Septal defect in children and its effect on the heart muscle

Ventricular septal defects (VSD) and atrial septal defects (ASD) are among the most common congenital heart defects in children, affecting how blood flows through the heart. Some children may have a small defect that causes no symptoms and closes on its own, while a large defect can lead to serious problems such as weakened heart muscle, shortness of breath, and recurrent chest infections.

In this article from Dalily Medical, we will explore:

Causes of VSD and ASD in children
Symptoms and early diagnosis of these heart defects
The best treatment options, including medication, catheterization, and surgery
Follow-up and care tips to ensure your child’s healthy growth and development

What Are Ventricular and Atrial Septal Defects (VSD / ASD) in Children?

Ventricular septal defects (VSD) and atrial septal defects (ASD) are congenital heart defects, meaning children are born with them. They affect the flow of blood through the heart and the body.

1️⃣ Ventricular Septal Defect (VSD)

A hole in the wall separating the right and left ventricles.
Blood flows from the oxygen-rich left ventricle to the right ventricle, increasing the amount of blood going to the lungs.
If the defect is large, it can cause shortness of breath or poor growth.

2️⃣ Atrial Septal Defect (ASD)

A hole in the wall separating the right and left atria.
Blood flows from the left atrium to the right atrium, which may cause the heart to enlarge over time and increase pressure on the lungs.
Most small defects do not cause symptoms and are monitored naturally, but large defects require follow-up or treatment.

1️⃣ Do all defects require surgery?

Small defects may close on their own as the child grows.
Large defects or those causing symptoms may need catheterization or surgery.

2️⃣ Difference between VSD and ASD

VSD: Symptoms usually appear early.
ASD: Symptoms may not appear until later in childhood or even adulthood.

3️⃣ Common Symptoms in Children

Difficulty feeding or poor weight gain (especially VSD).
Shortness of breath or fatigue during play.
Recurrent chest infections.
Palpitations or irregular heartbeat sometimes (especially large ASD).

4️⃣ How is the defect diagnosed?

Heart auscultation: Hearing a characteristic heart murmur.
Chest X-ray: Evaluates heart size and lung circulation.
Electrocardiogram (ECG): Monitors heart rhythm.
Echocardiography: The most important tool to locate and measure the size of the defect.

5️⃣ Can medication close the defect?

No, medications relieve symptoms and protect the heart from complications, but the defect itself is closed by catheterization or surgery if needed.

6️⃣ Can a child live a normal life after treatment?

Yes, most children recover and live normal lives after catheterization or surgery, with regular follow-up with a pediatric cardiologist.

7️⃣ Complications if the defect is untreated

Heart failure
Pulmonary hypertension
Recurrent chest infections
Heart rhythm problems

8️⃣ Can the defect return after treatment?

Very rare, but sometimes follow-up or additional intervention may be needed for small residual problems.

9️⃣ Effect of the defect on growth and daily activity

Small defect: Usually does not affect growth or daily activity.
Large defect: Before treatment, it may cause poor weight gain or fatigue, but after closure, everything usually improves naturally.

Stages of Ventricular and Atrial Septal Defects (VSD / ASD) in Children

1️⃣ Stages of Ventricular Septal Defect (VSD)

Newborn Stage (first few weeks)

Small defect: Usually shows no symptoms.
Large defect: The child may experience feeding difficulties, shortness of breath, and excessive sweating.

Stages of Ventricular and Atrial Septal Defects (VSD / ASD) in Children

First: Stages of Ventricular Septal Defect (VSD)

2️⃣ Infancy Stage (months up to 1 year)

Symptoms become more noticeable: poor weight gain, recurrent chest infections.
Some small defects may close on their own over time.

3️⃣ Early Childhood (1 – 5 years)

If the defect is medium or large and still open, it may cause heart muscle enlargement or pulmonary hypertension.
In some cases, the doctor may decide on catheterization or surgery at this stage if the defect affects the child’s health.

4️⃣ After 5 years

If untreated, the risk of complications such as heart failure or high pulmonary pressure increases.

Second: Stages of Atrial Septal Defect (ASD)

1️⃣ Early Childhood

In most cases, the child appears normal because symptoms are mild or absent.
Small defects may close on their own by age 2–3 years.

2️⃣ Late Childhood (5 – 10 years)

Shortness of breath during play or recurrent chest infections may appear in some children.
Sometimes the doctor discovers it by chance during routine checkups or hearing a heart murmur.

3️⃣ Adolescence and Young Adulthood

If the defect is large and still open, it may cause arrhythmias, fatigue with exertion, or enlargement of the heart chambers.
Surgery or catheter closure is usually recommended before this stage to prevent complications.

