Sinoauricular or sinoarterial blockade is a type of intracardiac conduction disorder. This condition is characterized by a slow speed or complete cessation of the cardiac impulse to the atria from the sinus node. There are interruptions or a sinking heart, general weakness, short-term dizziness.
There are many reasons why the sinus node stops. This requires a full cardiological examination, as a failure in the rhythm does not just happen. It is the cause that determines further treatment and the prognosis of the disease.
In some patients, the heart works in the rhythm of the atrioventricular junction or atrial rhythm throughout life. These reserve sources provide adequate work of the heart. If they cannot cope with this, then there is only one way out - the implantation of a pacemaker.
Description of the disease
Sinoauricular blockade is a condition in which there is weaknesssinus node. Conduction of an electrical impulse is blocked between the sinus node and the atria. With this disorder, temporary atrial asystole is observed when one or more than one ventricular complex falls out.
Manifestations of sinoauricular blockade are rare, and if they develop, then most often in the male half of the population (in 65% of cases). The disease is determined at any age.
What is a blockade of 1, 2, 3 degrees and type? More on that later.
Degrees and types of disease
The disease can be classified according to severity. It comes in the first, second and third degrees:
The first degree is difficult to determine the electrocardiogram. There is a rarer occurrence of cardiac impulses that completely reach the atria. Blockade may be indicated by the presence of sinus bradycardia
- But the second degree can already be determined by the ECG. It is divided into 2 types. Sinoauricular blockade of the 2nd degree (type 1) - the blockade of the heart gradually increases, there are sudden episodes of complete loss of impulses. SA blockade of the 2nd degree (type 2) - cardiac impulses drop out irregularly, there are episodic and temporary complete blockades of conduction. Some impulses do not reach the ventricles and atria. Samoilov-Wenkerbach periods appear on the cardiogram. This indicates a sinoauricular blockade of the 2nd degree 2: 1. One cardiac cycle falls out, while the increased R-R interval is equal to two main intervals. In some cases, every second pulse is blocked,that follow normal contractions. This could mean allorhythmia.
- With the third degree (complete) sinoauricular blockade on the ECG, the picture is as follows - all impulses from the sinus node are blocked. This most often leads to asystole and death. The driver is the atrioventricular node, the conduction systems of the atria and ventricles.
What causes the blockade?
Sinoauricular blockade occurs when:
- organic myocardial damage;
- increased vagal tone;
- sinus node lesion.
The disease is most likely to occur in a person who suffers from the following pathologies:
- heart disease;
- IHD (manifested by heart attack, atherosclerosis);
- myocarditis.
Let's name some more possible reasons for the development of the blockade:
- Adrenoblockers, cardiac glycosides, drugs K, quinidine, which caused intoxication of the body.
- Defibrillation.
- Reflex-increased tone of the vagus nerve.
Thus, various factors can lead to blockade of impulses in the sinus node, which are often associated with the fact that cardiac activity is impaired. So, the development of this disease occurs when:
- inflammatory processes in the right atrium;
- metabolic-dystrophic disorders present in the atria;
- myocardial infarction;
- heart surgery.
Symptomatics
Sinoauricular blockade of the 1st degree is very difficult to identify, because it does not manifest itself in any way. It is determined only in the absence of a subsequent heartbeat after 2-3 normal cycles.
Sinus beat frequency has an impact on the clinical signs of second-degree block. If there is infrequent loss of heart contractions, then the patient will suffer:
- dizzy;
- chest discomfort;
- general weakness;
- short of breath.
Symptoms of the blockade, which is characterized by some lack of heartbeat cycles, will be as follows:
- heart-stopping;
- tinnitus;
- bradycardia.
When an ailment is accompanied by organic damage to the myocardium, heart failure is formed.
Asystole leads to the development of Morgagni-Adams-Stokes syndrome in patients. In this case, there is pallor of the skin, unexpected dizziness, flashing points before the eyes, convulsions, loss of consciousness, ringing in the ears.
So, we can conclude that the second and third stages appear:
- chest discomfort;
- bouts of dizziness;
- short of breath;
- general weakness;
- loss of heart beat;
- with bated breath;
- pale skin;
- tinnitus;
- convulsions.
Methodsdiagnostics
How to identify this disease? It is known that sinoauricular blockade on the ECG manifests itself. Is that right?
