Complete Atrioventricular Septal Defect (Complete AVSD)

Complete atrioventricular septal defect (complete AVSD) is a serious heart problem that a baby is born with. [1] In this problem, there is a big hole in the center of the heart, where two walls should meet. One normal wall divides the top chambers (the atria). Another wall divides the bottom chambers (the ventricles). In complete AVSD, these walls do not form properly, so blood can move freely between all four chambers. [1]

In a normal heart, there are two separate valves in the middle: the mitral valve on the left side and the tricuspid valve on the right side. They open and close to control blood flow between the atria and the ventricles. In complete AVSD, these two valves do not form separately. Instead, there is one large “common” atrioventricular valve in the center of the heart. This valve often leaks and does not close well. [1]

Because of the big hole and the single common valve, blood moves from the left side (high-pressure side) to the right side (low-pressure side). This is called a left-to-right shunt. Extra blood is pushed to the lungs. Over time, this can cause heart failure, high pressure in the lung blood vessels (pulmonary hypertension), and enlargement of all four chambers of the heart if it is not treated. [2]

Complete AVSD almost always needs open-heart surgery, usually in the first months of life. Surgery closes the holes and tries to rebuild the common valve into two more normal valves. With timely surgery, many children can grow and live active lives, but they still need follow-up with a heart specialist. [3]

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Other names

Doctors use several other names for complete atrioventricular septal defect. All of the terms below describe the same basic problem: a big hole in the center of the heart and a common atrioventricular valve. [1]

Common other names include: [1]

• Atrioventricular septal defect (AVSD)

• Atrioventricular canal defect (AV canal defect, AVCD)

• Common atrioventricular canal

• Endocardial cushion defect (complete type)

• Complete atrioventricular canal (complete AV canal)

• Complete common AV canal defect

All of these names point to the same main idea: the central “cushion” tissue of the heart did not form correctly while the baby was in the womb. [1]

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Types of complete atrioventricular septal defect

Doctors group complete AVSD into types based on the shape and attachments of the common valve inside the heart. This is called the Rastelli classification (Types A, B, and C). These types help surgeons plan the repair. [2]

1. Rastelli Type A complete AVSD [2]
   In Type A, the main front leaflet of the common valve is mostly attached to the middle wall (septum) between the ventricles by many small strings (chordae). This is the most common type. The hole between the ventricles is just under this leaflet. Because the leaflet is attached firmly, the shape of the left heart outflow is long and narrow. [2]

2. Rastelli Type B complete AVSD [2]
   In Type B, the front leaflet of the common valve is partly attached to an abnormal muscle on the right side of the ventricular wall instead of to the center of the septum. This type is rare. It often appears in babies with more complex heart layouts, like heterotaxy (abnormal right–left organ arrangement). The unusual attachments can make surgery more difficult. [2]

3. Rastelli Type C complete AVSD [2]
   In Type C, the front leaflet of the common valve does not attach to the septum at all. It “floats” freely between the two ventricles. The ventricular hole is usually very large. Because there is very little tissue in the middle, the mixing of blood can be severe, and heart failure often appears early in life if not repaired. [2]

Doctors may also describe complete AVSD as balanced (both ventricles similar in size) or unbalanced (one ventricle much smaller). This helps decide whether the baby can have a two-ventricle repair or will need more complex single-ventricle surgery later. [3]

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Causes (risk factors)

The exact cause of complete AVSD in many babies is not fully known. Most experts think it comes from a mix of genetic changes and things in the mother’s environment during pregnancy. [3]

1. Down syndrome (trisomy 21) [1]
   Complete AVSD is strongly linked with Down syndrome. A large number of babies with complete AVSD have an extra copy of chromosome 21. The extra chromosome affects how the heart cushions grow and join, leading to the central hole and common valve. [1]

2. Other chromosomal problems [2]
   Other chromosome changes, such as trisomy 18, trisomy 13, 3p deletion, and Noonan syndrome, can also raise the risk of AVSD. These changes disturb normal heart development, especially the tissue that forms the septum and the valves. [2]

3. Single-gene mutations [3]
   Mutations in certain heart-development genes (for example, genes involved in endocardial cushion formation) can lead to AVSD, sometimes as part of a family pattern. These gene changes may be inherited or may appear for the first time in the baby. [3]

4. Defective endocardial cushion development [1]
   The “endocardial cushions” are thick pads of tissue in the center of the forming heart. If these cushions do not grow and fuse properly, the walls between the chambers and the AV valves cannot form normally, causing AVSD. [1]

5. Disturbed dorsal mesenchymal protrusion (DMP) development [2]
   Research shows that problems in another tissue called the dorsal mesenchymal protrusion can also cause AVSD. This structure helps bring the septal tissues together. When it does not form correctly, the central parts of the atrial and ventricular septa are missing. [2]

