on the cardiogram.
Extrasystole indicates additional foci of excitation, in which heart contractions are recorded out of sequence. Depending on the location of the excitation, atrial, atrioventricular or ventricular extrasystoles are distinguished. Each type of dysfunction has characteristic features on the electrocardiogram.
Atrial supraventricular extrasystoles appear with deformed or negative P, with intact PQ, with a disturbed R-R interval and the coupling segment zone.
Anti-ventricular extrasystoles on the ECG are detected in the form of the absence of P waves due to their overlap with the ventricular QRS with each extraordinary contraction. A compensatory pause occurs in the form of an interval between the R wave of the complex of the preceding extrasystole and the subsequent R, which looks on the ECG as:
Ventricular ones are determined in the absence of P and the subsequent PQ interval, and the presence of altered QRST complexes.
Blockades occur when the passage of impulses through the cardiac conduction system slows down. AV block is recorded when there is a failure at the level of the atrioventricular node or part of the trunk of the His. Depending on the degree of conduction disturbance, four types of arrhythmia are distinguished:
- the first is characterized by a slowdown in conduction, but the complexes do not fall out and PQ remains > 0.2 sec;
- the second - Mobitz 1 is manifested by slow conduction with a gradual lengthening and shortening of the PQ interval, loss of 1-2 ventricular contractions;
- the second type, Mobitz 2, is characterized by impulse conduction and loss of every second or third ventricular QRS complex;
- the third - complete block - develops when impulses do not pass from the upper sections to the ventricles, which is manifested by sinus rhythm with a normal heart rate of 60-80 and a reduced number of atrial contractions of about 40 beats per minute. Individual P waves and the manifestation of pacemaker dissociation are visible.
Arrhythmia looks like this on a cardiogram:
The most dangerous are mixed arrhythmias, which occur when several pathological foci of excitation are active and chaotic contractions develop, with loss of coordinated functioning of the upper and lower parts of the heart. The disorder requires urgent help. There is flutter, atrial fibrillation or ventricular fibrillation. ECG data for arrhythmias are presented in the photo with interpretation below:
Arrhythmia in the form of flutter manifests itself as characteristic changes on the cardiogram:

Conclusions

Heart rhythm disturbances differ depending on the cause of their occurrence, the type of cardiac pathology and clinical symptoms. To identify arrhythmia, an electrocardiogram is used, which is examined and interpreted to determine the type of disorder and the conclusion. After this, the doctor prescribes tests and a course of therapy to prevent complications and maintain quality of life.

The following sources of information were used to prepare the material.

Sinus arrhythmia of the heart

In modern society, it is no longer fashionable to smoke and drink alcohol; now it is fashionable to monitor your health and lead a healthy lifestyle. After all, the quality of life depends primarily on a person’s well-being.

It is for the purpose of early detection of diseases and their prevention that medical examinations are carried out annually in clinics; you can also take tests and have an electrocardiogram done, reflecting the work of the heart, in private medical centers.

The possibilities for examination today are very wide, if there is a desire. But it is not always possible for a person, after undergoing an examination, to be clearly and intelligibly explained what this or that indicator in the analysis means, or what the interpretation of his cardiogram means. When reading the ECG conclusion “sinus arrhythmia,” the patient does not always understand what this wording means, what is happening with the work of his heart, is sinus arrhythmia of the heart subject to treatment? Meanwhile, the patient’s primary right is to know what is happening to his health.

1 What is sinus arrhythmia?

Moderate sinus arrhythmia

If you read “moderate sinus arrhythmia” or “sinus respiratory arrhythmia” in the transcript of your electrocardiogram, you should not immediately panic and classify yourself as a cardiac patient, especially if before the ECG you felt like a completely healthy person and did not have any heart problems. You should know that this definition does not always signal a disease; it can also be a physiological condition.

Sinus arrhythmia is an irregular heart rhythm, which is characterized by a periodic increase and decrease in electrical impulses in the sinus node with a changing frequency. The sinus node, which normally rhythmically generates impulses with a frequency of 60-90 beats per minute, under the influence of certain factors, ceases to maintain the correct rhythm and begins to “be lazy” - produce impulses less than 60 beats per minute with the development of bradyarrhythmia, or “hurry” - produce increased generation of impulses of more than 90 beats per minute with the development of tachyarrhythmia.

2 Disease or physiology?

Sinus respiratory arrhythmia

There are two forms of sinus arrhythmia: respiratory (cyclic) and not associated with breathing (non-cyclical).

Respiratory arrhythmia is not a pathology, it does not require treatment, and does not cause clinical symptoms. Doctors associate its occurrence with insufficient maturity and imbalance of the autonomic nervous system, which controls the heart. With this form, the predominance of the influence of the n.vagi or vagus nerve on cardiac activity is clearly visible.

Sinus respiratory arrhythmia is characterized by an increased heart rate during inspiration and a slower heart rate during expiration. It often occurs in children, young healthy people, adolescents during puberty, athletes, patients with a tendency to neurosis, and patients with vegetative-vascular dystonia.

The non-cyclic form indicates the presence of some disease that is accompanied by cardiac arrhythmia. This form is more serious in prognostic significance, especially if it is severe sinus arrhythmia.

3 Reasons for the occurrence of a non-cyclic form

Rheumatic valve disease

Non-cyclic moderate or severe sinus arrhythmia can occur under the following conditions:

heart and vascular diseases (myocarditis, rheumatic valve disease, arterial hypertension, myocardial ischemia, congenital and acquired defects);
hormonal disorders (hyperfunction of the thyroid gland or insufficient production of thyroid hormones, kidney and adrenal diseases, diabetes mellitus);
blood diseases (anemia of various origins);
underweight, cachexia;
mental disorders (neuroses, depressive states, mania);
infectious diseases (rheumatism, tuberculosis, brucellosis);
intoxication with alcohol, nicotine;
electrolyte disorders (lack of potassium, calcium, magnesium in the blood);
overdose of antiarrhythmics, antidepressants, hormonal drugs.

Arrhythmia in older people when waking up after sleep or falling asleep

All these diseases can cause disturbances in the functioning of the sinus node and, as a result, arrhythmia. Also, the non-cyclic form is a common occurrence in older people; it occurs in them when waking up after sleep or when falling asleep. This is due, on the one hand, to age-related changes in the heart muscle, and on the other hand, to a reduced controlling influence of the central nervous system during periods of transition from sleep to wakefulness and vice versa.

Knowing the cause of rhythm disturbances is very important for determining further treatment tactics.

4 Clinical symptoms

The respiratory form or moderately severe non-cyclic arrhythmia may not manifest itself in any way and can only be detected on an ECG. Severe sinus arrhythmia is characterized by such symptoms as palpitations, if there is a tachyarrhythmia, or interruptions in the work of the heart, a feeling of heart failure, if a bradyarrhythmia occurs. Often with bradyarrhythmias, dizziness, vestibular disorders, and fainting are observed. Symptoms such as weakness, shortness of breath, and pain in the heart area may appear. Symptoms will be predominantly associated with the disease that caused the heart rhythm disturbance.

5 How to determine sinus arrhythmia?

The doctor, after a thorough interview and collection of complaints, will begin the examination. The pulse in the radial arteries will be irregular; when listening to heart sounds, irregular contractions are also noted. With respiratory arrhythmia, a relationship with breathing will be heard: when you inhale, the heart rate will accelerate, and when you exhale, it will slow down. In a non-cyclic form, such a connection will not be traced.

