In which of the following heart diseases maternal mortality is found to be highest ?
(A) Eisenmenger's complex (B) Coarctation of aorta (C) Mitral stenosis (D) Aortic stenosis
(A) Eisenmenger’s syndrome is the presence of secondary pulmonary hypertension that develops from any cardiac lesion.

The syndrome develops when increased pulmonary blood flow due to left to right shunt produces a right side pressure more than left side and hence reversal of shunt occurs and subsequently cyanosis develops.
It is the heart disease with the worst prognosis during pregnancy with a maternal mortality of 50%.Q Hence, pregnancy is contraindicated is patients of eisenmengers.
If diagnosis of Eisenmenger is made in the first trimester, termination of pregnancy is advised.
Most common cause of death in Eisenmenger’s syndrome is right ventricular failure with cardiogenic shock.