Eisenmenger syndrome and ventricular septal defect have distinct pathophysiological differences

The claim states that Eisenmenger syndrome and ventricular septal defect have distinct pathophysiological differences. A ventricular septal defect is an anatomical shunt lesion characterized initially by left-to-right shunting and volume or pressure overloads, whereas Eisenmenger syndrome is the end-stage consequence where chronic pulmonary overcirculation causes irreversible pulmonary vascular obstructive disease, elevated pulmonary vascular resistance, and subsequent right-to-left shunting with cyanosis. The retrieved literature (such as papers 4 and 9) supports the distinction between simple shunt mechanics and the complex multisystem pathophysiology of Eisenmenger syndrome.