Helpers in making a diagnosis - instrumental and laboratory examination methods:

Holter ECG monitoring,
EchoCG
general clinical, biochemical tests,
Ultrasound of the thyroid gland, kidneys, adrenal glands,
Electrophysiological study of the heart.

6 How to distinguish respiratory arrhythmia from pathological one?

There are medical methods and techniques that can easily distinguish between the two forms of arrhythmia.

The respiratory form disappears on the ECG when holding the breath, the pathological form does not disappear after holding the breath;
Respiratory arrhythmia increases after taking beta-blockers, but non-cyclic arrhythmia does not change;
The non-respiratory form does not disappear under the influence of atropine, but the respiratory form does.

7 How to treat sinus node rhythm disturbances

The respiratory form does not require treatment. Treatment of the non-cyclic form depends on the treatment of the disease that contributed to the occurrence of the rhythm disorder. Often, after adjusting the electrolyte balance of the blood, curing anemia, hormonal disorders, the arrhythmia disappears and the normal heart rhythm is restored.

In case of severe tachyarrhythmia, beta-blockers, antiarrhythmics, antithrombotic drugs are used to reduce heart rate; in case of severe bradyarrhythmia, atropine-based drugs, electrical pulse therapy can be used, or if drug treatment is ineffective, surgical treatment can be used: implantation of a pacemaker. Treatment of sinus arrhythmia is carried out in the presence of clinical symptoms and hemodynamic disturbances.

Based on the ECG results, the doctor will be able to identify the cause of the arrhythmia.

There are a great number of factors that cause manifestations of arrhythmia, ranging from a neuropsychiatric disorder to severe organic damage to the heart. There are main groups of etiological factors:

Organic or functional diseases of the cardiovascular system (myocardial infarction, ischemic heart disease, pericarditis).
Extracardiac factors – nervous regulation disorders, stress conditions, hormonal disorders.
Bad habits – alcohol abuse, smoking, drug addiction.
Traumatic injuries, hypothermia or, conversely, overheating, oxygen deficiency.
Taking certain types of medications - diuretics, cardiac glycosides as side effects causes arrhythmia.
Idiopathic (independent) arrhythmias - in this case there are no changes in the heart, arrhythmia acts as an independent disease.

From this article you will learn: how and for what reason sinus arrhythmia develops, and what symptoms are characteristic of it. How the pathology is treated, and what needs to be done to prevent arrhythmia from occurring.

You can consult a therapist with the problem, but the treatment of this disease, depending on the cause, may be the responsibility of a cardiologist, neurologist, or even a psychotherapist.

In the heart wall there is a sinus node, which is a source of electrical impulses that ensure contraction of the muscular system of the heart - the myocardium. After generation, the impulse is transmitted through the fibers of each muscle cell of the organ, as a result they contract.

This process occurs at certain (equal) intervals of time, and normally has a frequency of 60–90 beats per minute. It is this impulse conduction that ensures uniform, consistent and coordinated contraction of the ventricles and atria.

When, as a result of unfavorable factors, the activity of the conduction system of the heart is disrupted, arrhythmia occurs - a violation of the rhythm of heart contractions (it can be of varying degrees of severity).

Causes of the disease

Sinus arrhythmia can occur for three groups of reasons.

Data from the World Health Organization show that about one percent of all people suffer from atrial fibrillation, and the pathology is more often registered in European males. Violation of cardiac activity is immediately reflected in the results of the cardiogram. Atrial fibrillation on the ECG is distinguished by typical symptoms by which doctors can determine heart rhythm disturbances.

In pathology, the number of chaotic contractions is impressive - patients can experience up to eight hundred times per minute. The impulses that enter the atrioventricular node vary in frequency and strength; often such impulses simply do not reach the ventricles. In this case, the frequency of ventricular contractions will not exceed two hundred times, and on average this parameter is in the range from 80 to 130 contractions. With disorderly contraction of the departments, the so-called absolute arrhythmia occurs - severe cardiac pathology.

Depending on the heart rate, the following types of atrial fibrillation are distinguished:

tachysystolic;
normosystolic;
Bradysystolic.

If the pathology is bradysystolic, then the number of contractions is less than sixty; with normosystole, the indicator reaches ninety beats per minute, and the tachysystolic type is the number of contractions over ninety beats per minute.

On the cardiogram, arrhythmia manifests itself with typical signs:

absence of the P wave - instead of it, signs of irregular excitation appear;
violation of the complex

Causes of pathology

Atrial fibrillation is a severe pathology; it has a significant cause that must be treated along with the arrhythmia itself.

Among the causes of the disease are:

dysfunction in the endocrine system;
atherosclerotic changes in blood vessels;
cardiovascular failure;
disturbances in the body's water-salt balance;
cardiosclerosis;
acid-base balance disorders;
congenital or acquired heart defects;
cardiomyopathy;
hypertension;
neoplasms of the heart;
renal failure;
surgical interventions on the heart and blood vessels;
myocarditis.

The cause of the disease can be determined after a comprehensive examination of the patient, and an ECG for atrial fibrillation will play an important role in this matter - the doctor will notice the characteristic signs of pathology on it.

Symptoms of pathology

Clinical manifestations of the pathology largely depend on hemodynamic disturbances and heart rate. Patients complain mainly of shortness of breath, disturbances in the functioning of the organ, which mainly occur even with the slightest physical activity. Less often, patients feel a dull and aching pain behind the sternum.

Important! The symptoms of pathology when examining patients are very diverse. Not all patients complain of feeling unwell - quite a large number of patients do not consider themselves sick or indicate only minor disorders. Patients are diagnosed with heart failure, atrial fibrillation provokes pale skin, swollen veins, swelling of the legs, and blue lips.

When listening, patients experience abnormal heart contractions with disturbed rhythm, different tonality, which depends on the duration of diastole. The preceding short pause provokes the first loud tone, and the second one either weakens significantly or disappears completely. Atrial fibrillation does not cause hypertension or hypotension, the pulse remains rhythmic, but in the tachysystolic form the pulse lags behind the heart rate.

When interpreting the electrocardiogram of patients with suspected atrial fibrillation, doctors pay attention to the following analysis features:

Absence of P-wave at abduction sites.
The presence of atrial fibrillation waves, which are frequent and irregular, which is provoked by chaotic excitation and atrial contractions. There are large-wave and small-wave forms of f-wave amplitude. The large-wave form with an indicator of more than one millimeter is observed in people suffering from chronic pulmonary heart disease, as well as in those who suffer from mitral stenosis. The shallow-wave form is characteristic of patients with myocarditis, myocardial infarction, thyrotoxicosis, intoxication, and cardiosclerosis.

Several main groups of causes of arrhythmia can be distinguished, namely cardiac, non-cardiac and drug causes.

Cardiac causes are when arrhythmia occurs due to diseases of the cardiovascular system:

myocardial infarction and ischemic disease;
cardiomyopathy;
heart defects;
myocarditis;
heart failure;

Non-cardiac causes:

vegetative-vascular dystonia;
bronchopulmonary diseases;
anemia;
diseases of the endocrine system.

Human endocrine system

This only occurs if medications are taken without the supervision of a doctor for a long time, with an independent increase in the dose of the drug, etc. Also, arrhythmia can be caused by electrolyte imbalances, that is, if the ratio of potassium, magnesium and sodium in the body changes.

