Atrial Septal Defect

Treating Cardiovascular Diseases in Wisconsin and Northern Illinois

Atrial septal defect (ASD) is often referred to as a hole in the heart. This is a congenital defect, meaning it develops before birth.

The atrial septum is a muscular wall inside the heart that separates the heart’s two upper chambers, or atria. An atrial septal defect occurs when a hole forms in this wall, allowing blood to mix between the atria.

With each heartbeat, the right side of the heart receives oxygen-poor blood from the body and pumps it to the lungs. The left side receives oxygen-rich blood from the lungs and pumps it to the body.

If you were born with an atrial septal defect, oxygen-rich blood from your left atrium can mix with oxygen-poor blood from your right atrium. As a result, some oxygen-rich blood is pumped to your lungs, where it has just been, instead of your body.

Types of Atrial Septal Defects

Atrial septal defects can be small, medium or large, and they can occur in the lower, middle or upper parts of the atrial septum.

Holes in the middle part of the septum are the most common type, affecting about 80 percent of those born with this condition. As least half of these defects close as the heart grows during childhood, but this is less likely when the hole is medium or large.

Holes in the lower and upper parts of the atrial septum are very rare. They can cause an abnormal blood return from the lungs or heart valve abnormalities.

Atrial Septal Defect Symptoms 

Most babies who are born with this condition have no atrial septal defect symptoms, even when the hole is large. And because most holes close as the heart grows or are repaired during childhood, younger people rarely experience complications.

If symptoms of atrial septal defect do occur, a heart murmur is the most common. This is an extra or unusual sound during a heartbeat. Doctors can listen to heart murmurs and tell whether they’re harmless or require treatment.

It’s usually after age 30, when the heart tires from extra blood flowing to the right side of the heart and lungs, that symptoms ofatrial septal defect occur. At this point, symptoms appear as other heart conditions and disorders, including:

  • A stroke may occur when a blood clot forms in the heart and is pumped out to the body, where it can travel to an artery in the brain and cause a blockage.
  • Arrhythmia, which occurs when extra blood flowing into the right atrium causes the atrium to stretch and enlarge. Over time, this can lead to irregular heartbeats. Symptoms may include palpitations or a rapid heartbeat.
  • Pulmonary hypertension occurs when pressure builds up in the lung arteries, making them thick and stiff. This makes it difficult for blood to flow through them when picking up oxygen. 
  • Right heart failure, which occurs when the heart can no longer pump blood to the lungs efficiently, causing fluid to accumulate. Signs of this condition may include swollen ankles or legs.

Causes of Atrial Septal Defect

Although smoking during pregnancy has been linked to ASD, the cause of atrial septal defect is often unknown. Scientists continue to search for other causes.

Diagnosing and Treating Atrial Septal Defects

Because symptoms are seldom obvious, doctors often don’t diagnose atrial septal defects until later in childhood or adulthood. If an ASD is suspected during a physical exam, your doctor is likely to perform additional cardiac tests(link), which may include:

Treatment varies, depending on the severity of the symptoms. Children and adults who don’t have symptoms don’t need treatment. If treatment is necessary, most ASDs are treated with cardiac catheterization. During this procedure, a device is inserted over the hole, and within months, tissue grows in and over the device. The device remains in permanently. In rare cases, surgery is performed.

A Leader in Treating Congenital Heart Disease

Aurora Health Care offers the only specialty center in Wisconsin for treating adult congenital heart disease. Whether you’ve been newly diagnosed with an atrial septal defect or have lived with it for years, you should have your condition monitored and treated by a team that specializes in these conditions.

At the Adult Congenital Heart Disease Center, we offer you access to some of the most respected experts in the field. A. Jamil Tajik, MD is a world-renown expert in the diagnosis and treatment of complex cardiovascular conditions. He leads a multidisciplinary team that specializes in adult congenital heart disease.

Aurora doctors are conveniently located throughout eastern Wisconsin and northeastern Illinois. Find a doctor or heart specialist near you. To get a second opinion or if you need assistance finding a provider, please call 888-649-6892.