Eisenmenger syndrome is a late-stage complication of certain untreated or late-treated congenital heart defects (CHDs) that cause a longstanding left-to-right shunt — a condition where oxygen-rich blood from the left side of the heart mixes with oxygen-poor blood on the right side.

Over time, the increased blood flow to the lungs causes:

1. Thickening and stiffening of the pulmonary arteries (pulmonary vascular remodeling)
2. Increased pulmonary artery pressure(pulmonary hypertension)
3. Reversal of the shunt — blood begins to flow from the right side of the heart to the left, carrying oxygen-poor blood into the body's circulation.

This reversal results in cyanosis (bluish skin, lips, and nails) and multiple complications involving the heart, lungs, and other organs.

Common congenital heart defects that can lead to Eisenmenger syndrome include:

• Ventricular septal defect (VSD) — most common cause
• Atrial septal defect (ASD)
• Patent ductus arteriosus (PDA)
• Atrioventricular septal defect (AVSD)

If these defects are large and remain unrepaired, the chronic extra blood flow to the lungs causes irreversible pulmonary vascular disease — usually over years, but sometimes more rapidly in severe defects.

Although Eisenmenger syndrome is more common in adolescents and adults, it can occur in children, especially if diagnosis and repair of the underlying CHD is delayed or if the pulmonary vascular changes progress unusually quickly.

Causes and risk factors include:

• Unrepaired large congenital heart defects causing a significant left-to-right shunt
• Delayed diagnosis or repair of CHDs
• Rarely, progressive pulmonary hypertension despite early surgical repair
• Genetic factors and certain syndromes (such as trisomy 21) may increase risk

The following are the most common symptoms of Eisenmenger syndrome:

• Blue or grayish skin from less oxygen in the blood (cyanosis)
• Shortness of breath at rest or with activity
• Feeling tired
• Chest pain or chest tightness
• Skipping or racing heartbeats
• Headache
• Dizziness or fainting (syncope)
• Numbness or tingling of fingers and toes, or both
• Blurred vision
• Changes in the fingers and toes (clubbing)
• Swelling
• Enlarged liver

Your child's doctor will ask about your child's symptoms. The doctor may see signs when examining your child. Your doctor may hear an abnormal heart sound when listening to your child's heart with a stethoscope.

Your child may be referred to a pediatric cardiologist. This is a doctor with special training to treat heart problems in babies and children.

Your child may need tests. These may include:

• Pulse oximetry. A small probe is used to check the amount of oxygen in the blood.
• Blood tests. Tests may be done to check for a high or low red blood cell counts.
• Chest X-ray. A chest X-ray shows the heart and lungs. There may be changes in the lungs because of extra blood flow.
• Electrocardiogram (ECG). An ECG records the electrical activity of the heart. It also shows abnormal rhythms and detects heart muscle stress.
• Echocardiogram (echo). An echo uses sound waves to make a moving picture of the heart and heart valves. An echo can show the direction of blood flow. It can find out the size of a defect. Different types of echo tests may be done.
• Pulmonary (lung) function testing. Lung function testing checks how well your child's lungs are working.
• Cardiac cath (catheterization). A cardiac cath gives very detailed information about the structures inside the heart. The doctor puts a small, flexible tube (catheter) into a large blood vessel in the groin. The doctor guides the catheter to the heart. They measure blood pressure and oxygen. In some cases, the doctor may inject contrast dye to more clearly see the blood flow and structures inside the heart.
• Cardiovascular MRI (CMRI). This test makes detailed images of the heart and blood vessels. MRI may be used to check the amount and direction of blood shunting.
• CT scan and CT angiography. These tests may be used to check for blood clots in the lung arteries and lung.
• Stress test. This is an ECG done while the child is exercising.

Treatment will depend on your child's symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment focuses on lowering the pressure in the pulmonary artery. It also aims to bring more oxygen to the lung tissues and ease the cyanosis.