It should be noted that the following factors can cause this pathology:

smoking;
alcohol abuse;
insufficient sleep;
malnutrition.

The main symptoms of arrhythmic disorders are:

Pain on the left side in the heart area, especially when inhaling, or discomfort.

The patient feels abnormal heart contractions, there is a feeling that the heart is turning over, being compressed, and not working rhythmically;

general weakness of the body;
dizziness, fainting;
shortness of breath, rapid breathing.

Diagnosis of a disease such as atrial fibrillation is impossible without an ECG. The pathology is characterized by disturbances in heart rhythm, chaotic contraction and excitation of the atria, the so-called fibrillation of atrial muscle fibers. The diagnostic procedure provides an opportunity to get acquainted with the full picture of the course of the pathological process, thanks to which the doctor is able to establish the correct diagnosis. Based on the data obtained, the cardiologist prescribes a course of therapy.

Atrial fibrillation is a rhythm disorder in which, during one cardiac cycle, random excitation and contraction of individual atrium muscle fibers occurs.

Heart diseases require a comprehensive study. These include cardiac arrhythmia. The first diagnostic test to which the cardiologist refers the patient is an ECG.

On an electrocardiogram, the bioelectric activity of the heart is reflected in the form of teeth, intervals and sections. Their length, width, and distance between the teeth normally have certain values. Changing these parameters allows the doctor to determine abnormalities in the functioning of the heart muscle.

In most cases, an ECG is sufficient for the cardiologist to correctly diagnose the patient. Additional types of research are carried out to determine the type of pathological process.

Changes in the ECG make it possible to determine whether the patient is suffering from atrial fibrillation (flicker) or atrial flutter. Decoding the result will make it clear exactly what is bothering the patient. Atrial flutter is characterized by a rapid but regular rhythm of heart contractions, while with fibrillation the rhythm is disturbed, different groups of muscle fibers in the atria contract inconsistently with each other. Since the heart rate reaches high numbers during these disorders (up to 200 contractions per minute), it is impossible to determine the form of arrhythmia by ear, using a phonendoscope. Only an ECG gives the doctor the necessary information.

First signs

The electrocardiogram shows signs characteristic of the disease. Atrial fibrillation on an ECG will look like this:

There is no P wave on any electrocardiographic lead (this wave is a mandatory component of a normal ECG).
Presence of erratic f waves throughout the entire cardiac cycle. They differ from each other in amplitude and shape. In certain leads these waves are recorded best. These include V1, V2, II, III. aVF. These waves occur as a result of atrial fibrillation.
Irregularity of ventricular R-R complexes (unevenness, different lengths of R-R intervals). It indicates an abnormal ventricular rhythm;
QRS complexes are distinguished by their unchanged appearance and the absence of signs of deformation.

On the ECG, a small- or large-wave form of atrial fibrillation is distinguished (depending on the scale of the f waves).

Symptoms as the disease progresses

Chest pain is one of the possible symptoms of atrial fibrillation

Clinical symptoms of atrial fibrillation become more pronounced as the disease progresses. They can vary significantly from patient to patient.

Signs of atrial fibrillation, which appear on the electrocardiogram, are complemented by symptoms that are noticeable to the patient himself. We are talking about such painful conditions:

profuse sweating;
weakness;
rapid heartbeat;
chest pain.

A patient with chronic atrial fibrillation may not even be aware of his illness if it is characterized by an asymptomatic course. In this case, only the result of an electrocardiographic study can determine the presence of pathology.

The types of electrocardiographic manifestations, that is, the symptoms that are visible on the ECG, correspond to the clinical signs of the disease in the patient. Thanks to this, a competent specialist is able to accurately understand what exactly is bothering the patient and what kind of help he needs to provide.

The procedure for taking an electrocardiogram is not complicated. All you need to do is adhere to the step-by-step implementation of the action plan that every specialist is familiar with. He will explain in detail what the patient should do at the time of diagnosis. The total duration of the procedure does not exceed 10 minutes on average.

Electrodes are attached to the patient's body, the position of which is changed by the doctor or laboratory assistant to obtain different ECG leads.

It is very important that the patient lies calm and still during the ECG. In this case, you can guarantee an informative result. Any movement, coughing, or sneezing negatively affects the results of the electrocardiogram, and they can no longer be called reliable.

ECG interpretation

Arrhythmia of heart contractions can only be recognized by a competent specialist who describes the ECG for atrial fibrillation. The interpretation of the results obtained is available only to the doctor. If the case is urgent, then the task can be entrusted to a paramedic, who has repeatedly had to take and interpret the ECG.

The patient can also try to decipher his cardiogram. To do this, he needs to study the medical literature in order to assess the location and height of the teeth, the size of the intervals between them. Without basic knowledge about ECG, a person risks making a serious mistake.

Patients who need an electrocardiogram are interested in the cost of this diagnosis. In Russian clinics, such a service costs from 650 to 2300 rubles. Additionally, you may be required to pay for interpretation of the ECG results obtained.

Other diagnostic methods

In standard situations, a person is diagnosed with atrial fibrillation based on his complaints and the symptoms of the disease identified during the initial diagnosis. A survey of the patient and the results of electrocardiographic diagnostics are quite sufficient if there are no serious complications of the disease.

If the ECG does not provide sufficient information about the patient’s condition, the cardiologist will refer him for additional studies:

Echocardioscopy.
Radiography.
Biochemical tests of blood and urine.
Transesophageal examination of the cardiac conduction system.

An important stage in the study of a patient with atrial fibrillation is differential diagnosis: it is necessary to distinguish the disease from other pathological conditions that may have similar symptoms. Differential diagnosis is carried out with the following pathologies:

sinus tachycardia;
atrial flutter;
supraventricular paroxysmal tachycardia;
ventricular paroxysmal tachycardia.

ECG results allow the cardiologist to distinguish atrial fibrillation from the above-mentioned heart diseases.

ECG frequency

Regular examination by a cardiologist will allow you to promptly identify the presence of disturbances in the functioning of the heart.

Patients may ask questions about the frequency of electrocardiography to check the status of the cardiovascular system. This diagnostic option is absolutely safe for human health. During the procedure, indicators of the bioelectrical activity of the heart are simply taken. There are no negative effects on the body.

The frequency of an ECG depends on several factors. Doctors recommend that all people be tested to prevent atrial fibrillation about once a year. If a person’s profession involves serious stress, then he should visit a cardiologist once every six months. Elderly persons should be checked every 3 months. They are at risk, so regular checks of the cardiovascular system are mandatory for them.

A routine examination by a cardiologist and taking an ECG allows you to promptly identify whether a person has heart problems.

If a patient has been diagnosed with atrial fibrillation, he will have to repeat the ECG procedure at the frequency determined by the cardiologist.

The main method for diagnosing cardiovascular disease is electrocardiography.

The diagnosis of “sinus arrhythmia” refers to a condition in which the heart rate increases or decreases. The disorder is caused by the uneven generation of impulses that occur in the sinus node.

First signs

To calculate the disease that results from an abnormal heart rhythm, it is enough to take a cardiogram under normal conditions, without resorting to physical exertion.

