Atrial Septal Defect (ASD)

There are several distinct types of ASD, each with its unique characteristics and implications. The most prevalent form of ASD is the secundum type, found in approximately 80% of cases. Secundum ASDs typically develop in the middle of the atrial septum.

The second most common type is primum ASD, affecting the lower part of the atrial septum. Babies born with this defect may also have other associated heart conditions, and it is often linked to Down syndrome. Sinus venosus ASD is a rarer subtype, typically occurring in the upper or lower part of the septum and predominantly affecting the right pulmonary vein or the superior and inferior vena cava. It is often associated with additional congenital heart abnormalities.

The least common ASD variant is the unroofed coronary sinus, occurring in less than 1% of cases and involving incomplete or entirely missing portions of the wall separating the coronary sinus.

ASDs develop during embryonic development when a necessary opening between the upper heart chambers doesn’t close properly. While genetic factors play a role in many congenital heart defects, pregnant women who consume alcohol, smoke or take certain medications can increase the risk of congenital heart defects in babies.

Children with ASD may exhibit symptoms such as slow growth, frequent respiratory infections or, in severe cases, arrhythmias, exercise intolerance and breathing difficulties. In adults, symptoms may manifest around age 40 and can include fatigue, exercise-induced shortness of breath, heart palpitations, rapid heartbeat, limb swelling and cyanosis (bluish skin tone).

ASD leads to abnormal blood flow between the heart chambers, which can strain the heart and damage the pulmonary arteries over time. Larger ASDs may result in right-sided heart failure, arrhythmias, strokes, pulmonary hypertension and early mortality.

Most children with ASD do not exhibit noticeable symptoms but may have a heart murmur detected during a routine examination. Diagnosis often involves tests such as echocardiograms, chest X-rays, electrocardiographs (ECGs or EKGs), cardiac magnetic resonance imaging (MRI) or computed tomography (CT) scans.

Treatment for ASD depends on the size and location of the defect, as well as the presence of other congenital heart issues. While many childhood ASDs close naturally, larger or persistent defects may require intervention. Cardiac catheterization is a minimally invasive option for closing larger defects, while open-heart surgery may be necessary for specific types. Medications can alleviate symptoms but do not treat the ASD itself.

Patients who have undergone ASD surgery require regular checkups to monitor potential complications. While ASDs cannot be prevented outright, pregnant women can minimize risk factors by avoiding smoking, alcohol, secondhand smoke, drug use (especially cocaine) and discussing medications with their healthcare provider.

Receiving a diagnosis of ASD can be alarming. However, by becoming knowledgeable and consulting with a healthcare provider, you can understand your options and benefit from modern medical advancements that enable many ASD patients to lead full, healthy lives.

At Sheba’s Leviev Heart Center, recognized as a global leader in the field, we provide congenital heart defect patients worldwide with the most advanced care available while following a 360-degree care model that prioritizes the general wellbeing of patients and their families. We invite you to schedule a consultation with Sheba’s experts to learn more: