Treatment of sinus node weakness syndrome

Emergency treatment of sick sinus syndrome with the development of dizziness, syncopal states, severe asystole against the background of bradycardic rhythm disturbances includes the administration of vagolytic drugs (atropine) or drugs with pronounced beta-adrenergic activity (isoprenaline).

The tactics for bringing a child out of a syncopal state are indirect heart massage and artificial respiration. The administration of one of the following drugs is indicated:

• epinephrine at a dose of 0.05 mg/year intramuscularly or intravenously once;
• isoprenaline IM 0.5-1.0 ml (0.1-0.2 mg) IM or IV once;
• atropine 0.1% solution intravenously at a dose of 0.01-0.02 mg/kg, no more than 2.0 mg;
• phenylephrine 1% solution intramuscularly 0.1 ml/year of life (no more than 1.0 ml).

If severe bradyarrhythmia persists, accompanied by symptoms of weakness, dizziness, presyncopal and syncopal conditions, the child should be taken to a hospital, where the issue of the need for electrical stimulation of the heart will be decided.

The goals of maintenance, long-term therapy are to prevent progression of damage to the sinus node and development of complications (attacks of loss of consciousness, critical bradyarrhythmia) and reduce the degree of impairment of the functional state of the sinus node.

The basis of drug treatment is stimulating therapy with a wide range of action, resorption, membrane stabilizing and metabolic therapy. The following principles must be taken into account during treatment:

• drugs of different groups are prescribed in combination, and not sequentially;
• no more than three drugs from the main groups of oral administration should be prescribed at the same time;
• treatment should be long-term (at least 6 months for option I and at least 12 months for more severe dysfunctions of the sinus node);
• If a long course of treatment is required, drugs of the same group are alternated and prescribed in cycles of 2-3 months;
• all drugs are prescribed in generally accepted age-appropriate doses;
• monitoring of the patient should be regular (at least once every 6 months) and long-term (at least 1 year) after normalization of the rhythm;
• it is necessary to obtain examination data or take an ECG from all relatives of the first and second degree of kinship;
• To monitor the effectiveness of treatment for each child, a method is selected that allows for the most reliable assessment of the individual dynamics of electrophysiological disturbances in the myocardium.

For all variants of sick sinus syndrome, it is indicated to prescribe adaptogens and drugs with a nootropic effect: ginseng, Eleutherococcus senticosus rhizomes and roots, glutamic acid, gamma-aminobutyric acid, pyritinol. Metabolic drugs are used: multivitamins + other drugs (Vitrum Beauty, coenzyme Q10). carnitine, meldonium (mildronate). With a high representation of high-frequency substitution heterotopic rhythm and the addition of arrhythmogenic myocardial dysfunction in children with variant III of the syndrome, antiarrhythmic therapy may be required under the control of heart rate according to ECG and Holter monitoring. Antiarrhythmic therapy is contraindicated in children with a history of syncope, severe suppression of sinus node functions, the presence of a large number of rhythm pauses according to Holter monitoring and / or concomitant AV conduction disorder. In variant IV of the syndrome, stimulating and metabolic therapy is carried out for a longer period (at least 6 months). If high titers of autoantibodies to the cells of the cardiac conduction system are detected (1:160 and higher), courses of NSAIDs and hydroxychloroquine (plaquenil) are recommended.

After high-degree AV blocks, sick sinus syndrome is the most common indication for pacemaker placement, accounting for 20 to 50% of all pacemaker implantations in adults.

Class I indications for pacemaker implantation in children with sick sinus syndrome:

• recurrence of arrhythmogenic syncopal attacks during therapy;
• documented symptomatic bradycardia in patients with sick sinus syndrome with a heart rate below the critical value for a given age.

Class IIa indications:

• tachycardia-bradycardia syndrome (variant III of the sick sinus syndrome, leading to the need to prescribe antiarrhythmic therapy:
• asymptomatic sinus bradycardia with a resting heart rate of less than 35 beats per minute and rhythm pauses of more than 3 s in children with congenital heart defects.

Class IIb indications:

• syncope associated with severe bradycardia, without effect from the therapy;
• the presence of asymptomatic rhythm pauses in a child lasting more than 3 seconds against the background of complex drug therapy carried out for at least 3 months;
• asymptomatic sinus bradycardia with a resting heart rate of less than 35 beats per minute;
• binodal disease with symptoms of AV node damage (AV block II-III degree).

Class III indications: symptomatic sinus bradycardia in adolescents with rhythm pauses of less than 3 s and minimum resting heart rate values of more than 40 beats per minute.

The principles of assessing the effectiveness of treatment of children with sick sinus syndrome differ from those for other rhythm and conduction disorders. One of the differences is the need for clear and reliable registration of the dynamics of not only qualitative but also quantitative indicators, which is due to the large number of ECG phenomena in almost every patient. In the case where there is no positive dynamics, but the manifestations of the syndrome do not worsen, contrary to generally accepted ideas, a "conditionally positive result" should be stated. We justify the latter position by the progressive course of the disease in the absence of adequate treatment. Consequently, stabilization of the electrocardiographic picture indicates a suspension of further development of the pathological process.

Forecast

Unfavorable prognostic signs in children with sick sinus syndrome are considered to be attacks of loss of consciousness, progressive decrease in average daytime, maximum and minimum daytime and nighttime heart rate indicators according to Holter monitoring data, increase in the number and duration of rhythm pauses, occurrence of additional rhythm and conduction disturbances, inadequate increase in sinus rhythm heart rate during a test with dosed physical activity, aggravation or provocation of additional rhythm disturbances during tests. Familial cases of the disease are prognostically unfavorable. Sudden cardiac death in families in direct relatives at a young age (up to 40 years) is considered an unfavorable prognostic factor.