Atrial septal defect is a congenital heart condition where a hole exists in the wall between the heart’s upper chambers. While some small openings close naturally during childhood, larger defects may require medical intervention to prevent serious complications and protect both heart and lung function throughout a person’s lifetime.

How Treatment Helps Patients Live with a Hole in the Heart

An atrial septal defect, often called ASD, creates an abnormal opening in the wall that divides the two upper chambers of the heart. This wall is known as the atrial septum. When this opening exists, blood flows in a direction it should not, allowing oxygen-rich blood from the left atrium to leak into the right atrium. This abnormal flow increases the amount of blood traveling to the lungs, which over time can strain both the heart and the blood vessels in the lungs.^[1]

The primary goal of treatment is to prevent complications that can develop when the heart works harder than it should. For people born with very small defects—those measuring less than 5 millimeters—symptoms may never appear, and the hole might not cause any problems throughout life. However, larger openings can lead to serious issues including pulmonary hypertension, which is high blood pressure in the lungs, irregular heart rhythms called arrhythmias, and an increased risk of stroke. These complications tend to appear as people age, often becoming noticeable by the time someone reaches their 40s.^[2]

Treatment decisions depend on multiple factors. Doctors consider the size and location of the hole, whether symptoms are present, the patient’s age at diagnosis, and whether the defect is causing the right side of the heart to enlarge. The amount of blood flowing through the hole is also important—medical professionals measure this using something called the pulmonary-to-systemic flow ratio, which compares blood flow to the lungs versus the rest of the body. When this ratio exceeds 1.5, meaning significantly more blood is flowing to the lungs than should be, closure is typically recommended.^[16]

Modern medicine offers both established surgical techniques and newer, less invasive procedures to repair atrial septal defects. The choice between these approaches depends on the specific characteristics of each person’s defect, their overall health, and whether other heart abnormalities are present. Medical societies and healthcare guidelines recommend intervention before age 25 when possible, as outcomes are generally better when treatment occurs early, especially before pressure in the lung arteries becomes elevated.^[16]

Standard Treatment Approaches for Atrial Septal Defect

For many years, open-heart surgery was the only option to repair an atrial septal defect. This traditional surgical approach involves opening the chest and using a heart-lung bypass machine to temporarily take over the work of the heart while surgeons repair the defect. During the procedure, surgeons either stitch the hole closed directly or sew a patch made from the patient’s own tissue or synthetic material over the opening. This patch eventually becomes covered with the heart’s natural tissue as healing occurs.^[7]

Open-heart surgery remains necessary for certain types of atrial septal defects. When the hole is located in areas where catheter-based devices cannot reach, such as some primum defects in the lower part of the atrial wall or sinus venosus defects in the upper or back portions, traditional surgery is the only option. Surgery is also required when other heart problems exist alongside the atrial septal defect, such as abnormalities in the heart valves or additional holes in other parts of the heart’s walls.^[2]

The duration of surgery typically ranges from two to four hours, followed by several days of hospital recovery. Patients usually need to stay in the intensive care unit immediately after surgery, then move to a regular hospital room as they recover. Full recovery at home can take several weeks, during which physical activity is gradually increased under medical supervision. Despite being major surgery, the mortality rate for uncomplicated atrial septal defect repair in both children and adults is less than 1 percent, making it a very safe procedure.^[16]

A newer alternative called percutaneous closure or catheter-based repair has become increasingly common for appropriate candidates. This minimally invasive technique does not require opening the chest. Instead, doctors make a small incision, usually in the groin area, and insert thin, flexible tubes called catheters into a blood vessel. These catheters are carefully guided through the blood vessels until they reach the heart. Once positioned correctly, a closure device is deployed through the catheter to seal the hole.^[7]

The most commonly used devices for catheter-based closure include the Amplatzer Septal Occluder for single holes and the Amplatzer Multifenestrated Septal Occluder, sometimes called the “Cribriform” device, for defects that consist of multiple small openings rather than one large hole. These devices are made from a braided metal called nitinol, which has shape memory properties. This means the device can be compressed to fit through the catheter, then expands to its designed shape once released at the defect site. The device remains permanently in place, and over time, the heart’s own tissue grows over it, creating a natural seal.^[12]

The catheter-based procedure takes about one to two hours and is performed in a specialized room called a cardiac catheterization laboratory. Patients typically receive sedation or light anesthesia and should not feel significant discomfort during the procedure. Most people can go home the next day and return to normal activities within a week, a much faster recovery than open-heart surgery offers. However, this approach is only suitable for certain types of defects, specifically secundum atrial septal defects located in the middle of the atrial wall, and only when there is enough surrounding tissue to hold the device securely in place.^[12]

After either surgical or catheter-based closure, patients need to take preventive measures against infection. Before the closure site is fully healed, which typically takes about six months, there is a small risk of bacteria from dental or surgical procedures traveling through the bloodstream and causing an infection in the heart. For this reason, doctors often prescribe antibiotics to be taken before dental work or certain medical procedures during this healing period. The type and duration of these preventive antibiotics vary depending on individual circumstances and the specific procedure performed.^[7]

Some patients with atrial septal defects also need medications to manage symptoms or related conditions, even though medications cannot repair the hole itself. Diuretics, which help the body eliminate excess fluid, may be prescribed if swelling develops in the legs, feet, or abdomen. These medications reduce the workload on the heart by decreasing the volume of blood it must pump. People who develop irregular heart rhythms might need antiarrhythmic drugs to help maintain a normal heartbeat. If blood clots become a concern, particularly in adults with longstanding defects, blood-thinning medications might be necessary.^[16]

