home Consultations Av blockade 1st degree on ecg treatment. What is AV block? Atrioventricular block: causes, symptoms, diagnosis and treatment. Clinical diagnostic criteria

Av blockade 1st degree on ecg treatment. What is AV block? Atrioventricular block: causes, symptoms, diagnosis and treatment. Clinical diagnostic criteria

A B heart block is a particular variant of impaired contractility of the heart muscle. At its core, this is a weakening or complete cessation of the conduction of an electrical impulse through the atrioventricular node.

Treatment is not always required. In the early stages, recovery is not carried out at all; dynamic observation is indicated.

As it progresses, drug therapy is prescribed. The duration of the full development cycle of the deviation is approximately 3-10 years.

Symptoms appear much earlier than the terminal phase. They are quite pronounced. Therefore, there is time for diagnosis and treatment.

All activities are carried out under the supervision of a cardiologist and, as necessary, related specialists.

The division is carried out on three grounds.

Depending on the nature of the flow:

Spicy. It is relatively rare and occurs as a result of severe external factors. Injuries, vomiting, sudden changes in body position, the course of somatic pathologies, all these are moments in the development of the process. Risks of cardiac arrest are greatest. Correction of the condition and stabilization of patients is carried out in a hospital setting, under the supervision of a group of doctors.
Chronic form. Diagnosed in every second case of the total number of AV blocks. It is a lightweight option. Manifestations are minimal, and the likelihood of death is also not high. Restoration is carried out as planned. Treatment is medicinal or surgical, depending on the stage.

According to the degree of impairment of the functional activity of fibers:

Complete AV block. There is no conduction of the electrical impulse from the sinus node to the atrioventricular node at all. The result is cardiac arrest and death. This is an emergency condition and can be treated in intensive care.
Partial blockade of the atrioventricular node. It occurs more easily and accounts for the majority of clinical cases. But we must remember that progression may be abrupt, but this is relatively rare.

It is possible to subdivide the process according to the duration of the flow:

Constant blockade. As the name suggests, it does not go away on its own.
Transient (transient). The duration of the episode is from a couple of hours to several weeks and even months.
Paroxysmal or paroxysmal. Duration about 2-3 hours.

Four degrees of severity

The generally accepted clinical classification is based on severity. Accordingly, there are 4 stages in the development of the process.

1st degree (mild)

It occurs against the background of other cardiac and extracardiac pathologies. Manifestations of the subjective plan are minimal or completely absent. At the level of diagnostic techniques, there are minor deviations in the ECG picture.

Recovery is possible within 6-12 months, but is not always required. Dynamic observation is indicated, and, if necessary, the use of medications.

2nd degree (medium)

It is further divided into 2 types, depending on electrocardiographic data.

AV block 2nd degree Mobitz 1 characterized by a gradual lengthening of the PQ interval. Symptoms are also uncharacteristic. Minimal manifestations occur that are practically unnoticeable if you do not overload the body. Provocative tests are quite informative, but can pose a danger to health and even life. Treatment is identical, with more emphasis on medication.
AV block 2nd degree Mobitz 2 is determined by the loss of ventricular complexes, which indicates incomplete contraction of cardiac structures. Because the symptoms are much brighter, it’s difficult not to notice them.

3rd degree (severe)

It is determined by pronounced deviations in the functioning of a muscular organ. Changes on the ECG are easy to detect, the manifestations are intense - an arrhythmia occurs, such as a slowdown in contractions.

Such signs do not bode well. Against the background of complex organic defects, weakening of hemodynamics, tissue ischemia occurs, and multiple organ failure is possible in the initial phase.

4th degree (terminal)

Determined by complete blockade, heart rate 30-50. As a compensatory mechanism, the ventricles begin to contract at their own rhythm, separate areas of excitation arise.

All cameras work in their own way, which leads to fibrillation and. The death of the patient is the most likely scenario.

Clinical classifications are used to identify a specific type of disease, stage, determine treatment tactics and diagnosis.

Causes of 1st degree AV block

These are mainly external factors. They can be eliminated by the patient himself, with rare exceptions.

Intense physical activity, excessive activity. There is such a thing as a sports heart. Conduction disorders are the result of the development of cardiac structures. Such causes account for up to 10% of all clinical situations. But such a diagnosis can be made after long-term observation and exclusion of organic pathologies.
Excess of medications. Cardiac glycosides, psychotropic drugs, calcium channel blockers, antispasmodics, muscle relaxants, narcotic analgesics, corticosteroids.
Violation of the processes of inhibition of the nervous system. A relatively harmless factor. Usually it is part of a symptom complex of a disease.

Causes of 2-3 degree blockade

Much more serious. Possible factors include:

Myocarditis. Inflammatory pathology of the muscular layers of an organ of infectious or autoimmune (less commonly) origin. Occurs as a consequence in most cases.

Treatment in a hospital, the clinical picture is clear. A terrible complication - destruction of the ventricles is determined in every tenth case.

Especially without special antibacterial and supportive effects.

Heart attack. Acute disturbance of trophism of cardiac structures. Occurs at any age, mainly in elderly patients. Also against the background of current ischemic heart disease, as a complication.

It ends with necrosis of cardiomyocytes (heart cells), replacement of active tissue with scar tissue. It is unable to contract and conduct a signal. Hence the AV block.

Depending on the extent, we can talk about the degree of severity. The more structures damaged, the more dangerous the consequences.

Rheumatism. Autoimmune process affecting the myocardium. The treatment is long-term, lifelong maintenance therapy is the result.

It is possible to slow down the destruction and prevent relapses, but complete relief is unlikely.

The neglected phenomenon ends with damage to the His bundles and conduction disturbances.

Ischemic disease. It is similar in nature to a heart attack, but the process does not reach a certain critical mass, since the blood supply still remains at an acceptable level. However, necrosis of the muscle layer will not take long to occur without treatment. This is the logical conclusion.

Coronary insufficiency. As a result of atherosclerosis with narrowing or occlusion of the corresponding arteries supplying cardiac structures. Manifestations occur in later stages. Blockade is one of the organic disorders. Read more about coronary insufficiency.

Cardiomyopathy. The generic name of a group of processes. Arises as a consequence of severe somatic pathologies.

The essence lies in dystrophy of the muscular layer of the heart. Contractility decreases, the signal is transmitted through damaged tissues worse than in the normal position.

Weakened hemodynamics, ischemia, multiple organ failure as a consequence. Types of cardiomyopathy, causes and treatment methods are described.

The presence of pathologies of the adrenal glands of the deficient type, the thyroid gland, and blood vessels, including the aorta, also affects.

Symptoms depending on the degree

The clinical picture depends on the stage of the pathological process.

Stage 1:

Manifestations are completely or mostly absent. The patient feels normal, there are no deviations in his vital functions.

Functional defects can be detected only by electrocardiography results. Often this is an accidental finding, discovered during a preventive examination of a person.

Mild shortness of breath is possible during intense physical activity (work, running, exhausting sporting events).

Attention:

First degree atrioventricular block is clinically favorable. If detected early, there is a chance of complete recovery without consequences.

Stage 2:

Chest pain of unknown origin. Occurs in most cases. This is a non-specific sign. The duration of the episode is no more than a few minutes.
Shortness of breath due to intense physical activity. She is not in a calm state.
Weakness, drowsiness, lack of performance. Apathy and reluctance to do anything are possible.
. Change in heart rate downwards. It is not yet threatening.

Stage 3:

Shortness of breath with little physical activity. Even with simple walking.
Headache. Determined by ischemic disorders in cerebral structures. The duration varies from a few minutes to hours and even days. It is necessary to differentiate from migraine.
Vertigo. Up to uncoordination of movements, inability to navigate in space.
Arrhythmia of several types at once. The slowdown in cardiac activity is accompanied by a change in the time intervals between contractions.
Fainting.
Lowering blood pressure to critical levels.
A sharp drop in heart rate.

