Atrioventricular septal defect is a congenital heart condition that affects the walls between the heart’s chambers and the valves. People with atrioventricular septal defect often have fast breathing, trouble feeding, poor weight gain, and tiring easily in infancy. Severity varies, and some have mild features while others develop heart failure if untreated. Treatment usually involves surgery in the first year of life, plus medicines to manage fluid and blood flow. With timely repair and follow-up, many people with atrioventricular septal defect live long and active lives.
Overview
Atrioventricular septal defectSymptoms
Early symptoms of atrioventricular septal defect often appear in infancy: fast breathing, poor feeding, and trouble gaining weight. You may notice tiring during feeds, sweating, or a bluish tint to lips or skin. Doctors may hear a heart murmur.
Outlook and prognosis
Many people with atrioventricular septal defect do well long-term, especially after timely surgery in infancy or childhood. Outcomes depend on defect size, valve function, associated conditions (like Down syndrome), and how early complications are addressed. Ongoing cardiology follow-up helps protect heart function and quality of life.
Causes and risk factors
Atrioventricular septal defect usually arises from early heart development changes before birth. Genetic factors—especially Down syndrome—and family history increase risk. Additional risk factors for atrioventricular septal defect include maternal diabetes, certain medications, alcohol, smoking, and some viral infections during pregnancy.
Genetic influences
Genetics play a major role in atrioventricular septal defect. Many cases link to chromosomal changes like trisomy 21 (Down syndrome), and some involve single‑gene variants or familial patterns. Genetic counseling and testing can clarify risks for future pregnancies.
Diagnosis
Doctors suspect an atrioventricular septal defect before birth on ultrasound, or after birth from a heart murmur, low oxygen, or poor growth. The diagnosis of atrioventricular septal defect is confirmed with echocardiography; genetic tests may check for associated chromosomal changes.
Treatment and drugs
Treatment for atrioventricular septal defect often combines heart medicines to ease strain, nutrition support, and timely surgery to close the holes and repair the valves. Care is individualized by defect size, symptoms, and age. Ongoing cardiology follow‑up guides activity, medications, and endocarditis prevention.
Symptoms
Feeding can be hard, and breathing may seem faster than expected in the first weeks of life. The changes are often subtle at first, blending into daily life until they become more noticeable. Parents may notice early features of atrioventricular septal defect such as poor weight gain, sweating with feeds, or a bluish tint around the lips. Some children with a milder form show signs later, especially with exercise or frequent chest infections.
Breathing may be quicker than usual or look like extra effort, with nostrils flaring or the chest pulling in. It often gets more noticeable during feeding or crying.
Feeds can be slow, with pausing to catch breath or sweating while nursing or taking a bottle. This can make it hard to finish a feed. In atrioventricular septal defect, the heart is working harder, so feeding takes extra energy.
Weight may not increase as expected, and clothes may stay the same size longer than you’d anticipate. Growth charts may show falling percentiles.
A bluish tint around the lips, fingertips, or toes can appear, especially with crying or feeding. If it persists or worsens, seek prompt medical care.
How people usually first notice Atrioventricular septal defect?
Many families first notice something is off in the first days or weeks after birth: a baby who breathes fast, sweats with feeds, tires easily, or isn’t gaining weight as expected, and a clinician may hear a heart murmur during a routine exam. These early clues often prompt an echocardiogram, which shows the atrioventricular septal defect (a hole between the heart’s chambers with valve abnormalities). When AVSD is part of a genetic condition like Down syndrome, it’s sometimes suspected before birth on ultrasound, so the first signs of atrioventricular septal defect may be picked up during prenatal screening rather than after delivery.
Types of Atrioventricular septal defect
Atrioventricular septal defect (AVSD) has distinct clinical variants that differ in how the heart’s walls and valves are formed and how blood flows between chambers. These variants influence when symptoms appear, how severe they feel, and the timing of surgery. Some babies show early symptoms of AVSD like fast breathing, poor feeding, or trouble gaining weight, while others are diagnosed later based on a heart murmur or enlarged heart on imaging. Not everyone will experience every type.
