Violation of repolarization processes on ECG

If both the ST segment and the T tooth are altered (shifted), the physician records a repolarization disorder on the ECG. In a healthy person, the ST segment is isoelectric and has the same potential as in the interval between the T and P teeth.

The ST segment change from isoline may be due to various factors, from myocardial injury and asynchrony of ventricular myocardial depolarization to response to exposure to certain medications or electrolyte imbalances.

Causes ECG repolarization abnormalities

Repolarization is the phase of restoration of the initial resting potential of the nerve cell barrier after a nerve oscillation. During the oscillation, the structure of the barrier at the molecular level is temporarily changed, as a result of which it becomes passable for ions. The ions are able to diffuse back, which is necessary to restore the original electrical charge. After that, the nerve again shows readiness for further oscillations.

The most common causes of repolarization abnormalities on ECG are:

• coronary heart disease;
• Increased and excessive strain of ventricular muscle tissue;
• an incorrect depolarization sequence;
• Disruption of water-electrolyte equilibrium;
• a reaction to taking certain medications.

Individuals of primary school age and up to adolescence often have quite intense repolarization disorders, which correlate with positive dynamics without special therapeutic measures.

A positive prognosis may occur in patients with metabolic (functional) origin of repolarization disorders. It is important to thoroughly examine persons with such disorders in hospital conditions, with further involvement of appropriate specialists for complex therapeutic measures. It is possible to prescribe corticosteroid drugs, Panangin, Anaprilin, vitamins, cocarboxylase. Dispensary control is obligatory.

Pathogenesis

The mechanism of repolarization disorder formation on ECG has not been sufficiently studied to date. Presumably, the failure occurs due to changes in ion flow at the stage of repolarization of cardiomyocytes, including those associated with the imbalance of potassium and sodium ions. The imbalance negatively affects the quality of myocardial conduction and excitability, which is manifested accordingly on the electrocardiogram.

In the course of numerous experiments, scientists have found that a variety of factors can cause repolarization failure. They can be divided into several categories:

• Pathological processes due to dysfunction or improper function of the neuroendocrine apparatus, which indirectly coordinates the coherence of the entire cardiovascular mechanism;
• cardiac pathologies (coronary artery disease, hypertrophic changes, disorders of water-electrolytic balance);
• medication influences, the use of certain drugs that have an unfavorable effect on the condition and work of the heart.

It is important to consider possible nonspecific repolarization abnormalities on ECG - particularly those diagnosed in adolescent patients. The exact causes of the problem in adolescents have not been established to date. Practicing physicians indicate that this problem is quite often detected, although they note that in many cases the disorder in adolescents disappears without any medical intervention.

Electrical instability of the heart muscle is considered an important prognostic factor, reflecting myocardial vulnerability to the occurrence of dangerous rhythm disturbances.

Drugs that can cause Q-T interval prolongation

• Antiarrhythmic drugs (Quinidine, Lidocaine, Flecainide, Amiodarone, Bepridil).
• Cardiac medications (Adrenaline, Vinpocetine).
• Anti-allergic drugs (Terfenadine, Ebastine).
• Antibacterial drugs (Erythromycin, Azithromycin, Epirubicin, Clarithromycin, oleandomycin phosphate esters).

Forms

Myocardial repolarization disorder on ECG is diagnosed in approximately 6-12% of the population. Early repolarization can have a favorable course if the patient does not have dangerous signs such as impaired consciousness, seizure-like tachycardia, family history (family history of sudden cardiac death).

Depending on the ECG changes, early repolarization syndrome is divided into several types:

1. A syndrome with a favorable course.
2. Medium-Intermediate Risk.
3. Intermediate risk.
4. A syndrome with a dangerous course.

Sex and ethnicity, concomitant cardiovascular diseases play a prognostic role. For example, older male patients have a worse prognosis.

Meanwhile, repolarization disorder on ECG in adults can be a variant of norm if ST segment elevation is combined with upward movement of the ST segment separation point from the QRS complex.

In adolescence, the problem is quite common, which may be associated with both excessively intense sports activities and organic lesions of the heart muscle mitral valve prolapse.

Violation of repolarization on ECG in women can be associated with peculiarities of hormonal activity. Thus, female sex hormones estrogen and progesterone are able to change these processes. In the first phase of the monthly cycle, prolongation of corrected Q-Tc during ibutilide infusion is noted. Presumably, a favorable effect in the period of menopause may be provided by substitution of progestins.

