Sinoatrial block is different from sinus arrhythmia. Video lesson on sinoatrial block on ECG (SA block). Complications of sinoatrial blockade

Sinoatrial or sinoauricular block is a form of disorder heart rate. Impulses are generated in the sinus node, but do not propagate through the atria. As a result, the heart does not contract. Clinically, this condition can manifest as syncope and in some cases requires the installation of a pacemaker.

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What is

Normal heartbeat is controlled by electrical signals that are regularly produced in the sinus node. This cluster of special cells is located in the upper part of the right atrium. From there, the impulse spreads through the atria, causing their excitation and contraction. As a result, blood is pushed out of them into the ventricles.

brain tumor;

(increased cerebrospinal fluid pressure in the cavities of the ventricles of the brain);

hypothyroidism (insufficient production of thyroid hormones);

progressive liver diseases (hepatitis or cirrhosis);

hyperkalemia (increased potassium concentration in the blood, for example, with renal failure).

Heart disease can cause SA blockade:

caused by ischemic heart disease or the consequences of myocardial infarction;

myocarditis;

pericarditis;

(impregnation with protein masses, for example, in chronic osteomyelitis);

age-related changes associated with atherosclerosis of the coronary vessels.

This rhythm disturbance is one of the manifestations of sick sinus syndrome (SSNS). The disease is accompanied by a disruption in the production of normal impulses, a slow heartbeat, attacks of tachycardia and the formation of long pauses.

Sinoauricular block can be caused by an overdose of the following medications:

digoxin;

quinidine;

beta blockers;

In many cases, it is not possible to determine the exact cause of the pathology.

Degrees of manifestation and their features

Sinoatrial block I degree– delay in the output of the electrical signal. In this case, the time required for the excitation to spread to the atria increases. At this stage, sinoauricular block does not appear on the ECG. It can only be diagnosed using electrophysiological testing (EPS).

SA blockade 2nd degree characterized by periodic complete cessation of impulse flow into the atria. This is accompanied by the absence of the P wave and the ventricular complex on the ECG. There is a pause in the work of the heart.

Sinoauricular block 3rd degree characterized by the absence of several sinus impulses. The ECG records a long pause, which usually ends with the formation of a replacement rhythm. Its source is the underlying portion of the conduction system, located in the atria. usually has a frequency of 60 - 80 per minute.

If a replacement rhythm is not formed, the heart stops working. The brain experiences a lack of oxygen. This is accompanied by loss of consciousness.

To see how sinoatrial block looks on an ECG and the mechanism of its development, watch this video:

Symptoms of pathology

1st degree SA blockade has no clinical manifestations.

Second degree sinoauricular block is usually well tolerated by the patient. Sometimes the patient complains of a feeling of interruptions, a sinking heart, and slight dizziness. Clinical symptoms are associated predominantly with the underlying disease (for example, myocarditis).

With complete SA blockade, attacks of weakness, dizziness, sudden loss consciousness. In such cases, doctors decide to implant a pacemaker in the patient.

Diagnostics

An ECG taken at rest can detect manifestations of 2nd and 3rd degree SA blockade.

Sinoauricular block, 2nd degree, type 1 associated with a gradual slowdown in the output of the impulse from the sinus node. The cardiogram shows an increasing shortening of the intervals between the P waves, and after the shortest interval a pause appears. It is shorter than the previous one P-P interval, multiplied by 2.

Sinoauricular block 2nd degree, type 2 caused by a sudden blockage of the electrical signal output. A pause occurs equal to twice the interval between adjacent P waves. If a 2:1 blockade appears, then every second P wave falls out, and sinus bradycardia is recorded on the cardiogram. The presence of SA blockade can be suspected given the low heart rate - 30 - 50 per minute.

Complete SA blockade on the ECG it is characterized by the absence of atrial contractions and the formation of a replacement atrial or AV nodal rhythm.

a) Sinoauricular block 2nd degree, type 1; b) Sinoauricular block 2nd degree, type 2; c) Complete SA blockade

For a better diagnosis of such arrhythmia, cardiograms are prescribed. The method makes it possible to determine the average heart rate and calculate the number and duration of pauses. The cardiologist needs these characteristics to determine whether the patient needs it.

An electrophysiological study helps differentiate autonomic dysfunction of the sinus node (normal state) and SA conduction disorders. It is often assigned to conscripts and people in socially significant professions (drivers, air traffic controllers, etc.).