Complete AVSD
Both the wall between the top chambers and the wall between the bottom chambers are open, and there is one shared valve. Symptoms often start early in infancy with fast breathing, sweating with feeds, and poor weight gain. This type usually needs surgery in the first months of life.
Partial AVSD
The wall between the upper chambers is open and the valve between them and the lower chambers is split but with two openings. People may have fewer symptoms early on, sometimes just a heart murmur or exercise intolerance as they grow. Valve leakage can increase over time and may require surgery later in childhood or adulthood.
Transitional AVSD
There is a large hole between the upper chambers and a small hole between the lower chambers with a divided but abnormal valve. Symptoms can be milder than in complete AVSD, yet valve leakage or the small lower hole can still strain the heart. Treatment timing depends on symptoms and ultrasound findings.
Balanced AVSD
Blood flow is relatively even to both sides of the heart, and both pumping chambers are adequately sized. Symptoms may be more related to extra blood flow to the lungs and valve leakage rather than underdevelopment of a chamber. Many undergo repair aimed at preserving two-ventricle circulation.
Unbalanced AVSD
One pumping chamber is smaller, so blood flow favors one side of the heart. Babies often develop symptoms early due to limited pumping capacity and lung overcirculation. Care plans may include staged procedures or single-ventricle pathways depending on chamber size.
Associated Down syndrome
AVSD is common in babies with Down syndrome, and the heart anatomy often follows the complete type. Symptoms may appear early, but surgical outcomes are generally good in experienced centers. Shared care with cardiology and genetics teams supports timing and recovery.
Valve-focused variant
The main issue is the abnormal atrioventricular valves, often with leakage even when the holes are smaller. People may notice fatigue, shortness of breath with activity, or palpitations as the first signs. Decisions often center on repairing the valves to protect heart function.
What genetics can tell you about symptoms
Down syndrome–related AVSD often brings earlier symptoms like rapid breathing, poor feeding, and slow weight gain because the shared genetic changes disrupt heart valve and wall development more broadly. Variants in CRELD1 or GATA4 can lead to similar defects, causing heart murmurs and fatigue.
Causes and risk factors
Many cases arise during early heart development in pregnancy with no clear cause.
Atrioventricular septal defect is strongly linked with chromosomal differences, especially Down syndrome.
Older maternal age raises the chance of Down syndrome, and this can raise AVSD risk.
Risk factors for atrioventricular septal defect also include preexisting diabetes, rubella infection, alcohol or tobacco use, and certain medicines taken in early pregnancy.
Some risks are modifiable (things you can change), others are non-modifiable (things you can’t).
Environmental and biological risk factors
Below are environmental and biological factors that can raise the chance of atrioventricular septal defect (AVSD) during fetal development. Some risks are carried inside the body, others come from the world around us. These points focus on influences during the earliest weeks of pregnancy, when the heart forms.
Conception at age 35 or older is linked with a higher chance of AVSD in the baby. Age-related changes in eggs can affect early heart formation.
Conception with a father aged 40 or older may slightly raise the risk of congenital heart defects, including AVSD. The increase appears small but has been noted in several studies.
Diabetes that exists before pregnancy is associated with more congenital heart defects. Higher glucose levels in the first weeks can disrupt the midline walls of the heart, raising AVSD risk.
When phenylketonuria is not well controlled before and during early pregnancy, the chance of heart defects goes up. High phenylalanine can interfere with normal septum development, sometimes contributing to AVSD.
Genetic risk factors
Atrioventricular septal defect is strongly linked to certain genetic findings, most commonly an extra copy of chromosome 21 (Down syndrome). Most genetic causes of atrioventricular septal defect involve changes in chromosomes or single genes that guide early heart formation. Some risk factors are inherited through our genes. Genetic counseling and, in some cases, testing can clarify who in a family may be at higher risk.
Down syndrome: This is the most common genetic association with atrioventricular septal defect. Many babies with Down syndrome have congenital heart differences, and this defect is among the most frequent.
Other aneuploidies: An extra copy of chromosome 13 or 18 can include heart defects such as atrioventricular septal defect. These conditions are rarer than Down syndrome but carry higher overall risks for heart differences.
Copy number changes: Small missing or extra pieces of DNA (microdeletions or duplications) on various chromosomes can affect heart development. These changes often happen for the first time in a child but can occasionally be inherited.
Single-gene variants: Rare changes in genes that shape the heart’s inner walls and valves can raise risk for this defect. In some families, one changed copy of a gene is enough to increase risk, while in others the change appears for the first time in the child.
Left-right disorders: Genetic conditions that disturb the body’s left-right layout (heterotaxy) are linked with defects of the heart’s central walls and valves. The genes involved often guide tiny cell structures called cilia and early organ positioning.
Family recurrence: Having a close relative with atrioventricular septal defect slightly raises the chance in future pregnancies. Risk can be higher if a parent has the defect or carries a related gene change, so genetic counseling can help estimate personal odds.
Lifestyle risk factors
Lifestyle choices do not cause Atrioventricular septal defect, but they can influence symptoms, recovery after repair, and risk of complications like heart failure, arrhythmias, or pulmonary hypertension. When considering lifestyle risk factors for Atrioventricular septal defect, focus on habits that change heart workload, lung pressures, or infection risk. Work with your cardiology team to tailor these to your anatomy (repaired or unrepaired) and current status. Small, consistent changes can make day‑to‑day breathing and activity easier.
Regular, moderate exercise can improve stamina and breathing efficiency without overstraining the heart. Very intense or isometric workouts may worsen valve leak symptoms or provoke arrhythmias, so get individualized limits.
High-salt eating promotes fluid retention and raises cardiac workload, aggravating shortness of breath and swelling. Following sodium limits and any fluid guidance can ease valve-related volume stress.
Excess body weight increases blood volume and lung pressure, worsening fatigue and heart failure risk in AVSD. Gradual weight loss can reduce strain on the repaired or unrepaired valves.
Nicotine and smoke increase pulmonary vascular resistance and irritate the heart’s rhythm. Quitting helps prevent worsening pulmonary hypertension and reduces postoperative complications.
Risk prevention
Atrioventricular septal defect (AVSD) is a congenital heart difference that forms early in pregnancy. In most cases, there’s no way to fully prevent AVSD, but you can lower some risks before and during pregnancy and reduce complications for children living with AVSD. Some prevention is universal, others are tailored to people with specific risks.
Meet a cardiologist or genetic counselor before pregnancy if there’s a family history, a prior child with AVSD, or known chromosomal conditions like Down syndrome. They can review your personal risk and walk through options such as targeted prenatal screening.
Keep blood sugar in target range before conception and in early pregnancy. Tight diabetes control lowers the chance of congenital heart defects, including AVSD.
Take 400–800 micrograms (0.4–0.8 mg) of folic acid daily starting before conception and through early pregnancy. While it mainly prevents brain and spine defects, it may also modestly reduce overall congenital heart defect risk.
Go over all prescription, over-the-counter, and herbal medicines before trying to conceive. Some drugs can affect fetal heart development, and safer alternatives may be available.
Transmission
Atrioventricular septal defect is a congenital heart condition, not an infection, so it isn’t contagious or something you can catch from others. Most cases begin while the heart is forming early in pregnancy and aren’t directly inherited; they arise from a one-time change in development. Sometimes Atrioventricular septal defect occurs with a chromosome difference such as Down syndrome, and, less often, it can run in families. If a parent or a child has a congenital heart defect, the chance for another child to have one is slightly higher than average; a genetics professional can explain how Atrioventricular septal defect is inherited and discuss your family’s specific risks.
When to test your genes
Atrioventricular septal defect is a congenital heart condition, so genetic testing is generally considered when there’s a personal diagnosis, a first‑degree relative with AVSD or related congenital heart disease, or features suggesting a genetic syndrome (like Down syndrome). Testing can guide care, surgery planning, and family planning. Ask a cardiologist or genetic counselor to tailor timing.
Diagnosis
Atrioventricular septal defect is usually recognized by how the heart is built and how blood flows, either before birth or soon after. Early and accurate diagnosis can help you plan ahead with confidence. Many babies are flagged during pregnancy, while others are noticed in the newborn period because of a heart murmur, low oxygen levels, or breathing and feeding difficulties. Echocardiography (an ultrasound of the heart) is the key test to confirm the details and guide treatment planning.