6. Maternal diabetes (especially gestational diabetes) [3]
   Diabetes during pregnancy can increase the risk of many congenital heart defects, including AVSD. High blood sugar may affect how the baby’s heart forms in early pregnancy. [3]

7. Maternal obesity [3]
   Being very overweight during pregnancy is linked with a higher chance of having a baby with a congenital heart defect. The exact mechanism is not clear, but it may relate to inflammation, hormones, or changes in blood sugar and fats. [3]

8. Maternal smoking [4]
   Smoking in pregnancy can damage blood vessels and reduce oxygen to the developing baby. Studies suggest it increases the risk of congenital heart disease in general, including septal defects. [4]

9. Maternal exposure to organic solvents and some chemicals [4]
   Working with certain paints, glues, or industrial solvents in early pregnancy may raise the risk of heart defects. These substances can interfere with the baby’s organ formation during the first weeks after conception. [4]

10. Maternal autoimmune diseases (for example, lupus) [2]
    Some autoimmune diseases in the mother are linked to a higher risk of heart defects in the baby. Abnormal antibodies and inflammation may affect the heart tissue as it forms. [2]

11. Advanced maternal age [3]
    Mothers who are older (for example older than 35 years) have a higher chance of having a baby with chromosome problems such as Down syndrome, and therefore an increased risk of AVSD. [3]

12. Family history of congenital heart disease [2]
    If a parent or a close relative was born with a heart defect, the risk for the baby is higher than in the general population. This suggests that some inherited factors influence the formation of the heart. [2]

13. Genetic syndromes affecting left–right body pattern (heterotaxy) [3]
    Conditions where organs are not in their usual left–right positions are often associated with complex heart defects, including AVSD. The same developmental pathways that set up body sidedness also guide heart structure. [3]

14. Poor maternal nutrition (including folate deficiency) [4]
    Not having enough key vitamins and nutrients before and during early pregnancy may interfere with normal heart formation. Folate is especially important for early organ development. [4]

15. Maternal alcohol use in early pregnancy [4]
    Heavy alcohol use in the first trimester can cause fetal alcohol spectrum disorders and raise the risk of heart defects, including septal defects. Alcohol may directly damage developing heart cells. [4]

16. Maternal infections (for example, rubella) in early pregnancy [4]
    Some viral infections, especially if they occur in the first trimester, can affect the developing heart. Rubella is a well-known example that can cause various congenital heart problems. [4]

17. Uncontrolled maternal phenylketonuria (PKU) [3]
    If a mother with PKU does not control her blood phenylalanine levels during pregnancy, her baby has a higher risk of congenital heart disease, including septal defects. [3]

18. Use of certain medicines in early pregnancy [4]
    Some drugs that affect cell growth or vitamin A pathways may be linked to heart defects if taken early in pregnancy. Doctors try to avoid known teratogenic medicines in women who may become pregnant. [4]

19. Assisted reproductive technologies (IVF and others) [3]
    Some studies suggest a slightly higher rate of congenital heart defects in babies conceived using IVF or similar methods. The exact reason is unclear and may involve both the procedures and the parents’ underlying conditions. [3]

20. Unknown or multifactorial causes [1]
    In many babies with complete AVSD, no single clear cause is found. Most experts think many small genetic and environmental factors act together. This is called a multifactorial cause. [1]

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Symptoms

Babies with complete AVSD often look well at birth. As lung pressure falls in the first weeks of life, more blood flows through the defect to the lungs, and symptoms appear. [2]

1. Fast breathing (tachypnea) [1]
   The baby breathes quickly, even at rest. This happens because too much blood is going to the lungs, making them wet and heavy. The lungs need more effort to move air in and out. [1]

2. Shortness of breath, especially while feeding [1]
   The baby may have trouble sucking and breathing at the same time. They may stop feeding to catch their breath or become tired and sweaty during feeds. [1]

3. Poor weight gain or failure to thrive [2]
   Feeding is hard work, and the heart is using a lot of energy. The baby may not take enough milk and may not gain weight as expected. This is a common early sign. [2]

4. Sweating during feeds or mild activity [2]
   Parents often notice cold, clammy sweat on the baby’s head or body while feeding. This is a sign that the heart is under stress and working too hard. [2]

5. Fast heart rate (tachycardia) [2]
   The heart beats quickly to try to push more blood to the body and lungs. Doctors can feel this on exam or see it on a monitor or ECG. [2]

6. Heart murmur [3]
   When a doctor listens with a stethoscope, they often hear extra whooshing sounds (murmurs). These come from blood moving through the holes and the leaky common valve. Sometimes the murmur is the first clue. [3]

7. Bluish lips, tongue, or fingers (cyanosis) [3]
   Some babies may show a blue color, especially when crying or feeding. This happens when blood oxygen levels are low, either because of severe mixing or very high lung artery pressure. [3]