Treatment of pathology

SA blockade of the 1st and 2nd degrees does not require treatment. Treatment is carried out for the disease that caused conduction disturbances.

Treatment of 3rd degree sinoauricular block includes 3 stages:

therapy of the leading disease;

taking medications;

pacemaker implantation.

For suddenly developed SA blockade, atropine is used. This medicine suppresses the activity of the parasympathetic nervous system, speeds up the heartbeat, and increases the efficiency of blood circulation. Ephedrine and norepinephrine stimulate the sympathetic nervous system, speeding up the heartbeat and improving blood flow. These medications are used as emergency measures only.

The main treatment method for 3rd degree SA blockade is. It fits under the skin chest, and its electrodes are inserted into the heart. They produce electrical impulses, replacing normal work sinus node. Cardiac stimulation allows you to completely eliminate the manifestations of arrhythmia.

Forecast

SA blockade itself practically does not cause serious complications. Dangerous SSSU, of which it is a part. This disease may cause:

fainting and injuries caused by falls;

heart failure;

Implanting a pacemaker eliminates the risk of these complications.

In other cases, the prognosis for SA blockade is determined by the underlying disease (myocardial infarction, cardiosclerosis, myocarditis, etc.).

Prevention

Sinoatrial block is not a disease, but only a syndrome that complicates the course
various diseases. Therefore, its prevention comes down to eliminating risk factors cardiovascular pathology(smoking, excess weight, inactivity, increased blood pressure).

Sinoauricular block is a violation of heart contractions caused by a slowdown or cessation of the output of the stimulating signal from the sinus node. Complete SA blockade, which is accompanied by oxygen starvation brain The main method of eliminating pathology is.

I. SA blockade of the 1st degree

The conduction time of excitation from the sinus node to the atria is prolonged. However, this prolongation is not visible on the surface ECG, and the block itself has no clinical significance.

II. SA blockade II degree

SA blockade of the second degree, type I (SA-Wenckebach period). Rarely observed. Similar to second degree AV block (Wenckebach period), as the sinoatrial conduction time gradually increases, the cardiac complex (P wave and QRS complex) falls out. The pause that occurs is shorter than the double PP interval.

SA blockade of the second degree, type II. The occasional loss of sinoatrial conduction is characteristic. On the ECG this is manifested by the loss of the P wave and the corresponding QRS complex.

Second degree sinoatrial block (type II) is sometimes combined with another rhythm disorder, in particular sinus arrhythmia, which makes ECG interpretation difficult. If there is a significant decrease in the frequency of ventricular contractions, it is necessary to discuss the implantation of a pacemaker.

Second degree SA block, type II.
The first 2 complexes correspond sinus rhythm, then there is a sudden loss of the entire atrioventricular complex, after which the heart contracts again in sinus rhythm.
After the 5th cardiac complex, prolapse of the entire atrioventricular complex is again observed. Belt speed 25 mm/s.

III. III degree SA block (complete SA block)

Third degree sinoatrial block is also called complete SA block. During the analysis, loss of the P wave and the QRS complex is noted for some time; During this period of time, blood circulation stops. Characteristic of third degree SA block is the intermittent appearance of pauses after the loss of the sinus complex, i.e. short ventricular asystole. This is the reason why patients complain of dizziness. In these cases, implantation of a pacemaker is also indicated.

Sinus arrest is often indistinguishable from complete SA block.

The causes of SA blockade are often coronary artery disease, heart defects, myocarditis and sick sinus syndrome (sinus node dysfunction, manifested by pronounced sinus bradycardia and SA blockade).

Complete SA block (sinus node arrest).
A 71-year-old patient complains of seizures associated with epilepsy diagnosed 2 years ago.
During ECG recording, a convulsive seizure occurred, the asystolic pause was 7.5 s.

Complete SA blockade.
The frequency of ventricular contractions is 37-39 per minute.
Due to the low frequency of ventricular contractions, an escape rhythm appears in the upper part of the AV junction (see limb leads) and partially in the middle part of the AV junction (not shown in the figure).
Complete blockade of PNPG. IN in this case one can assume complete SA blockade with a slipping rhythm.