Sonographers may see unusual connections between the heart’s chambers or valves. These clinical features can prompt referral for a detailed fetal heart scan.
This detailed ultrasound maps the baby’s heart structure and blood flow. Imaging findings can confirm AVSD and help plan delivery and early care.
Doctors listen for a heart murmur and check oxygen levels with pulse oximetry. Signs like fast breathing, poor feeding, or bluish color can raise concern for AVSD.
This is the main test after birth to confirm the holes between chambers and the shared valve. Imaging findings show size, location, and valve leakage to guide surgery timing.
Stages of Atrioventricular septal defect
Atrioventricular septal defect does not have defined progression stages. This is a structural heart difference present from birth; how it affects someone varies with the size of the openings, how well the valves close, and when repair is done, so it isn’t tracked in step-by-step stages. Doctors often diagnose it in infancy or early childhood based on signs like fast breathing, poor feeding, or a heart murmur—what many refer to as early symptoms of atrioventricular septal defect—and confirm it with an echocardiogram. Different tests may be suggested to help outline the heart’s structure and monitor valve function over time, such as ECG, chest X-ray, pulse oximetry, and regular follow-up echocardiograms.
Outlook and prognosis
Many people ask, “What does this mean for my future?”, and the answer for atrioventricular septal defect (AVSD) depends on the type of defect and how early it’s treated. For babies with complete AVSD, surgery in the first months of life is common and has greatly improved survival into adulthood. Partial AVSD may be repaired later, sometimes in childhood or even adulthood, depending on symptoms and valve leakage. When repairs are done in timely fashion at experienced centers, most children grow, go to school, and join activities with few limits, though they’ll need routine heart checkups over time. In medical terms, the long-term outlook is often shaped by both genetics and lifestyle.
Looking at the long-term picture can be helpful. After repair, some people with AVSD develop valve leakage, rhythm issues, or heart pumping strain years later; these are usually monitored and managed with medicines or a touch-up procedure, and only a minority need another surgery. Early symptoms of AVSD in infants can include fast breathing, poor weight gain, and tiring with feeds—getting care quickly reduces lung pressure problems and improves outcomes. For adults whose AVSD wasn’t repaired in childhood, risks can include pulmonary hypertension and heart failure, which may limit surgical options and affect life expectancy, so specialist evaluation is important. With ongoing care, many people maintain good quality of life, work, exercise within recommendations, and have healthy pregnancies with coordinated high-risk obstetric and cardiology support.
The outlook is not the same for everyone, but serious complications and early mortality have fallen sharply over the past few decades thanks to earlier diagnosis, safer surgery, and better follow-up. People with AVSD linked to genetic conditions, such as Down syndrome, often do well after repair but may face higher chances of lung or airway issues, so closer monitoring helps. Talk with your doctor about what your personal outlook might look like.
Long-term effects
Many people grow up and live well after repair, yet some long-term features can follow into adolescence and adulthood. Early symptoms of atrioventricular septal defect in infancy often fade after surgery, but certain heart changes may persist or appear later. Long-term effects vary widely, and not everyone experiences the same issues. These patterns can differ by when the defect was repaired and whether valve leakage or lung pressure changes developed over time.
The left-sided valve created during repair can leak over the years. This may enlarge the heart and lead to breathlessness or swelling.
Extra-fast or irregular heartbeats can appear months to decades after surgery. They may come and go or become persistent.
Scarring near the repair can affect the heart’s wiring. Some develop slow heart rhythms that, in some cases, require device support later in life.
If lung pressures were high before repair or remain elevated, strain on the right side of the heart can continue. This can limit stamina and raise long-term risk.
How is it to live with Atrioventricular septal defect?
