Sinus node weakness syndrome (SSS) is a complex of electrocardiographic and clinical symptoms due to a decrease in the automatism of the sinus atrium and a violation of CA-conduction (sinoatrial conduction).
(1) persistent sinus bradycardia, which can lead to dizziness, fainting, the onset and / or progression of heart failure and coronary insufficiency;
(2) transient blockade of the sinus-atrial node ΙΙ – ΙΙΙ degree or stoppage of the sinus-atrial node with loss of consciousness;
(3) tachycardia-bradycardia syndrome: paroxysmal supraventricular tachycardia or atrial fibrillation / flutter, which stops after a long episode of asystole (loss of consciousness and cramps are possible), followed by restoration of the sinus rhythm with a low frequency.
Epidemiology. The exact prevalence is unknown, more often SSU occurs in old age.
Etiology and pathogenesis. SSSU develops as a result of IHD, arterial hypertension, and primary myocardial diseases. The basis of the syndrome is directly organic damage to the tissue of the sinus-atrial node and the atrial myocardium surrounding it.
The clinical picture. With bradycardia and episodes of asystole, dizziness and fainting, sometimes convulsions (attacks of Morgagni-Adams-Stokes) are possible. In the case of persistent bradycardia, symptoms of heart failure or coronary insufficiency may develop, especially poor exercise tolerance due to inadequate increase in heart rate (HR). Attacks of tachycardia can be accompanied by a feeling of palpitations, shortness of breath, angina pectoris.
(1) medical history and observation: syncope, persistent bradycardia;
(2) results of daily monitoring of ECG according to Holter: assessment of episodes of bradycardia, the presence and duration of asystole episodes due to CA blockade or stop of the sinus-atrial node;
(3) these samples with physical activity: the lack of an adequate increase in heart rate during exercise, that is, heart rate at maximum load does not reach 100 / min or 70% of the calculated maximum;
(4) the result of the atropine test: in patients with SSSU after iv administration of 2 mg of atropine, heart rate does not exceed 80 / min;
(5) transesophageal atrial electrostimulation: the recovery time of the function of the sinus atrium, i.e. the time before the onset of impulse from the sinus atrium after the termination of the increasing electrostimulation of the atria exceeds 1600 ms or the time of CA conduction exceeds 300 ms.
Differential diagnosis. A thorough history should be taken. The use of drugs that inhibit the function of the sinus-atrial node (cardiac glycosides, antiarrhythmic drugs) should be excluded as a possible cause of impaired function. In the presence of fainting, it is necessary to exclude other causes of loss of consciousness (neurological, cerebrovascular, metabolic, cardioobstructive, tachyarrhythmic, low-release syndromes).
General principles of treatment. With severe bradycardia, accompanied by appropriate symptoms, and with fainting caused by prolonged asystole, implantation of a permanent pacemaker (EX) is indicated.
In the absence of clinical symptoms, implantation of ECS is indicated in those cases where heart rate less than 40 / min or asystole lasting 3 seconds or more is registered. In the process of preparing the patient for surgery, as needed, iv administration of atropine or isopernaline is used.
With hemodynamically significant bradycardia, the following drugs are used: iv atropine or s.c. at 0,6 – 0,2 mg up to 2 – 3 times a day or iv isoprenaline 2 – 20 μg per minute or isoprenaline inside 2,5. 5 – 3 mg to 4- times a day.
With tachycardia-bradycardia syndrome with the development of pre-syncope, patients are implanted with ECS and antiarrhythmic therapy is started.
Evaluation of the effectiveness of treatment. The criterion for effective treatment is the absence of hemodynamic disturbances, angina attacks, fainting, dizziness in conditions of normalization of heart rate (drug or by ECS).
- Features of the course of the disease
- List of Abbreviations
- Healing process
- Terms and definitions
- Operative intervention
- 1.2 Etiology and pathogenesis
- The use of folk remedies
- 1.3 Epidemiology
- Outcomes and Forecast
- 2.1 Complaints and medical history
- 2.3 Laboratory Diagnostics
- 2.5 Other diagnostics
Features of the course of the disease
In the heart muscle there is a center that sets the rhythm of its heartbeat. This function is performed by the so-called sinus node, which is considered a pacemaker. It creates an electrical impulse and redirects it to the heart.