All three symptoms presented above are included in the structure of the so-called. This is an emergency. It lasts a few minutes, but poses an enormous danger to life.

Injury, stroke, heart attack or cardiac arrest are possible. If this kind of manifestation occurs, surgical treatment is necessary, the essence of which is the implantation of a pacemaker.

Stage 4:

It is not always called. It is a variation of the previous one, but is characterized by even more severe symptoms. Massive organic disturbances are noted in all systems.

Death with 4th degree AV block becomes inevitable, it’s a matter of time. However, in order to trigger pathology in this way, you need to try and consciously ignore all the signals from your own body.

Diagnostic methods

Management of persons with abnormalities in the conduction of cardiac structures is under the supervision of a cardiologist. If the process is complicated and dangerous, consult a specialized surgeon.

An approximate survey scheme includes the following elements:

Questioning the patient about complaints, their age and duration. Objectification of symptoms and fixation.
Anamnesis collection. Including family history, determination of lifestyle, presence of bad habits and others. Aimed at early identification of the source of the problem.
Blood pressure measurement. Against the background of an advanced process, by the second stage, or even more so the third, jumps in blood pressure are likely. It is difficult to catch such a condition using routine techniques.
24-hour Holter monitoring. More informative way. Blood pressure and heart rate are assessed every half hour or more often, depending on the program. Can be performed repeatedly to improve accuracy.
Electrocardiography. Allows you to identify functional disorders of the heart. Plays a key role in early diagnosis.
EFI. Modified version of the previous survey. However, it is invasive. A special probe is inserted through the femoral artery. The activity of individual areas of cardiac structures is assessed. Quite a difficult study, but sometimes there are no alternatives to it.
Echocardiography. In order to identify organic disorders. The classic option as a result of a long course of blockade is cardiomyopathy of varying severity.
Blood analysis. For hormones, general and biochemical. For a comprehensive assessment of the state of the body, in particular the endocrine system and metabolism in general.

As necessary, if previous methods do not provide answers to questions, CT, MRI, coronography, and radioisotope studies are used. The decision is made by a group of leading specialists.

Variants of deviations on the ECG

Among the characteristic features:

Prolongation of the QT interval by more than 0.2 s. At the first stage this is a typical finding.
PQ extension. Changes in the frequency of occurrence of ventricular complexes. The so-called Mobitz 1.
Complete loss of contractions of the lower chambers of the heart. Or alternately, in a symmetrical order.
Decreased heart rate (bradycardia) of varying severity. Depends on the stage of the pathological process.

AV block is specifically noted on the ECG, and the more severe the phase, the easier it is to diagnose the problem.

Treatment depending on the degree

The therapy is complex.

1st degree.

Long-term follow-up is indicated. Such tactics can be repeated for more than one year. If there is no progression, gradually the frequency of consultations with a cardiologist becomes less frequent.

Against the background of deterioration, medications from several pharmaceutical groups are prescribed:

Antihypertensive drugs. Different types.
Antiarrhythmic.

If there is an inflammatory infectious pathology, antibiotics, NSAIDs and corticosteroids are used. Treatment is strictly in a hospital.

Transient 1st degree AV block (transient) is the only dangerous case requiring therapy, provided it is of viral or bacterial origin.

2nd degree

The same type of drugs are used. If the condition quickly worsens, there is no point in waiting. The installation of a pacemaker is shown.

Regardless of age. The only exception is older patients who may not be able to withstand surgery. The issue is resolved individually.

3-4 degrees

Implantation of an artificial pacemaker is mandatory. Once the terminal phase occurs, the chances of cure are minimal.

Throughout the entire period of therapy, lifestyle changes are indicated:

Quitting bad habits.
Diet (treatment table No. 3 and No. 10).
Adequate sleep (8 hours).
Walks, exercise therapy. The main thing is not to overwork. The duration is arbitrary.
Avoiding stress.

Traditional recipes can be dangerous, so they are not used.

Prognosis and possible complications

Typical consequences:

Heart failure. Resuscitation in such a situation is minimally effective; as soon as it is restored, the rhythm will change again. A relapse is likely within a few days.
Cardiogenic shock. Potentially fatal consequence. Moreover, death occurs in almost 100% of cases.
Fainting and, as a result, injury may be incompatible with life.
Heart attack or stroke. Acute malnutrition of cardiac structures and brain, respectively.
Vascular dementia.

Forecasts depend on the stage of the pathological process:

In the terminal phase, death is inevitable. Therapy is ineffective.

Radical surgery with the installation of a pacemaker significantly improves the prognosis.

Finally

Atrioventricular block is a disorder of conduction from the sinus node to the atria and ventricles. The result is total dysfunction of the muscular organ. The mortality rate is high, but there is enough time for treatment and diagnosis. This is encouraging.

anonymously

Good afternoon Please tell me. I am very concerned about the condition of my heart. 6 years ago I was admitted to the hospital with an attack of severe palpitations, they examined me, found nothing except mitral valve prolapse, and diagnosed me with “self-tophoric autonomic dysfunction with the axioms of supraventricular tachycardia.” Further, the condition was not very good, frequent attacks and fear, I went to many doctors, they assured me that there were no problems with my heart, I should go to a psychotherapist. But first they prescribed anaprilin, then concor to relieve the attacks. I drank them for a very short time, later I switched to obzidan, it helped better. Gradually, I partially coped with my fears and attacks and drank a quarter of obsidan only if something arose, rarely, rather to calm myself down. Then, for many months, I didn’t drink anything at all, I coped with it, and if attacks occurred, I endured them and they passed. At this stage I am pregnant, 20 weeks. Due to pregnancy, I was sent for an ECG, I have a terrible fear of these studies, since I have developed a phobia, and accordingly, when I enter the office, my pulse jumps terribly. Having seen 120 on the ecg and having learned about prolapse, I was sent for a consultation to a maternity hospital for heart patients. Why was it necessary to collect all the research again? I did an echo, the result: left atrium: PZR (Plax) 32 mm (N up to 40 mm), volume (A4ChV) 38 ml (N up to 60 ml); left ventricle: not dilated Cdr 45 mm (N up to 56 mm) cdr 27 mm (N up to 38 mm) cdr 93 ml (N up to 155) cdr 28 ml (N up to 75 ml); contractility of the left ventricular myocardium: no zones of asynergy were detected. Ejection fraction 70% (N >55%); LV diastolic function: not impaired. Right atrium: not dilated, volume (A4ChV) 32 ml (N up to 60 ml). Right ventricle: not dilated. Interatrial septum: intact. Interventricular septum: correct movement TMZH 9 mm (N 6-11 mm), LVTS 7 mm (N 6-11 mm); mitral valve: the leaflets are thin, mobile, movement in antiphase. The anterior leaflet of the mitral valve will expand into the vulgarity of the left atrium to 4.8 mm. Mitral regurgitation: 1st -2nd degree. Aortic valve: The valves are not sealed. Aortic root diameter 31 mm ((N 21-36 mm) amplitude of aortic valve opening 19 mm (N 15-26 mm) regurgitation: not determined. PSV 107 cm/sec (85-170 cm/sec) PeakGD 4.3 mm hg Tricuspid valve: leaflets are not sealed, movement is in antiphase. Tricuspid regurgitation grade 1. Pulmonary artery: not dilated. There are no signs of pulmonary hypertension. Pericardial and pleural effusion: not visualized. Echo conclusion: the heart chambers are not dilated, the global contractility of the left ventricle myocardium is satisfactory, no zones of local contractility disturbances have been identified, the indicators of systolic and diastolic functions of the left ventricle are normal. Mitral valve prolapse grade 1. Mitral regurgitation of 1-2 degrees. Tricuspid rugugitation stage 1. Holter: the main rhythm is sinus tachycardia, the average heart rate per day is 102 per minute. Transient 1st degree AV block with a max PQ of 0.24" during daytime rest. Maximum heart rate 171 per minute during exercise. Minimum heart rate 69 during night rest. 1 single supraventricular extrasystole was recorded. 2 single polymorphic polytopic early ventricular extrasystoles were registered. Analysis of temporary ( Time Domain) analysis of heart rate variability: sdnn - 82, mc- below normal: sdnn1-31 - below normal: rmssd - 12 - below normal: pnn50% - 0 - below normal Circadian index 1.20 (normal 1.24-1.44) , which indicates a normal circadian heart rate profile. Maximum QT interval 0.40. No diagnostically significant shift of the st segment was registered. Pauses (loss of QRS) for more than 2 seconds. No. Doctor, what can you say based on what you read? Nobody really listened to me in the cardio-maternity hospital , in 3 minutes they looked at these papers, didn’t like the blockade and wrote to give birth to them. I’m very scared, because I only made myself believe that I don’t have a heart pathology. But then why a special maternity hospital? I also read that such a blockade is caused by VSD, passes and is purely functional. Is it so? Are doctors simply playing it safe? Just based on what I read, I didn’t have any causes or illnesses before the blockade developed. How dangerous is all this during childbirth? Thank you very much in advance.

