Extrasystoles, the causes of their occurrence

Extrasystolia is a kind of arrhythmia that occurs as a result of abnormal automatism and the mechanism of re-enter and manifested by early contraction of the heart or any of its departments. Extrasystoles, the causes and place of occurrence of early excitation, are different. Depending on the place of appearance, there are atrial, ventricular extrasystoles and contractions occurring in the atrioventricular junction.

Extrasystoles, whose causes are determined by the time of appearance, calls early and late. The time that passes from the previous complex to the appearance of a new extrasystole is called the preectopic interval (the time of adhesion). It is strictly fixed, indicating a common source of early excitation. Uneven interval length is associated with extrasystoles from different sites. At the same time, their shape also changes.

The close connection between the appearance of early contraction and the basic rhythm of the heart is caused by the appearance of extraordinary stimuli by the main (normal) impulses - the mechanism of postdepolarization, asynchronous repolarization or re-enter.

The features of the extrasystole are noted and the subsequent pause, this is the time interval that passes between the early contraction and the subsequent impulse of the main rhythm. The duration of this pause depends on whether or not the sinus node has discharged. When the sinus node is discharged by the ectopic impulse, which was formed as a result of early atrial excitation, a new impulse begins to form in it with a time interval equal to the basic sinus rhythm. Then the value of pre- and postectopic intervals is less than the duration of two normal cardiac cycles, this is an incomplete compensatory pause. If the discharge of the main node does not occur, a complete pause occurs, that is, the sum of the pre- and postectopic intervals is equal to the duration of two normal cardiac cycles.

Extrasystoles, the causes of their appearance, are determined by the frequency and time of their appearance. Infrequent early cuts (for example, extrasystoles after eating) have virtually no effect on hemodynamics, but can sometimes have prognostic significance, being a harbinger of more serious rhythm disturbances. Constant extrasystoles, which alternate with a normal rhythm, are complicated by hemodynamic disorders. If three premature contractions are fixed in a row, this situation is interpreted as a paroxysm of tachycardia. Heart fibrillation may occur if early premature contractions occur that are associated with impaired metabolic processes in the myocardium.

Early contractions occurring in the atrium are manifested by the appearance of the P wave, which differs from the normal shape and duration. The QRS complex itself remains the same. Abbreviations from the ventricular atrial junction on the cardiogram are manifested by an altered ventricular complex. The tooth is absent, since the excitation in the atria coincides with the excitation of the ventricles. If the contraction of the ventricles occurs earlier than the atria, the P-wave is negative and appears after the ventricular complex.

Early contractions from the ventricles on the cardiogram are seen as an early ventricular complex having a supraventricular shape. Before the extrasystole there is no P wave, the ventricular complex is enlarged and changed. Extrasystoles of the left ventricle are manifested by blockade of the right leg of the bundle Guiss and vice versa.

Extrasystoles, the causes of their appearance

Early contractions can accompany any heart disease, but can also appear independently, due to diseases of the nervous system, drug overdose, electrolyte disorders, and the consumption of alcohol in large quantities.

How to get rid of extrasystole

It is necessary to eliminate all factors contributing to early reduction. Assign a sedative nervous system drugs. Rare reduction of special treatment does not require. When a combination of extrasystoles with hypertension is prescribed antihypertensive and antiarrhythmic drugs (propranolol, verapamil, etc.), potassium preparations, if there are no contraindications to them.