Sinus arrhythmia is indicated by the following signs that can be found on the cardiogram:

Presence of sinus rhythm. There will be a P wave in all leads. It is positive in lead II, and negative in aVR. The electrical axis can be detected within the boundary, which corresponds to a variant of the age norm. In other leads, this wave can have different values, both positive and negative. This indicator depends on the EOS.
Periodic change of R-R intervals. It may be greater by just 0.1 seconds. As a rule, such changes are directly related to the breathing phase. Occasionally, after the shortest interval, the longest period is observed. The intervals that are present between the R waves can be shortened or lengthened if the development of a physiological form of arrhythmia is observed. Organic disorders lead to intermittent disruptions in the duration of intervals. They can exceed normal values by 0.15 seconds.
There is no difference in the duration of the R-R intervals at the moment of holding the breath during inhalation. This symptom is usually observed in children and adolescents. This symptom is not typical for elderly patients. Their disorder persists even during breathing manipulations (air retention in the lungs).

If the doctor knows these signs and can see them on the electrocardiogram, then it will not be difficult for him to give the patient the correct diagnosis.

Symptoms as the disease progresses

The heart rate as sinus arrhythmia develops reaches 71-100 beats per minute

It is better to trust a specialist doctor to take an electrocardiogram and interpret it

Electrophysiological diagnostics.
Orthostatic test.
Echocardiogram.
Holter monitoring.
Load test.

A specialist should decipher the results of the electrocardiogram. He has a sufficient level of knowledge that allows him to correctly assess the current state of a person.

Atrial fibrillation occurs especially often in emergency medicine practice. Under this concept, flutter and atrial fibrillation (or fibrillation) are often clinically combined. atrial fibrillation. Their manifestations are similar. Patients complain of irregular heartbeat, fluttering in the chest, sometimes pain, weakness, and shortness of breath. Cardiac output decreases, blood pressure may drop, and heart failure may develop. The pulse becomes irregular, variable in amplitude, and sometimes thread-like. Heart sounds are muffled and irregular.

Signs of atrial fibrillation on the ECG

A characteristic sign of atrial fibrillation- pulse deficiency, i.e. the heart rate determined by auscultation exceeds the pulse rate. This happens because individual groups of muscle fibers of the atria contract chaotically, and the ventricles sometimes contract in vain, not having time to fill enough with blood. In this case, a pulse wave cannot be formed. Therefore, heart rate should be assessed by cardiac auscultation, or better yet by ECG, but not by pulse.

On the ECG there is no P wave (since there is no single atrial systole); instead, F waves of various amplitudes are present on the isoline (Fig. 196, c), reflecting contractions of individual muscle fibers of the atria. Sometimes they can merge with noise or be low-amplitude and therefore invisible on the ECG. The frequency of F waves can reach 350-700 per minute.

Atrial flutter is a significant increase in atrial contractions (up to 200-400 per minute) while maintaining the atrial rhythm (Fig. 19a). F waves are recorded on the ECG.

Ventricular contractions during atrial fibrillation and flutter can be rhythmic or nonrhythmic (which is more common), and a normal heart rate, bradycardia, or tachycardia may be observed. A typical ECG for atrial fibrillation is a finely wavy isoline (due to F waves), the absence of P waves in all leads and different R-R intervals, the QRS complexes are not changed. They distinguish between a permanent form, that is, a long-standing one, and a paroxysmal form, that is, a form that occurs suddenly in the form of attacks. Patients get used to the permanent form of atrial fibrillation, stop feeling it and seek help only when the heart rate (ventricles) increases above 100-120 beats per minute. Their heart rate should be reduced to normal, but there is no need to restore sinus rhythm, since this is difficult to do and can lead to complications (blood clots). It is advisable to convert the paroxysmal form of atrial fibrillation and flutter into sinus rhythm, and the heart rate should also be reduced to normal.

Treatment and tactics for patients at the prehospital stage are almost the same as for paroxysmal supraventricular tachycardias (see above).

Guide to Cardiology in four volumes

Cardiology

Chapter 5. Analysis of the electrocardiogram

S. Pogvizd

I. Determination of heart rate. To determine heart rate, the number of cardiac cycles (RR intervals) per 3 s is multiplied by 20.

II. Rhythm Analysis

A. Heart rate< 100 мин –1. отдельные виды аритмий see also fig. 5.1.

1. Normal sinus rhythm. Correct rhythm with heart rate 60 x 100 min –1. The P wave is positive in leads I, II, aVF, negative in aVR. Each P wave is followed by a QRS complex (in the absence of AV block). PQ interval 0.12 s (in the absence of additional conduction pathways).

2. Sinus bradycardia. The right rhythm. Heart rate< 60 мин –1. Синусовые зубцы P. Интервал PQ 0,12 с. Причины: повышение парасимпатического тонуса (часто у здоровых лиц, особенно во время сна; у спортсменов; вызванное рефлексом БецольдаЯриша; при нижнем инфаркте миокарда или ТЭЛА); инфаркт миокарда (особенно нижний); прием лекарственных средств (бета-адреноблокаторов, верапамила. дилтиазема. сердечных гликозидов, антиаритмических средств классов Ia, Ib, Ic, амиодарона. клонидина. метилдофы. резерпина. гуанетидина. циметидина. лития); гипотиреоз, гипотермия, механическая желтуха, гиперкалиемия, повышение ВЧД. синдром слабости синусового узла. На фоне брадикардии нередко наблюдается синусовая аритмия (разброс интервалов PP превышает 0,16 с). Лечение см. гл. 6, п. III.Б.

3. Ectopic atrial rhythm. The right rhythm. Heart rate 50 x 100 min –1. The P wave is usually negative in leads II, III, aVF. The PQ interval is typically 0.12 s. It is observed in healthy individuals and with organic heart lesions. Typically occurs when sinus rhythm slows (due to increased parasympathetic tone, medications, or sinus node dysfunction).

4. Pacemaker migration. Correct or incorrect rhythm. Heart rate< 100 мин –1. Синусовые и несинусовые зубцы P. Интервал PQ варьирует, может быть < 0,12 с. Наблюдается у здоровых лиц, спортсменов при органических поражениях сердца. Происходит перемещение водителя ритма из синусового узла в предсердия или АВ -узел. Лечения не требует.

5. AV-nodal rhythm. Slow regular rhythm with narrow QRS complexes (< 0,12 с). ЧСС 3560 мин –1. Ретроградные зубцы P (могут располагаться как до, так и после комплекса QRS, а также наслаиваться на него; могут быть отрицательными в отведениях II, III, aVF). Интервал PQ < 0,12 с. Обычно возникает при замедлении синусового ритма (вследствие повышения парасимпатического тонуса, приема лекарственных средств или дисфункции синусового узла) или при АВ -блокаде. Accelerated AV-nodal rhythm(heart rate 70 x 130 min –1) is observed with glycoside intoxication, myocardial infarction (usually lower), rheumatic attack, myocarditis and after heart surgery.

6. Accelerated idioventricular rhythm. Regular or irregular rhythm with wide QRS complexes (> 0.12 s). Heart rate 60110 min –1. P waves: absent, retrograde (occur after the QRS complex) or not associated with the QRS complexes (AV dissociation). Causes: myocardial ischemia, condition after restoration of coronary perfusion, glycoside intoxication, sometimes in healthy people. With a slow idioventricular rhythm, the QRS complexes look the same, but the heart rate is 30×40 min–1. Treatment see chap. 6, paragraph V.D.