The sinus node of the heart is located in the right atrium in the area where the vena cava joins. It is a kind of power plant that distributes charges that set the rhythm of the heartbeat. The deterioration of the work of this body creates various kinds of interruptions in the functioning of the heart. This pathology manifests itself equally in both sexes and often occurs in older people.
Syndrome weakness syndrome is not one specific disease, but several interconnected cardiac arrhythmias. This concept includes:
Such a pathology is quite common and lends itself well to therapy, especially in the initial stages of the course of the disease. To determine the presence of a disease, it is necessary to know the causes that provoke it and the characteristic signs.
Many people wonder, sinus arrhythmia – what is it, how is this disease classified and what is characteristic of it? We can distinguish such types of pathologies as:
- sinus bradycardia;
- tachycardia-bradycardia syndrome;
- sinoatrial blockade;
- fading of the sinus node.
Bradycardia is characterized by the fact that there is a decrease in the number of pulses and this leads to a decrease in contractions of the heart muscle. If less than fifty contractions occur in a minute, then this is considered the main symptom of bradycardia.
Syndrome of bradycardia-tachycardia is characterized by the fact that periods of slow work of the heart muscle are replaced by heart palpitations. Sometimes, with the subsequent development of pathology, atrial fibrillation is observed.
With sinoatrial blockade, the sinus node functions without changes, however, a failure occurs during the transmission of pulses. The rhythm of contraction of the heart muscle largely depends on how clearly and evenly the impulse blockage occurs.
Stopping the sinus impulse implies that the pacemaker takes a break in the generation of the impulse for a certain time. Violation of the activity of the node also varies in the nature of the pathology, namely, it is divided into:
- latent current;
- intermittent course;
- manifest flow.
Latent flow is expressed in the fact that impaired functioning of the sinus node is almost imperceptible. Failures are very rare and pathology can only be detected with a comprehensive examination.
The intermittent course of the disease is characterized by the fact that the weakness of the sinus node is observed mainly at night. This is due to the impact on the rhythm of the autonomic system. With the manifesting course of pathology, malfunctions in the work of the heart are more pronounced.
In children, 4 stable clinical and electrocardiographic variants of impaired SU function were identified (table 1): the first of which includes minimal manifestations in the form of sinus bradycardia and rhythm migration; the second – replacing rhythms, stops of SU, sinoatrial blockade against a background of more pronounced depression of the main rhythm;
Each of the options in a fairly high percentage of cases is characterized by the addition of atrioventricular (AB) conduction disorders. There is a staged formation of violations of the function of SU in children: from the first to the second (or third, depending on the presence of electrophysiological conditions for the development of tachyarrhythmias) and the fourth option.
Table 1 – Clinical and electrocardiographic options for sick sinus syndrome in children
Violations of the function of the sinus node
Impaired function of the underlying levels of the conduction system of the heart
I option. Sinus bradycardia with a heart rate of 20% below the age norm, migration of a pacemaker. Pause rhythm with SM ECG up to 1500 ms. Adequate increase in heart rate during exercise
Slowing of atrioventricular conduction to AV block of I degree. Alternation of AV holding
II option. Sinoatrial blockade, stoppage of the sinus node, slipping contractions and accelerated rhythms. Pause rhythm with SM ECG from 1500 ms to 2000 ms. Inadequate increase in heart rate during exercise
Atrioventricular dissociation, atrioventricular block II-III degree
III option. Tachy-bradycardia syndrome. Rhythm pauses with SM ECG from 1500 ms to 2000 ms
Atrioventricular dissociation, atrioventricular block II-III degree
IV option. Rigid sinus bradycardia with a heart rate of less than 40 beats / min, ectopic rhythms with single sinus complexes, atrial fibrillation-flutter. Lack of restoration of a steady sinus rhythm and its adequate acceleration during physical activity. Pause rhythm with SM ECG more than 2000 ms
Violations of atrioventricular and intraventricular conduction. Secondary lengthening of the QT interval. Violation of the repolarization process (ST segment depression, decrease in the amplitude of T in the left chest leads)
List of Abbreviations
SSSU – sick sinus syndrome
SM ECG – -hour ECG monitoring
Heart rate – heart rate
Blood Pressure – Blood Pressure
NPES – transesophageal pacing
VVFSU – time of restoration of the function of the sinus node
KVVFSU – corrected time to restore the function of the sinus node
EX – pacemaker (pacemaker)
Sinus node weakness syndrome (SSS) is a special type of arrhythmia caused by a violation of the automatic function of the sinoatrial node (SSS). In this case, the heart ceases to be rhythmically excited and contract. Perhaps a complete cessation of the production of electrical impulses. This clinical symptom complex is characterized by inadequate blood supply to internal organs, bradycardia and its corresponding signs. The outcome of the pathology often becomes a sudden cardiac arrest. The disease according to ICD-10 has the code I49.5.