Video lesson on sinoatrial block on ECG (SA block)

If you have problems watching, download the video from the page

– a form of intracardiac conduction disorder, characterized by a slowdown or complete cessation of impulse transmission from the sinus node to the atria. Sinoauricular block is manifested by sensations of interruptions and cardiac arrest, short-term dizziness, general weakness, and the development of Morgagni-Adams-Stokes syndrome. The decisive methods for diagnosing sinoauricular block are electrocardiography, daily ECG monitoring, and atropine test. Treatment of sinoauricular block involves eliminating the causes of conduction disturbances, prescribing atropine and adrenergic agonists; at severe forms blockade, temporary or permanent electrical stimulation of the atria is indicated.

General information

Sinoauricular (sinoatrial) block is a type of sick sinus syndrome in which the conduction of electrical impulses between the sinoatrial node and the atria is blocked. With sinoauricular block, temporary atrial asystole and loss of one or more ventricular complexes occur. Sinoauricular block is relatively rare in cardiology. According to statistics, this conduction disorder develops more often in men (65%) than in women (35%). Sinoauricular block can be detected at any age.

Causes of sinoauricular block

The development of sinoauricular block can be caused by damage to the sinus node itself, organic damage to the myocardium, and increased tone of the vagus nerve. Sinoauricular block occurs in patients with heart defects, myocarditis, ischemic heart disease (atherosclerotic cardiosclerosis, acute myocardial infarction, often posterior phrenic), cardiomyopathies. Sinoauricular block can develop as a result of intoxication with cardiac glycosides, potassium preparations, quinidine, adrenergic blockers, and poisoning with organophosphorus compounds.

Sometimes sinoatrial conduction disturbance occurs after defibrillation. In practically healthy individuals, sinoauricular block occurs when there is a reflex increase in the tone of the vagus nerve innervating the atrioventricular node and atrium. The mechanism of development of sinoauricular block may be directly related to the lack of impulse generation in the sinus node; weakness of the impulse, unable to cause atrial depolarization; blocking impulse transmission in the area between the sinus node and the right atrium.

Classification of sinoauricular block

There are sinoauricular blockades of I, II and III degrees. Sinoauricular block of the first degree is not detected on a regular electrocardiogram. In this case, all impulses generated by the sinus node reach the atria, but they originate less frequently than normal. Persistent sinus bradycardia may indirectly indicate sinoauricular block of the first degree.

With sinoauricular block of the second degree, some impulses do not reach the atria and ventricles, which is accompanied by the appearance of Samoilov-Wenckebach periods on the ECG - loss of the P wave and the associated QRST complex. In case of loss of one cardiac cycle, the increased interval R-R is equal two main R-R intervals; if more cardiac cycles occur, the pause may be 3 R-R, 4 R-R. Sometimes the conduction of every second impulse following one normal contraction is blocked (sinoauricular block 2:1) - in this case they talk about allorhythmia.

Forecast and prevention of sinoauricular block

The development of events during sinoauricular block is largely determined by the course of the underlying disease, the degree of conduction disturbance, and the presence of other rhythm disturbances. Asymptomatic sinoauricular block does not cause severe hemodynamic disturbances; the development of Morgagni-Adams-Stokes syndrome is regarded as prognostically unfavorable.

Due to insufficient knowledge of the pathogenesis of sinoauricular blockade, its prevention has not been developed. The primary tasks in this direction are to eliminate the causes of conduction disturbances and monitor

Defects of the cardiovascular system are mostly invisible to the patient. But up to a certain point. Many diagnoses are made after the fact, after an autopsy. Some diseases do not produce any symptoms at all and do not affect the anatomical state of the muscle organ.

Sinoatrial block is a disruption of the movement of electrical impulses from the natural pacemaker (sinus node) to the underlying chambers of the heart (atria and ventricles). Several structures of the heart are involved at once, hence the generalized disruption of its functioning.

The signal does not reach the ventricles, so they contract incorrectly (beats are skipped).

With prolonged damage, it develops: chambers that do not receive an external impulse begin to generate it independently. This can be fatal in the short term.

Treatment is carried out under the supervision of a cardiologist, preferably in a hospital until all the nuances are identified. Full recovery presents some difficulties: More often, sinoatrial blockade acts as a secondary pathology, occurring against the background of other diseases.

The correct treatment regimen is a simultaneous impact on the cause and symptomatic component.

In the normal state of affairs, muscular organ works autonomously and does not require third-party stimulation. Uninterrupted functioning is ensured by the presence of a special accumulation of active cardiomyocyte cells - the sinus node. It is located in the right atrium.

The job of this anatomical structure is to generate an electrical impulse that causes the other chambers to contract.

