Under premature ventricular contractions means one of the types of heart rhythm disorders, which is characterized by extraordinary contractions of the ventricular myocardium. This pathology, unlike supraventricular tachycardia, usually not associated with functional disorders of regulation of cardiac activity, and with some organic changes of the myocardium.
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The pathogenesis is a violation of electrical homogeneity of the myocardium as a result of inflammatory disease or scarring (e.g. after myocardial infarction). As a result, in the cardiac muscle of the ventricles appears a hotbed of increased automaticity and excitability, which generates a nerve impulse, passing through the conduction system and causes an extraordinary reduction of the myocardium.
There are several variants of classification of ventricular arrythmia. The necessity of knowing all possible options of dividing them into groups due to differences in symptomatology, prognosis, and treatment of disease.
One of the most important criteria in the classification of this arrhythmia – the frequency of occurrence of extrasystoles. Under the beat (ES) understand a single extraordinary reduction. Thus, there are:
- Rare (up to 5 min).
- Less rare (ES medium frequency). Their number may reach 16 per minute.
- Frequent (more than 16 V for one minute).
An equally important division of ES groups is the density of their occurrence. This is sometimes called the “density of ECG”.
- Individual beats.
- Pair (two ES next to each other).
- Group (three or more).
Depending on the place of origin of the release:
- Left ventricular.
The division of the number of foci of pathological excitation:
- Monotonie (one hearth).
- Polytopes (multiple foci of excitation, which can be located in one ventricle, or in both).
Classification of the rhythm:
- Algoritmicheskie – periodic beats. In this case, instead of each second, third, fourth, etc., normal reduction occurs ventricular beat:
- bigeminy – every second beat is a reduction;
- trigeminy – every third;
- quadrigemina – every third, and so on.
- Sporadic – not regular, independent of normal cardiac rhythm, extrasystoles.
Results of the interpretation of Holter monitoring there are several classes of extrasystoles:
- 0 class – ES do not exist;
- class 1 – a single rare monotonie ES not exceeding 30 per hour;
- class 2 – same as class 1 but with a frequency of more than 30 for one hour;
- class 3 – single polytopes ES;
- class 4A – polytopes pair of ES;
- class 4B – any group of ES with periods of ventricular tachycardia;
- class 5 – the emergence of early extrasystoles arising in the moment of relaxation of the heart muscle tissue. Such ES is extremely dangerous, because they can be precursors to cardiac arrest.
This classification wolf-Launa is designed for more convenient evaluation of the risk and the prognosis of the disease. 0 – 2 class practically does not pose a threat to the patient.
When choosing a method of treatment, the doctors rely mainly on a classification depending on the degree of purity arrythmia. Distinguish benign, potentially malignant and malignant course.
Classification depending on the degree of purity of the ventricular extrasistolia ventricular arrythmia
Despite the fact that the change in the functional properties of the myocardium is mostly viewed as prerequisites to the development of supraventricular arrhythmia, such deviations can sometimes facilitate the occurrence of ventricular and ES. In rare cases, large doses of nicotine, caffeine, or emotional stress can cause isolated ventricular extrasystole. This may occur at the VVD (vegetovascular dystonia).
The main reason for the development of ventricular arrythmia are organic lesions of the heart muscle. More than half of the cases the pathology develops on the background of ischemic heart disease (IHD). Any lesion, such as myocardial infarction, postinfarction state, various cardiomyopathies, arterial hypertension and congenital abnormalities are the cause of ventricular ES.
In some cases, the disease develops on the background of chronic thyrotoxicosis, in which the myocardium is exposed to the toxic action of thyroid hormones. The effect on the heart muscle of certain antiarrhythmic drugs, cardiac glycosides and drugs used for the treatment of pulmonary diseases (Berodual, Salbutamol, Aminophylline) also contribute to the emergence of ES.
The symptoms of the disease is Not very common cases where ventricular arrhythmia did not subjectively felt. However, almost always the primary complaint of patients is the feeling of disruption of the heart, a sense of fear or “lump from the throat” with a sinking heart. For group ES you may feel palpitations, often accompanied by a sudden dizziness and weakness. If the rhythm disturbance is significantly impaired pumping function of the heart muscle, it is possible to fainting up to a long loss of consciousness.
If the complaints bother you for the first time and accompanied by a rise in heart rate (heart rate) of more than 120 per minute, should immediately contact the medical facility or to call an ambulance.
Any concomitant heart damage can add to the symptoms of ventricular arrhythmia, painful sensation in the chest or bouts of shortness of breath. It is often found in chronic heart failure (CHF) and coronary artery disease.
Group or polytopes frequent ventricular ES can lead to ventricular fibrillation. In this case, besides the loss of consciousness the patient may stop breathing with the development of clinical death.
Diagnosis of ventricular arrythmia
To determine this type of arrhythmia only three main types of diagnosis: a survey and examination of the patient, some laboratory and instrumental research.