The heart is the only organ in which electricity self-generates. The sinus node leads this process. It is he who produces electrical impulses. Myocardial cells are excited and simultaneously contracted, which allows muscle fibers to push blood. The sinus node is located in the wall of the right atrium.
Impulses are generated in it, which are transmitted to typical contractile cardiomyocytes and extend to the atrioventricular (AB) node. Regulation of the functions of the sinus node is carried out by the autonomic department of the central nervous system. Changes in heart rhythm are due to the needs of hemodynamics: during physical activity, it becomes more frequent, at rest and in sleep it slows down.
the work of the sinus node and the conduction system of the heart, providing contractions
With pathology, the sinus node ceases to generate nerve impulses. He is weakening. The frequency and strength of myocardial contractions are reduced. The process of conducting excitation throughout the heart muscle is disrupted. Weak impulses are not carried out to all parts of the myocardium, and rare contractions cause bradycardia. As a result, the blood supply to all organs and systems is disrupted.
The causes of the syndrome are very diverse. The true or primary form of pathology is caused by organic damage to the heart. A violation of automatism may be associated with a change in the activity of the vagus nerve or the use of certain medications. SSSU occurs in elderly people who have a history of cardiac disease.
Diagnosis and treatment of the syndrome is carried out by cardiologists and cardiac surgeons. For the diagnosis, the results of electrocardiography, Holter monitoring, stress tests, invasive studies are necessary. With the help of modern therapeutic methods, it is possible not only to normalize the heart rhythm, but also to completely cure the disease, eliminating its cause. If necessary, a pacemaker is implanted into patients.
SSSU adrift happens:
- Acute – developing with myocardial infarction and characterized by the sudden onset of heart attacks.
- Chronic – characterized by a slowly progressive course with frequent relapses. In patients, the rhythm constantly slows down, the general condition worsens, fatigue and ongoing weakness quickly sets in.
Depending on the etiopathogenetic factor, the syndrome is divided into:
- True or primary, directly caused by heart disease – coronary heart disease, hypertension, malformations, cardiomyopathy;
- Secondary, developing as a result of a violation of autonomic regulation.
Stages of the development of the syndrome and its main manifestations:
- Latent stage – without obvious clinical manifestations and ECG signs. In this case, the results of an electrophysiological study make it possible to make a diagnosis. Patients with a latent form of pathology do not need treatment.
- Compensated stage – patients complain of dizziness, weakness and general deterioration of well-being. Patients are shown symptomatic treatment with disability.
- The decompensated stage is manifested by persistent bradycardia, signs of discirculatory changes in the brain and myocardium. Patients experience fainting and fainting conditions, paresis, heart pain, shortness of breath. In case of decompensation, implantation of a pacemaker is indicated. Patients are recognized as completely disabled.