The main examination methods include:
- electrocardiography (ECG), since sinoauricular blockade is clearly visible on it;
- ultrasound examination of the heart (ultrasound).
According to the results of the ECG, the presence and severity of SA are determined. With 1, there are almost no manifestations - only sinus bradycardia is noted, which many people have and is considered a variant of the norm.
The first type of 2nd degree blockade on the ECG is expressed as follows - periodic rhythmic loss of cardiac cycles (loss of the P-P wave or the whole PQRST complex). In the second type - non-rhythmic and repeated prolapse of the P-P wave, PQRST complexes, when 2 or more cardiac cycles disappear, pathological blood circulation is formed.
So, electrocardiography was performed, but it is important to distinguish between sinoauricular block and sinus bradycardia and arrhythmia, as well as atrial premature beats, second-degree atrioventricular block.
If sinus bradycardia is confirmed, then tests with atropine are prescribed. After that, in patients, the heart rate doubles, and then also falls sharply by half. This provokes a blockade. And in the case of normal operation of the sinus node, the rhythm will gradually become more frequent. What is the treatment for the diagnosis of sinoauricular blockade?
What is therapy?
If a first-degree sinoauricular block is found in a person, then no therapy is required. Forrestoration of normal cardiac conduction, it is necessary to cure the underlying disease or refuse to take medications that led to violations.
If vagotonia led to type 2 sinoauricular blockade of the 2nd degree, then the use of atropine subcutaneously or intravenously will be effective:
- To stimulate the automatism of the sinus node, sympathomimetic drugs are used, such as "Ephedrine", "Alupten", "Izadrin".
- To improve the metabolism of the heart muscle, cocarboxylase, ribaxin, ATP are prescribed. In case of an overdose of these drugs, a headache, nausea, insomnia, twitching of the limbs, and vomiting may begin.
The intake of cardiac glycosides is contraindicated for patients, as well as treatment with beta-blockers, antiarrhythmic drugs of the quinidine series, K s alts, cordarone, rauwolfia.
When a patient with sinoauricular blockade has a significant deterioration in he alth, if asystole attacks often occur, doctors perform temporary or permanent stimulation of the atria with a pacemaker.
Provision of emergency assistance in case of blockade
Treatment consists in eliminating the cause that provoked sinoauricular blockade (such as intoxication with cardiac glycosides, rheumatism, coronary heart disease, etc.). Sometimes conduction can be restored only after the treatment of the underlying disease or the withdrawal of medications that caused its violation.
With frequent dizziness anda significant decrease in heart rate is prescribed to take a solution of atropine sulfate subcutaneously, intravenously or in drops. Sometimes adrenomimetic agents are prescribed - "Ephedrine" and preparations of isopronyl norepinephrine.
"Ephedrine" is taken orally twice a day or subcutaneously as a solution.
"Orciprenaline" ("Alupent") is administered slowly intravenously, subcutaneously or intramuscularly or orally in tablets twice a day.
"Izadrin" ("Novodrin") is a tablet. It is prescribed to take under the tongue (until completely dissolved) half a tablet three times a day or more.
Overdose of these drugs leads to headaches, palpitations, trembling limbs, sweating, insomnia, nausea, vomiting.
Prevention measures
All heart diseases should be detected in a timely manner. Such a disease as sinoauricular blockade is still poorly understood, in connection with this, there are no preventive measures as such. Basically, what should be done is to attend to the elimination of the cause of the change in cardiac conduction. It should be regularly examined by a cardiologist (or arrhythmologist). Also, increased heart risk is hypertension, obesity, malnutrition, bad habits, which include smoking and drinking alcohol.
What complications can this lead to?
The presence of negative consequences of sinoauricular blockade is explained by a slow rhythm due toorganic heart disease. The pathology we usually describe leads to chronic heart failure or aggravates it, if it already exists, contributes to the formation of ventricular and ectopic arrhythmias.
What is the forecast?
Further manifestations of sinoauricular blockade completely depend on the cause, that is, on the underlying disease. The degree of conduction and the presence of other cardiac arrhythmias also play an important role.
A disease that does not manifest itself in any way does not cause any disturbances in hemodynamics.
When Morgagni-Adams-Stokes syndrome occurs, the prognosis is unfavorable.