B. Heart rate > 100 min –1. certain types of arrhythmias see also fig. 5.2.

1. Sinus tachycardia. The right rhythm. Sinus P waves have a normal configuration (their amplitude can be increased). Heart rate 100 x 180 min –1. in young people up to 200 min –1. Gradual onset and cessation. Causes: physiological reaction to stress, including emotional, pain, fever, hypovolemia, arterial hypotension, anemia, thyrotoxicosis, myocardial ischemia, myocardial infarction, heart failure, myocarditis, pulmonary embolism. pheochromocytoma, arteriovenous fistulas, the effect of drugs and other drugs (caffeine, alcohol, nicotine, catecholamines, hydralazine, thyroid hormones, atropine, aminophylline). Tachycardia is not eliminated by massage of the carotid sinus. Treatment see chap. 6, paragraph III.A.

2. Atrial fibrillation. The rhythm is “wrong wrong.” Absence of P waves, erratic large- or small-wave isoline fluctuations. The frequency of atrial waves is 350×600 min –1. In the absence of treatment, ventricular rate 100 180 min –1. Causes: mitral defects, myocardial infarction, thyrotoxicosis, pulmonary embolism. condition after surgery, hypoxia, COPD. atrial septal defect, WPW syndrome. Sick sinus syndrome, consumption of large doses of alcohol, can also be observed in healthy individuals. If, in the absence of treatment, the frequency of ventricular contractions is low, then one can think of impaired conduction. With glycoside intoxication (accelerated AV nodal rhythm and complete AV block) or against the background of a very high heart rate (for example, with WPW syndrome), the rhythm of ventricular contractions may be correct. Treatment see chap. 6, paragraph IV.B.

3. Atrial flutter. Regular or irregular rhythm with sawtooth atrial waves (f), most distinct in leads II, III, aVF or V 1. The rhythm is often correct with AV conduction from 2:1 to 4:1, but may be irregular if AV conduction changes. The frequency of atrial waves is 250 x 350 min –1 for type I flutter and 350 x 450 min –1 for type II flutter. Reasons: see chap. 6, paragraph IV. With AV conduction 1:1, the frequency of ventricular contractions can reach 300 min–1. in this case, due to aberrant conduction, expansion of the QRS complex is possible. The ECG in this case resembles that of ventricular tachycardia; This is especially often observed when using class Ia antiarrhythmic drugs without simultaneous administration of AV blockers, as well as with WPW syndrome. Atrial fibrillation-flutter with chaotic atrial waves of different shapes is possible with flutter of one atrium and flicker of the other. Treatment see chap. 6, paragraph III.G.

4. Paroxysmal AV-nodal reciprocal tachycardia. Supraventricular tachycardia with narrow QRS complexes. Heart rate 150 x 220 min –1. usually 180 x 200 min –1. The P wave usually overlaps or immediately follows the QRS complex (RP< 0,09 с). Начинается и прекращается внезапно. Причины: обычно иных поражений сердца нет. Контур обратного входа волны возбуждения в АВ -узле. Возбуждение проводится антероградно по медленному (альфа) и ретроградно по быстрому (бета) внутриузловому пути. Пароксизм обычно запускается предсердными экстрасистолами. Составляет 6070% всех наджелудочковых тахикардий. Массаж каротидного синуса замедляет ЧСС и часто прекращает пароксизм. Лечение см. гл. 6, п. III.Д.1.

5. Orthodromic supraventricular tachycardia in WPW syndrome. The right rhythm. Heart rate 150 x 250 min –1. The RP interval is usually short but can be prolonged by slow retrograde conduction from the ventricles to the atria. Starts and stops suddenly. Usually triggered by atrial extrasystoles. Causes: WPW syndrome. hidden additional pathways (see Chapter 6, paragraph XI.G.2). Usually there are no other heart lesions, but a combination with Ebstein's anomaly, hypertrophic cardiomyopathy, or mitral valve prolapse is possible. Carotid sinus massage is often effective. In atrial fibrillation in patients with a clear accessory pathway, impulses to the ventricles can be conducted extremely quickly; The QRS complexes are wide, as in ventricular tachycardia, and the rhythm is incorrect. There is a danger of ventricular fibrillation. Treatment see chap. 6, paragraph XI.G.3.

6. Atrial tachycardia (automatic or reciprocal intraatrial). The right rhythm. Atrial rhythm 100×200 min –1. Non-sinus P waves. The RP interval is usually lengthened, but with 1st degree AV block it can be shortened. Causes: unstable atrial tachycardia is possible in the absence of organic lesions of the heart, stable in case of myocardial infarction, cor pulmonale, and other organic lesions of the heart. Mechanism ectopic focus or reverse entry of the excitation wave inside the atria. Accounts for 10% of all supraventricular tachycardias. Massage of the carotid sinus causes a slowdown of AV conduction, but does not eliminate the arrhythmia. Treatment see chap. 6, paragraph III.D.4.

7. Sinoatrial reciprocal tachycardia. ECG as for sinus tachycardia (see Chapter 5, paragraph II.B.1). The right rhythm. RP intervals are long. Starts and stops suddenly. Heart rate 100 x 160 min –1. The shape of the P wave is indistinguishable from a sinus wave. Causes: can be observed normally, but more often with organic lesions of the heart. Mechanism reverse entry of the excitation wave inside the sinus node or in the sinoatrial zone. Accounts for 5×10% of all supraventricular tachycardias. Massage of the carotid sinus causes a slowdown of AV conduction, but does not eliminate the arrhythmia. Treatment see chap. 6, paragraph III.D.3.

8. Atypical form of paroxysmal AV-nodal reciprocal tachycardia. ECG as for atrial tachycardia (see Chapter 5, paragraph II.B.4). QRS complexes are narrow, RP intervals are long. The P wave is usually negative in leads II, III, aVF. Circuit of the return input of the excitation wave in the AV node. Excitation is carried out anterogradely along the fast (beta) intranodal pathway and retrogradely along the slow (alpha) pathway. Diagnosis may require electrophysiological testing of the heart. Accounts for 510% of all cases of reciprocal AV-nodal tachycardias (25% of all supraventricular tachycardias). Massage of the carotid sinus can stop the paroxysm.

9. Orthodromic supraventricular tachycardia with slow retrograde conduction. ECG as for atrial tachycardia (see Chapter 5, paragraph II.B.4). QRS complexes are narrow, RP intervals are long. The P wave is usually negative in leads II, III, aVF. Orthodromic supraventricular tachycardia with slow retrograde conduction along an accessory pathway (usually posterior localization). Tachycardia is often persistent. It can be difficult to distinguish it from automatic atrial tachycardia and reciprocal intra-atrial supraventricular tachycardia. Diagnosis may require electrophysiological testing of the heart. Massage of the carotid sinus sometimes stops the paroxysm. Treatment see chap. 6, paragraph XI.G.3.

10. Polytopic atrial tachycardia. Wrong rhythm. Heart rate > 100 min –1. Non-sinus P waves of three or more different configurations. Different PP, PQ and RR intervals. Causes: in the elderly with COPD. with cor pulmonale, treatment with aminophylline. hypoxia, heart failure, after operations, with sepsis, pulmonary edema, diabetes. Often misdiagnosed as atrial fibrillation. May progress to atrial fibrillation/flutter. Treatment see chap. 6, paragraph III.G.

