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Atrial septal defects

What is the most common atrial septal defect?

What is the most common atrial septal defect?

Secundum. This is the most common type of ASD and occurs in the middle of the wall between the atria (atrial septum). Primum. This defect occurs in the lower part of the atrial septum and might occur with other congenital heart problems.

Atrial septal defects

During the development of the fetus, an opening (a hole) is formed between the atria, but it heals after birth and does not remain after it, in the normal position, that is, the possibility for blood to pass between the atria. In the left atrium red blood flows (which returns through the veins of the lungs and is rich in oxygen), while in the right atrium flows blue blood (which returns through the systemic veins, after the various organs in the body have absorbed the bulk of the oxygen from it, and therefore the concentration of little oxygen). Considered atrial septal defects (ASD – atrial septal defect) of the most common birth defects, and can appear individually, or as a compound of a group of birth defects of complex heart (in the unilateral image constitutes a defect rate of 10% of cases of congenital deformity of the heart). This congenital malformation allows blood to pass from the left atrium to the right atrium.

The blood flows from the left ventricle to the right ventricle, and not the other way around, since in the normal case the pressure in the right part of the heart is lower than in the left. Because of this, more blood flows into the ventricle, the right atrium, and the lung artery, and as a result, these spaces enlarge, and this means overloading the right side of the heart.

Often, this phenomenon does not cause any disturbances in the performance of the heart, in childhood. The results of the examination are relatively few. (When conducting a heart listening examination, we find a wide difference between the second sound of the heart and the heart murmur (murmur), for this reason this congenital defect is one of the defects that are not noticed in childhood, and it is diagnosed later, in a more advanced generation, when different symptoms appear. The patient in the age of 30-40 years and above, symptoms such as shortness of breath, feeling tired (symptoms of ischemic heart failure) and an imbalance in the velocity of the auricles ( atrial fibrillation)) (Atrialfibrillation). Some patients have changes in the arteries of the lungs (a cumulative damage caused by the heavy flow of blood over many years), which causes an increase in resistance and pressure in the arteries of the lungs, which causes opposite leakage. That is, a portion of the blood leaks from the right ventricle to the left through an atrial septal defect or abnormalities of the left atrium to the right. When this condition occurs, a part of the blood that contains a low concentration of oxygen is leaked, which causes what is known as cyanosis. These phenomena damage the quality of life and cause premature death.

It is necessary to diagnose and treat the defect in childhood, even in cases where the child feels in good health, thus avoiding the health problems and disease symptoms caused by this condition (which were previously mentioned). If this defect remains untreated until the symptoms appear and the patient begins to complain, the treatment will result in only a partial improvement, and thus it will be difficult to avoid all the complications and signs of the disease accumulated since childhood.

Defects are categorized in accordance with the location of the opening in the atrial septum:

1. Secundum ASD – is centered in the middle of the septum. This deformation is the most common, and it is usually solitary, i.e. a pathological phenomenon in itself.

2. Primum ASD – The center of the defect is close to the valves located between the atria and the ventricles, and this deformation is usually accompanied by a defect in the mitral valve – this condition is also common in people with Down syndrome.

3. Venosus ASD – located close to the junction of the large veins, and is usually accompanied by improper emptying of the left upper vein of the lung and the right atrium instead of the left atrium.

Diagnosis of atrial septal defects

Atrial septal defects are diagnosed by an echocardiogram (cardiac ECHO). Sometimes, the diagnosis requires conducting this examination through the esophagus, in adults.

Atrial septal defects treatment

All atrial septal defects , in every generation, can be treated by surgical procedures ( open- heart surgery in a relatively short time, successful and with a very low death rate). This defect is often treated at the age of three to six years (there are cases in which the hole heals spontaneously) or later if it is discovered late, provided there is evidence of significant pertussis leading to enlargement of the right part of the heart. If the abnormalities are relatively small and do not cause a critical amount of blood leakage, there is no need to perform the operation.

Recently, a method has been developed to block the opening by means of a catheter, in which a device resembling a double umbrella is inserted into the opening through a vein in the groin.

Stages of filling the hole by catheterization and using an Amplatzer balloon:

1. Examination of the birth defect before repairing it.

2. Measure the size of the defect with a flexible balloon.

3. Inserting a long sleeve into the left ventricle and inflating the balloon inside it, then the umbrella or balloon expands and becomes narrow and long inside the sleeve thanks to the material from which it was made, Nitinol, a flexible substance with the ability to expand and then return to its normal size.

4. Firing of the left disc into the left atrium.

5. Pulling the left disc into the septal wall and releasing the right disc into the right atrium.

6. The canopy is released from the wire that connected it to the inside, by unscrewing the screw from the outside (therefore, the parachute becomes free and fixed to the wall by discs from both sides of the bulkhead).

When treating this condition early in childhood by catheterization, the defect is repaired and the patient recovers completely.

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