What is (are) Eisenmenger syndrome ?
Eisenmenger syndrome is a rare progressive heart condition caused by a structural error in the heart, typically a "hole in the heart" (ventricular septal defect) present at birth (congenital heart defect). This causes abnormal blood flow in the heart, resulting in high pressure within the pulmonary artery, the main blood vessel that connects the heart to the lungs (pulmonary hypertension).