With sinoatrial (SA) blockade, the generation or propagation of an impulse into the underlying chambers of the heart is disrupted. The result is the impossibility of proper stimulation of the ventricles.

Because they don't get the required command, a full reduction also does not occur. The body strives to compensate for this situation. The cameras begin to produce a signal themselves and become spontaneously excited.

But on the one hand, the intensity is not enough for a high-quality release of blood, on the other, the ventricles stop coordinating actions.

The contractions turn out to be chaotic and disorderly. Fibrillation develops, which most likely leads to cardiac arrest.

Another point is the excessive activity of the sinus node itself. This is another compensatory mechanism. The organ begins to produce impulses more often in order to somehow reach the ventricles.

As a result, a patient with advanced sinoatrial block has a history of two dangerous processes: tachycardia as a result of excessive work of the natural pacemaker and fibrillation.

It’s difficult not to notice these signs, so the diagnosis is prescribed relatively early early stages. Although the situation described is not always so critical. A patient can live with the pathology for years without even suspecting any problems.

Classification and degrees

Typing is carried out according to the severity of the condition.

SA blockade 1st degree. Represents the initial phase of the disease. There are no symptoms as such, there are no changes in well-being. The patient is active and goes about his daily activities.

It is possible to detect problems during sports activities, especially during professional level. Excessive load leads to increased heart rate, impaired myocardial contractility, and chest discomfort.

Additionally, intense shortness of breath and loss of consciousness similar to superficial fainting are detected. After rest, everything falls into place. The objective picture consists of a slight drop in blood pressure and heart rate.

SA block 2nd degree- This is an incomplete violation of impulse conduction. Contractility is still normal, the activity of the sinus node is normal or slightly reduced.

At this stage, severe tachycardia occurs, but the reverse process is also possible. Shortness of breath, sleep disturbances, poor exercise tolerance. All these are moments inherent in pathology.

Depending on the ECG pictures There are two types of the described condition:

SA blockade 2nd degree, type 1 - the graph reveals chaotic transmission of contractions, usually two or more in a row, possibly with an increase in the impulse conduction time (Samoilov-Wenckebach periods). Clinically, this form is especially dangerous, since it more often causes spontaneous cardiac arrest without the possibility of urgent resuscitation using routine methods.

SA blockade 2nd degree, type 2 - there are no beats symmetrically: there is an alternation of normal contraction and its omission.

Sinoauricular block of the 3rd degree is considered terminal stage. It takes from several months to years to develop, depending on the aggressiveness of the condition and its underlying cause.

Electrocardiography shows weak contractions. In severe cases, the indicator degenerates almost into a straight line. There is a high risk of asystole or cardiac arrest. This can happen at any time.

The patient needs to be hospitalized urgently. Third degree sinoatrial block is extremely difficult to treat. Radical measures are required. If you are lucky and there are no abnormalities in other organs yet, transplantation will help, which in itself is difficult to implement due to the lack of donors.

At its core, sinoatrial blockade is a type. It is similar to bundle branch lesions in both manifestations and prognosis.

But it flows much more aggressively, gives more complications and carries great danger, since the disorder affects both ventricles at once, and at stages 2-3 the atria also suffer.

Causes

Development factors are always cardiac. On the one hand, this makes diagnosis easier. On the other hand, it initially worsens the prognosis.

Poisoning with phosphorus compounds. Usually these are mineral fertilizers. Patients working in hazardous chemical plants are especially at risk. Once the dangerous factor is eliminated, the likelihood of restoring normal health is almost maximum.

Patients with acute intoxications should be immediately hospitalized for specific therapeutic measures. The prognosis in this case is relatively favorable.

Congenital and acquired heart defects. What kind doesn't play a big role. This may be stenosis, prolapse of the mitral, aortic valves, disturbances in the anatomical development of the septum and other conditions.

The problem is that it is extremely difficult to detect them if you do not contact a cardiologist every six months or a year for a routine examination.

Findings are mostly accidental, because pathological processes are detected already at irreversible stages. Some cases are even dealt with after the fact, when the person has died.

Sinoatrial blockade of this type is relieved as part of the main surgical treatment.

Drug overdose. It’s ironic, but drugs designed to lower blood pressure and eliminate arrhythmia, that is, medications aimed at improving the heart, can kill the patient in a matter of hours.

Amiodarone, Quinidine, Digoxin, glycosides in general, and beta blockers are especially dangerous. Among the third-party drugs are psychotropic drugs, including neuroleptics, antidepressants, and tranquilizers.

