Eisenmenger syndrome describes the reversal of a left-to-right shunt to a right-to-left shunt. It is thus an acquired right-to-left shunt.

Aetiology

3 underlying lesions causing the right to left shunt:

• Atrial septal defect
• Ventricular septal defect
• Patent ductus arteriosus

Shunt reveral:

• Increased pulmonary pressures cause changes in the pulmonary vasculature resulting in pulmonary hypertension
• This results in the shunt reversing and is accompanied with right ventricular hypertrophy

PC

• Typically occurs in late teens
• Cyanosis
• May develop right heart failure
  • Peripheral oedema
  • Raised JVP

Examination:

• Right ventricular heave: the right ventricle contracts forcefully against increased pressure in the lungs
• Loud P2: loud second heart sound due to forceful shutting of the pulmonary valve

Management