Repolarization disorder on ECG in pregnancy can be a variant of the norm, being a kind of reaction of the cardiovascular apparatus to a new condition for it. Nevertheless, all women with a detected problem should be comprehensively examined to exclude cardiovascular pathology.

Violation of repolarization on ECG in a child is far from always poses any danger to health and life. The problem may be temporary, caused by a recent acute respiratory viral infection, anemia (low hemoglobin), malnutrition. In such situations, dynamic monitoring is often established with regular scheduled visits to a pediatric cardiologist.

Inferior wall repolarization disorder on ECG represents a displacement of the ST segment and T tooth. In a healthy person, electrocardiography reveals an isoelectric ST segment with the same potential as the gap between the T and P teeth.

Lateral wall repolarization disorder on ECG is often detected in people with idiopathic ventricular tachycardia. Two variations of shortened Q-T interval are known:

• constant (has no effect on heart rate);
• transient (determined due to a slowing of the heart rate).
• The problem is usually associated with genetic disorders, elevated body temperature, elevated potassium and calcium levels in the blood;
• increasing acidosis, changes in the tone of the nervous system.

Anterior wall repolarization abnormality on ECG itself is most often a congenital anatomical feature rather than a disease. If there are no other risk factors, such as obesity, smoking, high cholesterol - there are usually no complications. A more significant risk in this situation is misdiagnosis, when a mild ventricular repolarization disorder on ECG is mistaken for more serious pathological conditions - in particular, myocarditis or ischemic heart disease. If misdiagnosed, the patient is prescribed treatment that is not really necessary, so in general it can cause irreparable harm. To prevent this from happening, a thorough diagnosis should be carried out, involving a number of techniques and several specialists at the same time.

Diffuse repolarization disorder on ECG may mean:

• a variant of the norm in some cases;
• inflammatory process in the myocardium;
• improper metabolic processes in the myocardium - for example, associated with changes in hormonal balance;
• the development of cardiosclerosis;
• Disorders of water-electrolyte metabolism - particularly in the heart muscle.

It is important to realize that the intensity of diffuse changes can be different, including quite small. For example, this is often due to mere age-related changes in the myocardium.

Diffuse repolarization disorders are not a stand-alone diagnosis or a single pathology. It is only one of the diagnostic markers that indicate the need for a more thorough examination.

Diagnostics ECG repolarization abnormalities

Diagnostic measures are based on the results of electrocardiography. The specialist pays attention to typical changes - in particular, ST-segment elevation and J wave.

Additional techniques such as echocardiography, stress tests, Holter monitoring, electrophysiologic diagnostics are often used to clarify the diagnosis and differential workup.

Instrumental diagnostics in the form of echocardiography (ECHO-CG, cardiac ultrasound) involves the use of ultrasound vibrations to visualize the structure of the heart and study its function. ECHO-CG allows you to establish the size, shape and performance of the heart, assess the state of the valve system, pericardium and heart muscle, detect malformations and other pathologies. Thanks to echocardiography, it is possible to monitor the dynamics of treatment of repolarization disorders. The method is considered safe and accessible, not requiring special preparatory measures.

In addition, a patient with repolarization disorder is prescribed laboratory tests:

• general clinical examinations of blood and urine;
• blood biochemical study (blood glucose index, total cholesterol with fractions, somatotropin, catecholamines, ALT, AST);
• molecular genetic testing of the blood;
• cytanalysis of cardiac biopsy specimens (to assess the morphostructure of cardiac tissues).

Differential diagnosis

Patients who complain of chest pain and at the same time have repolarization abnormalities on electrocardiogram always require differential diagnosis. For example, early ventricular repolarization abnormalities on ECG should be distinguished from anterior myocardial infarction, in which ST elevation is greater, QT interval is longer, and R amplitude in _V4 is smaller.

• To clearly distinguish between early repolarization and infarction, a special indexing based on three electrocardiographic parameters is used:
• STe - ST elevation 60 ms after J in lead _V3 (mm);
• QTs - QT interval corrected for heart rate (ms);
• _RV4 is the amplitude of the R waveform in lead _V4 (mm).

