Ventricular extrasystole - Causes, symptoms and treatment. MF.
Jun 26, 2018
Causes of extrasystole
Lifestyle, complications and prognosis of
The contraction of the ventricles of the heart along with atria is carried out by conducting electrical impulses along a conductive system that includes the sinoatrial and atrioventricular nodes, the bundle of the Hisnia and the Purkinje fibers. The fibers transmit signals to the muscle cells of the ventricles that directly discharge the blood from the heart into large vessels( the aorta and the pulmonary artery).In a normally functioning heart, the atria contract synchronously with the ventricles, ensuring a correct rhythm of contractions with a frequency of 60 to 80 beats per minute.
If any pathological process( inflammation, necrosis, scarring) takes place in the cardiac muscle of the ventricles, it can create electrical inhomogeneity( heterogeneity) of the ventricular muscle cells. The mechanism of re-entry of the excitation wave develops, that is, if there is some block in the path of the impulse, an electrically neutral scar tissue, for example, the impulse can not be bypassed, and the muscle cells re-stimulated up to the block level. Thus, a heterotopic( located at the wrong place) foci of excitation in the ventricles arises, causing their extraordinary reduction, called extrasystole. Extrasystolia can occur in the atria, atrioventricular( atrioventricular) connection and in the ventricles. The latter option is called ventricular extrasystole.
Ventricular extrasystole is one of the rhythm disorders, characterized by premature, extraordinary contractions of the ventricles. Distinguish the following types:
- rare( less than 5 per minute),
- medium frequency( 6 - 15 per minute),
- frequent( more than 15 per minute).
2. On the density of the location on the cardiogram, isolated and paired( two contractions in succession) extrasystoles.
3. Localization - right - and left ventricular extrasystoles, which can be distinguished by ECG, but this division has no special significance.
4. By the nature of the locus of excitation
- monotopic extrasystoles emanating from the same focus
- polytopic originating from the located in different parts of the ventricular myocardium of foci of
5. In the form of ventricular complexes
- monomorphic extrasystoles having the same shape over therecords of one cardiogram
- polymorphic, having different forms
6. By rhythmicity
- periodic( allorhythmic) extrasystoles - an extraordinary contraction of the ventricles occurs with a periodicity, for example, every second normal complex "drops out", instead of which there is an extrasystole - bigemini, every third - trigeminia, every fourth -
quadrimony - non-periodic( sporadic) extrasystoles occur irregularly regardless of the leading heart rhythm.
7. Depending on the results of daily monitoring, extrasystoles are classified according to the criteria developed by Laun and Wolff. There are five classes of extrasystoles:
- 0 class - extrasystoles not recorded within 24 hours
- 1st class - rare, up to 30 per hour, monomorphic monotopic extrasystoles
- class 2 - frequent, more than 30 - per hour, single, monomorphic, monotopic extrasystoles
- Grade 3 - single polytopic extrasystoles
- 4A class - paired polytope extrasystoles
- 4B class - volley extrasystoles( more than three in a row at once) and jogging of ventricular tachycardia
- Grade 5 - early and supernumeraryextrasystoles, type «R on T» ECG arising in the early, initial phase of ventricular diastole, when the muscle tissue relaxation observed. Such extrasystoles can lead to ventricular fibrillation and asystole( cardiac arrest).
This classification is important in the prognostic plan, since 0-1 classes of threat to life and health do not represent, and 2 to 5 classes, usually occur against the background of organic heart lesions and have a tendency to malignant course, that is, they can lead to a suddencardiac death.
Causes of ventricular extrasystole
Ventricular extrasystole may develop with the following conditions and diseases:
1. Functional Reasons. Often the appearance of single rare extrasystoles on the ECG is recorded in healthy individuals without any kind of heart disease. This can result in emotional stress, vegeto-vascular dystonia, drinking coffee, energy drinks in large quantities, smoking a large number of cigarettes.
2. Organic heart attack. included in this group of causes:
- ischemic heart disease, 60% of ventricular arrhythmia caused by this disease
- acute myocardial
myocardium - myocardial infarction
- post-infarction left ventricular aneurysm
- postmiokarditichesky cardio
- congenital and acquired heart defects
- small cardiac abnormalities, in particular, mitral valve prolapse
- arterial gPurton
- Chronic heart failure
3. toxic effect on the heart muscle. Develops when the body is intoxicated with alcohol, narcotic substances, drugs - cardiac glycosides, drugs used in the treatment of bronchial asthma( euphyllin, salbutamol, berodual), antiarrhythmic drugs 1 C class( propafenone, etmozin).Also extrasystole can develop with thyrotoxicosis, when there is an intoxication of the body with hormones of the thyroid gland and their cardiotoxic effect.
