Atrial Septal Defect (Secundum Type)

Symptoms

Common signs and symptoms of Atrial Septal Defect (Secundum Type) include:

Shortness of breath during physical activity

Fatigue or feeling tired easily

Heart murmur heard during physical exam

Frequent respiratory infections or pneumonia

Swelling in legs, feet, or abdomen

Heart palpitations or irregular heartbeat

Poor weight gain in infants and children

Bluish tint to skin, lips, or fingernails

Difficulty feeding in babies

Stroke-like symptoms in rare cases

When to see a doctor

If you experience severe or worsening symptoms, seek immediate medical attention. Always consult with a healthcare professional for proper diagnosis and treatment.

Causes & Risk Factors

Several factors can contribute to Atrial Septal Defect (Secundum Type).

Secundum atrial septal defects develop during the earliest weeks of pregnancy when the heart is forming.

Secundum atrial septal defects develop during the earliest weeks of pregnancy when the heart is forming. Between the fourth and sixth weeks of fetal development, a thin wall called the septum normally grows to separate the heart's right and left atria. This process involves several tissue flaps that must align and fuse properly. When the central portion of this septum, called the septum secundum, fails to develop completely or has an abnormally large opening, blood can flow between the chambers after birth.

The exact reason why this developmental process goes wrong remains largely unknown in most cases.

The exact reason why this developmental process goes wrong remains largely unknown in most cases. Genetic factors play a role, as the condition sometimes runs in families. Certain genetic syndromes, such as Holt-Oram syndrome or Down syndrome, are associated with higher rates of atrial septal defects. Environmental factors during pregnancy may also contribute, though researchers haven't identified specific triggers that consistently cause this type of heart defect.

Unlike some heart conditions that develop due to lifestyle choices or infections, secundum atrial septal defects are purely developmental.

Unlike some heart conditions that develop due to lifestyle choices or infections, secundum atrial septal defects are purely developmental. They're not caused by anything the mother did or didn't do during pregnancy. The heart simply formed differently during those crucial early weeks when most women don't even know they're pregnant. This random developmental variation affects families across all backgrounds and ethnicities.

Risk Factors

Family history of congenital heart defects
Genetic syndromes like Down syndrome or Holt-Oram syndrome
Maternal diabetes during pregnancy
Maternal alcohol consumption during pregnancy
Maternal use of certain medications during pregnancy
Maternal viral infections during early pregnancy
Being born female (2:1 female predominance)
Having other congenital anomalies

Diagnosis

How healthcare professionals diagnose Atrial Septal Defect (Secundum Type):

1
Diagnosing a secundum atrial septal defect often begins when a doctor hears an unusual heart sound during a routine physical exam.
Diagnosing a secundum atrial septal defect often begins when a doctor hears an unusual heart sound during a routine physical exam. This heart murmur occurs because blood flowing through the hole creates turbulence that can be detected with a stethoscope. However, not all heart murmurs indicate a problem, so additional tests are needed to confirm the diagnosis and determine the size and location of the defect.
2
Echocardiography serves as the primary diagnostic tool for atrial septal defects.
Echocardiography serves as the primary diagnostic tool for atrial septal defects. This painless ultrasound test creates detailed images of the heart's structure and shows how blood flows through the chambers. The test can measure the exact size of the hole, determine its precise location, and assess how much extra blood volume the right side of the heart is handling. Sometimes a special type of echocardiogram called a transesophageal echo provides even clearer images by placing the ultrasound probe in the esophagus.
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Additional tests may include an electrocardiogram to check the heart's electrical activity, chest X-rays to evaluate heart size and lung blood flow, or cardiac catheterization in complex cases.
Additional tests may include an electrocardiogram to check the heart's electrical activity, chest X-rays to evaluate heart size and lung blood flow, or cardiac catheterization in complex cases. Some doctors also order exercise stress tests to see how well the heart functions during physical activity. Blood tests to check oxygen levels might be performed if there are concerns about the defect's impact on circulation.

Complications

Most small secundum atrial septal defects cause no complications throughout life.
However, larger defects that remain untreated can lead to several serious problems over time.
The most common long-term complication is right heart enlargement, which occurs because the right ventricle must pump extra blood that flows through the defect.
This extra workload can eventually lead to heart failure, typically developing in the fourth or fifth decade of life if the defect hasn't been repaired.
Other potential complications include irregular heart rhythms, particularly atrial fibrillation, and increased risk of stroke due to blood clots that can form in the enlarged right atrium.
Some adults develop pulmonary hypertension, a condition where blood pressure in the lung arteries becomes dangerously elevated.
Paradoxical embolism, where blood clots bypass the lungs and travel to other parts of the body, represents a rare but serious complication.
The encouraging news is that timely repair of significant defects prevents most of these complications entirely, and even adults who undergo closure see substantial improvements in their long-term health outlook.

Prevention

Since secundum atrial septal defects are congenital conditions that develop during early fetal heart formation, complete prevention isn't possible.
The developmental process that creates these defects occurs so early in pregnancy that most women don't yet know they're expecting.
However, women planning to become pregnant can take several steps that support overall fetal heart development and reduce risks of various birth defects.
General prenatal health measures include taking folic acid supplements before conception and during early pregnancy, avoiding alcohol and recreational drugs, managing diabetes carefully if present, and discussing all medications with healthcare providers.
Women with family histories of congenital heart defects should consider genetic counseling to understand their risks and options for prenatal screening.
For families with one child who has an atrial septal defect, the risk of having another affected child is slightly higher than average but still relatively low.
Fetal echocardiography during pregnancy can sometimes detect heart defects early, allowing families to plan for specialized care at birth if needed.
While these measures can't guarantee prevention, they represent the best current approach to supporting healthy fetal development.