Living with an atrioventricular septal defect can range from nearly typical daily life after a well-healed repair to carefully paced days shaped by fatigue, breathlessness, or frequent medical check-ins. For many, childhood involves surgeries and cardiology visits, while adulthood may mean watching for valve leaks, rhythm issues, or pregnancy-related risks and planning activities to match energy levels. Families and partners often become skilled at reading subtle signs—like slower weight gain in infants, exercise intolerance in teens, or swelling and cough in adults—and they share in scheduling care, encouraging movement, and balancing rest with participation. With good follow-up, heart-healthy habits, and clear communication at school, work, and home, most people find a rhythm that supports connection, growth, and meaningful routines.
Treatment and drugs
Treatment for atrioventricular septal defect (AVSD) focuses on repairing the heart’s inner wall so the chambers and valves work as they should. In most cases, this requires open-heart surgery, often in infancy or early childhood, to close the hole(s) and rebuild the valves; timing depends on the child’s growth, symptoms, and any other health conditions. Before surgery, some babies take medicines that ease symptoms of heart failure—such as helping the body get rid of extra fluid or supporting heart function—and doctors carefully manage feeding and nutrition to support weight gain. After repair, regular follow-up with a cardiologist tracks valve function, heart rhythm, and blood pressure, and some people may need additional procedures later if a valve leaks or narrows over time. Not every treatment works the same way for every person, so your doctor can help weigh the pros and cons of each option.
Non-drug treatment
Atrioventricular septal defect can affect feeding, growth, and energy from infancy, and it can shape daily activity as children get older. Care plans often combine procedures, hands-on therapies, and steady follow-up to support heart health and development. Alongside medicines, non-drug therapies can make everyday life safer and more comfortable while you and your care team plan the timing of repair.
Open-heart surgery closes the holes and reshapes the valves to direct blood the right way. Timing depends on symptoms, growth, and test results, and many children do well long term.
Regular visits track heart function with echocardiograms and ECGs. These check valve leaks, heart size, and rhythm to catch changes early.
High-calorie feeds, fortified milk, or tube feeding can help babies gain weight. This matters because early symptoms of atrioventricular septal defect often include tiring with feeds and slow growth.
A speech or occupational therapist can help with pacing, positioning, and swallowing. This can reduce fatigue during feeds and improve intake.
Your genes may have an impact on how drugs work for you
Genes can change how your body processes heart medicines after surgery for atrioventricular septal defect, affecting dose needs and side‑effect risk. Pharmacogenetic testing and careful monitoring help clinicians choose safer, more effective medications for each person.
Pharmacological treatments
Medicines can help control symptoms and support growth, often as a bridge to surgery. Drugs that target symptoms directly are called symptomatic treatments. For infants with atrioventricular septal defect, early symptoms of atrioventricular septal defect like fast breathing or poor weight gain may improve with the right mix of medicines.
Medicines like furosemide, chlorothiazide, or spironolactone help the body shed extra fluid so the lungs feel less congested and breathing eases. They’re commonly used in babies while waiting for repair. Blood tests may be needed to watch salts and kidney function.
Captopril or enalapril relax blood vessels so the heart pumps against less resistance and valve leakage strains the heart less. They may lower blood pressure and raise potassium, so labs and dosing checks are important.
This drug can strengthen the heart’s squeeze and help control heart rate in some infants. Dosing is weight‑based and carefully adjusted, with monitoring for vomiting, poor feeding, or rhythm changes.
Propranolol or carvedilol slow the heart rate and reduce workload when heart failure symptoms persist or valve leakage remains. They can cause tiredness or cool hands and feet, and doses are slowly increased to effect.
Genetic influences
Genetic factors play a meaningful role in atrioventricular septal defect (AVSD), and doctors often discuss the genetic causes of atrioventricular septal defect when a chromosome difference such as Down syndrome is involved. AVSD is one of the most common heart differences seen in babies with Down syndrome, yet it can also occur on its own without a known chromosome change. When AVSD appears without a chromosome condition, it is usually a one-off event, though in a small number of families a single gene change may contribute and the pattern can repeat in relatives. Family history is one of the strongest clues to a genetic influence. Your care team may suggest genetic testing of your baby or during pregnancy to look for chromosome differences and, in select cases, specific gene changes; results can help estimate the chance of AVSD in a future pregnancy. Even when a genetic cause is found, how severe the heart difference is can vary widely from person to person.
