Cardiology. Oval window

An open oval window in the heart is located between the atria. This small opening during embryonic development takes part in the fetal circulation. At its core, the oval window in the heart is an adaptive-physiological mechanism. In connection with the inactivity of the lungs, there is no need for a large flow of blood to them, oxygen enriched blood penetrates the fetus through the placenta.

An open aperture between the atria allows you to bypass a small (pulmonary) circle. This process was called "shunting". In addition, blood circulation along such a path facilitates the direct ingestion of enriched blood to the brain, which actively develops during the embryonic period.

As a rule, the oval window is closed after birth. This is due to increased pressure (arterial) in the left part of the heart.

It should be noted that all newborns are always born with an open oval window. As practice shows, in norm, the hole closes during the first months. However, about 15-20% of patients live to the age of forty with an open oval window. This indicator is associated with some features in the structure of the hole itself. The fact is that the oval window has a flap, which during the contraction in the left atrium is covered. Thus, the penetration of blood into the right atrium is prevented.

But in some situations, associated with increased pressure in the chest against the background of physical stress (with the act of defecation, sneezing, coughing and other stress), the flap opens. The preservation of an open hole is also facilitated by some structural defects of the partition, as well as the size of the oval window itself.

As observations show, shunting from left to right of blood from the atrium of the left to the right is not accompanied by any signs indicating its presence, thus flowing, is asymptomatic. Along with this, the release of blood in the opposite direction (from the right to the left atrium) can provoke permanent or transient symptoms of cyanosis. As a rule, this condition is caused by an increase in the vascular resistance of the pulmonary artery system against the background of an apnea attack, a delay in breathing, screaming and other stresses. In connection with the pathological discharge of blood into the left atrium, throughout the newborn age, permanent cyanosis may persist (cyanotic coloration of skin and mucosa). Eliminates the condition after the onset of a decrease in resistance in the arteries of the lungs.

The oval window that closes prematurely can cause the formation of various vices. Thus, early closure of the opening may be accompanied by a disorder in the development of the left half of the heart, the appearance of hypoplasia in these parts of the heart.

The oval window, enlarged in size, can provoke the formation of paradoxical embolism, accompanied by signs of transient attack (ischemic) or stroke. According to the studies, the window that does not close increases the probability of developing ischemic stroke by about 40%.

To attributes of presence of an open window in heart carry also paroxysmal migraine headache. Today, the mechanism of development of such a state is still insufficiently studied against the background of an unclosed hole. Most often, the occurrence of pain is explained by microembolization in the brain with blood clots (small blood clots), as well as the effect of substances that form in the veins and penetrate directly into the vessels of the brain.

Rarely, in the presence of an open hole in the heart, the orthodoxy platypnea syndrome can develop. This condition is characterized by a decrease in the saturation (saturation) of blood with oxygen in the vertical position of the trunk, accompanied by dyspnea.