I will say that you have a severe neurotic disorder. I can’t imagine how to treat it (you can’t get away with drugs here), but you will drive everyone crazy - that’s for sure. I don’t see any special cardiac problems, except for the mention of “paroxysms of supraventricular tachycardia.” Transient 1st degree AV block did not impress me, this happens very often. With this you can give birth even in a barn. A good way out of the situation now would be verbal psychotherapy. The only problem is that this is not a very cheap pleasure.

anonymously

Thank you very much. Very calming. I know about nervous disorders and psychotherapy, and I’m trying to work on it. It’s just very difficult to concentrate on treating neurosis if you are made to doubt your physical health. The cardiologist at the maternity hospital was just confused by the transient 1st degree autoblockade and she said that childbirth in the maternity hospital was indicated for me with a cardiotype. For me, this sounded like a death sentence after a 6-year struggle with neurosis and at least some confidence that such conditions were really generated by my sick imagination and they were not dangerous. That is, if I understand correctly, this blockage came out, perhaps just once, on my halter and the doctor did not look into it and take responsibility since I was pregnant? It is very important for me to understand that this is not a real heart problem that has arisen that needs to be solved. As a layman in the field of medicine, I may not correctly interpret the words of doctors. After all, not everyone will delve into the peculiarities of my psyche and construct sentences in such a way that I would not consider it a serious illness. Perhaps if I had understood this, I would not have been so scared because of the increased pulse and would not have rushed to the hospital with such consequences for the nervous system. Sorry it's so confusing. Thank you again.

anonymously

What kind of certificate for pregnant women? In principle, I’m not working right now, if you meant sick leave. I was just very stressed by the conclusion of the maternity hospital. I was thinking of entering into a contract with a maternity hospital so that I could go with my husband, but that cardiac maternity hospital might close for cleaning just in time for my birth, and the second one, which will replace it, will close next. That is, I have either or for free, and neither one nor the other will enter into contact with me. And in others they simply don’t take you with such an entry in the exchange. That is, the only option is to go by ambulance and so be it. I was prescribed a repeat holter around 30 weeks. If this doesn’t come up there, they might still think again and set up a regular maternity hospital, or at least a maternity hospital at the hospital, and not just one, what do you think?

anonymously

Good afternoon I have already contacted you regarding transient 1st degree AV block. She told her story in detail and laid out all the studies: ECHO and holter at about 20 weeks of pregnancy. Now I’m almost 30 weeks pregnant and I had the Holter done again for a second consultation at the maternity hospital. Please comment. Very worried. Conclusion: During daily ECG monitoring, the main recorded rhythm was sinus, with a max heart rate of 145 per minute and a min heart rate of 92 per minute. The circadian index is reduced and amounts to 1.08. During the study period, a single ventricular extrasystole was recorded. No supraventricular rhythm disturbances were detected. No paroxysmal rhythm disturbances were registered. Fluctuations in AV conduction were 0.16-0.19 sec. No diagnostically significant pauses were identified. According to the indicators of heart rate variability, a constant and pronounced predominance of sympathetic influences on the heart rhythm is noted throughout the entire observation period (SDNN 48 ms). The dynamics of the ST segment against the background of tachycardial syndrome has a natural character of an oblique ascending type. No reliable ischemic dynamics of the ST segment were recorded. Please see the previous Holter and Echo to compare. I couldn’t figure out whether there was an AV block on this holter, but the reduced circadian index really scared me. I read horror stories about this on the Internet. Tell me, how serious is this? Or is this a one-time indicator that doesn’t mean anything. I am worried that I had a holter done on the day when I generally felt very bad: I had an upset stomach, my intestines were full, nausea at night and very poor sleep. The night before the installation of the device, I was also emotionally overloaded and slept little. Could this affect these circadian index values? I’m already afraid to go to the maternity hospital, what they will tell me there. Sorry for the confusion. Thank you in advance.

Atrioventricular block (hereinafter referred to as AV) is a type of blockage of the heart in which conduction between its atria and ventricles is disrupted. Under normal conditions, the sinus node in the atrium sets the pace, and these impulses travel downwards. With this disease, this impulse fails to reach the ventricles, or its intensity is weakened along the way.

The chambers of the heart have their own pacing mechanisms that are able to maintain a reduced heart rate in the absence of stimulation of the sinus node. In other words, it is a violation of the electrical conduction system of the heart muscle, as a result of which the activity of the organ is disrupted. The disease affects people regardless of gender and age category; signs can be observed even in newborns.

What happens in the body?

The heart beats using electrical impulses that follow a specific path. These tracts are sometimes grouped into specialized areas called ganglia and fascicles: together with fibers, they are responsible for the heartbeat and the speed at which it occurs. A defect along any of these paths can lead to heart block, but this does not mean that the lumen of the blood vessels is blocked and blood circulation in them stops.

Classification according to the degree of disease

First degree atrioventricular block: there is a slowdown in conduction between the atria and ventricles, but all beats are carried out;
AV block 2nd degree: some beats from the atrium are not conducted into the ventricles - electrical signals from the upper chamber of the heart do not reach the lower chamber, which leads to the so-called skipping of beats. In the second degree, there are 3 more subtypes: Mobitz type 1, Mobitz type 2 and incomplete.
AV block 3rd degree: beats occur in the atria and ventricles completely independently of each other. When this happens, the lower part of the heart cannot beat quickly or regularly enough to keep blood flowing to vital organs.

To learn more about what is happening inside the heart on an electrical level in order to develop a treatment plan based on the patient's needs, the cardiologist orders an ECG.

Causes

Even highly qualified trained athletes are susceptible to the occurrence of this pathology, but the only symptom of the pathology in them is a slow heartbeat. In this case, a large physical load on the myocardium acts as a predisposing factor.

A block that has existed for a long time cannot pose any threat. A sudden blockade can occur either due to a new heart problem or as a result of an existing, old one, therefore, the so-called risk group includes people who have:

previous heart attacks;
coronary heart disease;
infectious heart diseases such as endocarditis, pericarditis or myocarditis;
hereditary heart defect, called congenital;
physiological aging of the body;
strong stimulation of the vagus nerve.

