Atrial Septal Defect (ASD): What is it, what are its symptoms and treatment methods?

The heart has a four-chambered structure consisting of two ventricles and two atria. It ensures circulation by pumping blood to the body, and also ensures that dirty blood is transmitted to the lungs, where it is cleaned and delivered to the tissues. The upper chambers of the heart are called atria and the lower chambers are called ventricles. Some congenital heart diseases may cause various disorders related to the structure of these chambers. One of these is atrial septal defect, or ASD for short.

The heart has a four-chambered structure consisting of two ventricles and two atria. It ensures circulation by pumping blood to the body, and also ensures that dirty blood is transmitted to the lungs, where it is cleaned and delivered to the tissues. The upper chambers of the heart are called atria and the lower chambers are called ventricles. Some congenital heart diseases may cause various disorders related to the structure of these chambers. One of these is atrial septal defect, or ASD for short.

The heart has a four-chambered structure consisting of two ventricles and two atria. It ensures circulation by pumping blood to the body, and also ensures that dirty blood is transmitted to the lungs, where it is cleaned and delivered to the tissues. The upper chambers of the heart are called atria and the lower chambers are called ventricles. Some congenital heart diseases may cause various disorders related to the structure of these chambers. One of these is atrial septal defect, or ASD for short.

What is Atrial Septal Defect (ASD)?

Atrial septal defect is the presence of a hole in the wall between the atria of the heart. Defects in the septum are seen between the upper two chambers (atrium), also called “atrium”. This condition, commonly known as a hole in the heart, causes blood to pass between the atria. Oxygen-poor blood, called dirty blood, leaks into the oxygen-rich clean blood coming from the lungs, causing the oxygen rate in the blood to fall below normal. Although this depends on the size of the hole, it can damage the heart and lungs. A small hole on the atrial septum may continue to exist or close over time without causing any health problems to the person. Larger holes cause certain symptoms and require intervention.

The most common type of ASD is the ostium secundum defect, which is the type in which there is a hole in the middle part of the interatrial wall. In the type of ASD called ostium primum defect, the hole is located near the lower part of the wall, and in the sinus venosus defect, the hole is located near the upper part. Another rare type, known as coronary sinus defect, is the type in which a defect is seen in the wall between the structure where blood flows in the veins called the coronary sinus and the left atrium. Since all types have different characters and effects, the type of ASD must be determined exactly in order to determine the treatment plan.

Prevalence of ASD in Children and Adults

Although the development of the heart is largely completed in babies while they are in the womb, each child is born with one or more small-sized holes between the atria in the heart. These fetal openings allow blood to move away from the lungs during the prenatal period. After birth, the holes close over time because the baby no longer needs these openings. This closure process is completed in most babies within a few weeks or months. In babies born with a congenital defect called atrial septal defect (ASD), this gap is larger than normal and does not close spontaneously in the postnatal period. As a result, the blood in the left atrium leaks through this hole into the other atrium and into the pulmonary artery. This condition, which forces the heart and lungs to work harder, can cause damage to these organs if left untreated. ASD, seen in one in every 1500-2000 babies, constitutes 10-15% of all congenital heart defects.

ASD (Atrial Septal Defect) Symptoms

Babies born with atrial septal defect usually do not have any symptoms in the first stage. However, if the defect is very advanced or does not close with age, various symptoms begin to appear. Some of these are as follows:

• frequent breathing
• difficulty breathing
• Fatigue and shortness of breath during daily movements or exercises
• Swelling in various parts of the body, such as the feet, legs or abdomen
• Hearing a humming sound (murmur) when listening to the heart with a stethoscope
• Feeling of heartbeats or interruptions in beats
• Feeding difficulties in babies
• Paralysis (stroke)

In some cases, septum holes that are not very large may not cause any symptoms until adulthood. In this case, atrial septal defect can be diagnosed in adulthood.

