Ventricular premature ventricular contraction

Description:

Ventricular premature ventricular contraction is the premature excitement arising under the influence of the impulses coming from various sites of the carrying-out system of ventricles. A source of ventricular premature ventricular contraction in most cases are branchings of a ventriculonector and Purkinye's fiber.

Ventricular premature ventricular contraction is the most widespread disturbance of a cordial rhythm. Its frequency depends on a diagnostic method and the contingent of inspected. At registration of an ECG in 12 assignments at rest ventricular extrasystoles are defined approximately at 5% of healthy faces of young age whereas at holterovsky monitoring of an ECG during 24 h their frequency makes 50%. Though most of them is presented by single extrasystoles, also irregular shapes can come to light. Prevalence of ventricular extrasystoles considerably increases in the presence of the organic heart diseases which are especially followed by damage of a myocardium of ventricles, correlating with expressiveness of its dysfunction. Irrespective of existence or absence of pathology of cardiovascular system the frequency of this disturbance of a rhythm increases with age. Also communication of emergence of ventricular extrasystoles with time of day is noted. So, in the morning they are observed more often, and at night, during sleep, - is more rare. Results of repeated carrying out holterovsky monitoring of an ECG showed considerable variability of quantity of ventricular extrasystoles for 1 h and for 1 days that considerably complicates assessment of their predictive value and efficiency of treatment.

Symptoms of Ventricular premature ventricular contraction:

Complaints are absent or consist in feeling of the "dying down" or "push" connected with the strengthened post-extrasystolic reduction. At the same time existence of subjective feelings and their expressiveness do not depend on frequency and the reason of extrasystoles. At frequent extrasystoles at patients with a serious illness of heart weakness, dizziness, anginous pain and shortage of air are occasionally noted.

At an objective research the expressed presystolic pulsation of cervical veins arising is defined from time to time when the next systole of the right auricle occurs at the closed three-leaved valve owing to premature reduction of ventricles. This pulsation carries the name of venous waves of Korrigan.

Arterial pulse is arrhythmic, with rather long pause after extraordinary pulse wave (a so-called full compensatory pause, see below). At frequent and group extrasystoles an impression about existence of a ciliary arrhythmia can be made. At a part of patients deficit of pulse is defined.

At heart auscultation sonority of the I tone can change owing to asynchronous reduction of ventricles and auricles and fluctuations of duration of an interval of R-Q. Extraordinary reductions can be followed also by splitting of the II tone.

The main electrocardiographic signs of a ventricular extrasystole are:

  1.prezhdevremennoye extraordinary emergence on an ECG of the changed ventricular QRS' complex;
  2.znachitelnoye expansion and deformation of the extrasystolic QRS' complex;
  3.raspolozheniye segment of RS-T and tooth of T of an extrasystole discordantly to the direction of the main tooth of the QRS' complex;
  4.otsutstviye before a ventricular extrasystole of a tooth P;
  5.nalichiye in most cases after a ventricular extrasystole of a full compensatory pause.

The current and the forecast of ventricular premature ventricular contraction depend on its form, existence or absence of organic heart diseases and expressiveness of dysfunction of a myocardium of ventricles. It is proved that persons without structural pathology of cardiovascular system have ventricular extrasystoles, even frequent and difficult, have no significant effect on the forecast. At the same time in the presence of organic lesion of heart ventricular extrasystoles can significantly increase risk of a sudden cardiac death and an over-all mortality, initiating persistent ventricular tachycardia and fibrillation of ventricles.

Reasons of Ventricular premature ventricular contraction:

Ventricular premature ventricular contraction arises both in the absence of organic heart diseases, and at their existence. In the first case it it is frequent (but it is not obligatory!) it is connected with the stress, smoking, the use of coffee and alcoholic drinks causing increase in activity of sympaticoadrenal system. However at a considerable part of healthy faces of an extrasystole arise for no apparent reason.

Though ventricular premature ventricular contraction can develop at any organic heart disease, her the ischemic heart disease is the frequent reason. At holterovsky monitoring of an ECG during 24 h it comes to light at 90% of such patients. Patients both with acute coronary syndromes, and from a chronic ischemic heart disease, especially had a myocardial infarction are subject to emergence of ventricular extrasystoles. It is necessary to carry to acute cardiovascular diseases which are the most common causes of ventricular premature ventricular contraction also myocarditis and a pericardis, and to chronic - various forms of cardiomyopathies and hypertensive heart at which its emergence is promoted by development of a hypertrophy of a myocardium of ventricles and congestive heart failure. Despite the lack of the last, ventricular extrasystoles often meet at a prolapse of the mitral valve. Also such iatrogenic factors as overdose of cardiac glycosides, use of ß-adrenostimulyatorov and, in some cases, membrane stabilizing antiarrhytmic drugs, especially in the presence of organic heart diseases belong to their possible reasons.

Treatment of Ventricular premature ventricular contraction:

Treatment and secondary prevention at ventricular premature ventricular contraction pursue 2 aims - to eliminate the related symptoms and to improve the forecast. At the same time consider premature ventricular contraction class, existence of an organic heart disease and its character and expressiveness of dysfunction of a myocardium defining a risk degree of potentially fatal ventricular arrhythmias and sudden death.

Persons without clinical signs of organic cardial pathology have asymptomatic ventricular premature ventricular contraction, even high gradation according to V. of Lown, does not demand special treatment. Patients need to explain that arrhythmia has high-quality character, to recommend the diet enriched with potassium salts and an exception of such provocative factors as smoking, the use of strong coffee and alcohol, and at a hypodynamia - increase in physical activity. Begin treatment with these non-drug actions and in symptomatic cases, passing to medicamentous therapy only at their inefficiency.

Row drugs I at treatment of such patients are sedatives (phytodrugs or small doses of tranquilizers, for example diazepam on 2,5-5 mg 3 times a day) and ß adrenoblockers. At most of patients they give good symptomatic effect, and not only due to reduction of quantity of extrasystoles, but also, irrespective of it, as a result of sedative action and reduction of force of post-extrasystolic reductions. Treatment of ß adrenoblockers there begin with small doses, for example on 10-20 mg of propranolol (Obsidanum, an anaprilin) 3 times a day which if necessary raise under control of ChSS. At some patients, however, delay of frequency of a sinoatrial rate is followed by increase in quantity of extrasystoles. At the initial bradycardia connected with the raised tone of a parasympathetic part of the autonomic nervous system, to inherent persons of young age, stopping of premature ventricular contraction can be promoted by increase in automatism of a sinus node by means of such means having cholinolytic effect as belladonna drugs (tablets of bellataminal, Belloidum, etc.) and итропиум.

In rather exceptional cases of inefficiency of sedative therapy and correction of a tone of the autonomic nervous system, at the expressed disturbance of health of patients it is necessary to resort to the tableted antiarrhytmic drugs IA (a retardny form of quinidine, новокаинамид, Disopyramidum), IB (мексилетин) or 1C (флекаинид, пропафенон) classes. In connection with considerably bigger frequency of side effects in comparison with ß adrenoblockers and the favorable forecast at such patients of purpose of membrane stabilizing means it it is necessary to avoid whenever possible.

ß-Adrenoblokatory and sedatives are drugs of the choice and at treatment of symptomatic ventricular premature ventricular contraction at patients with a prolapse of the mitral valve. As well as in cases of absence of organic heart diseases, use of antiarrhytmic drugs I of a class is justified only at the expressed disturbance of health.