Other causative factors include drugs that interfere with conduction:

beta blockers such as propranolol or pindolol;
calcium channel blockers, most often verapamil;
cardiac glycosides such as digoxin.

The disease can also develop as a result of electrolyte disturbances, cardiac surgery, and rheumatic inflammation. The cause of complete transverse atrioventricular heart block is toxic damage to the atrioventricular node, which occurs in the case of drug poisoning. In children, as they grow older, this can cause the formation of heart tumors, atherosclerotic plaques, or narrowing of the lumen of the vessels supplying the atrioventricular junction with blood and oxygen.

Symptoms

With 1st degree AV block, the signs are symptomatic and do not require any treatment. Second and third degree symptoms include a feeling of a slow heartbeat and fainting; Signs of low blood pressure or stroke rapidly increase. The person may feel dizzy, weak, and confused; he is deprived of the ability to exercise physical activity. Nausea, shortness of breath, and chest pain may be of concern to varying degrees of intensity.

As the disease progresses, blood flow inside the heart is disrupted, which leads to poor nutrition of the myocardium and other organs. The result of this is that a child with this diagnosis lags behind in physical and mental development. Atrioventricular block can cause complications such as heart failure.

In schoolchildren, this condition is accompanied by a thread-like pulse and blue lips. Systolic pause poses a threat to the child's life. The attacks develop simultaneously with weakness and inability to remain in an upright position. Fainting can occur due to psycho-emotional shock or physical exertion.

It should be noted that if the ventricles make more than 40 beats per minute, the manifestations of AV block are less pronounced and are reduced only to a feeling of excessive fatigue, weakness, drowsiness and shortness of breath. Episodes of bradycardia occur.

Diagnostics

With 3rd degree AV block, as a rule, signs such as loss of consciousness develop against the background of complete well-being; dizziness and sudden development of heart failure, which requires immediate medical attention. A physical examination confirms the presence of a block in the heart.

To exclude electrolyte disturbances, the patient must undergo a biochemical blood test. The second most important type of diagnosis is the study of the functional capacity of the thyroid gland to assess the level of its production of hormones. Changes in the heartbeat and visual display of electrical signals in the heart can be seen on an ECG - this is an informative type of study.

Neurological disorders such as mental excitability and behavioral disorders, as well as changes in intellectual functions, should attract attention.

Treatment with traditional medicine

The long-term effects of heart block depend on the underlying disease, so treatment for heart block must begin with eliminating the root cause. Initially, you need to obtain a referral for hospitalization from a cardiologist - only a specialist can make a diagnosis, prescribe and monitor a therapeutic program.

Monitoring the patient’s condition: this way the doctor will be able to track his vital signs, response to treatment and certain medications in particular.

Severe cases are considered only in cardiac surgery departments: electrical pacing is used to restore the heart rhythm.

Emergency assistance consists of intravenous administration of 1 ml of 0.1% atropine solution and taking isadrin tablets under the tongue.

Complete AV block due to myocarditis involves the inclusion of corticosteroids and cardiotropic drugs in the therapeutic program. The patient should absolutely not take glycosides and potassium supplements.

If the treatment does not bring the desired effect, frequent fainting occurs, the doctor may prescribe the installation of a pacemaker to temporarily solve the emergency problem. Implantation is also performed on a permanent basis - this is no less widespread. The congenital form of complete AV block does not require the use of medications because they do not provide a positive result. Children should be limited from physical work. In the case of constantly recurring attacks of asystole and bradycardia, only the installation of an artificial heart rate stimulator helps.

Treatment using traditional medicine methods

First of all, you need to get the approval of the supervising doctor, since the specialist is knowledgeable about the characteristics of your body and the course of the disease. In addition, the doctor has the results of the examination and can advise you on whether you need this or that folk remedy, or whether its use is strictly contraindicated.

If there are still no restrictions, then the following recipes will be effective:

Forecast

This depends on the severity of the dysfunction and the nature of the arrhythmia.

For a first-degree block, the prospects are good, since the violations are minor, the pathology at this stage remains undetected, and the patient himself does not complain. There is no need for treatment;
Second degree heart block does not always require treatment, but it is important to consult a specialist about further tactics aimed at preventing the disease from progressing to a more serious stage. If, as a result of a comprehensive examination, the cardiologist determines that the disorder is progressing, it may be necessary to install a pacemaker;
The third degree of heart block can lead to cardiac arrest, so the issue of installing a pacemaker is not considered - this is necessary at the life level.

Prevention of AV heart block

Treatment of existing cardiovascular diseases;
Timely contact with a pediatrician, cardiologist and/or therapist;
Lack of physical activity;
Annual medical examinations for the purpose of timely detection and treatment of cardiovascular diseases.

When the conduction of electrical impulses through the AV node is impaired, atrioventricular block develops, the degree of which can vary. Her ECG and clinical manifestations change accordingly. In most cases, the pathology does not cause a serious deterioration in well-being. It requires mandatory diagnosis using daily ECG monitoring.

Normally, the impulse generated in the sinus node travels along the atrial pathways, exciting the atria. Then it enters the atrioventricular (AV), that is, the atrioventricular node, in which its conduction speed drops sharply. This is necessary so that the atrial myocardium contracts completely and blood enters the ventricles. The electrical signal then travels to the ventricular myocardium, where it causes them to contract.

With pathological changes in the AV node caused by heart disease or tension in the autonomic nervous system, the passage of the signal through it slows down or stops altogether. A conduction block occurs from the atria to the ventricles. If the impulses still pass into the ventricular myocardium, this is an incomplete atrioventricular block.

A complete blockade, when the atria contract normally, but not a single impulse penetrates the ventricles, is much more dangerous for health. The latter are forced to “connect backup sources” of impulses lying below the AV connection. Such pacemakers operate at a low frequency (from 30 to 60 per minute). At this rate, the heart cannot provide the body with oxygen, and clinical signs of pathology arise, in particular, fainting.

The incidence of AV block increases with age. Complete blockade is observed mainly in people over 70 years of age, in 60% of men. It can also be congenital, and then the ratio of girls to boys is 3:2.

Classification of pathology

AV block is classified according to ECG signs that reflect electrical processes in the heart. There are 3 degrees of blockade. The 1st degree is accompanied only by a slowdown in the conduction of the impulse through the AV node.

1st degree AV block

With the 2nd degree of blockade, the signals are increasingly delayed in the AV node until one of them is blocked, that is, the atria are excited, but the ventricles are not. With the regular loss of every 3rd, 4th, and so on, contractions speak of AV block with Samoilov-Wenckebach periodicity or Mobitz-1 type. If the impulse block occurs irregularly, it is AV block without the specified periodicity or Mobitz-2 type.

AV block II degree, Mobitz type I (Samoilov-Wenckebach block)

With the loss of every 2nd complex, a picture of 2nd degree AV block appears with 2:1 conduction. The first digit in this regard indicates the number of sinus impulses, and the second - the number of signals transmitted to the ventricles.

Second degree AV block, Mobitz type II

Finally, if electrical signals from the atria do not travel to the ventricles, third degree atrioventricular block develops. It is characterized by the formation of replacement rhythms, causing the ventricles to contract, albeit slowly.

First degree blockade

All impulses emanating from the sinus node enter the ventricles. However, their conduction through the AV node is slow. In this case, the P-Q interval on the ECG is more than 0.20 s.

AV blockade, first degree

Second degree blockade

Atrioventricular block of the 2nd degree with Wenckebach periodicity is manifested on the ECG by a progressive lengthening of P-Q followed by the appearance of a single unconducted P-wave, resulting in a pause being recorded. This pause is shorter than the sum of any two consecutive R-R intervals.

