Eisenmenger Syndrome

Eisenmenger syndrome develops when too much blood flows through the arteries that carry blood to your lungs from your heart. The result is pulmonary hypertension — high blood pressure in the blood vessels of your lungs and the right side of your heart. It also leads to blood shunting between the left and right sides of your heart. This means there’s an abnormal connection that causes blood flow from the left side of your heart to the right side of your heart.

Eisenmenger syndrome is usually the result of one or more untreated congenital (present at birth) heart defects. Over time, it can lead to permanent lung damage and other complications.

Who gets Eisenmenger syndrome?

Eisenmenger syndrome typically develops in children and young adults who have an uncorrected ventricular septal defect (VSD). VSD is a congenital heart defect where there’s a hole in the wall (septum) between the heart’s two bottom pumping chambers (left and right ventricles).

Eisenmenger syndrome also can result from other unrepaired congenital heart defects such as:

Atrioventricular canal defect.
Atrial septal defect.
Cyanotic heart disease.
Patent ductus arteriosus.
Tetralogy of Fallot.
Truncus arteriosus.

Children with Down syndrome may also be at a higher risk for congenital heart defects and Eisenmenger syndrome. Between 25% and 50% of adult people with Eisenmenger syndrome have Down syndrome.