People with heart defects such as large holes in the heart or abnormal blood vessels can cause excess blood flow into the lung arteries (pulmonary arteries). This “shunting” of blood away from its normal path can over time cause the pulmonary artery pressures to increase like we see in other forms of PAH.

However, at a certain point the pressures in the lungs can occasionally or continuously be higher than the body’s regular blood pressure (systemic pressure). This is called suprasystemic pulmonary hypertension and it causes blood flow to reverse through any shunt connection.

This will result in low oxygen blood crossing into the left side of the heart where the higher oxygen blood is located before going to the rest of the body. Mixing low oxygen blood with the higher blood oxygen will lower the body’s total oxygen levels. The amount of low oxygen level (desaturation) a person experiences depends upon the size of the shunt.

Who is at risk?

If you have any of the following conditions, you may be at risk of developing Eisenmenger syndrome.

People who have additional blood flow into the lungs with certain moderate to large sized congenital heart defects, such as:

• Ventricular septal defect
• Atrial septal defect
• Patent ductus arteriosus

If the defect is not found and corrected in children, over time the shunt flow will continue to increase the pulmonary pressures and cause the reversal of blood flow as described above. At that point, corrective heart surgery cannot be performed.

Signs, symptoms and risks

One of the key features of Eisenmenger syndrome is lower than normal oxygen levels. Having constant lower oxygen levels causes the body to make more red blood cells. These patients can have very elevated levels of red blood cells and hemoglobin (called polycythemia).

These factors can lead to increased risk of:

• Blood clots.
• Strokes.
• Further elevation of blood pressure.
• Increased risk of infection in different organs*
• Heart failure.

Doctors should monitor patients closely for infections, specifically monitoring ones that may attack the brain. An infection can occur when the blood bypasses the normal filtration provided by the lungs. The lungs help to filter certain bacteria and clots from the blood before it reaches the brain.

Warning signs for Eisenmenger syndrome

Doctors may look for additional signs and symptoms, such as:

• Bluish coloring around the lips, face and extremities.
• Fingernail changes known as clubbing.
• Low oxygen levels during physical activity*

Patients may experience low oxygen during activity because more low oxygen blood crosses the shunt. Because of this, their activity tolerance can be limited.

Treatment options

Management of Eisenmenger syndrome requires PH programs to understand PAH and CHD. With this understanding, doctors can create a treatment plan that works for you. Some medications used for PAH have shown benefits in patients with Eisenmenger syndrome.

Additionally, other options include:

• Use of oxygen
• Having your shunt act as a “pop-off” to protect the right side of the heart from failing.

If heart failure is suspected or severe symptoms become a problem, then transplantation (lung or heart and lung) would be required.