Causes of Ventricular and Atrial Septal Defects in Children

1️⃣ Congenital defect during fetal heart development

The fetal heart develops from small tubes and tissues that fuse together.
If this fusion or growth is incomplete, a hole appears between the ventricles or atria.

2️⃣ Genetic and hereditary factors

Family history of congenital heart defects.
Certain syndromes, like Down syndrome, may be associated with heart defects.

3️⃣ Maternal infections during pregnancy

Viral infections such as rubella in early pregnancy.
Exposure to harmful substances like alcohol or smoking.
Certain medications not safe during pregnancy that affect heart development.

4️⃣ Maternal chronic diseases

Uncontrolled diabetes or systemic lupus.

5️⃣ Unknown causes

In many cases, the exact cause is unclear, likely a combination of genetic and environmental factors.

Symptoms of Ventricular and Atrial Septal Defects (VSD / ASD) in Children

1️⃣ Ventricular Septal Defect (VSD)

Small defect: Usually no obvious symptoms, often detected incidentally by hearing a heart murmur.
Large defect: Symptoms may include:
- Difficulty feeding or poor weight gain.
- Shortness of breath or persistent rapid breathing.
- Excessive sweating during feeding or crying.
- Recurrent chest infections (pneumonia or bronchitis).
- Delayed physical growth compared to peers.

2️⃣ Atrial Septal Defect (ASD)

Small defect: May remain asymptomatic for years, often discovered incidentally.
Large defect: Symptoms appear gradually with age, such as:
- Shortness of breath with exertion or play.
- Recurrent chest infections.
- Palpitations or irregular heartbeat in older children.
- Delayed growth or poor weight gain in some cases.
- In advanced cases, mild cyanosis of lips or extremities due to reduced oxygen.

Types of Ventricular and Atrial Septal Defects (VSD / ASD)

First: Types of Ventricular Septal Defect (VSD)

The defect is located in the wall separating the right and left ventricles, classified by location:

1️⃣ Perimembranous VSD

The most common type.
Located in the upper part of the ventricular septum.

2️⃣ Muscular VSD

Located in the lower (muscular) part of the septum.
Sometimes closes spontaneously as the child grows.

3️⃣ Subarterial / Outlet VSD

Located near the heart valves (aortic and pulmonary).
May affect the valves and cause regurgitation.

Types of Ventricular and Atrial Septal Defects (VSD / ASD) in Children

1️⃣ Inlet VSD

Located near the entry of blood into the ventricles.
Sometimes associated with genetic syndromes such as Down syndrome.

Second: Types of Atrial Septal Defect (ASD)

The defect is in the wall separating the right and left atria, and includes:

1️⃣ Ostium Secundum ASD

The most common type, located in the middle of the atrial septum.

2️⃣ Ostium Primum ASD

Located in the lower part of the septum.
Often associated with valve defects, such as the mitral valve.

3️⃣ Sinus Venosus ASD

Located in the upper part of the septum, near the entry of veins into the heart.

4️⃣ Coronary Sinus ASD

Very rare, located near the coronary sinus vein.

Complications of Ventricular Septal Defect (VSD)

Growth failure: The child may not gain weight or grow normally due to extra workload on the heart and lungs.
Congestive heart failure: Blood leaking from the left ventricle to the right increases heart workload, weakening the heart muscle over time.
Pulmonary hypertension: Increased blood flow to the lungs raises pressure and may cause serious complications if persistent.
Recurrent chest infections: Such as pneumonia or bronchitis.
Arrhythmias: Due to enlargement of heart chambers or electrical conduction issues.
Endocarditis: Infection of the heart lining or valves; children with VSD are more at risk.

Complications of Atrial Septal Defect (ASD)

Growth delay and fatigue with exertion: Usually becomes noticeable with age rather than early childhood.
Atrial arrhythmias: Especially during adolescence or young adulthood.
Pulmonary hypertension: If the defect is large and untreated early.
Heart failure in adulthood: Due to increased load on the right atrium and ventricle.
Blood clots or stroke (rare): A defect may allow a small clot to pass from right to left, reaching the brain.

Diagnosis of Ventricular and Atrial Septal Defects (VSD / ASD) in Children

Steps for Diagnosis

1️⃣ Clinical examination by a pediatric cardiologist

Listening to the child’s heart with a stethoscope for a distinct murmur indicating a defect.
General assessment of weight, growth, and breathing.

2️⃣ Electrocardiogram (ECG)

Helps detect chamber enlargement or electrical disturbances in the heart.

3️⃣ Chest X-ray

Shows heart enlargement.
Demonstrates increased blood flow to the lungs, especially in large defects.

4️⃣ Echocardiography (Heart Ultrasound)

The most important diagnostic tool.
Shows location and size of the defect.
Measures blood flow between atria or ventricles.
Detects any effect on valves or heart muscle.