The specified parameters are used in the formula:

Index definition = (1.196 * Ste) + (0.059 * QTc) + (0.326 * _RV4)

A score greater than 23.4 in most cases indicates acute coronary syndrome with ST-segment elevation due to occlusion of the anterior interventricular branch.

Treatment ECG repolarization abnormalities

The treatment strategy used depends on the underlying cause of the ECG repolarization disorder. If the doctor was able to identify this cause, then the main direction of therapeutic measures should be the impact on it, after which a second diagnosis is carried out. If the cause of repolarization disorder has not been identified, then treatment is based on the use of the following groups of drugs:

• Multivitamins (used to maintain full cardiac function, ensuring the intake of important components in the body);
• corticosteroid hormones (first of all, it is important to take cortisone, which has a beneficial effect on the cardiovascular system);
• cocarboxylase g/x (helps optimize carbohydrate metabolism, improves trophic processes in the central and peripheral nervous system);
• Panangin, Anaprilin (group of β-blockers, prescribed only in extreme cases).

The standard of treatment of active ECG repolarization disorders is the use of β-adrenoreceptor blockers in excessive dosages (in children - up to 2 mg per kilogram of weight per day. The beneficial effect of such medications is associated with blocking sympathetic influences on the cardiovascular apparatus and reducing the dispersion of repolarization of the muscular wall of the ventricles, which allows to prevent subsequent arrhythmic attacks.

β-adrenoreceptor blockers are successfully combined with magnesium (magnesium sulfate), potassium, and sodium channel blockers (Flecainide, Mexiletine).

If the patient against the background of repolarization disorder is noted anxiety, phobias, treatment is supplemented with short courses of tranquilizers (eg, Diazepam).

Sedatives are prescribed 3 times a day, less often - once a day (in the afternoon). It is recommended to take such drugs on an unscheduled basis during periods of excitement, psycho-emotional stress.

Regular courses of sedative phytotherapy can often help avoid the prescription of neuroleptics and tranquilizers.

Plant adaptogens capable of stimulating the central nervous system and sympathetic section of the central nervous system are appropriate for patients who complain of feelings of lethargy, lethargy, apathy, persistent drowsiness and a drop in performance.

In some cases of repolarization disorder, the use of nootropics - drugs that activate the central nervous system - is indicated. Among such medications: Piracetam (2.4-3.2 g per day, possible side effects - dizziness, ataxia), Aminolone, Picamilon.

In hyperexcitability prescribe nootropics that have a sedative effect: Phenibut, Pantogam, Glycine (3-6 tablets per day for three doses), and so on.

To prevent cardiac muscle dystrophy, stabilization of cardiocerebral connections use membrane-stabilizing agents with energy-tropic and antioxidant activity. Such drugs are:

• Ubiquinone;
• L-carnitine;
• Mexicor;
• Lipoic Acid;
• B vitamins.

An essential energy-forming cellular component - coenzyme Q10 (Ubiquinone)- is of great importance in ATP synthesis processes. The drug is standardly taken 30 mg daily, once a day, to improve energetic processes in the body.

Therapeutic measures for repolarization disorder on ECG also include competent organization of work and rest, compliance with the daily routine, regular physical activity, massage, aromatherapy, psychotherapy, nutrition, acupuncture (when indicated). Proper daily routine, adequate time for sleep, body weight control, balanced quality nutrition and avoidance of bad habits - these factors play a paramount role in stabilizing biological rhythms, improving the cardiovascular, parasympathetic and sympathoadrenal system.

Therapeutic physical training plays a special role. The basis of physical therapy in repolarization disorder should be training that optimizes overall performance, heart and lung function, adapts the cardiovascular and respiratory apparatus to a variety of physical and psycho-emotional stresses, and increases the endurance of the organism. Any therapeutic exercise should be prescribed and coordinated by a medical specialist, depending on the general state of health of the person, his or her fitness, clinical picture of pathology, etc.

If ischemic heart disease is diagnosed, the patient is recommended to do dosed physical activity, walking at a moderate pace, dosed climbing stairs. If the loading moments are calculated correctly, the patient will not experience shortness of breath, weakness, chest pain, changes in blood pressure, heart rhythm disturbances.

Therapeutic exercises may include a variety of breathing exercises, relaxation, balance and coordination exercises. Corrective exercises, endurance training are mandatory. Properly selected load improves metabolic processes in the myocardium, reduces its need for oxygen, prevents the development of complications (including thrombosis).