8. Recurrent chest infections [2]
   Extra blood into the lungs makes them wet and irritated. This can lead to frequent coughs, wheezing, or pneumonia. The baby may need hospital care for breathing support. [2]

9. Enlarged liver (hepatomegaly) [2]
   When the heart cannot pump effectively, blood backs up into the veins and into the liver. Doctors can feel the edge of the liver below the ribs. This is a sign of heart failure in infants. [2]

10. Swelling of legs, feet, or around the eyes (edema) [3]
    In more advanced heart failure, fluid can leak into the tissues. In babies, swelling is often subtle but may be seen in the feet, ankles, or eyelids. [3]

11. Fatigue and low energy [2]
    Older infants and children may seem tired and less active than peers. They may stop playing early, lie down often, or seem uninterested in usual activities. [2]

12. Poor growth in height and head size [3]
    Long-term poor nutrition and chronic illness can slow overall growth. Height and head circumference may fall below normal curves if the heart defect is not treated. [3]

13. Palpitations or abnormal heart rhythms (arrhythmias) [3]
    Older children or adults with unrepaired or repaired AVSD can feel fluttering or pounding in the chest. These are arrhythmias caused by stretched heart chambers or surgical scars. [3]

14. Signs of pulmonary hypertension [3]
    If high blood pressure in the lung arteries develops, the person may become more breathless, cyanotic, and tired. In advanced cases, symptoms may resemble right-sided heart failure. [3]

15. No symptoms (rare, usually partial or mild forms) [2]
    Complete AVSD almost always causes symptoms early. However, in unusual or borderline cases, symptoms can be mild at first, and the defect may be found on a routine exam or during tests for another reason. [2]

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Diagnostic tests

Doctors use history, physical exam, and many tests to confirm complete AVSD, measure its severity, and plan treatment. [3]

Physical exam tests

1. General inspection and growth assessment [1]
   The doctor looks at the baby’s overall appearance, breathing pattern, color, and body size. They check weight, length, and head size against growth charts. Poor growth, fast breathing, or bluish color can suggest a serious heart problem like complete AVSD. [1]

2. Cardiac auscultation (listening to the heart) [1]
   Using a stethoscope, the doctor listens for murmurs, extra heart sounds, and changes in the loudness of the second heart sound. In complete AVSD, a loud, mixed systolic murmur and an abnormal second sound are common clues. [1]

3. Respiratory and abdominal examination [2]
   The doctor checks the lungs for crackles or wheezing, which may show fluid from heart failure. They also feel the liver to see if it is enlarged, a sign of poor heart pumping. These findings help judge how sick the baby is before more tests. [2]

Manual tests

4. Peripheral pulse palpation [2]
   The doctor feels the pulses in the arms and legs. Strong, bounding pulses may suggest a large left-to-right shunt. Weak pulses may suggest low output or other problems. Pulse quality helps show how hard the heart is working. [2]

5. Capillary refill and skin perfusion check [2]
   By pressing on the skin (for example on a finger or the chest) and seeing how fast color returns, the doctor can estimate blood flow to the tissues. Slow capillary refill can mean poor circulation from heart failure. [2]

6. Manual blood pressure measurement [2]
   Blood pressure in the arms and legs gives information about overall circulation and heart function. Very low pressure can suggest shock or severe failure, while high pressure can affect how blood flows through the defect. [2]

Lab and pathological tests

7. Complete blood count (CBC) [3]
   A CBC checks red blood cells, white blood cells, and platelets. Babies with long-standing cyanosis may have extra red cells (polycythemia). Infection or anemia can also be seen, and these conditions can worsen heart symptoms. [3]

8. Arterial or venous blood gas (ABG/VBG) [3]
   This test measures oxygen and carbon dioxide in the blood. It helps show how well the lungs are working and how serious the mixing of oxygen-poor and oxygen-rich blood is. Low oxygen and high carbon dioxide support the diagnosis of significant heart or lung disease. [3]

9. Serum biochemistry (electrolytes, kidney and liver tests) [3]
   These tests look at organ function and salt balance. Heart failure medicines (like diuretics) can affect electrolytes. Poor blood flow from heart failure can affect kidney and liver function, which must be monitored before and after surgery. [3]

10. Brain natriuretic peptide (BNP or NT-proBNP) [3]
    BNP is a hormone released when the heart muscle is stretched. High levels suggest significant heart failure. In babies with AVSD, a high BNP can support the need for treatment or surgery. [3]

Electrodiagnostic tests

11. Resting 12-lead electrocardiogram (ECG) [1]
    An ECG records the electrical activity of the heart. In complete AVSD, it often shows left-axis deviation, enlarged atria and ventricles, and sometimes abnormal conduction. These patterns help confirm the diagnosis and detect rhythm problems. [1]

