Atrial septal defect

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at May 29, 2016
StartDiseasesAtrial septal defect

Heart disease is a serious issue for many people. Some are affected by heart disease that is linked to diet, lifestyle, or heredity. Others are affected by congenital heart defects that are present from birth. Left undetected and untreated, these defects can seriously damage the quality of life of the affected individual. Atrial septal defect (ASD) is a congenital heart defect that affects the upper two chambers of the patient's heart.

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Definition & Facts

ASD is a defect in which the septum that separates the two atria has a hole in it. It often goes unnoticed as sometimes the small hole causing the problems closes up before the patient reaches adulthood. The size of the hole ranges in size. The larger holes are less likely to close, causing serious health issues later in life. 

Atrial septal defects allow blood that is oxygenated to mix with deoxygenated blood within the heart. This causes the heart to become enlarged and overworked as oxygenated blood is pumped into the lungs. This could lead to pulmonary hypertension if left untreated. Eisenmenger's syndrome or permanent lung damage can also occur in a small number of cases if left untreated after many years. There are several types of atrial septal defects that can cause serious issues. These include: 

  • Coronary sinus- This defect affects the coronary sinus where deoxygenated blood is delivered. This defect is very rare.
  • Sinus venosus- Also a rarer defect, this is found in the upper part of the atrial septum.
  • Ostium secundum- This defect is found in the middle of the wall between the atria. It is the most commonly found defect, and accounts for roughly 70% of atrial septal defects.
  • Ostium primum- In the lower part of the atrial septum this defect may also be found in connection with other heart defects. 

Symptoms & Complaints 

Although they are born with the defect, children affected by this defect often will not show any sign of the problem; in many cases, symptoms will not show up for many years. Many patients start experiencing signs and symptoms around middle age. These symptoms may include:

If these signs/symptoms are experienced, it is important to see a doctor immediately or seek emergency medical attention where necessary.

Causes 

These defects occur during the heart's development process within the first eight weeks of pregnancy. Its causes are largely unknown, but there could be environmental or hereditary factors involved. There is a higher chance of having a child with a congenital heart defect if one's mother or father had such a defect.

Diagnosis & Tests

If people think that they or their child may have a heart defect based on some of the signs and symptoms, the first step is to make an appointment with a cardiologist. It may be a good idea to keep track of any issues that have been occurring and questions that need to be answered. Some topics to discuss and ask about might include:

  • Signs and symptoms
  • Any medications used
  • Family history
  • Any major events or life stresses
  • Treatment options
  • Tests
  • Activity restrictions

If the doctor suspects a atrial septal heart defect, he or she may order an echocardiogram or an electrocardiogram (EKG). During an echocardiogram, sound waves produce a picture of the heart. The doctor can see the chambers of the heart to determine if there is a problem. An electrocardiogram measures the electrical activity of the heart. If there is an abnormality in the rhythm, the doctor can look into the cause.

A CT scan may be used to examine the structure and anatomy of the heart to confirm the presence of a defect. Another option for detection is a chest X-ray. This can be used to rule out other conditions as well. The doctor can also order an MRI as another alternative. 

Treatment & Therapy 

Depending on the severity of the defect, treatment may or may not be necessary, and watchful waiting is often recommended. Many small holes close on their own or do not cause any serious problems. If the defect is detected in a child, he or she will most likely be monitored to see if the defect resolves itself. Whether or not the child has any other medical issues, such as other heart defects, will determine if treatment is necessary.

If medications are necessary, they will most likely be beta blockers to keep the heart pumping regularly or anticoagulants to reduce the chance of blood clots. Medication will not work to "fix" the defect, only to treat the symptoms and prevent other problems. If the doctor believes surgery is the best option, the surgeon will fix the abnormal opening between the atria preventing the blood from straying where it isn't supposed to. Options for surgery depend on the type of defect and include:

  • Cardiac catheterization: This method is used to repair secundum atrial septal defects. A thin tube is inserted in the groin area and guided by the surgeon using a type of camera. A small mesh piece is set in place to repair the hole in the heart.
  • Open heart surgery: For this type of surgery, a cardiopulmonary bypass (heart-lung machine) is used and the patient is put under general anesthesia. An incision is made in the chest and the hole is patched. This is the usual type of treatment for sinus venosus, primum, and coronary sinus defects. 

Prevention & Prophylaxis 

Since atrial septal defects are congenital, there is not much that can be done to prevent them. Those with a history of heart defects can talk with their doctor about issues to be aware of. Reviewing family history and undergoing genetic testing with a genetic counselor can determine risk factors to be prepared for.

The best way to prevent serious problems from escalating after conception is to be aware of signs that there may be a problem and to contact a doctor with any questions or concerns.