Ventricular extrasystole in children

Extrasystoles are an extraordinary, premature heart contraction. This is the most common type of cardiac arrhythmia, found in all age groups, and also observed in practically healthy people. In childhood, the share of extrasystolic arrhythmia accounts for 75% of all arrhythmias.

A common feature of all varieties of extrasystoles is their premature appearance. The adhesion interval (R ~ R) before the extrasystole is shorter than the RR interval of the sinus rhythm. Only recording the esophageal ECG can give an accurate topical diagnosis of extrasystole.

Ventricular extrasystole - premature with respect to the basic rhythm of excitation, coming from the ventricular myocardium. Ventricular extrasystole disturbs the correctness of the heart rhythm due to the prematureness of ventricular contractions, post-extrasystolic pauses and the associated asynchronous excitation of the myocardium. Ventricular extrasystole is often hemodynamically ineffective or accompanied by a decrease in cardiac output. The prognosis of ventricular extrasystole depends on the presence or absence of organic heart pathology, the electrophysiological characteristics of the extrasystole (frequency, degree of prematureness, localization), and also on the ability of ventricular extrasystole to have a negative effect on blood circulation - the hemodynamic efficiency of ventricular extrasystole.

Epidemiology

The frequency of the ventricular extrasystole depends on the method of their detection. With ECG, single ventricular extrasystoles are found in 0.8% of newborns and in 2.2% of adolescents, and in Holter monitoring, 18% of newborns and 50% of adolescents without organic heart disease.

[1], [2], [3], [4], [5], [6],

Causes of ventricular extrasystole in children

The causes of extrasystole are different, but in the overwhelming majority of cases, these are neurogenic disorders of extracardiac origin. Under the action of the parasympathetic system, the permeability of membranes, the level of intracellular and extracellular potassium and sodium changes, the intensity of transmembrane ion currents changes, which is the result of disturbances in excitability, automatism, conduction with the appearance of extrasystole. An important pre-exposure factor in the genesis of extrasystolic arrhythmia is often the migration of the rhythm between the sinus and atrioventricular nodes - a consequence of vagotonia, less frequent intoxication in the organic pathology of the heart.

Extrasystolia can be the result of increased automatism of some cells of the conductor system outside the sinus node.

Diagnostic electrocardiographic criteria are not always sufficient to distinguish between nodal and atrial extrasystoles, therefore the doctor has the right to use the general term "supraventricular extrasystoles".

Another type of extrasystole - ventricular - has long been considered the most common type of rhythm disturbance in children. But recently it has been established that many extrasystoles that were previously taken for ventricular, in fact represent supraventricular with an aberrant QRS complex. In healthy children, there are more frequent single-focus, as a rule, right ventricular extrasystoles. This extrasystole is based on vegetative dystonia.

[7], [8], [9], [10], [11], [12]

Symptoms and Diagnosis of Ventricular Extrasystoles

In most cases, idiopathic ventricular extrasystole is asymptomatic. About 15% of older children with frequent ventricular extrasystole describe "interruptions" or "dips", "missed strokes" in the heart rhythm. Among the other symptoms are asthenovegetative complaints that reflect the dysfunction of the sympathetic or parasympathetic part of the autonomic nervous system (fatigue, sleep disorders, headaches, sudden attacks of weakness, dizziness, poor transport tolerance, cardialgia). With ventricular extrasystole, which developed against the background of organic pathology of the heart, the severity of clinical symptoms depends on the underlying disease. Electrocardiographic criteria of ventricular extrasystole - the presence of premature contractions of the ventricles with a deformed wide QRS complex (more than 60 ms in children under 1 year, more than 90 ms in children from 1 year to 3 years, more than 100 ms in children 3-10 years, more than 120 ms children older than 10 years), sharply differing in morphology from the main sinus rhythm. Pins P are absent or inverted and recorded after the ventricular complex, the ST segment and the G tooth are discordant to the extrasystolic QRS complex, and there may be a drainage complex. Ventricular complexes can be hardly expanded or enlarged slightly in ventricular extrasystole from the base of the highly located posterior branching of the left branch of the bundle or with the participation of macro-re-entry along the legs of the bundle.

Topical non-invasive diagnosis of ventricular extrasystole according to ECG data is performed on the basis of a number of algorithms. Right ventricular extrasystoles are characterized by the morphology of the ventricular complex by the type of blockage of the left leg of the bundle of the Hisnia, left ventricular - by the type of blockade of the right leg of the bundle. This rule has exceptions, due to the fact that ECG data reflect more subepicardial electrophysiological processes, and extrasystoles emanating from zones located endocardially can change their morphology. Overcoming a considerable distance from the endocardium to the epicardium. The most unfavorable load (sympathetic), as well as early and super-early ventricular extrasystoles, superimposed on the descending bend of the T wave, its apex or ascending knee, sometimes to the end of the ST segment of the previous normal QRS complex.