12. Holter monitoring or ambulatory ECG [2]
    A Holter monitor records the heart’s rhythm over 24 hours or more. It can detect intermittent arrhythmias that may not appear on a short ECG. This is especially useful in older children or adults with repaired AVSD who complain of palpitations. [2]

13. Cardiopulmonary exercise test (CPET) in older patients [2]
    In older children and adults, CPET measures exercise capacity and how the heart and lungs respond to stress. It helps assess the impact of residual valve leakage, pulmonary hypertension, or other long-term effects of AVSD. [2]

Imaging tests

14. Chest X-ray [1]
    A chest X-ray shows the size and shape of the heart and the blood flow pattern in the lungs. In complete AVSD, the heart is often enlarged, and the lung vessels look brighter and fuller because of extra blood flow. [1]

15. Transthoracic echocardiography (TTE) [1]
    TTE is the main test for diagnosing AVSD. It uses ultrasound from the chest wall to show the heart in real time. It clearly displays the central hole, the common AV valve, the way blood flows between chambers, and the sizes of the ventricles. [1]

16. Transesophageal echocardiography (TEE) [2]
    In TEE, a small ultrasound probe is placed in the esophagus (food pipe) under sedation. It gives very detailed pictures of the valves and the septal defects. Surgeons and cardiologists may use TEE before, during, or after surgery to guide repair and check the result. [2]

17. Fetal echocardiography [2]
    This test looks at the baby’s heart while still in the womb. Many complete AVSDs can be detected before birth. Early diagnosis helps doctors plan delivery at a center with neonatal and cardiac surgery services. [2]

18. Cardiac magnetic resonance imaging (MRI) [3]
    Cardiac MRI can give very accurate 3-D pictures of heart structure and blood flow. In older children and adults with repaired AVSD, it can measure chamber size, valve function, and any residual shunts, especially when echo images are not clear enough. [3]

19. Cardiac CT angiography [3]
    CT scans can show detailed anatomy of the heart and great vessels. They are useful when surgeons need to see complex structures or when MRI is not possible. CT also helps detect associated vessel problems, such as narrowed arteries. [3]

20. Cardiac catheterization with oximetry and pressure measurements [3]
    In this invasive test, thin tubes (catheters) are passed through blood vessels into the heart. Doctors measure pressures and oxygen levels in all chambers and lung arteries. This shows how large the shunt is and how high the lung pressure is. It is especially important when pulmonary hypertension is suspected or when planning surgery in older patients. [3]

Non-pharmacological treatments (therapies and others)

Important note: These treatments help control symptoms and protect the heart and lungs, but they do not “fix” the hole or the valve. Surgery is usually needed for a long-term solution.

1. Careful monitoring by a pediatric cardiologist
   Regular visits allow the heart specialist to watch the baby’s growth, breathing, heart sounds, and oxygen levels. The doctor can adjust medicines, feeding plans, and the timing of surgery. Close follow-up helps pick up problems early, such as rising lung pressure or valve leakage, and prevents sudden worsening.

2. Optimized feeding and high-calorie nutrition
   Babies with complete AVSD use more energy to breathe and pump blood, so they often gain weight slowly. A dietitian may suggest high-calorie breast milk fortifiers or special formulas, given more often in small feeds. Sometimes a feeding tube is used to reduce tiredness during feeding and support growth before and after surgery.

3. Fluid and salt management
   Too much salt and fluid makes the body hold water, which can worsen lung congestion and heart failure symptoms. The care team may recommend limiting extra salt and keeping a close eye on fluid intake, especially in older children. The goal is to reduce swelling and breathing difficulty without causing dehydration.

4. Oxygen support when needed
   Some babies need extra oxygen, especially before surgery or during infections. Oxygen can lower the work of breathing and support the heart. However, in some cases of long-standing high lung pressure, oxygen is used carefully, so decisions are always made by the heart team based on the child’s exact condition.

5. Positioning and pacing of activities
   Keeping the baby in a slightly upright position can make breathing easier. For older children, pacing play, avoiding extreme exertion, and taking rest breaks reduces stress on the heart. Teachers and caregivers can help by allowing gentle activity and quick rest if the child becomes short of breath or very tired.

6. Infection prevention and vaccinations
   Respiratory infections can be very dangerous in children with complete AVSD because their lungs are already stressed. Routine vaccines, including influenza and pneumonia vaccines when recommended, good hand hygiene, and avoiding contact with sick people are important steps to reduce hospitalizations and protect lung function.

7. Endocarditis prevention measures
   Some children with AVSD have an increased risk of infection of the heart lining (endocarditis), especially around surgery or certain dental procedures. The cardiologist may advise antibiotic protection in specific high-risk situations and good dental care to reduce bacteria that can enter the bloodstream.