Perhaps you want to know about the new medication - Cardiol, which perfectly normalizes blood pressure. Cardiol capsules are an excellent tool for the prevention of many heart diseases, because they contain unique components. This drug is superior in its therapeutic properties to such drugs: Detonic. If you want to know detailed information about Cardiol, go to the .There you will find answers to questions related to the use of this drug, customer reviews and doctors. You can also find out the Cardiol capsules in your country and the delivery conditions. Some people manage to get a 50% discount on the purchase of this drug (how to do this and buy pills for the treatment of hypertension for 39 euros is written on the official website of the manufacturer.), ,
Primary causes are associated with damage to the heart and its main structures:
- cardiac muscle ischemia – myocardial infarction, its death and scarring, angina pectoris;
- various forms of cardiomyopathies;
- myocardial inflammation;
- heart defects;
- traumatic myocardial damage;
- surgical interventions or invasive manipulations on the heart;
- collagenoses, vasculitis, rheumatic heart disease and other systemic diseases;
- hormone-exchange cardiotoxic disorders;
Secondary CVS cause various exogenous and endogenous factors that disrupt the normal functioning of the heart. The most common among them are:
- a change in water-electrolyte balance – hyperkalemia and hypercalcemia;
- taking certain medications – adrenergic blockers, clonidine, reserpine, verapamil, cardiac glycosides;
- endocrinopathies – hypothyroidism, hypocorticism;
- natural processes of aging;
- syphilitic heart disease;
- severe intoxication.
With excessive activity of the vagus nerve, a vegetative form of pathology develops. Hypertonicity of the nerve normally occurs during urination, during coughing and sneezing, nausea and vomiting, in a dream. Its pathological activation is caused by damage to the nasopharynx, urogenital tract, digestive organs, hypothermia, hyperkalemia, septic conditions, intracranial hypertension.
A congenital dysfunction of the sinus node is isolated into a separate group. There is also an idiopathic form of pathology with an unknown cause.
The clinical manifestations of SSSU are very diverse. They will not leave the disease unnoticed. In some patients, the pathology for a long time is asymptomatic or has mild signs of general asthenia – weakness, lethargy, loss of strength, apathy, decreased performance, cooling hands and feet. Other patients have symptoms of rhythm disturbance – cephalgia, dizziness, fainting. The hemodynamic disorder that always accompanies the syndrome is manifested by signs of cardiac asthma, pulmonary edema, persistent coronary dysfunction.
Clinical signs of CVS are divided into two main groups – brain and cardiac:
- Symptoms of the first group include: fatigue, irritability, distraction, unstable mood, decreased intelligence. When the syndrome progresses, cerebral symptoms increase. It darkens in the eyes, the face reddens sharply, tinnitus, palpitations, cramps, fainting, numbness of the extremities. Patients turn pale, sweat excessively, their pressure drops sharply. Factors provoking fainting – coughing, sudden movements, tight collar of clothing. When bradycardia becomes severe, heart rate is less than 40 beats per minute, patients suddenly lose consciousness. Such processes are due to brain hypoxia associated with weak blood supply to its vessels. The electrical activity of the heart may be absent for 3-4 seconds. If the impulses are not generated longer, complete asystole occurs – the cessation of the activity of the heart. With the development of discirculatory encephalopathy, the manifestations of the disease intensify. Patients experience paresis and paralysis, instantaneous memory lapses, speech defects, irritability, insomnia, impaired thinking, depression, followed by aggression.
- Cardiac signs of pathology: slow heartbeat, weak pulse, cardialgia, shortness of breath, feeling of lack of air, frequent and deep breathing, weakness. In patients, sinus bradycardia and other forms of arrhythmias are detected. The pathology is characterized by the symptom of “tahi-brady” – a paroxysmal alternation of fast and slow heartbeats. As the syndrome progresses, ventricular fibrillation appears, and the risk of developing sudden cardiac remains increases.
- Other manifestations of the syndrome include: oliguria, intermittent claudication, muscle weakness, gastrointestinal disorders.
Typical clinical symptoms allow cardiologists to suspect this disease in a patient. Bradycardia, a marked reduction in heart rate, deserves special attention. In the diagnosis of SSSU instrumental research methods are of great importance: ECG, ultrasound and MRI of the heart.
- Electrocardiography data – bradycardia, sinus node weakness, periodic change in pacemaker.
