In the article, we consider single ventricular extrasystoles, what it is and how it is detected. Each person at least once in his life felt an unusual heartbeat. This pathological phenomenon does not cause pain, however, there is little pleasant in this. An extrasystole is called an extraordinary contraction of the heart muscle. This is the most common form of cardiac arrhythmia, common for all age categories, and it is often observed even in absolutely healthy people. In children, this phenomenon represents 75% of all varieties of arrhythmias.
Pathology Description
However, not everyone understands what it is. Single ventricular extrasystoles are a violation of the rhythm of the heart, which occurs under the influence of premature nerve impulses emanating from the walls of the right or left ventricle. Extrasystoles that develop in this case, as a rule, affect only the ventricular rhythm, without affecting the upper parts of the heart. But single extraordinary contractions that come from the atrioventricular septum and atria can cause ventricular extrasystoles.
Such a pathology, in the absence of organic damage to the heart, as a rule, poses no danger to life. The heart cycle is a certain sequence of processes that occur during a single cardiac contraction and its subsequent weakening. Each such cycle consists of systole ventricles, atria and diastole. This is a relaxation of the muscle in the period between systoles, in which the heart cavities expand.
Distinguish between electrical (activity stimulating the myocardium) and mechanical (contraction of the heart muscle, a decrease in the volume of its chambers) systole. At rest, the adult’s heart ventricle is able to eject approximately 50–70 ml of blood per systole. Normal heart impulses are produced in the sinus node, which is localized in the upper part of the heart. 1 single ventricular extrasystole is characterized by premature ventricular excitation in relation to the leading rhythm of the heart, emanating from the conducting system of this organ, in particular, Purkinje fibers and branching of the bundle of His.
What are single polymorphic ventricular extrasystoles, we will tell below.
Causes of occurrence
For all varieties, a common characteristic is their premature occurrence. The most accurate diagnosis of ventricular extrasystole can give an ECG record. Single extrasystoles arise due to premature excitation emanating from the myocardium of the heart ventricles. Premature extrasystoles contribute to the violation of the rhythms of the heartbeat. Their prediction depends on the following factors:
- the presence or absence of organic damage to the heart;
- electrophysiological characteristics of extrasystoles (frequency, localization, degree of premature occurrence);
- the ability of extrasystoles to have a negative effect on the overall functioning of the heart.
The causes of the appearance of single monomorphic ventricular extrasystoles are very diverse. Most often they cause disorders of extracardiac nervous origin. Departments of the parasympathetic system affect the permeability of cell membranes, the level of extracellular and intracellular potassium and sodium.
The intensity of movement of ionic transmembrane currents also changes. These factors cause impaired automatism, as well as processes of excitability and conduction of impulses with the occurrence of ventricular extrasystole. Single ventricular extrasystoles can also appear due to increased excitability of the cells of the conduction system outside the sinus node. ECG diagnostics are not always enough to adequately distinguish between atrial and nodal extrasystoles.
Supraventricular extrasystoles
This is the most convenient and general term for atrial and nodal extrasystoles. The most common type of rhythm disturbance in children is ventricular extrasystole. In the course of scientific research, it was found that some of them, which the doctors mistook for ventricular, were in fact supraventricular and were accompanied by an aberrant QRS complex. Healthy children are prone to the manifestation of right ventricular solitary extrasystoles caused by the development of vegetovascular dystonia.
Risk factors
Sinus rhythm and solitary ventricular extrasystoles often appear against a background of organic cardiac abnormalities, but may be of an unknown nature. In most cases, it develops in people with myocardial infarction, as well as with arterial hypertension, coronary heart disease, post-infarction cardiosclerosis, myocarditis, pericarditis, dilated or hypertrophic cardiomyopathy, mitral valve prolapse, chronic heart failure.
Risk factors include:
- vagotonia;
- cervical osteochondrosis;
- cardiopsychoneurosis;
- chronic hypoxia;
- metabolic disorders, endocrine disorders;
- taking certain medications (antidepressants, diuretics, antiarrhythmic drugs, high doses of cardiac glycosides);
- bad habits;
- excessive emotional and physical stress;
- poor nutrition.
Ventricular extrasystole in the form of single contractions can appear and disappear with physical activity and at rest in people with increased function of the parasympathetic system. It often happens in healthy people for no apparent reason. What is it - single ventricular extrasystoles, is now clear.
Classification
According to localization, extrasystoles are divided into left ventricular and right ventricular. There are single polytopic ventricular extrasystoles (several morphologies of the ventricular complex at the same time) and monomorphic (monotopic), which are the only morphology of the ventricular complex. By density, extrasystoles are paired and single, by periodicity - regular and sporadic. By the time of prematureness and manifestation - early, late and interpolated.
Here is the standard classification by Laun, which was created on the basis of the results of daily monitoring of ECG by Holter. 6 classes of ventricular extrasystole are distinguished:
- 0 class. There is a lack of frequent ventricular extrasystole on the ECG, the patient does not have any disturbances in the work of the heart or morphological changes.
- 1 class. Within an hour, less than 25-30 single monomorphic (monotopic, identical) pathological contractions were recorded.
- 2nd grade. During the hour of the study, more than 30 single monomorphic or 10-15 paired extrasystoles are recorded.
- 3rd grade. The first 15 minutes register at least 10 polymorphic extrasystoles. Atrial fibrillation is also often noted.
- 4a grade. Monomorphic paired ventricular extrasystoles are fixed within an hour.
- 4b class. Throughout the study, polymorphic extraordinary contractions are recorded.
- 5th grade. Group or salvo polymorphic contractions are fixed for 20 minutes.
