Ventricular ectopic rhythm or idioventricular rhythm

In rare cases, when the automatism of not only the sinus node decreases, but also the atrioventricular junction (conduction system of the heart), the automatic center of the third order, located in the ventricles of the heart, becomes the rhythm driver. The ectopic focus can be in the left or right branche of the bundle of His, in the interventricular septum or occasionally in Purkinje fibers. In such cases, they speak of a ventricular ectopic rhythm or idioventricular rhythm. The idioventricular rhythm is indicated by the presence of three or more successive contractions, the driver of the rhythm of which is the cente,r located in the ventricles.

In the presence of idioventricular rhythm, the course of excitation through the ventricles resembles its spread with the bundle branch block, therefore, the ECG with the idioventricular rhythm resembles the ECG, when the opposite bundle branch block occurs. If the impulse for excitation of the ventricles originates from the right ventricle, then the ECG is similar in shape to the ECG with the left bundle branch block and vice versa. The ventricular ectopic rhythm usually occurs when there is no or drastic reduction in the number of impulses from the sinus node and from the atrioventricular junction and therefore has a substitution value. The idioventricular rhythm can be caused by a sinoatrial block, stopping of the sinus node, atrial asystole, second-degree atrioventricular block or complete atrioventricular block. Often it is observed before death.