8. Parental education and counseling
   Explaining the heart defect in simple language helps caregivers recognize early warning signs such as fast breathing, poor feeding, or bluish lips. Counseling also supports families emotionally, as caring for a child with a congenital heart defect can be stressful. Informed parents can make safer day-to-day decisions.

9. Growth and development support
   Children with AVSD, especially those with , may have slower motor or language development. Early intervention programs, physiotherapy, speech therapy, and occupational therapy encourage normal development and improve long-term quality of life.

10. Respiratory therapy and airway care
    Some children need breathing exercises or physiotherapy to keep the lungs clear, especially after surgery. Techniques like gentle chest physiotherapy and breathing training reduce the risk of pneumonia and help the lungs recover faster after operations.

11. Careful temperature and environment control
    Babies with heart failure may not tolerate very hot or very cold environments. Keeping the room comfortably warm, avoiding overheating with many clothes, and preventing dehydration during hot weather protects the heart and circulation.

12. Sleep and rest hygiene
    Adequate sleep allows the heart and lungs to recover from daytime stress. A calm sleep environment, regular routines, and treating sleep-related breathing problems (such as obstructive sleep apnea in some children with Down syndrome) support heart health.

13. Psychological support for older children and parents
    Living with a heart defect, repeated tests, and surgery can cause anxiety and low mood. Psychologists or counselors help families build coping skills and reduce stress, which can indirectly improve symptom control and treatment adherence.

14. Cardiac rehabilitation (for older children/adolescents)
    In some centers, supervised exercise programs are used after surgery to rebuild strength safely. These programs teach safe exercise levels, breathing techniques, and pacing, while monitoring heart rate and oxygen levels.

15. Avoiding tobacco smoke exposure
    Second-hand smoke irritates the airways and increases lung pressure, which can worsen symptoms in children with AVSD. Keeping the home and car smoke-free is a simple but powerful way to reduce breathing problems and hospital visits.

16. Careful travel and altitude planning
    High altitudes can lower oxygen levels and increase stress on the heart. Families should discuss travel to mountains or long flights with the cardiologist. Sometimes extra oxygen or specific precautions are advised, especially before full repair.

17. Structured transition to adult congenital heart care
    As children grow older, they need to move from pediatric to adult congenital heart specialists. A planned transition helps ensure regular follow-up, especially if valve problems or arrhythmias appear later in life.

18. School and physical education planning
    Teachers should know about the child’s condition, warning signs, and activity limits. Adapting sports and physical education to match the cardiologist’s advice allows safe participation while avoiding over-exertion and dehydration.

19. Support groups and community resources
    Parents may benefit from connecting with other families of children with congenital heart disease or Down syndrome. Sharing experiences and practical tips can reduce isolation and improve coping with long-term treatment.

20. Pre-pregnancy counseling for future pregnancies
    Families with a history of AVSD can see a genetic counselor and cardiologist before planning another pregnancy. They discuss recurrence risk, prenatal screening, and fetal echocardiography in future pregnancies.

Drug treatments

Very important: Medicines help control heart failure and pulmonary hypertension around the time of surgery or when surgery is delayed. They do not close the defect. Exact drug choice and dose are always decided by a pediatric cardiologist based on age, weight, kidney function, and other illnesses. Never start, stop, or change these medicines without specialist advice.

Below are examples of important drug types used in complete AVSD care, with information supported by regulatory labels and heart-failure guidance where available.

1. Furosemide (loop diuretic)
   Furosemide is a strong “water tablet” that helps the kidneys remove extra salt and water from the body. This reduces lung congestion, swelling, and shortness of breath in children with heart failure due to AVSD. Doses are weight-based and adjusted to urine output and electrolytes. Main side effects include low potassium, dehydration, low blood pressure, and hearing issues at very high doses, so close monitoring is essential.

2. Spironolactone (potassium-sparing diuretic)
   Spironolactone blocks the hormone aldosterone and helps prevent the body holding too much salt and water. It is often added to loop diuretics to improve heart failure symptoms and protect the heart. It can raise blood potassium, so blood tests are needed. Side effects may include tummy upset and, rarely, breast tenderness or hormonal changes.

3. Thiazide diuretics (e.g., hydrochlorothiazide)
   Thiazide diuretics are sometimes combined with loop diuretics when extra fluid removal is needed. They act on a different part of the kidney tubule. Benefits include improved symptom control when fluid overload is severe. Possible side effects include low sodium, low potassium, and raised blood sugar, so they are used with careful lab monitoring.

4. Captopril (ACE inhibitor)
   Captopril relaxes blood vessels by blocking the angiotensin-converting enzyme. This lowers resistance to blood flow and reduces the workload on the heart, which can help children with AVSD and heart failure. Doses are slowly increased while watching blood pressure and kidney function. Side effects include cough, low blood pressure, high potassium, and, rarely, kidney problems or allergic reactions.