An episode of Mobitz-11 type blockade usually consists of 3 to 5 contractions with the ratio of impulses generated and conducted into the ventricles as 4:3, 3:2, and so on.

The ventricles contract under the influence of the replacement rhythm, which is generated in the upper part of the His bundle, either in its legs, or in even smaller pathways. If the source of the rhythm is in the upper part of the His bundle, then the QRS complexes are no wider than 0.12 s, their frequency is 40 - 60 per minute. With an idioventricular rhythm, that is, formed in the ventricles, the QRS complexes have an irregular shape, they are widened, and the heart rate is 30 - 40 per minute.

Diseases associated with infiltration of the heart muscle by pathological tissues that impede conduction through the AV node:

sarcoidosis;

hypothyroidism;

hemochromatosis;

Lyme disease;

Systemic diseases can also affect the degree of AV conduction: ankylosing spondylitis and Reiter's syndrome.

Iatrogenic causes of AV block (related to medical intervention):

aortic valve replacement;

Aortic valve replacement

surgeries for hypertrophic cardiomyopathy;

correction of congenital heart defects;

some medications: digoxin, beta blockers, adenosine and other antiarrhythmics.

Symptoms

Clinical signs of atrioventricular block depend on its degree.

With a 1st degree block, there are no symptoms, and conduction disturbances are detected only on an ECG. In addition, it can occur exclusively at night.

2nd degree blockade is accompanied by a feeling of interruptions in the heart. With complete AV block, the patient experiences weakness, dizziness, fainting, and a rare heartbeat.

The patient also experiences symptoms of the underlying disease (chest pain, shortness of breath, swelling, instability of blood pressure, and others).

Treatment

AV block is not a disease, but only one of the manifestations of any cardiac pathology. Therefore, therapy begins with treatment of the underlying disease (myocardial infarction, etc.).

First degree AV block and asymptomatic second degree block do not require treatment. You just need to stop using medications that worsen AV conduction.

If atrioventricular block on the ECG is accompanied by signs of oxygen starvation of the brain, medical attention is needed.

A remedy for quickly accelerating heart rate, but it is not always effective. In these cases, temporary cardiac pacing is used.

Treatment of third degree atrioventricular block consists of: Depending on the type of blockade, atrial-dependent ventricular pacing or on-demand ventricular pacing may be used.

In the first case, the device is adjusted in such a way that contraction of the atria is artificially carried out to the ventricles. In the second, the stimulator impulse is applied directly to the ventricular myocardium, causing them to contract rhythmically at the desired frequency.

Forecast

This conduction disorder can cause the following complications:

sudden death due to cardiac arrest or ventricular tachycardia;

cardiovascular failure with fainting, exacerbation of coronary artery disease or congestive heart failure;

head or limb injuries during...

When a pacemaker is implanted, all these unpleasant consequences are eliminated.

Scientists have shown that first-degree AV block is associated with an increased risk of heart failure, the need for pacing, heart failure, and mortality from all causes.

With congenital AV block, the prognosis depends on the heart defect that caused the disorder. With timely surgical intervention and implantation of a pacemaker, the child grows and develops normally.

About what AV block is, symptoms, complications, watch this video:

Prevention

Prevention of AV block is associated with general measures to prevent heart disease:

healthy eating;

maintaining normal weight;

daily physical activity;

control blood pressure, cholesterol and blood sugar levels;

cessation of alcohol abuse and smoking.

Patients with 1st degree blockade should avoid medications that worsen AV conduction, primarily beta blockers (, atenolol, metoprolol and others).

Secondary prevention of blockade complications is the timely installation of a pacemaker.

Atrioventricular block is a violation of the conduction of impulses from the atria to the ventricles. In mild cases it is asymptomatic. However, the 3rd degree of such blockade can lead to fainting and injury, as well as complicate the course of cardiac pathology. The main treatment method for advanced AV block is. This device causes the heart to work in a normal rhythm, and all manifestations of conduction disorders disappear.

What is a cardiogram

A cardiogram is a recording on a special film of electrical impulses produced by the myocardium. This recording allows you to judge the condition of the heart and diagnose various pathologies:

conduction disorders of the heart muscle - blockade;
disturbances in the rhythm of heart contractions - arrhythmias;
myocardial deformation - ischemia, necrosis (infarction).

To decipher the electrocardiogram, certain symbols have been created. With their help, they describe the function of the atria and ventricles of the heart, the state of the conduction nodes and the myocardium itself. By assessing all elements of the cardiogram, the specialist gives an opinion about the condition of the heart.

Knowing the symbols, a specialist can decipher any cardiogram

How is an ECG performed?

There are some rules for conducting an electrocardiographic study. An ECG can be performed at any age and with any concomitant pathology. The procedure has no contraindications.

The study is carried out using a cardiograph apparatus. In hospitals there are large devices, emergency doctors use portable portable cardiographs. It is arranged as follows:

the main part that analyzes incoming electrical impulses;
a recording device that records electrical impulses as a curve on paper film;
electrodes applied to the anterior surface of the chest and to the limbs.

While taking the cardiogram, the patient is in a supine position. He is warned to remove all metal jewelry, watches and other metal objects. The places where the electrodes will be placed are moistened with water. This is necessary for better connection of the electrode to the skin and conduction of the impulse.

There are certain points on the body for applying electrodes

There are standard points for applying electrodes - one is applied to the limbs, and eight electrodes are applied to the front surface of the chest. Standard leads are removed from the limbs to form Einthoven's triangle. Additional chest leads are removed from the chest, allowing the localization of the pathology to be more accurately determined. If there is an emergency need to take a cardiogram, use only standard limb leads.

An electrode with a red mark is applied to the right hand.
On the left hand - yellow.
On the left leg - green.
On the right leg - black, which is grounding.

What is AV block

The reason for this is a dysfunction of the atrioventricular node, which transmits electrical impulses through itself. Its function may be impaired due to a number of conditions: pathology of the parasympathetic nervous system, long-term use of certain cardiac drugs (glycosides, beta blockers), organic damage - fibrosis or inflammation of this area of the myocardium.

Causes of AV blocks

Various conditions can cause disruption of the conduction of electrical impulses in the heart tissue. They can be functional - that is, without changes in the heart tissue. There are also organic causes - with some kind of deformation of cardiomyocytes.

Functional reasons include the following:

long-term use of heart medications;
disruption of the innervation of the heart;
sometimes blockades occur in athletes as an adaptive reaction.

Organic causes include:

insufficient blood supply to cardiomyocytes and their ischemia;
replacement of a section of cardiac tissue with connective tissue;
formation of necrosis of cardiomyocytes.

Types of blockade on a cardiogram

Depending on how many impulses this node is capable of transmitting, three degrees of blockade are distinguished. On the ECG, all degrees manifest themselves with their own symptoms.

At grade 1, the duration of the PQ interval is more than 200 ms. The correct heart rhythm is maintained.

With first-degree AV block, a persistently prolonged PQ interval is observed.

For grade 2, there are two options. The first type, or Mobitz block 1 (Wenckebach period), is characterized by a gradual lengthening of the PQ interval with each heartbeat; at the end of the period, the ventricular complex (QRS) drops out and the period begins again. The second type, or Mobitz 2, is characterized by sudden loss of the ventricular complex. The PQ interval can be of normal duration all the time or increased all the time.

The second degree of AV block is characterized by a gradual prolongation of the PQ interval followed by loss of the ventricular complex

At grade 3, there is a complete cessation of impulse transmission to the ventricles. The atria and ventricles contract at different rhythms. Complete AV block - an ECG at this degree shows the superposition of waves of atrial contractions on the waves of ventricular contractions. The P waves and QRS complexes are randomly distributed.

With the third degree of AV block, complete separation of the rhythm of contractions of the atria and ventricles is visible

For each degree of blockade, there are its own varieties, which have distinctive features on the cardiographic film.