ECG signs: missed contractions, bradycardia
- Daily monitoring of ECG according to Holter allows you to detect changes in ECG signs during the day, after exercise and medication, determine the asymptomatic form of the syndrome, record the results of the atropine test and bicycle ergometry.
- EFI – the study of biological heart signals that helps diagnose pathology and choose the right treatment. The essence of the method is the electrical stimulation of a certain part of the heart, which interested cardiologists. During the study, electrograms are recorded. There are invasive and non-invasive techniques. A transesophageal examination consists of inserting an electrode through the esophagus and stimulating heart rate. The main goal of the method is to evaluate the rate of restoration of sinus rhythm using an ECG. When the pause exceeds 1,5 cm, suggest SSSU. If this technique does not reveal signs of pathology, and the patient continues to complain about the symptoms of the syndrome, an EFI with cardiac catheterization is performed.
- Ultrasound and tomographic examinations of the heart make it possible to identify the existing organic pathology and assess the structural and functional state of the organ.
General therapeutic measures for SSSU have two goals – the elimination of a causative disease or factor, the restoration of a normal heart rhythm. In order to fully recover and normalize the work of the heart, it is necessary to seek help from specialists in the field of cardiology and cardiac surgery. After determining the cause of the syndrome, complex therapy is carried out, including drug exposure, diet and special treatment, surgical intervention.
Terms and definitions
Bradyarrhythmia is a malfunction of first-order pacemaker cells (sinus node), or a structure responsible for conducting an excitation pulse from the atria to the ventricles (atrioventricular conduction).
Sinus node stop – loss by the sinus node of the ability to generate pulses in the pacemaker cells of the sinus node.
Sinoatrial blockade is a progressive increase in the blockade from the sinus node to the atria, as well as inside the conduction tissue of the atria, without changing the function of impulse formation in the sinus node.
Tachycardia-bradycardia syndrome – alternation on a standard or daily electrocardiogram of bradycardia with tachyarrhythmia (extrasystole, non-sinus tachycardia).
Binodal disease is a disease with damage to the sinus and atrioventricular nodes.
Pacemaker is a method in which the role of the natural pacemaker (sinus node) is played by an artificial pacemaker. This pacemaker produces electrical impulses of a certain strength and frequency. As an artificial pacemaker use special devices – pacemakers.
Sinus node weakness syndrome (SSS) is a condition caused by a decrease in the functional ability of the sinus node to perform the function of the main pacemaker or to ensure regular conduction of pulses to the atria, which determines the appearance of severe bradycardia and concomitant ectopic arrhythmias.
For the timely detection of children with borderline bradycardia, as well as a risk group for the formation of the syndrome and early diagnosis of the initial stages of CVS, an ECG examination is required. If a bradycardia with a heart rate of less than 5 percentile is found on a standard ECG relative to age norms, an examination by a cardiologist is shown, ECG monitoring of heart rate once a year for at least 1 years. If bradycardia with a heart rate of less than 5 percentiles is detected on a standard ECG, a cardiologist will be examined, ECG – heart rate monitoring once every 2 months.
In order to prevent post-myocarditis bradyarrhythmias, it is necessary to prevent infectious diseases in pregnant women and children, timely appointment of adequate therapy in patients with the development of an infectious disease.
Treatment of the sinus node begins with the elimination of the main factors that can provoke a violation of conduction. For this, the administration of prescribed medications is initially canceled. The main methodology of therapy, which guarantees the best result, is the installation of a pacemaker.
In addition to eliminating external causes, there must necessarily be compliance with the optimal level of load, the elimination of bad habits. It is also necessary to reduce the amount of caffeinated drinks consumed. If there are chronic diseases that affect the functioning of the sinus node, then they must be treated.
In order to prevent deterioration, it is necessary to conduct competent prevention. It implies the observance of the principles of good nutrition, you need to control the regime of the day. In a daily diet should be present foods with a high content of magnesium and potassium, which contribute to maintaining the health of the heart muscle.
Physical activity must be regular, and the load increases depending on the state of health and well-being of the patient. You need to try to exclude from your life psycho-emotional stress and stress. To calm the nervous system, it is advisable to use natural remedies and refuse to take medications.