Long-term follow-up care is essential after atrial septal defect repair. Regular checkups with a heart specialist, typically once or twice a year initially, help ensure the repair is working properly and no complications have developed. During these visits, doctors perform physical examinations, listen for heart murmurs, and order tests such as echocardiograms to visualize the repair site and assess heart function. Even when repairs are successful, some patients may continue to experience irregular heart rhythms or other issues that require ongoing monitoring and treatment.^[2]

Treatment in Clinical Trials

While standard treatments for atrial septal defect are well established and generally successful, research continues into new approaches that might offer additional benefits for certain patients. Clinical trials are scientific studies where new medical devices, procedures, or techniques are tested to determine if they work better than, or as well as, current treatments. These trials follow strict phases that ensure patient safety while gathering information about how well new treatments perform.

Research in atrial septal defect treatment focuses primarily on improving closure devices and techniques rather than on medications, since no drugs can physically repair the hole. Engineers and physicians work together to design better closure devices that can handle more complex defect shapes, are easier to implant, or cause fewer complications. Some trials examine devices specifically designed for defects that are particularly large, have unusual shapes, or are located in positions that make current devices difficult to use safely.^[16]

One area of investigation involves devices that can close multiple types of heart defects, not just atrial septal defects. These versatile devices might reduce the need for patients to undergo multiple procedures if they have more than one type of hole in their heart. Researchers test whether these multi-purpose devices work as safely and effectively as devices designed for specific defect types. Clinical trials for such devices typically progress through phases where they are first tested in small groups to confirm safety (Phase I), then in larger groups to determine if they work well (Phase II), and finally in very large studies that compare them directly to standard treatments (Phase III).

Another research direction explores improvements in imaging technology used during catheter-based procedures. Better imaging helps doctors see the defect more clearly during the repair, which can lead to more precise device placement and better outcomes. Some studies test new types of ultrasound or other imaging methods that provide three-dimensional views of the heart in real-time, allowing physicians to make better decisions during the procedure. These imaging advances may eventually allow closure of defects that currently require open-heart surgery.^[9]

Researchers also investigate the long-term effects of different closure methods. Some clinical trials follow patients for many years after their procedures to understand which approach—surgery versus catheter-based closure—leads to better quality of life, fewer complications, and better heart function over time. Studies have shown that both methods produce excellent results with similar rates of survival and prevention of major complications, but ongoing research continues to refine understanding of which approach is best for specific patient groups or defect characteristics.^[16]

Studies are also examining optimal timing for defect closure. While it is generally accepted that earlier closure leads to better outcomes, researchers work to identify the precise age or stage of defect development when intervention provides the most benefit while exposing patients to the least risk. Some trials specifically enroll elderly patients with newly diagnosed defects to determine if closure is beneficial even when discovered late in life, or if observation might be safer for certain older individuals.

For patients with atrial septal defects associated with other medical conditions or genetic syndromes, specialized research examines how best to coordinate treatment. Some people are born with complex combinations of heart abnormalities, and clinical trials help determine the safest order for performing multiple procedures and whether certain devices or surgical techniques work better for these complicated cases. This research is particularly important for children born with multiple heart defects who may need several interventions throughout their childhood and adolescence.

Clinical trials for atrial septal defect treatments are conducted at major medical centers around the world, including facilities in the United States, Europe, and other regions with advanced cardiac care programs. Patients typically work with specialized teams that include cardiologists, cardiac surgeons, nurses, and research coordinators who monitor their progress closely throughout the trial. These studies contribute valuable information that eventually improves care for all patients with congenital heart defects.

Most Common Treatment Methods

• Catheter-Based Closure
  • Minimally invasive procedure performed through a small groin incision using catheters to guide a closure device to the heart
  • Uses devices like the Amplatzer Septal Occluder made from nitinol, a shape-memory metal that expands to seal the hole
  • Suitable for secundum atrial septal defects in the middle of the atrial septum when adequate surrounding tissue exists
  • Procedure takes one to two hours with hospital discharge typically the next day
  • Recovery time is about one week before returning to normal activities
• Open-Heart Surgery
  • Traditional surgical repair performed by opening the chest and using heart-lung bypass
  • The defect is closed by direct stitching or by sewing a patch over the opening
  • Required for defects in locations unsuitable for catheter devices, such as primum or sinus venosus types
  • Necessary when other heart abnormalities exist alongside the atrial septal defect
  • Hospital stay of several days with full recovery taking several weeks
  • Mortality rate less than 1 percent for uncomplicated repairs
• Medical Management
  • Diuretics to reduce fluid accumulation and decrease heart workload
  • Antiarrhythmic medications to control irregular heart rhythms
  • Blood thinners to prevent clot formation in patients at risk for stroke
  • Antibiotic prophylaxis before dental or surgical procedures during the healing period after closure
  • Medications treat symptoms but cannot repair the hole itself
• Observation and Monitoring
  • Conservative approach for very small defects measuring less than 5 millimeters
  • Regular follow-up with echocardiography to monitor defect size and heart function
  • Appropriate when no symptoms are present and the heart shows no signs of strain
  • Some small defects in children may close spontaneously without intervention