In almost all cases of repolarization disorders on ECG, doctors recommend spa treatment. Contraindications may be:

• decompensated circulatory failure;
• severe atherosclerosis;
• severe hypertension with a tendency to probable cerebral circulatory failure;
• frequent angina attacks.

Weakened patients are recommended cardiological sanatorium rest, involving a gentle procedural program. Water procedures are limited to rubbing, and climatotherapy - to aerotherapy.

Physiotherapy treatment

An important part of the complex treatment of ECG repolarization disorders is non-medication therapy. It involves the use of psychotherapy, autotraining, increasing stress resistance and normalizing the general state of the nervous system.

Courses of physical therapy are recommended, including:

• magnesium electrophoresis;
• electrophoresis with bromine on the area of the upper cervical segment of the spinal column);
• hydrotherapy, therapeutic baths, mud treatment;
• manual therapy (back massage, chest massage).

To optimize the blood supply to the heart muscle in repolarization disorder can be used:

• paravertebral amplipulsterapy on the area _C5 - _D6;
• darsonvalization on reflexogenic areas of the cardiac site;
• magnetotherapy on the thoracic spine area or on the cardiac area to reduce increased platelet aggregation, improve microcirculation, and optimize myocardial oxygen supply;
• hydrobalneotherapy, rain and circular showers, hydrogen sulfide, pearl and iodobromic baths;
• general aeroionization;
• therapeutic exercise (walking, walking, therapeutic gymnastics);
• oxygen therapy.

Physical therapy is not prescribed to patients with unstable or spontaneous angina pectoris, severe circulatory insufficiency, chronic cardiac aneurysm, as well as in the acute period of myocardial infarction, with intense arrhythmias, acute vegeto-endocrine dysfunction.

Herbal treatment

Moderate symptomatic manifestations of repolarization disorder on ECG often do not require any specific therapeutic measures. The doctor may recommend phytotherapy with the use of herbs with sedative action - in particular, valerian root, motherwort. The following collection of medicinal plants is effective:

• sage;
• Ledum;
• motherwort;
• St. John's wort;
• hawthorn;
• valerian.

Such a collection not only improves heart function, but also has a mild dehydration effect.

In order to stabilize the heart, various herbal mixtures are recommended, depending on the specifics of the disorders present:

• Patients with tachycardia should drink infusions based on valerian root, motherwort, hop cones, anise seed, caraway seed, fennel.
• Patients with bradycardia are indicated decoctions and infusions of yarrow, aralia, eleutherococcus.
• In arrhythmias is useful to drink infusions of hawthorn and rose hips, raspberry and strawberry leaves, tea rose flowers.

In repolarization disorder, phytotherapy should not be practiced on its own, without the advice of a doctor. Medicinal plants also have contraindications for use:

• myocardial infarction;
• acute cerebral circulation disorder;
• acute angina attack;
• paroxysmal tachycardia.

Before using any phytopreparation, you should definitely consult with a cardiologist.

Surgical treatment

If drug treatment does not have a positive effect, implantation of electrical pacemakers is used. The minimum effective stimulation rate is 70 beats per minute. It is also possible to place cardioverter-defibrillators with simultaneous administration of β-blockers. Pacemaker placement is indicated in patients with severe bradycardia in the interictal phase.

Patients with intolerance or ineffectiveness of β-blockers, lack of effect from pacemakers and contraindications to cardioverter-defibrillator installation undergo left-cervical-thoracic sympathogangangliectomy. This allows leveling the sympathetic imbalance of cardiac innervation. Sympathectomy is performed at the level of _T1-T4 and the stellate ganglion (or its lower third). Despite the effectiveness of this method, there is information about possible subsequent recurrences of repolarization disorder on ECG in remote periods.

Long-term practice shows that a healthy lifestyle, adequate physical and stress load, as well as additional methods of spa and physiotherapy can significantly prevent the development of complications in patients with repolarization changes. Rehabilitation and preventive treatment is recommended when many chronic heart diseases are detected beyond the stage of recurrence and against the background of stability of the general condition. The need for additional treatment is assessed by the doctor individually.

Forecast

In general, repolarization disorder on ECG has a favorable prognosis in most cases.