Eisenmenger syndrome

Eisenmenger syndrome is a serious complication that occurs in some people with longstanding heart defects causing a shunt of blood between the heart's chambers, such as a large defect between the ventricles or atria. Over time, increased blood flow to the lungs causes high pressure in the lung arteries, leading to irreversible narrowing and resistance. This causes blood to flow in the opposite direction or become mixed, resulting in low oxygen levels in the blood. Symptoms include cyanosis (bluish skin), shortness of breath, and fatigue. It is a progressive condition that can lead to heart failure if not managed appropriately.