11. Paroxysmal atrial tachycardia with AV block. Irregular rhythm with a frequency of atrial waves of 150 x 250 min –1 and ventricular complexes of 100 x 180 min –1. Non-sinus P waves. Causes: glycoside intoxication (75%), organic heart damage (25%). On the ECG. as a rule, atrial tachycardia with 2nd degree AV block (usually Mobitz type I). Massage of the carotid sinus causes a slowdown of AV conduction, but does not eliminate the arrhythmia.

12. Ventricular tachycardia. Usually correct rhythm with a frequency of 110 x 250 min –1. QRS complex > 0.12 s, usually > 0.14 s. The ST segment and T wave are discordant with the QRS complex. Causes: organic heart damage, hypokalemia, hyperkalemia, hypoxia, acidosis, drugs and other drugs (glycoside intoxication, antiarrhythmic drugs, phenothiazines, tricyclic antidepressants, caffeine, alcohol, nicotine), mitral valve prolapse, in rare cases in healthy individuals. AV dissociation (independent contractions of the atria and ventricles) may be observed. The electrical axis of the heart is often deviated to the left, and drainage complexes are recorded. It can be unstable (3 or more QRS complexes, but the paroxysm lasts less than 30 s) or stable (> 30 s), monomorphic or polymorphic. Bidirectional ventricular tachycardia (with the opposite direction of QRS complexes) is observed mainly with glycoside intoxication. Ventricular tachycardia with narrow QRS complexes has been described (< 0,11 с). Дифференциальный диагноз желудочковой и наджелудочковой тахикардии с аберрантным проведением см. рис. 5.3. Лечение см. гл. 6, п. VI.Б.1.

13. Supraventricular tachycardia with aberrant conduction. Usually the rhythm is correct. The duration of the QRS complex is usually 0.12 x 0.14 s. There is no AB dissociation and fusion complexes. Deviation of the electrical axis of the heart to the left is not typical. Differential diagnosis of ventricular and supraventricular tachycardia with aberrant conduction see Fig. 5.3.

14. Torsades de pointes. Tachycardia with irregular rhythm and wide polymorphic ventricular complexes; A typical sinusoidal pattern is characteristic, in which groups of two or more ventricular complexes with one direction are replaced by groups of complexes with the opposite direction. It is observed with prolongation of the QT interval. Heart rate 150 250 min –1. Reasons: see chap. 6, paragraph XIII.A. The attacks are usually short-lived, but there is a risk of progression to ventricular fibrillation. Paroxysms are often preceded by alternating long and short RR cycles. In the absence of prolongation of the QT interval, such ventricular tachycardia is called polymorphic. Treatment see chap. 6, paragraph XIII.A.

15. Ventricular fibrillation. Chaotic irregular rhythm, QRS complexes and T waves are absent. Reasons: see chap. 5, paragraph II.B.12. In the absence of CPR, ventricular fibrillation quickly (within 4×5 minutes) leads to death. Treatment see chap. 7, paragraph IV.

16. Aberrant conduction. Manifests itself with wide QRS complexes due to slow conduction of impulses from the atria to the ventricles. Most often this is observed when extrasystolic excitation reaches the His-Purkinje system in the phase of relative refractoriness. The duration of the refractory period of the His-Purkinje system is inversely proportional to heart rate; if against the background of long RR intervals an extrasystole occurs (short RR interval) or supraventricular tachycardia begins, then aberrant conduction occurs. In this case, excitation is usually carried out along the left branch of the His bundle, and the aberrant complexes look like a blockade of the right branch of the His bundle. Occasionally, aberrant complexes look like left bundle branch block.

17. ECG for tachycardias with wide QRS complexes(differential diagnosis of ventricular and supraventricular tachycardia with aberrant conduction see Fig. 5.3). Criteria for ventricular tachycardia:

A. AB dissociation.

b. Deviation of the electrical axis of the heart to the left.

V. QRS > 0.14 s.

G. Features of the QRS complex in leads V 1 and V 6 (see Fig. 5.3).

B. Ectopic and replacement contractions

1. Atrial extrasystoles. An extraordinary non-sinus P wave followed by a normal or aberrant QRS complex. PQ interval 0.12 0.20 s. The PQ interval of early extrasystole can exceed 0.20 s. Causes: occurs in healthy individuals, with fatigue, stress, in smokers, under the influence of caffeine and alcohol, with organic heart damage, cor pulmonale. The compensatory pause is usually incomplete (the interval between the pre- and post-extrasystolic P waves is less than twice the normal PP interval). Treatment see chap. 6, paragraph III.B.

2. Blocked atrial extrasystoles. Extraordinary non-sinus P wave not followed by a QRS complex. An atrial extrasystole is not conducted through the AV node, which is in the refractory period. The extrasystolic P wave sometimes overlaps the T wave and is difficult to recognize; in these cases, the blocked atrial extrasystole is mistaken for sinoatrial block or sinus node arrest.

3. AV-nodal extrasystoles. An extraordinary QRS complex with a retrograde (negative in leads II, III, aVF) P wave, which can be recorded before or after the QRS complex or superimposed on it. The shape of the QRS complex is normal; when carried out aberrantly, it may resemble a ventricular extrasystole. Causes: occur in healthy individuals and in cases of organic heart damage. Source of extrasystole AV node. The compensatory pause can be complete or incomplete. Treatment see chap. 6, paragraph V.A.

4. Ventricular extrasystoles. Extraordinary, wide (> 0.12 s) and deformed QRS complex. The ST segment and T wave are discordant with the QRS complex. Reasons: see chap. 5, paragraph II.B.12. The P wave may not be associated with extrasystoles (AV dissociation) or may be negative and follow the QRS complex (retrograde P wave). The compensatory pause is usually complete (the interval between the pre- and post-extrasystolic P waves is equal to twice the normal PP interval). Treatment see chap. 6, paragraph V.V.

5. Substituting AV-nodal contractions. They resemble AV-nodal extrasystoles, however, the interval to the replacement complex is not shortened, but lengthened (corresponds to a heart rate of 35×60 min–1). Causes: occur in healthy individuals and in cases of organic heart damage. The source of the replacement impulse is the latent pacemaker in the AV node. Often observed when sinus rate is slowed as a result of increased parasympathetic tone, medications (eg, cardiac glycosides) and sinus node dysfunction.

6. Replacement idioventricular contractions. They resemble ventricular extrasystoles, but the interval before the replacement contraction is not shortened, but lengthened (corresponds to a heart rate of 20 x 50 min –1). Causes: occur in healthy individuals and in cases of organic heart damage. The replacement impulse comes from the ventricles. Idioventricular replacement contractions are usually observed when sinus and AV nodal rhythms slow.

D. Impaired conduction

1. Sinoatrial block. The extended PP interval is a multiple of the normal one. Causes: certain drugs (cardiac glycosides, quinidine, procainamide), hyperkalemia, sinus node dysfunction, myocardial infarction, increased parasympathetic tone. Sometimes Wenckebach periodicity is observed (a gradual shortening of the PP interval until the loss of the next cycle).

2. 1st degree AV block. PQ interval > 0.20 s. Each P wave corresponds to a QRS complex. Causes: observed in healthy individuals, athletes, with increased parasympathetic tone, taking certain medications (cardiac glycosides, quinidine, procainamide, propranolol, verapamil), rheumatic attack, myocarditis, congenital heart defects (atrial septal defect, patent ductus arteriosus). With narrow QRS complexes, the most likely level of blockade is the AV node. If the QRS complexes are wide, conduction disturbances are possible in both the AV node and the His bundle. Treatment see chap. 6, paragraph VIII.A.