It is possible to provoke a similar effect due to the use of oral contraceptives. All drugs should be prescribed only by a specialist after a thorough diagnosis.

Myocarditis. Inflammation of the heart muscle. It is infectious, less commonly autoimmune disease. Requires urgent medical care in the hospital.

Outpatient so dangerous condition is not treated, since complications are possible, including heart attack or cardiac arrest. Antibiotics are used in loading doses or immunosuppressants.

As a rule, the condition is secondary. Develops as a complication colds, rheumatism and others. Sinoatrial blockade after severe myocarditis does not go away on its own.

Vegetovascular dystonia. Strictly speaking, it does not apply to cardiac problems. However, the normal innervation of the cardiovascular system is disrupted. Hence the deviations in the conductivity of the electrical impulse.

It is a complex symptomatic complex. It manifests itself in many ways: from tachycardia, to dizziness, fainting, shortness of breath and others.

It is not considered an independent diagnosis; you need to look for the cause of this condition. Usually we are talking about hormonal imbalance or pathologies of the cerebral structures themselves.

Rheumatism. Autoimmune damage to cardiomyocyte cells. The body's protective forces, designed to cover the body, destroy its own tissues. The reasons for this deviation are not fully known. However, rheumatism quite quickly destructs cardiac cells, causing severe scarring and severe heart failure with sinoatrial block.
Myopathy. Proliferation of the muscle layer, as well as dilatation (expansion) of the chambers of the heart. Restoration is not possible due to the anatomical nature of the deviation. Maintenance therapy under the supervision of a specialist is required. Read more about cardiomyopathy and its types.

Heart attack and, as a consequence, scarring of the affected areas (cardiosclerosis). It ends with a significant decrease in the conductivity of the natural pathways of electrical impulses. Treatment is required urgently. There is always a risk of death.

U completely healthy people sinoatrial blockade is also possible. Spontaneous, transient, and transient SA blockades are a consequence of increased activity of the vagus nerve.

Such conditions can be dangerous, but they last only a few minutes, half an hour at most. Patients with no cardiac history and no organic abnormalities in the objective picture are observed by neurologists.

Attention:

There is a chance that the first attack will be the only one, but it is not great. Most likely, we are talking about a disruption of the brain or endocrine system.

In the absence of data for pathologies and functional disorders, they generally speak of an idiopathic form of sinoatrial block. This is a relatively rare option. Typically, diagnostic problems do not arise due to the obviousness of the underlying process.

Stage 1 symptoms

At an early stage, there are no manifestations at all or they are scanty. Clinical picture consists of two signs:

Severe shortness of breath. But only after intense physical activity. The average person is not active enough to notice a deviation from the norm. In part, problems can be suspected based on the results of specialized tests (bicycle ergometry), but such a test is prescribed only when indicated.
Tachycardia. Acceleration of the heart rate due to excessive generation of an electrical impulse, against the background of incomplete conduction of the signal to the ventricles. The compensatory mechanism is activated. But he is initially flawed, unable to influence the state of things.
Both signs are revealed only after intense physical exertion. A common person does not notice the problem, therefore diagnosis at stage 1 is almost impossible.

Symptoms at stages 2-3

Phases 2-3 are accompanied by a number of gross changes in condition:

Chest pain. Pressing or burning. Unlike angina, the episodes are so small that the patient does not have time to pay attention to them. The discomfort is described as immediate unpleasant feeling, which immediately disappears. Duration - from a couple of seconds to several minutes.
Dyspnea. Against the background of minimal physical activity or at rest. It is extremely difficult to tolerate, the patient is unable to work or perform daily duties. Even going to the store becomes akin to achievement. It is difficult to correct the condition. Usually such patients are given a disability group.
Heaviness in the chest. It feels like a huge stone has been sewn up.
Tachycardia and the reverse process. Increase and decrease in heart rate. One may be replaced by another. In parallel, other arrhythmias occur. Ventricular fibrillation. The number of movements reaches 300-400, but they are visible only on electrocardiography.
Cyanosis of the nasolabial triangle.
Increased sweating, especially at night.
Paleness of the skin.
Fainting may occur more than once during the same day.
Headache.
Vertigo, inability to navigate in space.
Weakness, drowsiness. Long-term decline in labor activity.
Apathy, unwillingness to do anything.