Is Atrioventricular septal defect genetic?
Genetics play a major role in atrioventricular septal defect. Many cases link to chromosomal changes like trisomy 21 (Down syndrome), and some involve single‑gene variants or familial patterns. Genetic counseling and testing can clarify risks for future pregnancies.
Pharmacogenetics—how genetics influence drug effects
For people with atrioventricular septal defect (AVSD), genetics can shape both the condition and parts of its treatment plan. AVSD often occurs with Down syndrome, and that broader genetic picture can influence surgical timing, lung health, and how someone handles certain medicines. Rare inherited traits, like a tendency toward malignant hyperthermia, may also steer anesthesia choices during repair.
Many teams individualize medicines used before and after surgery based on how the body processes them. Pharmacogenetics is the study of how genes influence your response to medicines and can help explain why one dose works well for one person but not another. For pain control, genetic differences in drug‑processing enzymes can make codeine unsafe or ineffective, so children with AVSD are often given alternatives; if blood thinners such as warfarin are needed, common gene variants can guide safer starting doses alongside regular blood tests, supporting more personalized medication choices for atrioventricular septal defect.
Interactions with other conditions
Colds, flu, or ongoing lung conditions can put extra strain on a heart with an atrioventricular septal defect (AVSD), sometimes leading to faster breathing, poor feeding in infants, or shortness of breath with activity. A condition may “exacerbate” (make worse) symptoms of another. AVSD often occurs in people with Down syndrome, and related issues such as sleep apnea, airway differences, or thyroid disease can complicate recovery and day-to-day heart management. High pressure in the lung arteries (pulmonary hypertension) can develop with AVSD; if chronic lung disease or sleep apnea is also present, that can push pressures higher and strain the heart more. People living with AVSD—whether repaired or not—also have a higher chance of rhythm problems and valve leakage over time, and certain medicines or pregnancy can change heart workload, so it’s important to review treatments with your care team. Early symptoms of atrioventricular septal defect can resemble frequent chest colds, so respiratory illnesses may mask or mimic heart-related issues; dental infections and some procedures can raise the risk of heart lining infections, making good dental care and clear planning with cardiology especially helpful.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
History
Throughout history, people have described babies who tired easily with feeding, breathed fast, or didn’t gain weight, and later were found to have heart differences present from birth. Community stories often described the condition as a “hole in the heart,” a simple phrase that captured what families noticed long before doctors could see the heart’s inner walls.
First described in the medical literature as a defect involving the central area of the heart where the upper and lower chambers meet, early reports focused on what could be heard with a stethoscope and seen during surgery or at autopsy. Before modern imaging, clinicians pieced together the picture from murmurs, cyanosis (a bluish tint), and heart failure symptoms in infants and young children. Initially understood only through symptoms, later it became clear that atrioventricular septal defect (AVSD) covers a spectrum—from complete forms affecting valves and walls between chambers, to partial forms that may go unnoticed until later in childhood or adulthood.
As medical science evolved, so did the tools to identify AVSD in living patients. The arrival of echocardiography in the late 20th century allowed doctors to watch blood flow in real time and map the exact shape of the hole and the shared valve. Prenatal ultrasound then brought the first chance to spot AVSD before birth, giving families and care teams time to plan delivery and early care. Over time, descriptions became more precise, and survival improved as surgical techniques advanced from staged operations to earlier, definitive repairs in infancy.
In recent decades, knowledge has built on a long tradition of observation. Clinicians recognized that AVSD is more common in children with certain chromosomal conditions, such as Down syndrome, which helped refine screening and counseling. At the same time, reports from adults living with repaired AVSD highlighted long‑term needs, like monitoring valve function and heart rhythm over the lifespan. Not every early description was complete, yet together they built the foundation of today’s knowledge.
Today, the history of AVSD reflects steady progress: from bedside observations to detailed imaging, from limited options to reliable surgical repair, and from childhood-focused care to lifelong follow‑up. Knowing the condition’s history helps explain why early diagnosis, coordinated heart care, and regular check‑ins remain central to the best outcomes for people with atrioventricular septal defect.