What is Eisenmenger syndrome?

Eisenmenger syndrome is a condition that includes a collection of symptoms: cyanosis (pale blue or grayish skin due to decreased oxygen in the blood), pulmonary hypertension (high blood pressure in the blood vessels of the lungs), and erythrocytosis (increased number of red blood cells in the blood due to decreased oxygen in the blood).

Eisenmenger syndrome primarily affects adolescents and adults with certain congenital heart defects that are repaired late (after the first year of life) or that are never repaired. Eisenmenger syndrome, however, can occur in infants or children born with pulmonary hypertension; therefore, symptoms related to cyanosis may occur much earlier in life.