Syndrome of weakness of the sinus node in children

Syndrome of weakness of the sinus node (SSSU) - one of the most polymorphic violations of the heart rhythm in children, associated with the risk of development of syncopal conditions.

The basis of the syndrome is the changes in the functional state of the main source of the heart rhythm, which for various reasons can not fully perform the role of a leading pacemaker and control the rhythm driver from a certain point.

ICD-10 code

In ICD 10, the sinus node has a weakness in the code 149.5 under the heading "Heart rhythm disturbances."

Epidemiology of sinus node weakness syndrome

The prevalence of sinus sinus weakness syndrome in childhood is quite high and amounts to 1.5 to 5 per 1000, according to different authors, reaching 1% among patients with cardiac pathology. In surgical clinics with sinus sinus syndrome, about 10% of all cardiac rhythm disturbances are associated. The syndrome of sinus node weakness accounts for up to 30% of all heart rhythm disturbances in children. Up to 50% of patients who need an electrocardiostimulator are affected by sinus node disorders. When examining healthy children, signs of a sinus node function violation with a standard ECG are detected in 2%, and in Holter monitoring - in 2.7%. Sinus bradycardia (the most common manifestation of sinus node dysfunction) is found in 3.5% of healthy school children. According to the population ECG screening of children in Russia, including ECG data 5441 children, the prevalence of rhythm migration is 1.9%, slipping and replacing supraventricular rhythms - 0.7%, and sinoatrial blockade - 0.3%. In the case of Holter monitoring of children of the first year of life, 19% note slipping and replacing idioventricular rhythms, 7% have sinus node episodes, and 11% have sinoatrial blockades. Thus, those or other phenomena that are an integral part of the symptom complex of sinus node sinus syndrome are common in the population, and a fairly large part of the population has from an early age electrophysiological features that are likely to predispose later to the formation of sinus node function disorders when exposed to various adverse factors.

Causes of sinus node weakness syndrome

While the syndrome of weakness of the sinus node in adults predominantly has ischemic genesis and manifests with atrial fibrillation, in most cases in children it develops in the absence of an organic pathology of the cardiovascular system. Disorders of the pacemaker in childhood are often due to vegetative imbalance with predominance of parasympathetic influences and age involution of the sinus node, as a consequence of inflammatory myocardial lesions, metabolic pathologies, autoimmune lesions by specific antibodies to the conduction system of the heart. For etiologic factors, the following types of sinus sinus weakness syndrome are distinguished.

Causes of sinus node weakness syndrome

Classification of sinus node weakness syndrome

Most of the sinus node weaknesses in the syndrome classification suggested the use of the presence or absence of clinical manifestations, ECG patterns on a standard ECG or Holter monitoring, an increase in heart rate when carrying out samples with physical activity. Since the beginning of the 90s, the division of this pathology into clinical and electrocardiographic variants of the sinus node weakness syndrome in children, depending on the nature, sequence of growth and the degree of manifestation of changes in the conduction system of the heart, taking into account a stable combination of ECG manifestations, circadian changes rhythm according to the holter monitoring, the response of the heart rhythm to the load and the concomitant lesions of the conduction system of the heart.

Classification of sinus node weakness syndrome

Symptoms and Diagnosis of Syndrome of Sinus Node Weakness

In half of the patients, the disease is asymptomatic, and manifestations characteristic of the weakness syndrome of the sinus node are detected accidentally. The reason for going to the doctor in other patients are complaints about syncopal conditions, dizziness, fits of weakness, a sense of interruption and pain in the heart, headaches. In cases where it was possible to obtain previously registered ECG, it was found that 4-5 years before the treatment in the clinic, children already had at least sinus bradycardia or migration of the pacemaker. Thus, in the absence of treatment, i.e. In the course of the natural course of the disease, sinus node dysfunctions progressively progress from sinus bradycardia and pacemaker migration to the appearance of a sinoatrial blockade in 40% of cases, as well as replacement rhythms against a complete failure of the sinus node.

Symptoms and Diagnosis of Syndrome of Sinus Node Weakness

Treatment of sinus node weakness syndrome

Emergency therapy for the development of vertigo, syncopal conditions, severe asystole against bradycardic rhythm disturbances includes the introduction of vagolytic drugs (atropine) or drugs with pronounced beta-adrenomimetic activity (isoprenaline).

The tactic of removing a child from a syncopal condition is an indirect cardiac massage and artificial respiration. The introduction of one of the following drugs is indicated:

• epinephrine in a dose of 0.05 mg / year IM or iv once;
• isoprenaline in / m 0.5-1.0 ml (0.1-0.2 mg) IM or IV once;
• atropine 0.1% solution iv in a dose of 0.01-0.02 mg / kg, not more than 2.0 mg;
• Phenylephrine 1% solution in / m 0.1 ml / year of life (not more than 1.0 ml).

Treatment of sinus node weakness syndrome

Forecast

Adverse sensory signs in children with syndrome of sinus node weakness are fits of loss of consciousness, a progressive decrease in the mean daily, maximum and minimum daily and night heart rate as measured by Holter monitoring, an increase in the number and duration of rhythm pauses, the appearance of additional rhythm and conduction disorders, an inadequate increase in heart rate sinus rhythm during a sample with a dosed physical exertion, aggravation or provocation of additional s rhythm disorders. Prognostically unfavorable family cases of the disease. Sudden cardiac death in families with direct relatives in young (up to 40 years) age is considered as an unfavorable prognosis factor.