AV blockade of the 2nd degree

author: doctor Pyataeva Margarita

Despite a huge number of methods for diagnosing heart disease, one of the most accessible and informative studies is still electrocardiography. The ECG makes it possible to detect not only and not so much myocardial infarction, as well as changes or disturbances in the conductivity of the electrical pulse in the heart, and not always these changes are accompanied by complaints from the patient. An example of such a pathology is atrioventricular blockade of the 2nd degree.

Heart Device

The heart muscle consists of four parts: two atria, each of which is connected to its ventricle by a special hole with a valve. The contraction of the heart is caused by a special site - a sinus node located in the eye of the left atrium, it generates electrical impulses with the necessary organism at this time. The electric signal that appears in it moves along special paths - conducting fibers that permeate and entangle the heart, like a web.

At first, the contraction extends through the atria, and after a short time delay spreads over the musculature of the ventricles. Normally, a short pause between contractions of the ventricles and the atria ensures the efficiency of the heart, so nature has separated them from each other by a boundary through which the impulse can pass only in one place - through the atrioventricular (atrioventricular) node.

• - If we draw an analogy with the real world, then the AV-node is a customs office, where documents are carefully checked, thus causing a delay in passengers crossing the atrium with ventricles.

Further along the ventricles, the signal for contraction spreads very rapidly along the conducting paths, called the bundle of His.

Heart blockade

Problems arising in the conductive system as a result of certain diseases often lead to a slowing or even stopping of the movement of electrical signals from one part of the heart to another. If it is a difficulty to conduct a pulse in the atrioventricular node, then this pathological condition is called the AV blockade.

There are only three degrees of severity of the AB blockade:

- I degree is characterized by the fact that the pause, which normally exists between contraction of the ventricles and atria, increases, but the patients themselves practically do not feel any discomfort;

- II degree - this is a more serious pathology, it is possible not only to slow down the pulse, but even to completely block individual signals.

- III degree or complete AV-blockade - no pulse from the atria is able to overcome the atrioventricular node. For this reason, the atria contract with the frequency of the sinus node, and the ventricles with a frequency much smaller, generated by the bundle of His. This blockade is usually accompanied by a sharp weakness and / or loss of consciousness.

The causes and manifestations of AV blockade II degree

The reasons for which the blockade of the atrioventricular node may develop are many:

- Ischemia of the heart muscle;

- some congenital malformations;

- Inflammatory heart diseases (various myocarditis, endocarditis);

- violations of mineral metabolism (potassium, magnesium);

- diseases with affection of connective tissue (scleroderma, systemic lupus erythematosus, etc.);

- taking some pharmaceuticals (some antiarrhythmics, digoxin, etc.).

For the most part, if AV blockade of the II degree is not periodically replaced by a complete blockade, and ventricular contractions occur more or less regularly, patients often do not notice it for a long time. In neglected cases, when abrupt ventricular contractions occur frequently, for example, if not every third signal passes, there may be irregularities in the rhythm of the heart.

Such conduction disorders require a responsible approach to the health of one's own heart, so it is necessary to carefully examine and listen to the recommendations of a specialist.