5️⃣ Cardiac Catheterization

Not always necessary, but used to assess pulmonary artery pressure or determine if the defect can be closed with a catheter instead of surgery.

6️⃣ Cardiac MRI (in some cases)

Provides detailed information about defect size and its effect on the heart and lungs.

Difference in Diagnosis between VSD and ASD

VSD (Ventricular Septal Defect):

Usually diagnosed early after birth or in the first months due to obvious symptoms like rapid breathing or recurrent chest infections.

ASD (Atrial Septal Defect):

May remain undetected for years, often discovered incidentally during routine checkups or when shortness of breath develops with exertion.

Treatment of Ventricular and Atrial Septal Defects (VSD / ASD) in Children

Role of Medications

Medications do not close the defect, but help control symptoms and prevent complications until the child undergoes catheterization or surgery if needed.

1️⃣ Heart failure medications (Diuretics)

Such as Furosemide to reduce fluid buildup in the lungs and body.
Other diuretics may be added depending on the child’s condition.

Medications for Ventricular and Atrial Septal Defects (VSD / ASD)

2️⃣ Medications to Improve Heart Strength (Digoxin)

Strengthens the heart muscle and helps it pump blood more efficiently, especially in mild to moderate heart failure.

3️⃣ Medications to Prevent Pulmonary Hypertension

Sometimes pediatric cardiologists prescribe drugs to reduce pulmonary artery pressure, such as ACE inhibitors or medications specifically for lung pressure.

4️⃣ Medications to Prevent Secondary Complications

Antibiotics: Used to prevent endocarditis in children with large VSD or ASD before medical or surgical procedures.

Important Notes:

Small defects: Most do not require any medication and are monitored over time.
Large defects: Medications are only supportive before closure via catheterization or surgery.
Regular follow-up is essential to adjust medication doses according to the child’s growth and condition.

Surgical Treatment of Heart Defects

1️⃣ Open Heart Surgery for Defect Closure

This is the definitive solution for large defects or those that do not close spontaneously.

✅ Surgery Steps:

The child is under general anesthesia.
The chest is opened either by minimally invasive approach or traditional incision.
The defect is closed using:
- Sutures if the defect is small.
- Synthetic patch if the defect is large.
The heart resumes normal function, and the body receives blood and oxygen efficiently.

✅ Benefits of Surgery:

Complete closure of the defect.
Reduces risk of heart failure and pulmonary hypertension.
Prevents future complications like endocarditis or arrhythmias.

⚠️ Potential Risks:

Bleeding or infection after surgery.
Some children may require monitoring for heart rhythm issues.
Rare complications such as reactions to anesthesia or valve problems.

2️⃣ Catheter-Based Defect Closure (Less Invasive)

Suitable for older children or selected cases.

✅ Procedure Steps:

A thin tube (catheter) is inserted through the groin or arm.
The catheter reaches the heart and places a small device that closes the defect.
The device stays in place, and the defect is closed without opening the chest.

✅ Benefits of Catheter Closure:

Less pain and shorter recovery time.
High success rate for suitable defects.
The child can usually go home the same day or after 1–2 days.

⚠️ Potential Risks:

Device may shift from its position (rare).
Local bleeding or sensitivity at the catheter entry site.

Key Parental Guidance for Children with VSD / ASD

1️⃣ Regular Follow-up with a Pediatric Cardiologist

Schedule routine checkups depending on defect size and the child’s condition.
Monitor weight and growth to ensure normal development.
Perform echocardiography (Echo) as recommended to track defect size and its effect on the heart and lungs.

2️⃣ Proper Nutrition

Feed the child appropriately to avoid weight loss or fatigue during meals.
Some children may need small, frequent meals for easier feeding.

3️⃣ Symptom Monitoring

Watch for rapid fatigue, shortness of breath, sweating during feeding or play, and recurrent chest infections.
Report any new or worsening symptoms to the doctor immediately.

4️⃣ Infection Prevention

Maintain good hygiene and avoid contact with sick children, especially those with chest infections.
Follow the routine vaccination schedule, especially for influenza and pneumococcal vaccines.
Some children may require antibiotics before medical or dental procedures to prevent endocarditis, according to the doctor’s instructions.

5️⃣ Physical Activity

Most children can engage in normal activities as advised by the cardiologist.
Children with large defects before intervention may need to avoid strenuous activities or contact sports.

6️⃣ Psychological Support

Reassure the child and reduce anxiety during medical visits and tests.
Family involvement helps reduce stress and fear.

7️⃣ After Catheter or Surgical Treatment

Monitor the incision or catheter entry site and keep it clean.
Follow scheduled post-procedure heart checkups.
Watch for severe fatigue, shortness of breath, or swelling, and inform the doctor immediately.