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.