Sinoatrial blockade of the 2nd degree is accompanied by all the described manifestations, but treatment still has promise.

Diagnostics

It is carried out under the supervision of a cardiologist. A group of techniques is assigned:

Oral questioning of the patient and collection of anamnesis. A way to objectify complaints, formalize symptoms and create a clinical picture.
Measurement of blood pressure, heart rate.
Daily monitoring using a special tonometer. Allows you to evaluate both heart rate and blood pressure over 24 hours in natural conditions for the patient.
Electrocardiography. Study of functional indicators. Used as a basic measure.
Echocardiography. Ultrasound method of tissue visualization. Defects are diagnosed in this way.
General blood test, hormones and biochemical.
MRI as indicated.

As part of an extended examination, a neurologist is involved. It is also possible to schedule a consultation with a specialist who works with hormonal imbalances.

Signs on ECG

At the first stage there are no changes. Problems cannot be detected. Or the features are so nonspecific that they do not give an idea of the nature of the process.

2nd degree reveals the most pronounced changes on ECG:

Passing several pulses in a row at once. Objectively manifested by the complete absence of PQRST complexes on the graph. This is type 1.

For the 2nd, alternating loss of contractions is typical. Yes, no, and so on. Inadequate movements may occur and appear as minor waves.

P-P extension.
Acceleration or deceleration of the intensity of work of a muscle organ.

SA blockade on the ECG has features of tachycardia or bradycardia and uneven contractile activity.

The third stage is accompanied by impaired functional activity. The graph degenerates almost into a straight line.

Treatment options

The main method of correcting the condition is surgical. Implantation of a pacemaker is indicated, which will artificially control the rhythm.

Medication is a temporary measure and its effect is incomplete.

During acute attacks against the background of vegetative, nervous dysfunction are appointed:

Nitroglycerine.
Atropine or Amizil.

You should not abuse drugs, they provoke dangerous forms arrhythmias with excessive use.

In the long term, vitamin and mineral complexes with sufficient amounts of magnesium and potassium, and cardioprotectors (Mildronate) are prescribed.

Attention:

The use of antiarrhythmic drugs is strictly not recommended, as the condition is likely to worsen.

Forecast

Relatively favorable against the background of systematic drug treatment.

If a pacemaker is implanted and the operation is successful, survival rate increases dramatically to 90-95% over a period of 10 years or more.

Lack of therapy is associated with an almost 100% chance of death within a short period of time.

The pathological process cannot always be cured surgically. For some patients, with severe heart defects, severe concomitant conditions, or old age, surgery may be contraindicated.

However, the chance cannot be neglected. First they try to stabilize the patient, then they still consider radical intervention. Otherwise there is no chance of recovery.

Possible complications

Among the consequences:

Asystole or cardiac arrest. The most likely outcome without treatment.
Heart attack.
Stroke. Acute disorder blood circulation in cerebral structures.
Vascular dementia as a result of insufficient nutrition of the brain.

Prevention of dangerous moments is one of the goals of therapy.

Finally

Sinoatrial (sinoauricular) blockade is a complex process: its essence is the disruption of the movement of an electrical impulse from the natural pacemaker to the ventricles and atria.

This is the path to a decrease in myocardial contractility, spontaneous formation of abnormal foci, and chaotic functioning of the muscular organ.

Treatment is urgent; delays reduce the chances of recovery. The prognosis for surgical intervention is favorable.

SA blockade (sinoatrial blockade) is a type of sinus node weakness. In general, this is a rather rare phenomenon from the category of arrhythmias and is diagnosed mainly in men. There is no age limit for SA blockade as such. In a completely healthy heart, an impulse of electrical charge from the right atrium passes unhindered along this path, creating muscle contraction in the heart. If, while traveling through our heart, the charge encounters an obstacle, then the contractions themselves automatically fail; it is these obstacles that are the blockade.

With SA blockade, there is a disruption in the creation of a charge and its subsequent distribution. Consequently - Disorganization of ventricular contractions occurs. After a while, the heart begins to systematically skip contractions.

Causes

The problems that SA blockade creates are node deformation and dysfunction of cardiac muscle contraction. It happens that because of it the impulse is too weak or not generated at all.

Reasons leading to blockade:

Rheumatism of certain forms;
Heart attack;
Overdose of drugs;
Myocarditis;
Ischemia;
Heart disease;
Injury to cardiac tissue;
Intoxication with organophosphorus substances;
Cardiomyopathy.