There is no cure for established Eisenmenger syndrome other than lung or heart-lung transplantation, but treatment can slow progression, improve quality of life, and reduce complications.

Medical management

• Pulmonary vasodilators
  • Endothelin receptor antagonists (such as bosentan or ambrisentan)
  • Phosphodiesterase-5 inhibitors (such as sildenafil or tadalafil)
  • Prostacyclin analogues (such as epoprostenol or treprostinil) These reduce pulmonary artery pressures and improve exercise tolerance.
• Oxygen therapy. Especially at night or during air travel.
• Phlebotomy. Occasionally used to reduce blood thickness (viscosity) if severe polycythemia causes symptoms — only with caution to avoid iron deficiency and hypotension.
• Diuretics. For fluid overload or heart failure symptoms.
• Antiarrhythmic therapy. If arrhythmias develop.
• Iron supplementation. If deficiency is present.

Surgical/interventional choices

• Transplantation. Lung or combined heart-lung transplant for advanced, treatment-refractory disease.
• Defect closure is generally not possible once irreversible pulmonary hypertension has developed, as it can make right heart failure worse.

Complications of this condition may include:

• Blood clots in the deep veins in the legs (deep vein thrombosis) or lungs (pulmonary embolus)
• Bleeding (hemorrhage)
• Coughing up blood (hemoptysis)
• Stroke
• Infected material in the brain (abscess)
• Infections of heart valves (endocarditis)
• Irregular heart rhythms (arrhythmias)
• Heart failure
• Gout
• Kidney dysfunction
• Gallstones
• Sudden death

Some children with Eisenmenger syndrome may live into middle adulthood. A few may live into their 50s or 60s.

Recommendations for children with Eisenmenger syndrome include:

• Anesthesia and surgery are considered very high risk and should be carefully planned. If your child needs surgery, the surgeon and other doctors should work with your child's pediatric cardiologist.
• Your child should not go to high altitudes. Your child may be able to fly as long as the plane is pressurized. Using oxygen during flights may also decrease the chance of complications.
• Your child should not smoke or drink.
• Protect your child from things that put them at higher risk. These include dehydration, exercise, excessive heat, and iron deficiency.
• Control or prevent coughing with cough-suppressing medicines. This helps lower the risk of bleeding from the lungs.
• Have your child get a flu shot every year. Talk with your child's doctor about the pneumococcal vaccine, COVID-19 vaccine, and other important vaccines.
• Counsel your older teen or young adult if they are considering pregnancy. The syndrome puts both mother and child at great risk. To prevent pregnancy, your teen or young adult can use progestin-only birth control pills. This doesn't raise the risk for blood clots.

Talk with your child's doctor about the specific long-term outlook for your child, teen, or young adult with Eisenmenger syndrome.

Symptoms that get worse or new symptoms can be early warning signs. Call your child's doctor as soon as possible.

Call 911 or your local emergency number if your child has any severe symptoms. These include:

• Serious bleeding
• Severe headache
• Fainting
• Loss of consciousness

• Eisenmenger syndrome means that the arteries that carry blood from the heart to the lungs are narrowed. This puts too much pressure on the walls of the arteries and damages the lungs.
• The condition mostly affects teens and young adults with certain congenital heart defects that are not repaired or repaired late.
• Treatment for Eisenmenger syndrome aims to lower the pressure in the pulmonary artery, bring more oxygen to lung tissues, and decrease bluish skin and nails (cyanosis).
• It is important to work with your child's health care team to reduce the risk for complications.

Tips to help you get the most from a visit to your child's doctor:

• Know the reason for the visit and what you want to happen.
• Before your visit, write down questions you want answered.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions the doctor gives you for your child.
• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
• Ask if your child's condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if your child does not take the medicine or have the test or procedure.
• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your child's doctor after office hours. This is important if your child becomes ill and you have questions or need advice.