Symptoms of ventricular extrasystole
Sometimes the extrasystole is not felt by the patient. But in most cases, the main manifestation of the disease are the sensations of cardiac disruptions. Patients describe, as it were, a "somersault", a "turning" of the heart, followed by a feeling of cardiac fading caused by a compensatory pause after the extrasystole, then perhaps a sensation of a push in the heart rhythm caused by an intensified contraction of the ventricle after a pause. In cases of frequent extrasystoles or episodes of ventricular tachycardia, a feeling of rapid heartbeat is possible. Sometimes such manifestations are accompanied by weakness, dizziness, sweating, anxiety. In cases of frequent extrasystole, loss of consciousness is possible.
Complaints that are poorly tolerated by the patient, which occurred suddenly or for the first time in life, require urgent medical attention, so you need to call an ambulance, especially if the pulse is more than a hundred beats per minute.
In the presence of organic heart disease, the symptoms of the extrasystole proper are supplemented with manifestations of the underlying disease - heart pain in IHD, dyspnea and edema with heart failure, etc.
In the case of ventricular fibrillation, clinical death occurs.
Diagnosis of the extrasystole
The following methods are used for the diagnosis of ventricular extrasystole:
1. Questioning and clinical examination of the patient.
- assessment of complaints and anamnesis( history of the disease) allows to presume a diagnosis, especially if there is an indication of the organic pathology of the heart in the patient. The frequency of occurrence of disruptions in the heart, subjective sensations, connection with the load is found out.
- auscultation( listening) of the chest. When listening to the heart, weakened heart tones, pathological noises( for heart defects, hypertrophic cardiomyopathy) can be determined.
- when probing the pulse, an irregular pulse of different amplitude is recorded - before the extrasystole, the contraction of the heart sets a small amplitude to the pulse wave, after the extrasystole - a large amplitude due to an increase in the blood filling of the ventricle during the compensatory pause.
- tonometry( measurement of blood pressure).BP can be lowered in healthy individuals with signs of vegetative-vascular dystonia, in patients with dilated cardiomyopathy, in late stages of heart failure or in aortic valve defects, and may be elevated or remain normal.
2. Laboratory testing methods. General blood and urine tests, biochemical blood tests, hormonal studies, immunological and rheumatological tests are prescribed, if necessary, to check the level of cholesterol in the blood, exclude endocrine pathology, autoimmune diseases or rheumatism leading to the development of acquired heart defects.
3. Instrumental survey methods.
- ECG does not always allow you to register extrasystoles if it is a question of healthy people without organic pathology of the heart. Often, the extrasystoles are recorded accidentally in the course of a planned examination without complaints of irregular heartbeats.
ECG - signs of extrasystole: an expanded, deformed ventricular complex QRS, appearing prematurely;Before it there is no tooth P, reflecting atrial contraction;complex is longer than 0.12 s, after it there is a complete compensatory pause, caused by the electrical excitability of the ventricles after extrasystoles.
Extrasystoles on the ECG by the type of trigemia.
In cases of the presence of the underlying disease, ECG shows signs of myocardial ischemia, left ventricular aneurysm, left ventricular hypertrophy or other heart chambers and other disorders.
- echocardiography( ultrasound of the heart) reveals the main pathology, if any - heart defects, cardiomyopathies, myocardial hypertrophy, areas of reduced or absent contraction in myocardial ischemia, ventricular aneurysm, etc. The study evaluates the cardiac activity( ejection fraction, pressurein the chambers of the heart) and the size of the atria and ventricles.
- Holter ECG monitoring should be performed for all individuals with cardiac pathology, especially for patients who underwent myocardial infarction for recording an extrasystole not perceived subjectively, heart attacks and heartbeats that are not confirmed by a single cardiogram, and for the detection of other rhythm disturbances and conduction. It is an important study in the medical and prognostic terms for patients with frequent ventricular extrasystole, as treatment and prognosis depend on the class of the extrasystole. Allows you to evaluate the nature of the extrasystole before treatment and monitor the effectiveness of therapy in the future.
- Tests with physical exertion( treadmill test) should be performed very carefully and only in cases when the appearance of heart attacks has a clear connection with the load, since in most cases this relationship indicates the coronarogenic nature of the extrasystole( caused by violation of coronary arteries patency and myocardial ischemia).If during the ECG recording after walking on the treadmill extrasystole with signs of myocardial ischemia is confirmed, it is quite possible that after the begun treatment of ischemia the prerequisites for occurrence of frequent extrasystoles will be eliminated.
Precautions should be taken because the load can provoke ventricular tachycardia or ventricular fibrillation. Therefore, in the study room, there must be a kit for cardiopulmonary resuscitation.