3. 2nd degree AV block, Mobitz type I (with Wenckebach periodicity). Increasing prolongation of the PQ interval until the loss of the QRS complex. Causes: observed in healthy individuals, athletes, when taking certain medications (cardiac glycosides, beta-blockers, calcium antagonists, clonidine, methyldopa, flecainide, encainide, propafenone, lithium), with myocardial infarction (especially lower), rheumatic attack, myocarditis . With narrow QRS complexes, the most likely level of blockade is the AV node. If the QRS complexes are wide, disruption of impulse conduction is possible both in the AV node and in the His bundle. Treatment see chap. 6, paragraph VIII.B.1.

4. 2nd degree AV block type Mobitz II. Periodic loss of QRS complexes. PQ intervals are the same. Causes: almost always occurs against the background of organic heart damage. The delay of the impulse occurs in the His bundle. 2:1 AV block can be either Mobitz type I or Mobitz II: narrow QRS complexes are more typical for Mobitz type AV block I, wide QRS complexes are more typical for Mobitz type AV block II. With high degree AV block, two or more consecutive ventricular complexes are lost. Treatment see chap. 6, paragraph VIII.B.2.

5. Complete AV block. The atria and ventricles are excited independently of each other. The frequency of contractions of the atria exceeds the frequency of contractions of the ventricles. Same PP intervals and same RR intervals, PQ intervals vary. Causes: complete AV block can be congenital. The acquired form of complete AV block occurs with myocardial infarction, isolated disease of the cardiac conduction system (Lenegra's disease), aortic defects, taking certain medications (cardiac glycosides, quinidine, procainamide), endocarditis, Lyme disease, hyperkalemia, infiltrative diseases (amyloidosis, sarcoidosis ), collagenosis, trauma, rheumatic attack. Impulse conduction blockade is possible at the level of the AV node (for example, with congenital complete AV block with narrow QRS complexes), the His bundle, or the distal fibers of the His-Purkinje system. Treatment see chap. 6, paragraph VIII.B.

III. Determination of the electrical axis of the heart. The direction of the electrical axis of the heart approximately corresponds to the direction of the largest total vector of ventricular depolarization. To determine the direction of the electrical axis of the heart, it is necessary to calculate the algebraic sum of the QRS complex amplitude waves in leads I, II and aVF (subtract the amplitude of the negative part of the complex from the amplitude of the positive part of the complex) and then follow the table. 5.1.

A. Reasons for deviation of the electrical axis of the heart to the right: COPD. cor pulmonale, right ventricular hypertrophy, right bundle branch block, lateral myocardial infarction, left posterior branch block, pulmonary edema, dextrocardia, WPW syndrome. It happens normally. A similar picture is observed when electrodes are applied incorrectly.

B. Reasons for deviation of the electrical axis of the heart to the left: blockade of the anterior branch of the left bundle branch, inferior myocardial infarction, blockade of the left bundle branch, left ventricular hypertrophy, atrial septal defect of the ostium primum type, COPD. hyperkalemia. It happens normally.

B. Reasons for a sharp deviation of the electrical axis of the heart to the right: blockade of the anterior branch of the left bundle branch against the background of right ventricular hypertrophy, blockade of the anterior branch of the left bundle branch with lateral myocardial infarction, right ventricular hypertrophy, COPD.

IV. Analysis of teeth and intervals. ECG interval interval from the beginning of one wave to the beginning of another wave. ECG segment interval from the end of one wave to the beginning of the next wave. At a recording speed of 25 mm/s, each small cell on the paper tape corresponds to 0.04 s.

A. Normal 12-lead ECG

1. P wave. Positive in leads I, II, aVF, negative in aVR, can be negative or biphasic in leads III, aVL, V 1. V 2.

2. PQ interval. 0.120.20 s.

3. QRS complex. Width 0.06 0.10 s. Small Q wave (width< 0,04 с, амплитуда < 2 мм) бывает во всех отведениях кроме aVR, V 1 и V 2 . Переходная зона грудных отведений (отведение, в котором амплитуды положительной и отрицательной части комплекса QRS одинаковы) обычно находится между V 2 и V 4 .

4. ST segment. Usually on an isoline. In limb leads, depression of up to 0.5 mm and elevation of up to 1 mm are normally possible. In the chest leads, ST elevation up to 3 mm with a downward convexity is possible (early ventricular repolarization syndrome, see Chapter 5, paragraph IV.3.1.d).

5. T wave. Positive in leads I, II, V 3 V 6. Negative in aVR, V 1 . May be positive, flattened, negative, or biphasic in leads III, aVL, aVF, V 1 and V 2. Healthy young people have a negative T wave in leads V 1 V 3 (persistent juvenile type of ECG).

6. QT interval. Duration is inversely proportional to heart rate; usually fluctuates within 0.30 x 0.46 s. QT c = QT/ C RR, where QT c corrected QT interval; Normal QTc is 0.46 in men and 0.47 in women.

Below are some conditions, for each of which characteristic ECG signs are indicated. However, it must be borne in mind that ECG criteria do not have 100% sensitivity and specificity, so the listed signs can be detected separately or in different combinations, or be absent altogether.

1. High pointed P in lead II: enlargement of the right atrium. The amplitude of the P wave in lead II is > 2.5 mm (P pulmonale). Specificity is only 50%; in 1/3 of cases, P pulmonale is caused by left atrium enlargement. It is noted in COPD. congenital heart defects, congestive heart failure, ischemic heart disease.

2. Negative P in lead I

A. Dextrocardia. Negative P and T waves, inverted QRS complex in lead I without an increase in the amplitude of the R wave in the precordial leads. Dextrocardia can be one of the manifestations of situs inversus (reverse arrangement of internal organs) or isolated. Isolated dextrocardia is often combined with other congenital defects, including corrected transposition of the great arteries, pulmonary stenosis, ventricular and atrial septal defects.

b. The electrodes are not applied correctly. If the electrode intended for the left hand is applied to the right, then negative P and T waves and an inverted QRS complex with a normal location of the transition zone in the chest leads are recorded.

3. Deep negative P in lead V 1: enlargement of the left atrium. P mitrale: in lead V 1, the final part (ascending knee) of the P wave is widened (> 0.04 s), its amplitude is > 1 mm, the P wave is widened in lead II (> 0.12 s). It is observed with mitral and aortic defects, heart failure, myocardial infarction. The specificity of these signs is above 90%.

4. Negative P wave in lead II: ectopic atrial rhythm. The PQ interval is usually > 0.12 s, the P wave is negative in leads II, III, aVF. See chap. 5, paragraph II.A.3.

B. PQ Interval

1. Extending the PQ interval: 1st degree AV block. PQ intervals are the same and exceed 0.20 s (see Chapter 5, paragraph II.G.2). If the duration of the PQ interval varies, then 2nd degree AV block is possible (see Chapter 5, paragraph II.D.3).

2. Shortening the PQ interval

A. Functional shortening of the PQ interval. PQ< 0,12 с. Наблюдается в норме, при повышении симпатического тонуса, артериальной гипертонии, гликогенозах.

b. WPW syndrome. PQ< 0,12 с, наличие дельта-волны, комплексы QRS широкие, интервал ST и зубец T дискордантны комплексу QRS. См. гл. 6, п. XI.