5. Enalapril or other ACE inhibitors
   Enalapril works in a similar way to captopril but is often given less frequently. It can improve pumping function and symptoms when the lower heart chambers are weak or very overloaded. As with other ACE inhibitors, regular checks of blood pressure, kidney function, and potassium are important to prevent complications.

6. Angiotensin receptor blockers (e.g., losartan)
   When ACE inhibitors are not tolerated because of cough or other side effects, angiotensin receptor blockers may be used in some older children. They also relax blood vessels and reduce afterload. Side effects can include low blood pressure, dizziness, and high potassium. Their use in small infants is more limited and specialist-guided.

7. Digoxin (inotrope)
   Digoxin helps the heart pump more strongly and can slow a very fast heart rhythm. It may be used in some children with AVSD and heart failure or certain arrhythmias. The medicine has a narrow therapeutic window, so dosing is weight-based and blood levels are often checked. Signs of toxicity include vomiting, poor appetite, abnormal heart rhythms, and confusion in older patients.

8. Beta-blockers (e.g., carvedilol, metoprolol)
   Beta-blockers slow the heart rate and reduce the effect of stress hormones on the heart. In selected children with chronic heart failure, they can improve function over time. They are introduced very slowly and increased stepwise. Possible side effects include low heart rate, low blood pressure, tiredness, and sometimes wheezing in children with asthma.

9. Milrinone (intravenous inotrope and vasodilator)
   Milrinone is used in hospital, especially around surgery, to support the heart when it is very weak or when lung pressures are high. It improves squeezing of the heart and relaxes blood vessels. It is given by continuous infusion with close monitoring of blood pressure and heart rhythm.

10. Dopamine and dobutamine (intravenous inotropes)
    These medicines are also used in intensive care to support the circulation in very sick children, for example just after surgery. They increase heart pumping strength and can raise blood pressure. They are short-term treatments with careful monitoring for irregular heart rhythms or excessive blood pressure changes.

11. Sildenafil (pulmonary vasodilator)
    Sildenafil relaxes the blood vessels in the lungs and is sometimes used in children with AVSD who have high pulmonary artery pressures. By lowering lung resistance, it can improve oxygen delivery and reduce strain on the right side of the heart. Side effects can include flushing, headache, low blood pressure, and, rarely, visual changes.

12. Bosentan (endothelin-receptor antagonist)
    Bosentan is used for pulmonary arterial hypertension. It blocks endothelin-1, a strong vessel-tightening chemical, and helps relax lung blood vessels. It may be used in selected children with AVSD and advanced pulmonary vascular disease. Regular liver-function and hemoglobin tests are required because bosentan can cause liver injury and anemia.

13. Prostacyclin analogues (e.g., epoprostenol)
    These medicines are powerful vasodilators that widen lung blood vessels and are used in severe pulmonary hypertension. In AVSD, they may be considered in specialized centers when pulmonary pressure remains very high. They are given intravenously or by inhalation with careful monitoring for low blood pressure, bleeding risk, and jaw pain or flushing.

14. Low-dose aspirin (antiplatelet)
    Aspirin in low doses may be used after certain operations or when there are patches, prosthetic materials, or valve repairs, to lower the risk of small blood clots. Because aspirin can irritate the stomach and affect bleeding, the dose and duration are chosen carefully, especially in small children.

15. Warfarin (oral anticoagulant)
    Warfarin may be prescribed when there are artificial valves or other conditions with high clot risk. It “thins” the blood by blocking vitamin K-dependent clotting factors. Regular blood tests (INR) are essential to keep the level in a safe range and avoid both clotting and bleeding complications.

16. Heparin (parenteral anticoagulant)
    Heparin is often used in hospital around surgery and catheter procedures to prevent clots. It works quickly and is monitored by clotting tests. Side effects include bleeding and, rarely, low platelets (heparin-induced thrombocytopenia), so it is used under very close supervision.

17. Loop plus thiazide “sequential nephron blockade”
    In some children with severe heart failure, a combination of loop and thiazide diuretics is used to overcome fluid overload. This strategy blocks salt re-absorption at different parts of the kidney. It is powerful but increases the risk of dehydration and electrolyte imbalance, so frequent lab checks are needed.

18. ACE inhibitor plus beta-blocker heart-failure regimen
    In older children and adults with residual pumping weakness after AVSD repair, a combination of an ACE inhibitor and a beta-blocker may be used following heart-failure guidelines. This combination can improve symptoms and long-term outcomes when titrated slowly and monitored carefully.

19. Diuretic plus aldosterone-blocker combination
    Adding spironolactone to loop diuretics is common in chronic heart failure management. It helps control fluid while reducing the harmful effects of high aldosterone on the heart muscle and blood vessels. This approach must balance the benefits with the risk of high potassium.