At the beginning of the study of complaints. In case of similarity with those described above, should be suspected or to determine the presence of organic pathology affecting the heart. It turns out the dependence of symptoms from physical activity and other triggering factors.
By listening (auscultation) of the heart tones can be impaired, deaf or pathological. It is found in patients with hypertrophic cardiopathology or with cardiac defects.
The pulse is irregular, with different amplitudes. This is due to the occurrence of a compensatory pause after the extrasystole. Blood pressure can be anything. For group and/or frequent ventricular ES it may be reduced.
In order to exclude pathology of the endocrine system are appointed by analyzes on hormones, study of biochemical parameters of blood.
Among instrumental investigations the main ones are electrocardiography and Holter monitoring. Interpreting ECG results can be extended to detect altered ventricular QRS-complex, in front of which there is no atrial P-barb. This suggests the contraction of the ventricles, which occurs before atrial contractions. After this distorted beats, there is a pause followed by a normal sequential contraction of the cardiac chambers.
ECG in left ventricular and the right ventricular extrasystoles
Determined by echocardiography signs of ischemia or left ventricular hypertrophy only in the presence of concomitant lesions of the myocardium.
In the case of an underlying disease, an ECG revealed signs of myocardial ischemia, left ventricular aneurysm, left ventricular hypertrophy or other heart chamber and other violations.
Sometimes to provoke ventricular arrythmia and study the performance of the heart muscle at this point, you conduct load ECG test. The occurrence of ES indicates the appearance of arrhythmias due to coronary disease. Due to the fact that this study improper conduct may be complicated by ventricular fibrillation and death, it is carried out under the supervision of a physician. Office testing must be equipped for emergency resuscitation.
Coronary angiography done to rule out coronary origin of the extrasystole.
The treatment of the disease
The basis for treating the ventricular arrhythmia is a timely treatment of the disease, against which develops abnormal heart rhythm.
In the case of benign arrhythmia, there is usually no organic lesion of the myocardium and the course usually asymptomatic. In this variant of the disease receive no treatment. Antiarrhythmic drugs can be administered if seizures subjectively poorly tolerated by the patient.
When a potentially malignant course, arising on a background of any organic disease of the heart, are the place to be a moderately frequent or frequent ES. Sometimes there are “runs” of ventricular tachycardia (multiple PVCs). In this case, there is a risk of sudden cardiac death. To reduce the probability of lethal outcome and relief of symptoms of the disease in mandatory treatment.
Malignant arrhythmia of ventricular origin implies the presence of life-threatening symptoms in addition to the major manifestations of the disease. These include loss of consciousness, cardiac arrest. Because of the very high risk of cardiac death appointed complex therapy.
Any sudden frequent ventricular premature beats, regardless of the presence of such history is an emergency indication for the introduction of antiarrhythmic drugs and hospitalization.
In the selection of drugs requires an individual approach to determine the dose and study of various tests to exclude contraindications to receiving antiarrhythmic drugs. The dose of drugs gradually increased till the appearance of stable effect. Abrupt withdrawal of the drug unacceptable. The adequacy of treatment is assessed using Holter monitoring.
Almost all antiarrhythmic drugs have side proaritmicski action can cause arrhythmia. To reduce the likelihood of complications all antiaritmiki (Etatsizin, Propanorm, Sotalol, Amiodarone) are assigned beta-blockers (Propranolol, Metoprolol, Bisoprolol). The dosage of the latter should be minimal.
Patients with myocarditis or with a history of myocardial infarction it is advisable to use as antiarrhythmic agents Amiodarone or Cordarone. Other drugs from this group in this case can provoke the arrhythmia. For enhancing blood circulation and improve the properties of the myocardium to prevent ventricular arrhythmia additionally prescribe:
- antiplatelet agents (Cardiomagnyl, Aspirin);
- ACE inhibitors (enalapril, Perindopril);
- nitrates with the prolonged action (Kardiket, Nitrolon);
- calcium channel blockers (Diltiazem, Verapamil);
- comprehensive vitamins and minerals, improve myocardial metabolism (Panangin, Magnetic, Actovegin).
Lifestyle and prevention of ventricular arrhythmia
- Proper rest and moderate work.
- Walks in the fresh air.
- Rational nutrition.
- Exception of reception of alcohol, tobacco.
- Reducing the intake of caffeine.
- Avoiding stressful situations and emotional strain.
All of the above applies to people suffering from malignant xtracycle. When benign course such restrictions have no justification.
Complications and prognosis
Complications mainly occur when the malignant variants with frequent attacks. These include ventricular tachycardia with circulatory failure, atrial/ventricular fibrillation, leading to full cardiac arrest.
In other cases, the prognosis is often favorable. In compliance with all treatment recommendations even in the presence of comorbidities significantly reduced the mortality from this disease.