SA blockade appears when the nervus vagus begins to influence the sinus node through activation. In most situations, under such conditions, a transient blockade is performed. This type of SA blockade resolves over time on its own, without therapeutic or external intervention. Changes in the structure of the heart anatomically do not occur, which allows for the possibility of its manifestation in healthy and strong people. In very exceptional cases, SA blockade is idiomatic; the factor of its occurrence has not yet been found by scientific doctors.

Children are also susceptible to this pathology. Due to autonomic dysfunction From the age of seven to eight years, a child develops transit SA blockade. At the same time, it is possible to identify other arrhythmias.

Degrees of SA blockade

The degree is directly dependent on the intensity of arrhythmias.

First. At this level, impulses occur, but less frequently than in the normal state. The unit is operating as normal. The only problem is the speed of the pulse. An ECG will not show this degree;
Second. The heart does not contract every time; the prerequisite is a periodic deficit of impulse;
Third. Complete SA blockade. There is no necessary impulse, the muscle does not contract.

The first two stages are not complete because, although poorly, the sinus node performs its functions. With the latter, complete, the impulse does not reach the atrium at all.

SA blockade and ECG

An electrocardiogram is a key way to detect blockages. The first degree is not noticeable on the ECG, but is calculated by bradycardia. Only the second and third ECG will show as reliably as possible.

What will the ECG show in the second degree:

Longer intervals between impulsive muscle contractions (PP);
Decrease in P-P over time after a pause;
If the intervals are large, the impulses come from another source;
When several impulses and contractions occur in a row pauses R-R, as in normal condition.

With the third degree, any absence of electrical charges is observed. Not rare death person in such a situation.

How does SA blockade manifest and methods for diagnosing it

In the first degree, a person does not experience discomfort and there are no symptoms. The body becomes accustomed to frequent bradycardia and the person does not feel changes within himself and lives quite comfortably.

The latter degrees already have symptoms that are easily recognizable. These are unpleasant sensations in the chest area, periodic noise and ringing in the ears, shortness of breath, frequent dizziness. Weakness throughout the body also occurs due to rare rhythmic contractions. If there is a change in the structure of the muscle, signs such as:

Blue skin;
Enlarged liver;
Swelling;
Shortness of breath;
Heart failure;
Decreased ability to work.

The child has the same symptoms. We recommend that you take a closer look at the following: cyanosis of the nasolabial area, decreased performance and severe fatigue. If such symptoms are noticed, go to a cardiologist for check-up.

When the pause between contractions is long, paroxysms appear. Paroxysms are a process in which the brain stops receiving the required amount arterial blood, its supply is reduced significantly. Symptoms:

Noise and ringing in the ears;
Involuntary urination and bowel movements;
Systematically loss of consciousness;
Spasm.

If bradycardia begins to bother you, or a missed impulse is noticed on the ECG, you should undergo a full check by a cardiologist. Be sure to do daily monitoring in addition to the cardiogram. If the ECG gave only doubt about SA blockade, then wearing the monitor is necessary for a long time. The blockade is easiest to fix during a state of complete rest, sleep, or during physical activity.

The child should also be monitored. Bradycardia for about forty minutes, together with pauses between impulses of three seconds, are an alarm bell. It is common practice to test samples with atropine. If there are problems, the pulse instantly increases several times and just as sharply returns to the original one, or lower, this is a blockade.

In order to be directly convinced of this diagnosis, it is necessary to conduct an ultrasound of the heart to exclude other diseases, for example, problems.

Treatment of the disease

The first degree does not need intensive treatment. It will be enough to restore the correct daily routine, if it is disrupted, treat the main heart diseases, or stop using heart medications that can affect the performance of the sinus node.

Transient blockade can be treated with medications containing atropine. They are actively used in pediatrics for vagotonia. It should be remembered that reaction therapy is fleeting. Metabolic treatment is more effective with SA blockades. Riboxin, cocarboxylase and vitamin-mineral complexes are the leading fighters in the war against blockades.

If you have been given an SA blockade, you should not use beta blockers or potassium supplements. They will worsen bradycardia and further complicate the functioning of the sinus nodes. When stage three symptoms appear, the person is strongly advised to have a pacemaker inserted into the heart.

SA blockade is a heart disease that is extremely life-threatening; do not forget about routine examinations with a cardiologist.

Video about heart rhythm disturbances

In this video, Elena Malysheva will tell you how to treat cardiac arrhythmia: