The syndrome of early repolarization
Syndrome of early repolarization of the ventricles is the appearance of uncharacteristic changes in the normal electrocardiography in the form of a pseudo-coronary elevation of the ST segment above the isoline in the thoracic leads and an additional wave J in the terminal part of the QRS complex.
The first information on these ECG registration changes was noticed in the middle of the XX century and for a long time the cardiologists of the whole world did not betray these changes of great importance. In recent years, the attention of scientific figures in the field of cardiology has been turned to the problem of the phenomenon of early repolarization of the ventricles, since these changes have become more frequent in children and young able-bodied people, causing a persistent upsetting of cardiac activity.
According to the world statistics, in the general population the syndrome of early repolarization of the ventricles occurs in 1-9% of the population and the risk group includes: black men under 35 years old, patients suffering from collagen dysplastic nature, as well as patients with cardiac pathology accompanied by a cardiac disorder.
Syndrome of early repolarization of the cause of
The syndrome of early repolarization refers to the cardiac pathology of unknown etiology, since this pathology is equally important for both healthy individuals and people with various diseases. However, there are nonspecific factors that cause ECG changes that are characteristic of the early repolarization syndrome, which include:
- long-term administration or overdose with drugs of the adrenomimetic group;
- supercooling;
is a family type of hyperlipidemia( congenital increased low-density lipoprotein and insufficient level of high-density lipoproteins in the blood), which results in atherosclerotic heart disease;
- the patient has dysplastic disorders of connective tissue in the form of the appearance of additional chords in the cavity of the ventricles of the heart;
- obstructive hypertrophic cardiomyopathy in 12% of cases is associated with manifestations of the syndrome of early repolarization;
- the patient has congenital or acquired heart disease.
Recently, studies have begun to identify the possible genetic nature of this pathology, but so far there is no reliable data on the transmission of the syndrome of early repolarization by inheritance.
The basis of the etiopathogenetic mechanism of the appearance of early ventricular repolarization signs is the violation of the conduct of the electric pulse along the conducting paths going from the atria to the ventricles and the activation of abnormal pathways. Among the researchers, there is an opinion that the appearance of a notch in the final part of the QRS complex is nothing else than a delayed delta wave. In favor of data on the activation of additional ways of carrying out an electrical impulse, which are the primary cause of the syndrome of early repolarization, the shortening of the P-Q interval in most patients is indicative.
In addition, the basis for the emergence of the syndrome of early repolarization is the imbalance in the electrophysiological mechanism of changing the processes of repolarization and depolarization in individual myocardial structures localized at the apex of the heart and in its basal regions.
With normal cardiac activity, the processes of repolarization and depolarization occur in a strict order and in the same direction. So, repolarization always begins with the epicardium of the base of the heart and ends in the endocardium of the apex of the heart. With the syndrome of early repolarization, repolarization processes are sharply accelerated in the subepicardial layers of the myocardium.
There is a clear dependence of the development of the syndrome of early repolarization in dysfunctions of the autonomic nervous system. The vagal genesis of this phenomenon is proved by carrying out tests with dosed physical activity and drug test with isoproterenol, after which the patient has normalized ECG-indicators and opposite deterioration of ECG-signs during the night sleep.
An important factor in the development of the syndrome of early repolarization of the ventricles is the state of electrolyte balance in the body. Thus, under experimental conditions, during randomized trials, a clear dependence of the progression of signs of early repolarization syndrome with hypercalcaemia and hyperkalemia was revealed.
Syndrome of early repolarization symptoms
Concerning the definition of specific clinical symptoms, characteristic exclusively for the syndrome of early repolarization, many experimental large-scale studies were carried out, but they were unsuccessful. Changes in ECG indicators are recorded under equal conditions not only in patients with cardiac pathologies, but also among healthy young people.
Despite the absence of bright specific clinical manifestations of the syndrome of early repolarization, changes in the conduction system of the heart can be accompanied by the appearance of various forms of arrhythmia( supraventricular tachyarrhythmias, ventricular extrasystoles, ventricular fibrillation and other tachyarrhythmias).
Due to the increased risk of arrhythmogenic complications, the syndrome of early repolarization is a threat to the life and health of patients. In the world statistics, there are a large number of registered lethal outcomes from asystole in ventricular fibrillation, which arose against the background of the syndrome of early repolarization.
In addition, in 50% of cases, the syndrome of early repolarization is accompanied by diastolic and / or systolic dysfunction of the heart, manifested in various forms of central hemodynamics disorder.
Often the syndrome of early repolarization is combined with the syndromes caused by the influence of humoral factors on the hypothalamic-pituitary system( vagotonic, tachycardia, hyperamphotonic and dystrophic syndromes).These pathological disorders are more typical for children suffering from neurocirculatory dystonia.
Syndrome of early repolarization in children
Recently, cardiologists have noted a tendency to increase the incidence of the syndrome of early repolarization of the ventricles among children.
The phenomenon itself does not cause severe cardiac disorders, children with early repolarization syndrome must undergo a standard blood and urine test, ECG-registration in dynamics, as well as echocardiography in order to determine the possible cause of the disease and associated diseases.
If the child has an "isolated syndrome of early repolarization," that is not accompanied by another cardiac pathology, then it is not advisable for such patients to use medical therapy, but only to normalize eating behavior( to balance nutrition and enrich the child's menu with products containing micronutrients useful for the organism), To limit excess physical activity and to exclude the influence of stressful situations.
Obligatory is the prophylactic passage of ultrasound of the heart and ECG 2 r. A year and, if necessary, correction of drug treatment by a cardiologist.
Antiarrhythmic agents should be prescribed only with confirmed cardiac rhythm disturbances in ECG studies. For preventive purposes, children are recommended to use drugs that contain magnesium.
Early Repolarization Syndrome on ECG
The only reliable method for diagnosing the phenomenon of early ventricular repolarization is the ECG study. When the patient turns to the functional diagnostics room, the ECG-study allows to reveal the signs of the syndrome of early repolarization. To detail the diagnosis, it is necessary to resort to recording ECG with exercise, as well as daily monitoring of the ECG.
The main group of ECG signs characteristic of the phenomenon of early repolarization include:
- the ST segment displacement is more than 3 mm above the isoline;
- in the thoracic leads simultaneous increase of the R wave, leveling of the S-wave as a sign of disappearance of the transition zone;
- the appearance of a pseudorail r in the end part of the tooth R;
is an extension of the QRS complex;
- displacement of the electrical axis to the left;
- the appearance of high asymmetric waves T.
As a rule, in addition to the standard ECG study, patients should be registered ECG under additional loads( physical or drug loading) in order to determine the dynamics of ECG signs of the phenomenon of early repolarization.
For repeated visits to patients with a cardiologist, it is necessary to provide archival ECG records, since changes in the phenomenon of early repolarization can simulate an attack of acute coronary insufficiency. The main difference of the syndrome of early repolarization from acute myocardial infarction is the constancy of changes in the ECG and the absence of chest pain with typical irradiation.
Syndrome of early repolarization treatment of
To all persons suffering from the syndrome of early repolarization, severe physical activity is contraindicated. Correction of eating behavior implies the inclusion in the diet of products containing potassium, magnesium and B vitamins( greens, vegetables and fruits in its raw form, sea fish, soy and nuts).
In most cases, the syndrome of early ventricular repolarization does not need a medical correction, but if the patient has reliable signs of concomitant cardiac pathology( coronary syndrome, various forms of arrhythmia), then the appointment of specific drug therapy is recommended.
Numerous randomized trials have proven the efficacy of preparations of electro-tropic therapy in relieving symptoms of early repolarization syndrome in both children and adults. Of course, the drugs of this group do not belong to the drugs of choice for this pathology, but their use improves the trophism of the heart muscle and prevents possible complications from the heart. Among the most energotropic drugs, the most effective in this situation are: Kudesan in a daily dose of 2 mg per 1 kg of body weight, Carnitine 500 mg 2 r. A day, a complex of B vitamins, Neurovitan 1 dragee per day.
Among antiarrhythmic drugs, it is expedient to prescribe a group of drugs that slow down the process of repolarization - Novokainamid in a dose of 0.25 mg every 6 hours, Quinidine sulfate 200 mg 3 times a day, Etmozin 100 mg 3 times a day.
Among the invasive treatment methods, the most effective in the syndrome of early repolarization is catheter radiofrequency ablation, with the help of which it is possible to locally eliminate a bundle of pathological pathways that cause rhythm disturbance. This technique is used for severe cardiac rhythm disturbances that have arisen against the background of the syndrome of early repolarization.
Despite its effectiveness, catheter ablation, like any surgical manipulation, can cause complications that threaten the life of the patient( cardiac tamponade, pulmonary embolism, coronary artery disease), and therefore, it is necessary to differentiate the question of the appointment of this method of treatment.
In a situation where a patient with established early repolarization syndrome has repeated attacks of ventricular fibrillation, the patient should be prepared for the implantation of a defibrillator-cardioverter. Modern microsurgical approaches in cardiology allow to install defibrillators in a minimally invasive manner without thoracotomy. Cardioverter-defibrillators of the third generation do not cause adverse reactions and their operation is well tolerated by patients. Currently, this technique is the best in the treatment of arrhythmogenic pathologies.