Given the fact that not every type of extrasystole is indicative of autonomic dystonia, all patients with extrasystole should be followed by ECG recording at rest and under stress with cardiologist advice. In clinical practice, extrasystole, as a rule, is detected accidentally - during examination during a respiratory illness or soon after it. Apparently, this is due to the hyperactivity of trophotropic devices in the early period of recovalessence, when the tone of the vagus predominates, against the background of a decrease in the activity of sympathoadrenal mechanisms. Sometimes children themselves actively complain about "blows" in the chest, note violations of the rhythm of the heart, but this is more relevant to the older age group. In general, there are no complaints related to extrasystole or manifestations of hemodynamic disturbances. Such manifestations as dizziness, weakness, are noted only with extrasystolic arrhythmia against a background of severe heart damage with a disorder of general hemodynamics.

Children with extrasystole in the structure of vegetative dystonia make complaints of a traditional property - fatigue, irritability, dizziness, periodic headache, etc. An analysis of the history of life of these children shows that 2/3 children with extrasystole had pathology of the pre- and perinatal period. The role of foci of chronic infection, in particular of chronic tonsillitis, in the genesis of extrasystoles, as shown in recent years, is clearly exaggerated. Even tonsillectomy does not save the children from this arrhythmia, which confirms only the pre-disposition role of this type of pathology. According to their physical development, children with extrasystole do not differ from their peers. Therefore, the clinical evaluation of the extrasystole should be carried out necessarily comprehensively, taking into account complaints, anamnesis, the state of the cardiovascular, central and autonomic nervous systems.

An important feature of extrasystole in autonomic dystonia is a decrease in the frequency of extrasystoles in the orthoposition, with physical loads (bicycle ergometry), with a sample with atropine, which confirms the dependence of the arrhythmia on the condition of the parasympathetic department of the ANS (the so-called labile resting extrasystoles). Cardiologists divide the extrasystoles into rare (up to 5 in 1 min), medium frequency (6-15 per 1 min), frequent (more than 15 extrasystolic complexes in 1 min). It is customary to count extrasystoles for 100 QRS complexes; The components of more than 10% are considered to be frequent. When using daily heart rate monitoring, there is a clear connection between the frequency of the extrasystoles and the functional states of the child's organism - the contraction of the extrasystoles during the period of maximum activity, play; acceleration - in the period of relative dormancy, in the deep stages of sleep.

In the autonomic nervous system, evaluated on the basis of traditional criteria, in children with extrasystole the predominance of the parasympathetic department - vagotonia - or dystonia with prevalence of vagotonic signs (marbling of the skin, increased sweating, diffuse red, rising dermographism, etc.) is noted. These children often suffer from vestibulopathy, increased meteorological dependence and meteotropism. They have other viscervegetative manifestations - nocturnal enuresis, biliary dyskinesia, gastroduodenitis.

Vegetative reactivity in most cases is elevated - hypersympathicotonic. Children with vegetative dystonia and extrasystole usually have insufficient vegetative support of activity (hyperdiastolic, asymptotic-tonic variants of clinoortoprodes are registered in 2/3 of the children). Carrying out bicycle ergometric loading confirms the inadequacy of cardiovascular system reactions, which is manifested by increased heart rate with insufficient increase in arterial pressure (healthy systolic blood pressure increases in proportion to the increase in heart rate), physical performance and tolerance to exercise are reduced in patients. These data confirm the functional insufficiency of the ergotrophic apparatus of the autonomic nervous system, which is manifested by the maladaptive reactions of the sympathetic department.

The study of the central nervous system of children with extrasystole reveals a rough residual symptomatology in the form of separate microorganic signs. Their combination with hypertensive hydrocephalic syndrome, diagnosed by craniograms and echoencephaloscopy, indicates the residual nature of organic cerebral insufficiency, which is the result of unfavorable course of pregnancy, childbirth. Analysis of the state of nonspecific brain systems in children with extrasystole, carried out by the polygraph method in different functional states, shows the dysfunction of the structures of the limbic-reticular complex, which is manifested by the insufficiency of activating and the predominance of deactivating (inhibitory) devices. Cerebral changes are more pronounced with right ventricular extrasystoles with an aberrant QRS complex. Local epileptic activity on the electroencephalogram was not observed in patients with extrasystole.

