Atrial septal defect has no symptoms. Does it need treatment?

Author: Jin Mei, Chief Physician, Beijing Anzhen Hospital, Capital Medical University

Reviewer: Wang Fang, Chief Physician, Beijing Hospital

Atrial septal defect is a relatively common congenital heart disease, accounting for about 15-20% of congenital heart diseases. Generally, atrial septal defect may have no symptoms.

1. What is atrial septal defect?

A normal human heart has two atria and two ventricles, namely the left atrium and right atrium, the left ventricle and right ventricle. There is an atrial septum between the left and right atria, and a ventricular septum between the left and right ventricles.

Under normal circumstances, the atrial and ventricular septa are continuous. Atrial septal defect means that the septum between the two atria has a broken end. In layman's terms, there is a hole in the atrial septum, which is called atrial septal defect. Because the pressure in the left atrium is slightly higher than that in the right atrium, the blood in the left atrium will be diverted to the right atrium through this hole.

Figure 1 Original copyright image, no permission to reprint

Because the pressure difference between the left and right atria is not large, the shunt is not so obvious in atrial septal defect, and generally has little effect on the child's growth and development. Unlike patent ductus arteriosus and ventricular septal defect, there are obvious and prominent clinical symptoms.

Because the left ventricle pressure is very high and the right ventricle pressure is low, the ventricular septal defect shunt speed is very fast. The same is true for patent ductus arteriosus. The ductus arteriosus is a communication between the aorta and the pulmonary artery. The aortic pressure is very high and the pulmonary artery pressure is low. The pressure difference is large, the shunt is large, and the murmur is obvious. Children are particularly prone to pneumonia or are developmentally backward compared to children of the same age, so it is easier to detect.

However, the symptoms of an ASD of normal size may not be obvious and it is not easy to be found. A larger ASD has a relatively larger shunt. In the early stage, the child may be developmentally delayed and prone to pneumonia. There may be noise, which can lead to the child being found. Due to the large shunt volume, there is a lot of blood in the lungs, and the pulmonary artery has a process of increased pressure. Some people develop pulmonary hypertension. When the pulmonary hypertension reaches a certain level, the opportunity for surgery may be lost.

2. When is the best time to treat atrial septal defect?

Generally, atrial septal defect is difficult to heal on its own. Although the symptoms are not obvious, the horizontal shunt between the atrial and ventricular regions will cause right heart enlargement. Unless it is very small, no treatment is needed for the time being. In general, early treatment is required once it is discovered.

If an atrial septal defect is found in a newborn, and the baby is relatively small, the defect is not very large. We can wait until the baby is heavier and has better development in all aspects before considering treatment.

If the atrial septal defect of an infant is very small and the shunt volume is not large, the effect on hemodynamics is not great, and the child can be observed temporarily. If the defect is medium-sized, there is a certain shunt volume, and the right heart has enlarged, interventional treatment is recommended. If the atrial septal defect is large, the right heart is enlarged, and the child is young and underweight, interventional treatment is not suitable, and open-chest surgery is recommended.

If an atrial septal defect is discovered in adulthood, it should be treated as soon as possible.

3. What are the treatments for atrial septal defect?

The traditional method of treating atrial septal defect is open-chest surgery, which requires general anesthesia + extracorporeal circulation for repair. For children, the trauma is relatively large. Currently, most parents prefer interventional treatment without opening the chest.

In the 1890s, American pediatric cardiologists developed a device to close atrial septal defect, and then domestically produced devices were developed, bringing good news to children who did not want to undergo open-chest surgery. In 1997, Beijing Anzhen Hospital’s Pediatric Heart Center simultaneously started interventional treatment for atrial septal defect closure, completing nearly 1,000 interventional surgeries each year.

Currently, interventional treatment is the preferred treatment for atrial septal defect. If the patient's atrial septal defect is centrally located and has good margins, transcatheter interventional treatment can be considered.

Interventional treatment generally involves puncturing the femoral vein, placing the occluder at the site of the atrial septal defect through a catheter guidewire and sheath, and is performed under the guidance of echocardiography and X-ray.

Figure 2 Original copyright image, no permission to reprint

The overall interventional surgery time is not long, and general anesthesia is not required. Usually local anesthesia + intravenous sedation is used. For older children and adults with better self-control, local anesthesia can complete the surgery.

The risk of interventional surgery is much lower than that of open-chest surgery, with less trauma and faster recovery. Central atrial septal defect of normal size is suitable for interventional treatment, but for larger atrial septal defect with poor margins, interventional treatment is sometimes challenging. For large atrial septal defect with particularly poor margins, open-chest surgery is sometimes the only option.

In summary, interventional treatment has significant advantages, with less trauma and higher safety. Parents also need to find more experienced doctors in specialized hospitals to reduce the chance of complications.