Treatment Approaches

Treatment decisions for secundum atrial septal defects depend primarily on the size of the hole and its impact on heart function.

Treatment decisions for secundum atrial septal defects depend primarily on the size of the hole and its impact on heart function. Small defects that cause no symptoms often require only regular monitoring with periodic echocardiograms. Many small holes actually close on their own during the first two years of life as heart tissue continues to grow and develop. Children with small, asymptomatic defects can usually participate in normal activities without restrictions.

For larger defects or those causing symptoms, closure is typically recommended to prevent long-term complications.

For larger defects or those causing symptoms, closure is typically recommended to prevent long-term complications. The preferred method today is transcatheter closure, a minimally invasive procedure performed in a cardiac catheterization lab. During this procedure, a cardiologist guides a small umbrella-like device through blood vessels to plug the hole. The device is made of materials that allow heart tissue to grow over it, creating a permanent seal. Most patients go home the next day and return to normal activities within a week.

Surgical repair becomes necessary when the defect is too large for device closure or has an unusual shape.

Surgical repair becomes necessary when the defect is too large for device closure or has an unusual shape. Open-heart surgery involves making a small incision in the chest and using a patch or stitches to close the hole. While this approach requires a longer recovery period, it has excellent success rates with very low complication rates. Most children return to full activities within 6-8 weeks after surgery.

Surgical

Medications rarely cure atrial septal defects but may help manage symptoms while awaiting closure.

Medications rarely cure atrial septal defects but may help manage symptoms while awaiting closure. Diuretics can reduce fluid buildup, while medications to regulate heart rhythm might be prescribed if arrhythmias develop. Blood thinners may be recommended for adults who experience strokes related to their defect. Recent advances in device technology continue to expand treatment options, making closure possible for defects that previously required surgery.

SurgicalMedication

Living With Atrial Septal Defect (Secundum Type)

Children and adults with small, unoperated secundum atrial septal defects typically live normal lives with few activity restrictions. Regular checkups with a cardiologist help monitor the defect's size and the heart's function over time. Most children can participate fully in school sports and recreational activities. Parents should watch for signs of decreased exercise tolerance or unusual fatigue, but overprotection isn't necessary for most kids with small defects.

After successful closure of a larger defect, most people experience significant improvement in their energy levels and exercise capacity.After successful closure of a larger defect, most people experience significant improvement in their energy levels and exercise capacity. The recovery period varies depending on whether closure was done through catheterization or surgery, but most patients return to full activities within weeks to months. Some people need temporary activity restrictions during healing, but long-term limitations are unusual. Regular dental care becomes important since people with repaired heart defects have a slightly increased risk of heart valve infections.

Living well with this condition means staying informed about your specific situation and maintaining good communication with your healthcare team.Living well with this condition means staying informed about your specific situation and maintaining good communication with your healthcare team. Key strategies include: - Keeping regular cardiology appointments for monitoring - Staying up to date with vaccinations, especially for respiratory infections - Informing all healthcare providers about your heart condition - Maintaining good dental hygiene and getting regular cleanings - Learning to recognize symptoms that might indicate complications - Staying physically active within any recommended guidelines - Connecting with support groups or other families dealing with congenital heart conditions when helpful

Latest Medical Developments

Latest medical developments are being researched.

Frequently Asked Questions

Can my child play sports with a secundum atrial septal defect?

Most children with small defects can participate in all sports and activities without restrictions. Your cardiologist will evaluate your child's specific situation and may recommend avoiding highly competitive or contact sports if the defect is large or causing symptoms.

Will the hole in my baby's heart close on its own?

Small secundum atrial septal defects do sometimes close naturally during the first two years of life as heart tissue continues growing. However, defects larger than 5-8 millimeters rarely close spontaneously and typically require treatment.

Is the catheter closure procedure safe for children?

Transcatheter closure is very safe with success rates above 95% and serious complication rates less than 1%. Most children go home the next day and return to normal activities within a week.

How long will I need to take blood thinners after closure?

Most patients take aspirin for 6 months after device closure to prevent clots from forming on the device while tissue grows over it. Some people may need longer treatment depending on their individual risk factors.

Can I have more children if I have this condition?

Women with repaired atrial septal defects usually tolerate pregnancy well and can safely have children. Your cardiologist should evaluate your heart function before pregnancy and monitor you during prenatal care.

Will my other children have this condition too?

The risk is slightly higher than average but still relatively low. If one child has a congenital heart defect, the chance of having another affected child is about 2-3%, compared to less than 1% in the general population.

Do I need antibiotics before dental procedures?

People with unrepaired defects or recently repaired defects may need antibiotic prophylaxis for certain dental procedures. Discuss this with both your cardiologist and dentist to determine what's right for your situation.

How often do I need follow-up appointments?

This depends on your defect size and symptoms. Small defects might be monitored every few years, while larger ones may require annual visits. After repair, follow-up is typically needed annually or every few years.

Can air travel be dangerous with an unrepaired defect?

Commercial air travel is generally safe for people with atrial septal defects. The cabin pressure changes don't significantly affect most people with this condition, but discuss travel plans with your cardiologist if you have concerns.

What should I do if I experience new symptoms?

Contact your cardiologist if you develop new shortness of breath, chest pain, irregular heartbeats, or significant fatigue. These could indicate changes in your condition that need evaluation.

Update History

Mar 9, 2026v1.0.0

Published page overview and treatments by DiseaseDirectory