It is also necessary to control the amount of sugar in the blood and monitor the weight gain in children and adults. You can not take medications uncontrollably, since even the most harmless drugs can provoke a deterioration in the activity of the heart muscle. It is necessary to undergo timely examination and treatment in order to prevent the transition of the disease to a more complex stage.
If there is an increased activity of the nervous system, which is responsible for the activity of internal organs, or there are other, more serious disorders, then medication is performed for weakness of the sinus node. The doctor prescribes drugs that help eliminate dysfunction.
When conducting drug therapy, it is necessary to avoid taking drugs that provoke a decrease in the number of heart contractions and a decrease in pressure. In emergency cases, the drug “Atropine” is administered to the patient. Taking medications is aimed only at eliminating the main symptoms and is a preparatory stage in the surgical procedure.
To eliminate the dysfunction of the sinus node, it is necessary to establish a constant pace in the patient’s body. There are certain indications for installing a pacemaker, which include:
- the simultaneous presence of bradycardia and other heart rhythm disturbances;
- bradycardia with an excessively reduced pulse frequency;
- loss of consciousness with epileptic seizures;
- coronary insufficiency, regular dizziness and fainting.
In this case, the installation of a pacemaker is necessarily indicated, since if treatment is not done in a timely manner, the consequences can be more serious, even fatal.
1.2 Etiology and pathogenesis
SSSU in most cases in children develops in the absence of an organic pathology of the cardiovascular system. Violations of rhythmic driving in childhood can be caused by various factors, for example, autonomic imbalance with a predominance of parasympathetic influences, drug exposure, inflammatory myocardial damage, metabolic disturbance, autoimmune damage by antibodies to the cardiac conduction system [1, 2, 3, 4]. Etiological factors reveal:
- SSSU of organic nature (for cardiomyopathies, amyloidosis, sarcoidosis, collagenoses, coronary heart disease, heart tumors, hormone-exchange cardiotoxic disorders, etc.)
- Regulatory (vagal) dysfunctions of the sinus node (vegetovascular dystonia with a predominance of parasympathetic effects on the heart, hypervagotonia with increased intracranial pressure, cerebral edema, vasovagal reflexes with organ pathology).
- SSSU as a result of toxic effects (antiarrhythmic drugs, cardiac glycosides, antidepressants, hypnotics, poisoning with malathion and other compounds that block cholinesterase).
- Violation of the function of the sinus node (SU) in children after surgical operations on the heart (correction of congenital heart defects – transposition of the main vessels, atrial septal defect, etc.).
- Congenital dysfunction of SU
- Autoimmune dysfunction of SU
- Idiopathic (cause unknown)
In the first four cases, there is the so-called secondary SSSU, the elimination of which is directly dependent on the effectiveness of therapy for the underlying disease. In pediatric cardiological practice, it is often not possible to detect someone with a disease that can lead to impaired function of the sinus node.
Among the pathogenetic mechanisms in the development of idiopathic CVS, the importance of the autonomic nervous system, degenerative changes, apoptosis, and the role of inflammatory myocardial damage are discussed.
The significance of insufficiency of sympathetic influences on the heart in the pathogenesis of progressive dysfunction of the sinus node in children has been proven, while hypoxic lesions in the perinatal and early neonatal periods play an important role in the formation of disorders of the autonomic regulation of the heart .
In experimental works, a model for the development of SSSU was created in which a progressive increase in the severity of electrocardiographic changes was associated with a weakening of the effects of the central nervous system on rhythmogenesis . The issue of the role of autoimmune mechanisms in the development and progression of CVS is actively debated. An increase in titers of anticardial antibodies in patients, along with autonomic dysfunction, may be one of the links in the pathogenesis of the syndrome in children .
An autosomal dominant type and an autosomal recessive type of inheritance of SSSU are described, as well as gene polymorphism in the HCN1-4, CJA5, CJA1 genes responsible for the development of SSSU [8, 9, 10]. The presence of mutations can predispose to the development of sinus node dysfunction or lead to increased sensitivity of sinus node cells to drugs that affect heart rate.