20. Short-term vasodilators around surgery
    Drugs such as nitroprusside or nitroglycerin may be used briefly in intensive care to control blood pressure and reduce the load on the heart after repair. They act by relaxing blood vessels but require invasive monitoring to maintain safe pressures and avoid organ under-perfusion.

Dietary molecular supplements (supportive, not curative)

Supplements cannot close an AVSD or replace surgery or prescription medicines. Evidence in children with congenital heart disease is limited, so any supplement should only be used with cardiologist and pediatrician approval.

1. Omega-3 fatty acids (fish oil) – may support overall heart health and reduce inflammation, but dose and purity must be carefully chosen in children.

2. Vitamin D – helps bone and immune health; deficiency is common and may be corrected under medical guidance.

3. Iron (if deficient) – treats iron-deficiency anemia, which can worsen fatigue and breathlessness.

4. Folate and vitamin B12 – support red-blood-cell production when deficient.

5. Coenzyme Q10 – sometimes used as adjunct in heart failure; evidence in children is modest and mixed.

6. L-carnitine – may help in specific metabolic conditions affecting the heart; not routine in AVSD.

7. Magnesium (if low) – helps normal heart rhythm but must be closely dosed.

8. Zinc (if deficient) – supports growth and immune function.

9. Probiotics – may support gut health, but benefits for AVSD itself are indirect.

10. Multivitamin tailored for cardiac children – some centers use specialized formulas to ensure overall micronutrient adequacy.

(For all of the above, exact dosing is individualized and must be planned by the child’s clinical team.)

Regenerative, stem-cell and “immunity-support” drugs

At present, there are no approved stem-cell or regenerative “drugs” that can cure or reverse complete AVSD. Research is ongoing in advanced heart failure and post-surgical heart muscle damage, mostly in adults, using: cardiac progenitor cells, mesenchymal stem cells, and induced pluripotent stem-cell–derived cardiomyocytes. These remain experimental, used only in clinical trials with strict monitoring, and are not routine treatment for AVSD in children.

Immune support in AVSD mainly means good nutrition, vaccinations, and avoiding unnecessary infections and stress, not special “immune booster” medicines. Your cardiologist may use standard medicines, such as vaccines and sometimes immunoglobulins in special situations, but these are not targeted at the defect itself.

Surgeries (procedures and why they are done)

1. Complete AVSD repair (single-patch, double-patch, or modified single-patch technique)
   This is the main operation. The surgeon closes the large hole between the atria and ventricles with patches and separates the common valve into two valves (mitral and tricuspid). It is usually done in early infancy to prevent lung damage and heart failure. Success rates are now high in experienced centers.

2. Pulmonary artery banding (palliative)
   In some very small or complex infants, a band is placed around the pulmonary artery to limit blood flow to the lungs and reduce lung pressure. This is a temporary step used before complete repair when the baby is not yet ready for full surgery. A later operation removes the band and completes the repair.

3. Re-operation for residual shunts or valve regurgitation
   After repair, some children have leaks in the left atrioventricular (mitral) valve or small remaining holes. If these cause symptoms or heart enlargement, a second surgery may repair or, rarely, replace the valve or close the residual defect.

4. Left ventricular outflow tract obstruction relief
   Some patients develop narrowing where blood leaves the left ventricle after AVSD repair. A further operation may remove tissue or patch-enlarge this area to maintain smooth blood flow. This protects the left ventricle from extra workload and preserves function.

5. Heart transplantation (rare, last resort)
   In a small number of children with severe, irreversible lung vascular disease or repeated failed repairs, heart (or heart-lung) transplantation may be considered. This is a major step, requiring lifelong immunosuppression and careful follow-up in a transplant center.

Prevention and risk reduction

Complete AVSD cannot always be prevented, but several steps can reduce risk or improve outcomes:

1. Pre-pregnancy control of maternal diabetes and thyroid disease.

2. Rubella and other key vaccinations before pregnancy to avoid infections that can damage the fetal heart.

3. Avoidance of alcohol, smoking, and illicit drugs during pregnancy.

4. Folic acid supplementation as recommended for neural tube and possibly other birth-defect risk reduction.

5. Careful review of medicines in pregnancy to avoid known teratogens.

6. Early prenatal care and ultrasound; fetal echocardiography when there is family history or risk factors.

7. Genetic counseling for families with chromosomal conditions or previous child with AVSD.

8. After birth, strict infection-prevention practices to protect the lungs and heart.

9. Keeping follow-up appointments so surgery can be done at the best time.

10. Long-term healthy lifestyle (smoke-free home, active play as advised, balanced diet) to protect the repaired heart.

When to see a doctor

You should contact a doctor urgently or go to emergency care if a child with complete AVSD has:

• Fast or labored breathing, grunting, or flaring nostrils.

• Bluish lips, tongue, or fingernails.

• Very poor feeding, sweating with feeds, or vomiting most feeds.