First degree AV block comes in the following forms:

nodular form - only pathological prolongation of the PQ interval is observed;
atrial form - in addition to PQ elongation, a deformed P wave can be detected;
the distal form is characterized by a long PQ and deformation of the QRS complex.

In the second degree, the above-described forms are distinguished (Mobitz 1 and Mobitz 2). Two more forms are observed less frequently:

blockade 2:1 - periodic loss of ventricular contractions is observed (every second);
progressive form - several ventricular complexes may fall out in a row, without a specific sequence.

With the third degree, two forms are noted:

proximal - separation of the rhythm of contractions of the atria and ventricles, the QRS complex is not deformed;
distal - there is uncoordinated contraction of the ventricles and atria, the ventricular complex is deformed and widened.

There are also clinical syndromes that are a combination of AV block with other pathologies:

Frederick's syndrome - signs of this condition include fixation of F or f waves on the cardiogram, which indicate atrial fibrillation or flutter;
with MAS (Morgagni-Adams-Stokes) syndrome, periods of ventricular asystole are detected on the ECG.

Clinical manifestations of different degrees

AV block can be transient (quickly passing) or permanent. Transient blockades are quite difficult to diagnose. To detect them, Holter monitoring is required - recording a cardiogram throughout the day.

With first degree atrioventricular block there are no obvious clinical manifestations. The only symptom is bradycardia. Some patients may feel weak and fatigued.

A more pronounced clinical picture is observed in the second degree:

palpation can detect periodic loss of the pulse wave;
clinically, this will manifest itself as the patient’s feeling of interruptions in the functioning of the heart;
patients also feel weak and tired.

The most dangerous is the third degree of blockade:

periodic or constant dizziness;
ringing in the ears, flickering of spots before the eyes;
pain behind the sternum;
a feeling of interruptions in the work of the heart;
episodes of loss of consciousness.

When listening to the heart with a stethoscope, you can hear the correct rhythm, but with the appearance of long pauses, this is a loss of ventricular contraction. Bradycardia of varying severity is noted. A cannon heart sound, characteristic of blockades, appears, called Strazhesko's sound.

A complication of blockades can be ventricular tachycardia leading to asystole. With MAS syndrome, observed in conjunction with this blockade, attacks of ventricular asystole may also occur, threatening rhythm disruption and cessation of cardiac activity.

Treatment

Treatment of AV blockade consists of prescribing drugs to improve myocardial conduction and eliminate the underlying disease. In case of severe blockade, installation of an artificial pacemaker is required.

A first degree block does not require special treatment. Only observation of the patient and periodic Holter monitoring are indicated to determine the dynamics of the development of blockades.

In the second degree, the use of medications, for example, Corinfar, is indicated. The patient is also monitored.

A necrotic or fibrotic area of the myocardium can no longer be restored. In this case, first a course of beta-adrenergic agonists is administered, and then a pacemaker is implanted.

Treatment of 1st degree AV block: what is important to remember?

1st degree AV block is classified as a cardiovascular disease. It is characterized by the presence of fairly extensive symptoms, which allows the patient to determine it independently. Treatment of 1st degree AV block should be performed in a hospital setting by experienced specialists.

What is 1st degree AV block?

Arntioventricular block is a disease that disrupts the transmission of nerve impulses to the conduction system of the heart.

The disease may be transverse

The disease may have a transverse form, which is characterized by a disorder, since the Ashofa-Tavara node is affected.

With longitudinal blockade, conduction is also impaired. Arntioventricular block occurs with an increase in the PQ interval, more than 0.2 s. It is diagnosed in 0.5 percent of young patients.

In this case, there are no signs of heart disease. This disease can also occur in elderly patients. The most common cause of its appearance at this age is an isolated disease of the conduction system.

The most common disorder is at the level of the AV node. There is also a decrease in the AV node itself. 1st degree AV block can be chronic, which requires constant monitoring of the patient, as well as the use of certain treatment methods.

This pathological condition is very often observed in coronary heart diseases: ischemia or myocardial infarction.

The cause of atrioventricular block in isolated diseases of the cardiac conduction system. These diseases include Lev's disease or Lenegra's disease.

Find out what AV block is in this video.

Reasons for the development of the disease

There are a huge number of reasons due to which this pathological condition occurs.

Atrioventricular block may occur while taking certain medications:

Deta-blockers;
Certain calcium antagonists;
Digoxin;
Antiarrhythmic drugs that have quinidine action.

With congenital heart defects, in most cases, AV block is observed, the diagnosis of which is very often carried out during the course of lupus in females. If the patient experiences transposition of the great arteries, this can lead to atrioventricular block.

Also, the cause of this pathological condition is defects in the interatrial septa.

In most cases, the development of the disease is observed in myocardial diseases:

AV block is observed in myocarditis

The development of pathology can be observed with myocarditis, infective endocarditis, which belong to the category of inflammatory diseases.

With metabolic disorders: hyperkalemia and hypermagnesemia, the development of atrioventricular block is observed. In primary adrenal insufficiency, this process can also be observed.

The cause of atrioventricular block is very often damage to the AV node, which occurs as a result of surgical intervention in the heart, catheterization of the organ, irradiation of the mediastinum, catheter destruction.

The presence of tumors, namely melanoma, mesothelioma, rhabdomyosarcoma, lymphogranulomatosis, can also contribute to the development of AV block.

There are several neurogenic reasons why the pathological condition may appear. These include vasovagal reactions. The disease can also occur as a result of carotid sinus syndrome.

With atrophic myotonia, which belongs to the category of neuromuscular diseases, the development of the disease can also be observed.

Atrioventricular block is a fairly serious pathological process occurring in the heart. It can appear as a result of the development of various diseases and pathologies.

Clinical manifestations of the disease

In most cases, atrioventricular block practically does not manifest itself at the first stage. But in some patients it manifests itself very accurately. This is explained by the fact that it is accompanied by symptoms of the diseases as a result of which it occurs. In young patients this is a normal physiological phenomenon.

The level of conduction disturbance directly affects AV block

The level of conduction disturbance directly affects the nature of AV block. The severity and etiology of the disease that causes it also affects the manifestation of symptoms. There are no clinical manifestations of blockade, the development of which is observed at the level of the atrioventricular node.

As a result of their development, patients very often develop bradycardia, which is their main symptom. If bradycardia is pronounced, then atrioventricular block is accompanied by signs of this disease.

In this case, patients complain of weakness, shortness of breath and even angina attacks. This is explained by a small heart rate and a drop in cardiac output.

As this disease develops, patients experience reduced cerebral blood flow, which leads to dizziness. Their peculiarity is that a person feels confusion.

Determining atrioventricular block in most cases is quite difficult due to the lack of symptoms. But in some cases this can be done. When the first symptoms of the disease appear, it is imperative to seek help from a doctor.

Treatment of 1st degree AV block

Treatment of 1st degree AV block consists of constant doctor monitoring of the patient only if it occurs without symptoms. If the pathological condition appears as a result of taking certain medications, then their dose is adjusted or completely discontinued. Very often, the pathology is caused by cardiac glycosides, B-blockers, and antiarrhythmic drugs.

Atrioventricular block occurs as a result of myocardial infarction

Atrioventricular block, which has a cardiac origin and occurs as a result of the development of myocardial infarction, cardiosclerosis, myocarditis, etc., requires the use of B-agonists for treatment. Most often, patients are prescribed Isoprenaline, Orciprenaline and their analogues. After completing the course of medication, a pacemaker is implanted.