In the psychological aspect, this category of patients was largely similar to children with arterial hypotension. At the same time, anxiety and depressive disorders with extrasystole are much less severe, hypochondriacal fixation is less in the state of one's own health. It should be noted that, in spite of emotional lability and high level of neuroticism, children with extrasystole had a good time at school, the number of interpersonal conflicts in them was significantly less than with other types of arrhythmias.

Classification of ventricular extrasystole

Ventricular extrasystole is divided according to localization to right ventricular (most often in children from the withdrawal department) and left ventricular. The frequency of occurrence of ventricular extrasystole is subdivided as follows: less than 30 per hour, 30-100 per hour, 100-600 per hour, more than 600 per hour (or up to 5 per minute), 5-10 per minute, more than 10 per minute; or up to 15 000 for 24 hours and more than 15 000 for 24 hours. Ventricular extrasystoles with incidence of more than 5 per minute (according to ECG data) or more than 300 per hour (according to holter monitoring) are considered frequent. Critical in terms of assessing the likelihood of developing secondary arrhythmogenic changes in the myocardium in children is considered to be the ventricular extrasystole with a frequency of recording according to holter monitoring more than 15 000 per day.

Morphology distinguishes monomorphic ventricular extrasystoles (one morphology of the ventricular complex) and polymorphic (more than one morphology of the ventricular complex); on density of an extrasystole - single ventricular ekstrasistolii and paired (paired); Periodicity - sporadic and regular; by the time of occurrence and the degree of prematureness - early, late and interpolated. In view of circadian representation, ventricular extrasystoles are classified as day, night and mixed.

[13], [14], [15], [16]

Treatment of ventricular extrasystole in children

The treatment of extrasystole to the present time is extremely poorly developed, there is much controversy, apparently due to the different evaluation of the degree of organic interest of the heart with extrasystole. Children often do not have to prescribe antiarrhythmic drugs. Therapy should be comprehensive, long-lasting. The questions of drug treatment of extrasystole are described in detail in special manuals on cardiology of childhood. It is necessary to carry out the basic treatment according to the rules of therapy of the appropriate form of vegetative dystonia using the whole arsenal of non-medicament means (acupuncture, physiotherapy, etc.), psychotropic and general restorative drugs, psychotherapy.

Children with ventricular extrasystoles usually do not need emergency treatment. Children with rare ventricular extrasystoles in the absence of data for organic heart damage, violation of central hemodynamics do not need treatment. They need dynamic observation at least once a year, and in the presence of clinical symptoms, Holter monitoring is recommended once a year. Interventional treatment is not indicated.

With frequent idiopathic ventricular extrasystole, it is necessary to monitor the state of the central hemodynamics, the change of which in the form of a decrease in the ejection fraction and the increase in dilatation of the heart cavities is considered an indication for interventional treatment.

Drug treatment of VAG dependent ventricular extrasystoles includes correction of neurovegetative disorders. When detecting signs of diastolic myocardial dysfunction according to EchoCG, disorders of the repolarization process according to ECG or stress tests, metabolic and antioxidant therapy is recommended. Children with ventricular extrasystoles against the background of heart disease show treatment of the underlying disease, correction of metabolic disorders in the myocardium, hypokalemia and hypomagnesemia.

Indications for interventional treatment (radiofrequency catheter ablation) or antiarrhythmic therapy (with the inability to conduct radiofrequency catheter ablation) in children with ventricular extrasystoles are frequent (more than 15 000 ventricular extrasystoles per day) of extrasystole accompanied by the development of arrhythmogenic dysfunction. It is important for children to use the most sparing protocol of radio-frequency influences. In the near postoperative period, a control echocardiographic study, Holter monitoring is recommended. Advantage in the appointment of antiarrhythmic therapy is given to beta-blockers, they reduce the risk of ventricular tachycardia and ventricular fibrillation, do not worsen myocardial function in case of circulatory failure. Selection of antiarrhythmic drugs is carried out under the control of ECG and Holter monitoring data taking into account the saturation doses and the circadian pattern of arrhythmia. The maximum therapeutic effect of the drug is reasonable to calculate, taking into account what periods of the day the ventricular extrasystole is maximally expressed. Exceptions are long-acting drugs and amiodarone. If there is an indication in the anamnesis of a possible association of arrhythmia with an infectious disease, the course of treatment of NSAIDs is administered once. In case of joining the symptoms of circulatory insufficiency, ACE inhibitors are prescribed.

The prognosis in children with ventricular extrasystoles against the background of organic heart pathology depends on the effectiveness of treatment of the underlying disease and the degree of control of arrhythmia. Criteria for favorable prognosis: monomorphic ventricular extrasystole, suppressed at physical exertion, hemodynamically stable (effective), not associated with organic heart pathology.