• Very little urine or no wet diaper for many hours.

• Sudden swelling of legs, tummy, or around eyes.

• High fever, persistent cough, or unusual sleepiness or irritability.

Regular visits to the pediatric cardiologist are also needed even when the child seems well, both before and after surgery, to monitor heart function, valves, lung pressures, growth, and development.

Diet: what to eat and what to avoid

What to eat (guided by the cardiologist and dietitian)

1. For babies: breast milk whenever possible, sometimes with added calories, or specialized high-calorie formulas to support growth.

2. For older children: balanced meals with fruits, vegetables, whole grains, and lean protein to support growth and healing.

3. Foods naturally rich in potassium and magnesium (bananas, leafy greens) when blood tests allow, supporting normal heart rhythm.

4. Adequate fluids but not excess, following the cardiologist’s advice, especially when on diuretics.

5. Small, frequent meals if the child gets tired or breathless with large meals.

What to limit or avoid (always individualised)

6. Very salty snacks (chips, instant noodles, processed meats) that can worsen fluid retention.

7. Sugary drinks and energy drinks, which add empty calories and can affect heart rate and weight.

8. Herbal products and supplements not checked with the cardiologist, because some may interact with heart medicines or affect clotting.

9. Large caffeine loads (cola, strong tea or coffee in older teens) that may trigger palpitations in sensitive patients.

10. Any “miracle cure” diet that suggests stopping prescribed medicines or avoiding surgery. These claims are unsafe and not evidence-based.

FAQs

1. Can complete AVSD close by itself with medicines or diet?
   No. Complete AVSD is a structural problem involving a large central hole and a shared valve. Medicines and diet can improve symptoms but cannot close the defect. Surgery is usually needed for long-term survival and to protect the lungs.

2. What age is surgery usually done?
   Many centers aim to repair complete AVSD in early infancy, often between 3–6 months of age, depending on symptoms, lung pressure, and growth. Very sick babies may need earlier repair or temporary pulmonary artery banding first.

3. Is AVSD more common in children with Down syndrome?
   Yes. AVSD is one of the most common heart defects in babies with

4. What is the long-term outlook after surgery?
   Most children who have timely repair can grow, go to school, and live active lives. Some need further surgery or catheter procedures later for valve leaks or rhythm problems, so lifelong follow-up is important.

5. Will my child need medicines forever?
   Some medicines are used only around the time of surgery, while others may be continued longer for valve problems, rhythm issues, or heart failure. The cardiologist regularly reviews which medicines are still needed.

6. Can my child play sports?
   Many children with repaired AVSD can do regular school activities and even sports, depending on heart function and valve status. The cardiologist gives specific advice about which sports and how intensely the child can participate.

7. Is pregnancy safe for someone with repaired AVSD?
   Many women with repaired AVSD can have successful pregnancies, but risks vary. Pre-pregnancy counseling with an adult congenital heart specialist and high-risk obstetrician is strongly recommended to plan safely.

8. Does AVSD always occur with genetic problems?
   No. While it is very common in , AVSD can also occur in babies with normal chromosomes. Genetic counseling and testing may be offered to understand the cause in each family.

9. Will a future baby also have AVSD?
   The recurrence risk is higher than in the general population but still relatively low. Exact risk depends on family history and genetics. A genetic counselor can explain this and arrange fetal echocardiography in future pregnancies.

10. Can vaccines harm a child with AVSD?
    No. In fact, vaccines are especially important to protect against infections that can stress the heart and lungs. The cardiologist and pediatrician may recommend extra vaccines such as influenza or certain pneumonia vaccines.

11. Is there a special “heart diet” for AVSD?
    There is no single special diet, but a balanced, low-salt, nutrient-rich diet and high-calorie feeds when needed help support growth and heart function. Diet plans should be tailored by a dietitian and cardiologist for each child.

12. Are stem-cell therapies available now for my child’s AVSD?
    At this time, stem-cell and regenerative therapies are experimental and mostly studied in adults with other forms of heart failure. They are not standard care for AVSD and should only be considered, if at all, in formal research trials.

13. Can complementary or herbal treatments replace surgery?
    No. Herbal products cannot close a septal defect or repair a valve, and some herbs can be dangerous when combined with heart medicines or blood thinners. Always discuss any alternative products with the cardiologist before use.

14. Will my child always have to see a heart doctor?
    Yes. AVSD is a lifelong condition, even after repair. Regular visits to congenital heart specialists help detect late valve problems, rhythm issues, or other complications early, so they can be treated promptly.

15. What should parents remember most?
    Complete AVSD is serious but often very treatable. Early diagnosis, appropriate surgery, careful follow-up, good nutrition, infection prevention, and emotional support together offer the best chance for a healthy, active life. You are not alone; your heart team is there to guide each step.

Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members

Last Updated: February 27, 2025.