V. AV - nodal or lower atrial rhythm. PQ< 0,12 с, зубец P отрицательный в отведениях II, III, aVF. см. гл. 5, п. II.А.5 .

3. Depression of the PQ segment: pericarditis. Depression of the PQ segment in all leads except aVR is most pronounced in leads II, III and aVF. Depression of the PQ segment is also observed in atrial infarction, which occurs in 15% of cases of myocardial infarction.

D. Width of the QRS complex

1. 0.100.11 s

A. Block of the anterior branch of the left bundle branch. Deviation of the electrical axis of the heart to the left (from –30° to –90°). Low R wave and deep S wave in leads II, III and aVF. Tall R waves in leads I and aVL. A small Q wave may be recorded. There is a late activation wave (R') in lead aVR. A shift of the transition zone to the left in the precordial leads is characteristic. It is observed in congenital defects and other organic lesions of the heart, and occasionally in healthy people. Does not require treatment.

b. Block of the posterior branch of the left bundle branch. Deviation of the electrical axis of the heart to the right (> +90°). Low R wave and deep S wave in leads I and aVL. A small Q wave may be recorded in leads II, III, aVF. It is noted in cases of ischemic heart disease. occasionally in healthy people. Occurs infrequently. It is necessary to exclude other causes of deviation of the electrical axis of the heart to the right: right ventricular hypertrophy, COPD. cor pulmonale, lateral myocardial infarction, vertical position of the heart. Complete confidence in the diagnosis can only be achieved by comparison with previous ECGs. Does not require treatment.

V. Incomplete blockade of the left bundle branch. Jagged R waves or the presence of a late R wave (R’) in leads V5. V 6. Wide S wave in leads V 1. V 2. Absence of the Q wave in leads I, aVL, V 5. V 6.

d. Incomplete blockade of the right bundle branch. Late R wave (R’) in leads V 1. V 2. Wide S wave in leads V5. V 6.

A. Right bundle branch block. Late R wave in leads V 1. V 2 with an oblique ST segment and a negative T wave. Deep S wave in leads I, V 5. V 6. Observed in organic heart lesions: cor pulmonale, Lenegra disease, ischemic heart disease. occasionally normal. Masked right bundle branch block: the shape of the QRS complex in lead V 1 corresponds to right bundle branch block, but in leads I, aVL or V 5. V 6 the RSR’ complex is recorded. This is usually caused by blockade of the anterior branch of the left bundle branch, left ventricular hypertrophy, and myocardial infarction. Treatment see chap. 6, paragraph VIII.E.

b. Left bundle branch block. Wide jagged R wave in leads I, V 5. V 6. Deep S or QS wave in leads V 1. V 2. Absence of the Q wave in leads I, V 5. V 6. It is observed with left ventricular hypertrophy, myocardial infarction, Lenegra disease, and coronary artery disease. sometimes normal. Treatment see chap. 6, paragraph VIII.D.

V. Blockade of the right bundle branch and one of the branches of the left bundle branch. The combination of a two-fascicle block with 1st degree AV block should not be regarded as a three-fascicle block: the prolongation of the PQ interval may be due to a slowdown in conduction in the AV node, and not a blockade of the third branch of the His bundle. Treatment see chap. 6, paragraph VIII.G.

d. Violation of intraventricular conduction. Widening of the QRS complex (> 0.12 s) in the absence of signs of right or left bundle branch block. It is observed with organic heart lesions, hyperkalemia, left ventricular hypertrophy, taking antiarrhythmic drugs of classes Ia and Ic, and with WPW syndrome. Usually does not require treatment.

D. Amplitude of the QRS complex

1. Low amplitude of teeth. Amplitude of the QRS complex< 5 мм во всех отведениях от конечностей и < 10 мм во всех грудных отведениях. Встречается в норме, а также при экссудативном перикардите, амилоидозе, ХОЗЛ. ожирении, тяжелом гипотиреозе.

2. High-amplitude QRS complex

A. Left ventricular hypertrophy

1) Cornell criteria:(R in aVL + S in V 3) > 28 mm in men and > 20 mm in women (sensitivity 42%, specificity 96%).

2) Estes criteria

ECG for sinus arrhythmia. Atrial escape rhythms

Sinus arrhythmia expressed in periodic changes in the R - R intervals by more than 0.10 seconds. and most often depends on the phases of breathing. An essential electrocardiographic sign of sinus arrhythmia is a gradual change in the duration of the R-R interval: the shortest interval is rarely followed by the longest.

Same as with sinus tachycardia and bradycardia, a decrease and increase in the R - R interval occurs mainly due to the T - P interval. Small changes in the P - Q and Q - T intervals are observed.

ECG of a healthy 30 year old woman. The duration of the R-R interval ranges from 0.75 to 1.20 seconds. The average rhythm frequency (0.75 + 1.20 sec./2 = 0.975 sec.) is about 60 per 1 min. Interval P - Q = 0.15 - 0.16 sec. Q - T = 0.38 - 0.40 sec. PI,II,III,V6 positive. Complex

QRSI,II,III,V6 type RS. RII>RI>rIII

Conclusion. Sinus arrhythmia. S-type ECG. probably a variant of the norm.

In a healthy heart ectopic centers of automaticity, including those located in the atria, have a lower rate of diastolic depolarization and, accordingly, a lower impulse frequency than the sinus node. In this regard, the sinus impulse, spreading throughout the heart, excites both the contractile myocardium and the fibers of specialized heart tissue, interrupting the diastolic depolarization of the cells of the ectopic centers of automaticity.

Thus, sinus rhythm prevents the manifestation of automaticity of ectopic centers. Specialized automatic fibers are grouped in the right atrium in its upper part in front, in the lateral wall of the middle part and in the lower part of the atrium near the right atrioventricular opening. In the left atrium, automatic centers are located in the superoposterior and inferoposterior (near the atrioventricular orifice) regions. In addition, automatic cells are present in the area of the orifice of the coronary sinus in the lower part of the right atrium.

Atrial automaticity(and the automatism of other ectopic centers) can manifest itself in three cases: 1) when the automatism of the sinus node decreases below the automatism of the ectopic center; 2) with increased automaticity of the ectopic center in the atria; 3) with sinoatrial block or in other cases of large pauses in atrial excitation.

Atrial rhythm can be persistent, observed for several days, months and even years. It can be transient, sometimes short-lived if, for example, it appears in long intercycle intervals with sinus arrhythmia, sinoatrial block and other arrhythmias.

A characteristic sign of atrial rhythm is a change in the shape, direction and amplitude of the P wave. The latter changes differently depending on the localization of the ectopic source of rhythm and the direction of propagation of the excitation wave in the atria. In atrial rhythm, the P wave is located in front of the QRS complex. In most variations of this rhythm, the P wave differs from the P wave of sinus rhythm in polarity (direction up or down from the baseline), amplitude, or shape in several leads.

Exception makes up the rhythm from the upper part of the right atrium (the P wave is similar to the sinus wave). It is important to distinguish the atrial rhythm that replaced the sinus rhythm in the same person in terms of heart rate, P-Q duration and greater regularity. The QRS complex is supraventricular, but may be aberrant when combined with bundle branch blocks. Heart rate from 40 to 65 per minute. With an accelerated atrial rhythm, the heart rate is 66 - 100 per minute. (a high heart rate is classified as tachycardia).