- coronary angiography - allows eliminating the pathology of the coronary arteries, which causes myocardial ischemia and the coronarogenic nature of the ventricular extrasystole.
Treatment for ventricular extrasystole
Treatment of extrasystole is directed to therapy of the underlying disease, which is its cause and for relief of attacks of extrasystole. In order to determine the need for certain drugs, a classification of extrasystole has been developed depending on the benign nature of the course.
Benign ventricular extrasystole , as a rule, is observed in the absence of organic damage to the heart and is characterized by the presence of a rare or medium frequency of extrasystoles, asymptomatic flow or poorly expressed subjective manifestations. The risk of sudden cardiac death is extremely low. Therapy in such cases may not be prescribed. In case of poor tolerance of symptoms, antiarrhythmic drugs are prescribed.
Potentially malignant course of occurs with extrasystole against the background of the underlying cardiac disease, characterized by frequent or medium frequency of extrasystoles, absence or presence of symptoms, good or poor tolerability. The risk of sudden cardiac death is significant, since unstable ventricular tachycardia is recorded. Therapy in such cases is indicated for the purpose of relieving symptoms and reducing mortality.
The malignant ventricular extrasystole differs from potentially malignant in that, in addition to the main symptoms, there is an anamnesis indicating syncope( fainting) and / or cardiac arrest( experienced through resuscitation).The risk of cardiac death is very high, the therapy is aimed at reducing the risk.
Frequent ventricular extrasystole, which appeared for the first time in life or is already occurring earlier, but has now developed suddenly, is an indication for inpatient hospitalization and intravenous administration of drugs.
Selection of medications for treatment should be carefully performed by the attending physician in a polyclinic or in a hospital, with the obligatory analysis of possible contraindications and the selection of an individual dose. The beginning of therapy should be with a gradual increase in the dose, a drastic withdrawal of drugs is unacceptable. The duration of therapy is set individually, in cases of potentially malignant course, careful drug withdrawal should be secured by monitoring the ECG according to Holter to confirm the effectiveness of therapy. When malignant course of therapy lasts a long time, perhaps for life.
Antiarrhythmic drugs have pro-arrhythmic effects as side effects, that is, they themselves are capable of causing rhythm disturbances. Therefore, their use in pure form is not recommended, it is justified to co-prescribe them with beta-blockers, which reduces the risk of sudden cardiac death. Of the antiarrhythmics, the use of propanorm, etatsizina, allapinin, amiodarone, cordarone, sotalol in combination with low doses of beta-blockers( propranolol, bisoprolol, etc.) is preferable.
Persons with acute myocardial infarction and acute myocarditis are indicated for amiodarone or cordarone, since other antiarrhythmics can cause other rhythm disturbances in acute cardiac muscle pathology. In addition to these drugs, nitrates( nitroglycerin, cardiacet, nitrosorbide), ACE inhibitors( enalapril, lisinopril, perindopril), calcium channel blockers( verapamil, diltiazem), antiplatelet agents( aspirin), drugs that improve the nutrition of the heart muscle( panangin, magnerot, vitamins and antioxidants - actovegin, mexidol).
Therapy is performed under the control of the ECG every two to three days during the stay in the hospital and every 4 to 6 weeks at the polyclinic thereafter.
Lifestyle with ventricular extrasystole
With ventricular extrasystole, especially caused by other cardiac diseases, you need to rest more often, stay outdoors more often, observe the work and rest regime, eat right, exclude the use of coffee, alcohol, reduce or exclude tobacco smoking.
Patients with a benign type of ventricular extrasystole do not need to restrict physical activity. In malignant type, it is necessary to limit significant loads and psycho-emotional situations that can lead to the development of an attack.
Complications of benign ventricular extrasystole usually do not develop. Terrible complications in the malignant type are a sustained ventricular tachycardia that can go into flutter or fibrillation of the ventricles, and then lead to asystole, that is, to cardiac arrest and sudden cardiac death.
In case of benign course and absence of the main cardiological disease, the prognosis is favorable. In the case of a potentially malignant type and in the presence of an organic lesion of the heart, the prognosis is relatively unfavorable and is determined not only by the characteristics of the ventricular extrasystoles in ECG monitoring( frequent, average, paired, group), but also by the nature of the underlying disease and the stage of heart failure, in the late stages of which the prognosis is not favorable. In malignant course, the prognosis is unfavorable because of the very high risk of sudden cardiac death.
The use of antiarrhythmic drugs in combination with beta-blockers improves the prognosis, as the combination of these drugs not only improves the quality of life, but also reliably reduces the risk of complications and death.
Doctor therapist Sazykina O.Yu.