In order to prevent a Morgana-Adams-Stokes attack, subvaginal use of Izadrin is carried out. Atropine can also be administered subcutaneously or intravenously. If a patient is diagnosed with congestive heart failure, then they are prescribed cardiac glycosides, diuretics, and vasodilators.

The first of the medications must be taken as carefully as possible. If the patient has a chronic form of atrioventricular block, then this requires the use of symptomatic therapy. Most often in this case, Belloid, Teopek, Corinfar are prescribed.

If all of the above treatment methods are ineffective, then drastic methods are used.

They are committed to installing an electrical pacemaker, with the help of which the normal rhythm and heart rate are restored. If a patient has Morgan-Adams-Stokes attacks, then he must undergo implantation of an endocardial pacemaker.

This procedure is also performed when:

Arterial hypertension;
Congestive heart failure;
Angina pectoris with complete AV block.

If the patient has a ventricular rate of less than forty per minute, then he must undergo the procedure.

Treatment of atrioventricular block involves the use of drug therapy. If it is ineffective, surgical intervention is used.

Features of treatment for children

According to statistics, atrioventricular block in children occurs in 12 percent of cases. At this age, the disease very often progresses in children. The cause of fetal AV is a developmental pathology inside the mother's womb.

The baby's fetus can be affected by various infections

Very often, fetal damage occurs as a result of various infections: streptococci, staphylococci, chlamydia, etc. In some cases, the disease occurs as a result of a genetic predisposition. If surgery is performed to correct heart defects, this can also lead to atrioventricular block.

Children who develop this disease become tired very quickly. Young patients who can speak complain of headaches and pain in the heart area. In some cases, children may experience lack of concentration. When exercising, the child experiences shortness of breath. He becomes very weak. If the baby is critically ill, an artificial pacemaker is implanted.

Treatment of atrioventricular block in children directly depends on its causes. Most often, in the first stage of the disease, no treatment is performed. Most often, children are treated using drug therapy.

The use of a particular drug depends on the clinical course of the disease and the individual characteristics of the patient.

Atrioventricular block in children is diagnosed very often. If this disease does not progress and does not have concomitant diseases, then the child is simply monitored. Otherwise, medications or surgery are used.

Is the use of traditional medicine effective?

Treatment of atrioventricular block in the first degree can be done using traditional medicine. Very often, ordinary egg yolks are used to treat pathology.

Traditional medicine offers various recipes

To prepare the medicine, you need to boil 20 eggs, separate the yolks from them, put them on a plate and add olive oil to them.

The resulting product must be simmered in the oven for 20 minutes. After this time, the product is cooled and placed in the refrigerator. Take the medicine 1 tsp. a day before meals. At the end of the ten-day course of treatment, you must take the same break. After this, the course is repeated.

Very often, heart block can be treated with rose hips. In order to prepare the medicine, you need to take its fruits in the amount of 5 tablespoons. They fit in half a liter of water. Boiled fruits are kneaded with honey and poured into the resulting decoction. It is necessary to take the medicine before meals, a quarter glass, which will lead to an improvement in the condition.

Valerian roots can also be used to treat the disease. Traditional medicine is taken before meals. A single dose of the drug is one tablespoon. This medicine is characterized by a calming effect, which restores the functioning of the cardiovascular system.

Also, treatment of atrioventricular block can be carried out using horsetail. This remedy is characterized by a beneficial effect on the functioning of the heart and blood vessels. To prepare the medicine, you need to take two teaspoons of chopped herbs and pour a glass of boiling water. The medicine must be infused for 15 minutes. The folk remedy is taken every two hours. A single dose of the drug is two teaspoons.

Atrioventricular block is a fairly serious heart disease, which is characterized by the presence of three stages. At the first stage of the disease, which is characterized by rather sparse symptoms, the patient is mainly monitored. If complications occur, medication or surgery is performed.

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Comments (1) to the material “Treatment of 1st degree AV block: what is important to remember?”

To more accurately determine this heart disease, in addition to an electrocardiogram, you can examine the heart using the Holter method. I walked with such a device the whole day and recorded all the loads.

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Atrioventricular block

Atrioventricular (atrioventricular) block (AV block) is a disorder of conduction function, expressed in slowing down or stopping the passage of an electrical impulse between the atria and ventricles and leading to a disorder of heart rhythm and hemodynamics. AV block may be asymptomatic or accompanied by bradycardia, weakness, dizziness, attacks of angina and loss of consciousness. Atrioventricular block is confirmed using electrocardiography, Holter ECG monitoring, and EPI. Treatment of atrioventricular block can be medication or cardiac surgery (implantation of a pacemaker).

Atrioventricular block

The basis of atrioventricular block is the slowing down or complete cessation of the passage of the impulse from the atria to the ventricles due to damage to the AV node itself, the His bundle or the branches of the His bundle. Moreover, the lower the level of damage, the more severe the manifestations of the blockade and the more unsatisfactory the prognosis. The prevalence of atrioventricular block is higher among patients suffering from concomitant cardiac pathology. Among people with heart disease, I degree AV block occurs in 5% of cases, II degree - in 2% of cases, III degree AV block usually develops in patients over 70 years of age. Sudden cardiac death, according to statistics, occurs in 17% of patients with complete AV block.

The atrioventricular node (AV node) is part of the conduction system of the heart, providing sequential contraction of the atria and ventricles. The movement of electrical impulses coming from the sinus node is slowed down in the AV node, allowing the atria to contract and pump blood into the ventricles. After a short delay, the impulses spread along the His bundle and its legs to the right and left ventricles, promoting their excitation and contraction. This mechanism ensures alternate contraction of the atria and ventricles myocardium and maintains stable hemodynamics.

Classification of AV blocks

Depending on the level at which the disturbance of electrical impulse conduction develops, proximal, distal and combined atrioventricular blockades are distinguished. With proximal AV blockade, impulse conduction may be disrupted at the level of the atria, AV node, and His bundle branch; at distal – at the level of the branches of the His bundle; with combined ones, multi-level conduction disturbances are observed.

Taking into account the duration of development of atrioventricular block, it is divided into acute (with myocardial infarction, drug overdose, etc.), intermittent (intermittent - with ischemic heart disease, accompanied by transient coronary insufficiency) and chronic forms. According to electrocardiographic criteria (slowness, periodicity, or complete absence of impulse conduction to the ventricles), three degrees of atrioventricular block are distinguished:

I degree - atrioventricular conduction through the AV node is slowed down, but all impulses from the atria reach the ventricles. Clinically not recognized; on the ECG the P-Q interval is prolonged > 0.20 seconds.
II degree – incomplete atrioventricular block; not all atrial impulses reach the ventricles. The ECG shows periodic loss of ventricular complexes. There are three types of second-degree AV block according to Mobitz:

Mobitz type I - the delay of each subsequent impulse in the AV node leads to a complete delay of one of them and loss of the ventricular complex (Samoilov-Wenckebach period).

Mobitz type II - critical impulse delay develops suddenly, without a previous prolongation of the delay period. In this case, the absence of conduction of every second (2:1) or third (3:1) impulse is noted.

III degree - (complete atrioventricular block) - complete cessation of the passage of impulses from the atria to the ventricles. The atria contract under the influence of the sinus node, the ventricles contract at their own rhythm, less than 40 times per minute, which is not enough to ensure adequate blood circulation.

Atrioventricular blocks of the 1st and 2nd degrees are partial (incomplete), blockades of the 3rd degree are complete.

Reasons for the development of AV blockades

According to etiology, functional and organic atrioventricular blockades are distinguished. Functional AV blockades are caused by an increase in the tone of the parasympathetic nervous system. Atrioventricular block of the first and second degrees is observed in isolated cases in young physically healthy individuals, trained athletes, and pilots. It usually develops during sleep and disappears during physical activity, which is explained by increased activity of the vagus nerve and is considered a normal variant.

