What is Eisenmenger syndrome?
Eisenmenger syndrome is a complication of untreated high-pressure or high-flow CHD in which chronic pulmonary hypertension and shunt reversal (from left-to-right to right-to-left) occur.
This is most often seen with VSD, endocardial cushion defect, and PDA and usually develops before puberty, although it may develop in adolescence or early adulthood.
The imaging features are similar to those that occur due to pulmonary hypertension.
Small left-to-right shunts, such as with an atrial septal defect (ASD) or ventricular septal defect (VSD), are commonly asymptomatic early in life and may go undetected. Over time, the right side of the cardiopulmonary circulation responds to the increased volume with pulmonary arterial hyperplasia.
This hyperplasia ultimately leads to elevated pulmonary vascular resistance and an increase in right-sided pressures (pulmonary hypertension). When right-sided pressures exceed left-sided pressures, the left-to-right shunt switches to become a right-to-left shunt. Dyspnea, fatigue, and cyanosis develop. This syndrome usually manifests in young adulthood.