Single ventricular extrasystoles of type 1 pose no threat. However, they often become a signal that certain changes are occurring in the work of the heart and you need to consult a specialist. Single monomorphic ventricular extrasystoles in most cases are provoked by the only source of electrical impulses, which is characterized by a constant period of time of adhesion in the same compartment of the heart, has the same shape on the ECG.
Symptomatology
Most often, the occurrence of single ventricular extrasystoles does not have special symptoms. Patients describe them as the occurrence of interruptions in the heartbeat process, dips, lull, or missed beats of the heart rhythm. Other signs of this pathological phenomenon include:
- excessive fatigue;
- sleep disturbances;
- bouts of weakness;
- frequent dizziness;
- intolerance of trips in motor vehicles.
Ventricular extrasystole occurs due to heart pathologies, and the nature of the clinical symptoms directly depends on the underlying disease. During occurrence, there is a slight expansion of the ventricles. A study of the history of patients who suffered from this pathology showed that they had similar problems in the perinatal period. Past infections, such as tonsillitis, have a significant impact on this type of extrasystole.
The norm of single ventricular extrasystoles is discussed below.
Rate per day
Depending on the number of extrasystoles recorded per day, a diagnosis is made about the presence or absence of a certain cardiac pathology. The number of heart contractions, which are extrasystoles, for a healthy person is approximately 100 times. An increase in this indicator may indicate cardiological pathologies that require therapeutic treatment to prevent the development of more serious heart diseases.
The rate per day of single ventricular extrasystoles may differ depending on whether a person has abnormalities in the state of the cardiac system, which are expressed as follows:
- additional impulses in an amount from 650 to 960 are called the average norm for a person who has no heart pathologies;
- impulses in the amount of 960-1150 are not considered a pronounced danger to life and are classified as polymorphic;
- with an increase in the number of pulses affecting the heart muscle to 1,200 or more, a reason for excitement appears, since there is a risk of developing diseases.
The most common consequence of this pathological phenomenon is tachycardia and arrhythmia. Normally, about 580-850 pulses are accepted. In this situation, no pronounced changes in the state of the heart are observed.
The norm of single monomorphic ventricular extrasystoles in a healthy person is no more than 30-50 per day.
Diagnostics
Diagnosis and clinical evaluation of single ventricular extrasystoles is always carried out comprehensively, taking into account the patient’s complaints, as well as the general condition of the patient’s cardiovascular, central, autonomic and nervous systems. They are considered frequent when they exceed 10%. With the use of daily monitoring of the rhythm of contractions of the heart muscle, a direct relationship between the physical activity of a person and the appearance of ventricular extrasystoles was noticed.
So, athletes often complain of interruptions in the rhythm, a sinking heart during training or an overly active pastime.
A study of the functional properties of the central nervous system of patients diagnosed with vegetovascular dystonia and rare single ventricular extrasystoles showed mild residual symptoms.
So, the diagnosis is based on survey data. Complaints and medical history, objective examination and some laboratory tests are also taken into account. The features of ventricular extrasystole include splitting of the II cardiac sound and violation of the sonority of the I tone. On examination, the patient often reveals a presystolic pulsation of veins in the neck, when after an extraordinary pulse an arrhythmic pulse with an elongated compensatory pause is determined.
The main methods used in the diagnosis of single ventricular extrasystoles include Holter ECG monitoring and ECG.
In this case, determine:
- the extraordinary occurrence of an altered complex of QRS ventricles;
- absence of P wave before extrasystole;
- deformation and expansion of the extrasystolic complex;
- a full compensatory pause after extrasystole.
When conducting an ECG, single extrasystoles are determined in 5% of healthy young people, and during daily monitoring - in approximately 50% of cases. Diagnosis may also require echocardiography, sphygmography, rhythmocardiography, transesophageal electrocardiography, polycardiography, and magnetic resonance imaging.
The relationship between physical activity and the occurrence of extrasystoles is established using bicycle ergometry and a treadmill test. Among laboratory tests, the patient may be assigned a general analysis of urine and blood, a biochemical analysis, a blood test for hormones.
The norm of single monomorphic ventricular extrasystoles per day was sorted out. But what is the treatment?
Treatment
With asymptomatic ventricular extrasystoles and the absence of signs of organic heart damage, drug therapy is usually not required. The recommendations of doctors are to normalize lifestyle: elimination of bad habits, physical therapy, diet.
The main goal of drug treatment to eliminate ventricular extrasystole is considered to be the prevention of life-threatening arrhythmias. In this case, the patient is prescribed sedative medications (phytopreparations or small doses of tranquilizers), antiarrhythmic drugs, beta-blockers (their selection is carried out under the supervision of an ECG), antihypertensive drugs.
Concomitant bradycardia
In the presence of concomitant bradycardia, anticholinergic drugs may be prescribed. Two months after the main treatment, the patient undergoes control electrocardiography. With a significant decrease in the number of ventricular extrasystoles or their disappearance, the use of medicines, as a rule, ceases. With a slight improvement in the state of the heart, a certain period of therapy may be required.
In cases of the malignant course of this pathology, drug therapy is prescribed for life. In the absence of positive results from antiarrhythmic treatment, patients with ventricular extrasystole are shown catheter radiofrequency ablation of the ectopic focus, and in case of impossibility of its implementation, an open heart operation.
Do I need a defibrillator?
Implantation of cardioverter defibrillators is carried out only with a ventricular extrasystole of a malignant nature, when the patient has an extremely high risk of sudden death. The duration of such a device depends on the duration, frequency and intensity of cardiac stimulation. After surgery, the patient needs regular medical supervision. Now you know almost everything about single ventricular extrasystoles, what it is and how it is determined on a cardiogram.