AV blockades of organic (cardiac) origin develop as a result of idiopathic fibrosis and sclerosis of the conduction system of the heart in various diseases. The causes of cardiac AV blockades can be rheumatic processes in the myocardium, cardiosclerosis, syphilitic heart disease, interventricular septal infarction, heart defects, cardiomyopathies, myxedema, diffuse connective tissue diseases, myocarditis of various origins (autoimmune, diphtheria, thyrotoxic), amyloidosis, sarcoidosis, hemochromatosis oz , heart tumors, etc. With cardiac AV blockade, a partial blockade may initially be observed, however, as cardiac pathology progresses, a third-degree blockade develops.

Various surgical procedures can lead to the development of atrioventricular blockade: aortic valve replacement, plastic surgery of congenital heart defects, atrioventricular RFA of the heart, catheterization of the right side of the heart, etc.

Quite rarely in cardiology, a congenital form of atrioventricular block occurs (1: newborns). In the case of congenital AV block, there is an absence of sections of the conduction system (between the atria and the AV node, between the AV node and the ventricles, or both branches of the His bundle) with the development of the corresponding level of block. In a quarter of newborns, atrioventricular block is combined with other congenital cardiac anomalies.

Among the causes of the development of atrioventricular blockades, intoxication with drugs is often found: cardiac glycosides (digitalis), β-blockers, calcium channel blockers (verapamil, diltiazem, less commonly Corinfar), antiarrhythmics (quinidine), lithium salts, some other drugs and their combinations.

Symptoms of AV block

The nature of the clinical manifestations of atrioventricular block depends on the level of conduction disturbance, the degree of blockade, etiology and severity of concomitant heart disease. Blockades that have developed at the level of the atrioventricular node and do not cause bradycardia do not manifest themselves clinically. The clinical picture of AV block with this topography of disorders develops in cases of severe bradycardia. Due to low heart rate and a drop in cardiac output during physical activity, such patients experience weakness, shortness of breath, and sometimes angina attacks. Due to decreased cerebral blood flow, dizziness, transient sensations of confusion, and fainting may occur.

With second degree atrioventricular block, patients feel a loss of the pulse wave as interruptions in the heart area. With type III AV block, Morgagni-Adams-Stokes attacks occur: a decrease in heart rate to 40 or less beats per minute, dizziness, weakness, darkening of the eyes, short-term loss of consciousness, pain in the heart, cyanosis of the face, and possibly convulsions. Congenital AV block in patients of childhood and adolescence can be asymptomatic.

Complications of AV block

Complications from atrioventricular blockade are mainly caused by a pronounced slowdown in rhythm that develops against the background of organic heart damage. Most often, the course of AV block is accompanied by the appearance or worsening of chronic heart failure and the development of ectopic arrhythmias, including ventricular tachycardia.

The course of complete atrioventricular block may be complicated by the development of Morgagni-Adams-Stokes attacks associated with cerebral hypoxia as a result of bradycardia. The onset of an attack may be preceded by a feeling of heat in the head, attacks of weakness and dizziness; During an attack, the patient turns pale, then cyanosis and loss of consciousness develop. At this point, the patient may require chest compressions and mechanical ventilation, since prolonged asystole or the addition of ventricular arrhythmias increases the likelihood of sudden cardiac death.

Repeated episodes of loss of consciousness in elderly patients can lead to the development or worsening of intellectual-mnestic disorders. Less commonly, with AV blockade, the development of arrhythmogenic cardiogenic shock is possible, more often in patients with myocardial infarction.

In conditions of insufficient blood supply during AV blockade, phenomena of cardiovascular failure (collapse, fainting), exacerbation of coronary heart disease, and kidney diseases are sometimes observed.

Diagnosis of AV blocks

When assessing the patient's medical history in case of suspected atrioventricular block, the fact of past myocardial infarction, myocarditis, other cardiopathologies, and taking medications that interfere with atrioventricular conduction (digitalis, β-blockers, calcium channel blockers, etc.) is ascertained.

When auscultating the heart rhythm, a correct rhythm is heard, interrupted by long pauses, indicating loss of ventricular contractions, bradycardia, and the appearance of Strazhesko's cannon I tone. An increase in pulsation of the neck veins is determined compared to the carotid and radial arteries.

On the ECG, first degree AV block is manifested by a prolongation of the P-Q interval > 0.20 seconds; II degree - sinus rhythm with pauses, as a result of loss of ventricular complexes after the P wave, the appearance of Samoilov-Wenckebach complexes; III degree – a decrease in the number of ventricular complexes by 2-3 times compared to atrial complexes (from 20 to 50 per minute).

Carrying out 24-hour Holter ECG monitoring for AV blockade allows one to compare the patient’s subjective sensations with electrocardiographic changes (for example, fainting with sudden bradycardia), assess the degree of bradycardia and blockade, the relationship with the patient’s activity, medication intake, determine the presence of indications for pacemaker implantation, etc.

Using an electrophysiological study of the heart (EPS), the topography of AV block is clarified and indications for its surgical correction are determined. If there is concomitant cardiac pathology and to identify it during AV block, echocardiography, MSCT or cardiac MRI is performed.

Additional laboratory tests for AV blockade are indicated in the presence of concomitant conditions and diseases (determination of the level of electrolytes in the blood during hyperkalemia, the content of antiarrhythmics in case of their overdose, enzyme activity during myocardial infarction).

Treatment of AV blocks

With first degree atrioventricular block that occurs without clinical manifestations, only dynamic observation is possible. If AV block is caused by taking medications (cardiac glycosides, antiarrhythmic drugs, β-blockers), dose adjustment or complete discontinuation is necessary.

In case of AV blockades of cardiac origin (myocardial infarction, myocarditis, cardiosclerosis, etc.), a course of treatment with β-adrenergic stimulants (isoprenaline, orciprenaline) is carried out, and then implantation of a pacemaker is indicated.

First aid drugs for the relief of Morgagni-Adams-Stokes attacks are isoprenaline (sublingual), atropine (intravenous or subcutaneous). For symptoms of congestive heart failure, diuretics, cardiac glycosides (with caution), and vasodilators are prescribed. As symptomatic therapy for the chronic form of AV blockade, treatment is carried out with theophylline, belladonna extract, and nifedipine.

A radical method of treating AV block is the installation of an electrical pacemaker (pacemaker), which restores normal rhythm and heart rate. Indications for implantation of an endocardial pacemaker are a history of Morgagni-Adams-Stokes attacks (even a single one); ventricular rate less than 40 per minute and periods of asystole of 3 or more seconds; AV block II degree (Mobitz type II) or III degree; complete AV block, accompanied by angina pectoris, congestive heart failure, high arterial hypertension, etc. To decide on surgery, consultation with a cardiac surgeon is necessary.

Forecast and prevention of AV blocks

The influence of developed atrioventricular block on the patient’s future life and ability to work is determined by a number of factors and, above all, the level and degree of blockade and the underlying disease. The most serious prognosis is for grade III AV block: patients are unable to work, and the development of heart failure is noted.

The prognosis is complicated by the development of distal AV blocks due to the threat of complete blockade and rare ventricular rhythm, as well as their occurrence against the background of acute myocardial infarction. Early implantation of a pacemaker can increase the life expectancy of patients with AV block and improve their quality of life. Complete congenital atrioventricular blocks have a more favorable prognosis than acquired ones.

As a rule, atrioventricular block is caused by an underlying disease or pathological condition, so its prevention is the elimination of etiological factors (treatment of cardiac pathology, avoidance of uncontrolled use of drugs that affect the conduction of impulses, etc.). To prevent worsening of the degree of AV block, implantation of a pacemaker is indicated.