The use of folk remedies
Self-medication with a weak sinus node is unacceptable, which is why before using alternative therapy methods, you should always consult your doctor. When conducting therapy with traditional medicine, special infusions are made from medicinal plants, in particular, such as:
These medicinal herbs contribute to normalizing sleep, combating stress, and improving well-being.
The prevalence of electrocardiographic phenomena that are part of the SSSU symptom complex reaches 0,84% among children with diseases of the cardiovascular system . Among practically healthy children, signs of SU dysfunction on a standard electrocardiogram (ECG) are detected in 2% of children . Sinus bradycardia is the most common (up to 85%) type of bradyarrhythmia in children .
Daily ECG monitoring (SM ECG) reveals a significantly higher prevalence of ECG phenomena that are part of the SSSU symptom complex. When conducting a SM ECG among healthy children, signs of sinus node dysfunction occur in 2,7% of cases . Single nodular contractions at night are recorded in 13% of children , and nodal rhythms in 19% of newborns and 45% of older children [15, 16].
Outcomes and Forecast
It is important to remember that sick sinus syndrome is a dangerous disease that can have many negative consequences. This pathology occurs mainly in older people, however, recently it has also been diagnosed in young children, as well as adolescents. The consequences of the course of the disease can be very serious, in particular such as:
- the formation of permanent sinus bradycardia;
- regular blocking of the heart for several seconds;
- blocking the transmission of pulses of the sinus node;
- frequent attacks of tachycardia;
- atrial flutter.
With incorrect or untimely treatment of the pathological process, a stroke can happen, and this can provoke damage to brain tissue and impaired brain function. In addition, the consequence of such a disease can be the formation of blood clots, which is very life-threatening, since if a blood clot ruptures from the walls of blood vessels, it can lead to death.
Another pathology can be heart failure, which is often formed in the absence of timely therapy and the progression of the disease.
The violation of the impulse conduction by the pacemaker center is not dangerous and does not adversely affect the patient’s life expectancy. The threat is only those consequences that can be triggered by the course of pathology.
The forecast for life expectancy will largely depend on the nature and degree of damage. If abnormalities in the sinus node are formed as complications as a result of the course of the underlying disease, the prognosis for further survival will depend on how severe the damage to the body is.
The initial stage of the formation of SSSU is sinus bradycardia. A steady (more than 3 years) decrease in heart rate of less than 2 percentile on a standard ECG is associated with the development of progressive dysfunction of the sinus node in children [5, 7]. Timely detection of borderline bradycardia and an age-appropriate assessment of heart rate values can often prevent the further development of a generalized degenerative process of the entire cardiac conduction system, when, against the background of untreated treatment, the syndrome progresses in the form of complaints, changes in the ECG, deterioration of hemodynamics, and the addition of atrioventricular and intraventricular disorders .
To determine the prognosis of the disease in children, a comprehensive assessment of clinical and electrophysiological parameters should be carried out, although the presence of clinical symptoms is in some cases of great value in comparison with electrophysiological indicators of the sinus node function. The principles for evaluating the effectiveness of treatment of children with CVS differ from those for other rhythm disturbances.
2.1 Complaints and medical history
Complaints with CVS in children are not specific, and can often be absent. Most often, children complain of dizziness, poor exercise tolerance, shortness of breath on exertion, fatigue and episodes of weakness. The most threatening manifestations of CVD are arrhythmogenic syncope and sudden cardiac death.
In children with initial manifestations of CVS, reflex syncope may develop, resulting from a sharp drop in total peripheral vascular resistance or blood pressure, and arrhythmogenic syncope is more common in children with IV and III variants of the disease .
- Medical history is extremely important in patients with CVS. When collecting an anamnesis, it is recommended:
- to assess the presence and severity of bradycardia on a patient’s retrospective ECG,
- conduct an ECG analysis of relatives for the presence of hereditary bradycardia,
- to analyze clinical data (the presence of complaints of pre-fainting and fainting conditions, the age of their appearance, the connection with past diseases, provoking factors, the presence of aura, seizures and involuntary urination during syncope, subjective sensations of fainting and fainting, heart rate (HR) and blood pressure (BP) during syncope, duration of syncope, especially relief .