ASD Diagnosis and Treatment

Detection of atrial septal defect disease can sometimes be made in the womb in advanced cases, and after birth in smaller defects. However, since most cases do not have severe symptoms, the diagnosis is made towards adulthood. Individuals with ASD-like symptoms must be examined by a cardiologist. Hearing a murmur during an examination by a physician with a stethoscope creates a significant suspicion for ASD. In addition, transthoracic echocardiography and electrocardiography (ECG) are generally preferred diagnostic tests for symptomatic patients. Among these, examinations such as ultrasonic examination of the heart, chest radiography or computerized tomography may also be required.

In infants, children or adults diagnosed with ASD, a treatment plan can be determined according to the size of the hole between the chambers and the severity of the symptoms. Unless there is a situation that requires urgent intervention in babies, it may be recommended to keep the baby under follow-up for a while to reduce or close the hole. In severe cases and adults with serious symptoms, treatment is performed with surgical operations.

Long-Term Effects of ASD

In individuals diagnosed with ASD, when this hole is small, no problems or damage may occur. Although a significant portion of adults have a very small residual hole called patent foramen ovale (PFO), this condition does not cause any problems and does not affect life. However, if this hole, which does not close after birth, is too large, more blood than normal is pumped into the pulmonary artery. This causes the heart and lungs to work much harder and the pulmonary artery to become damaged over time. The effects of ASD can vary greatly depending on the type of ASD, its severity, the size of the hole, and the patient’s other health problems. Long-term negative effects are seen in people with severe ASD who neglect the treatment process or avoid surgery. For this reason, it is very important that follow-up and treatment processes are carried out meticulously.

Non-Surgical ASD Repair

In babies diagnosed with atrial septal defect, spontaneous recovery usually occurs when the hole in the interatrium wall is smaller than 5 millimeters. Therefore, in such cases, a follow-up process is usually initiated with regular examinations. Holes larger than 1 centimeter should be treated with medical or surgical methods. Drug therapy is generally preferred in patients where spontaneous recovery is expected. It does not cure ASD but helps relieve the symptoms and negativities it causes. In eligible patients requiring ASD repair, non-surgical ASD repair options may be considered first.

In cases of Secundum ASD, which is the most common type of ASD, non-surgical (percutaneous) repair (if the measurements of the disease are appropriate) is usually the first choice. In this method, a thin tube, also called a catheter, is guided to the heart using a vein in the groin. The closure device used for percutaneous ASD repair is attached to the tip of this catheter and opens like an umbrella once released from the catheter, covering the hole in the septum. Tissue formation occurs on this implant over time, and as a result, the implanted device integrates with the heart. After the procedure, blood thinners are used to prevent clot formation.

Non-surgical ASD repair can only be preferred for defects of the appropriate type and in the appropriate anatomical region. Therefore, whether the treatment will be performed with surgical or non-surgical methods is determined by the physician according to the patient’s condition.

Surgical ASD Repair

In cases of Secundum ASD with a large hole or in types of ASD that cannot be treated by non-surgical methods, surgical operations must be used for repair. Depending on the characteristics of the defect, ASD repair operation can be performed through a small incision or using robotic surgery methods in suitable patients. Repair is usually achieved by closing the hole using a tissue patch. The membrane surrounding the heart, called pericardium, is the tissue patch often preferred for ASD repair. ASD can be repaired by patching the patient’s own pericardium. In some ASDs, the hole is closed only with stitches.

After the surgery, blood thinners must be used for a period of 6-12 months. In addition, follow-up examinations should be performed at intervals recommended by the doctor. It is very important to carefully follow the doctor’s recommendations regarding the issues that need to be taken into consideration after the surgery and the limitations on issues such as physical activity and nutrition, in order to successfully complete the treatment and accelerate recovery.

If you are experiencing symptoms of atrial septal defect or if you have learned that your child has ASD, you can undergo a detailed examination by consulting a heart disease specialist. You can prevent ASD and the problems it may cause by getting the necessary treatment done in time, in line with the doctor’s recommendations.