2.3 Laboratory Diagnostics
- A clinical blood and urine test is recommended to rule out inflammatory changes.
The level of credibility of recommendations 2 (level of evidence reliability – A).
- A biochemical blood test is recommended with an assessment of the level of electrolytes and mercury damage to the myocardium (creatinine phosphokinase, troponin I, protein binding fatty acids, lactate dehydrogenesis), the blood lipid spectrum (cholesterol, triglycerides), the activity of cytolysis enzymes (alanine transaminase, aspara.
- It is recommended to determine the level of thyroid hormones (thyroid-stimulating hormone, T4 free, antibodies to thyroid pyroxidase to exclude the secondary genesis of bradyarrhythmias.
- An immunological study is recommended to determine the level of specific antibodies to antigens of the cardiac conduction system, cardiomyocytes (antifibrillar, antisarcolemma and antinuclear antibodies), smooth muscles and endothelium.
2.5 Other diagnostics
For the differential diagnosis of SSSU and autonomic sinus node dysfunctions, additional tests are used.
A test with active orthostasis or 10 squats when removing a standard resting ECG is recommended.
The level of credibility of recommendations is 1 (level of evidence is B).
Normally, when conducting minimal physical exertion, heart rate increases by 10-15% of the initial values . An insufficient increase in heart rate, the appearance of cardiac arrhythmias, impaired repolarization processes is a prognostically unfavorable factor and indicates the presence of CVS .
There are various methods for performing dynamic (dosed) physical exercises – bicycle ergometry using a bicycle ergometer, treadmill (track), etc. In pediatrics, the most physiological test is recommended – the treadmill test.
The arrhythmogenic effect of the load is due to a number of physiological factors – an increase in heart rate, an increase in blood pressure, an increase in the release of catecholamines and an increase in the activity of the sympathetic system, an increase in tissue hypoxia, acidosis, etc. The maximum heart rate during a physical exercise test is calculated using the formula 208 – 0.
7 x age in years . The increase in heart rate during a stress test reaches normally 70-85% of the initial heart rate . As a rule, the maximum heart rate in response to the load in healthy children and adolescents reaches 170-180 per minute. In patients with SSSU during dosed physical activity, heart rate rises to a maximum of 100-120 per minute.
If sinus bradycardia is associated with an increase in the activity of the parasympathetic system, then the increase in heart rate is more pronounced. The criterion for the presence of CVS during a test with a dosed physical load in children can be the maximum heart rate in response to a stress test less than 170 per minute, as well as an inadequate decrease in heart rate when it is stopped.
Additionally, it is recommended that an active clino-orthostatic test be performed to assess the effect of the autonomic nervous system.
The normal response is determined by the absence of complaints, an increase in heart rate by 20-40% from the initial, short-term rise in blood pressure by 5-10 mm Hg when standing up and returning to the initial values after 1-3 minutes with a horizontal position, as well as a decrease in pulse pressure in the process of performing the sample no more than 50% .
It is recommended that a test with atropine is used to eliminate parasympathetic effects on the heart rhythm.
A 0,1% solution of atropine sulfate in a dose of 0,02 mgkg is administered intravenously. After 1, 3 and 5 minutes after the introduction, the rhythm and increase in heart rate are compared with the outcome, and then the return of heart rate to the outcome is monitored. Normally, after administration of atropine, a steady sinus rhythm with a heart rate corresponding to age should be observed, and the relative increase in heart rate should be at least 30% .
Detonic – a unique medicine that helps fight hypertension at all stages of its development.
The complex effect of plant components of the drug Detonic on the walls of blood vessels and the autonomic nervous system contribute to a rapid decrease in blood pressure. In addition, this drug prevents the development of atherosclerosis, thanks to the unique components that are involved in the synthesis of lecithin, an amino acid that regulates cholesterol metabolism and prevents the formation of atherosclerotic plaques.
Detonic not addictive and withdrawal syndrome, since all components of the product are natural.
Detailed information about Detonic is located on the manufacturer’s page.