Introduction: Eisenmenger syndrome describes a condition in which a congenital heart defect has caused severe pulmonary vascular disease, resulting in reversed (right-left) or bidirectional shunting and chronic cyanosis.

Areas covered: In this paper, the progression of congenital heart defects to Eisenmenger syndrome, including early screening, diagnosis and operability are covered. The mechanisms of disease progression in Eisenmenger syndrome and management strategies to combat this, including the role of pulmonary arterial hypertension therapies, are also discussed.

Expert opinion/commentary: Patients with congenital heart disease (CHD) are at increased risk of developing pulmonary arterial hypertension with Eisenmenger syndrome being its extreme manifestation. All CHD patients should be regularly assessed for pulmonary hypertension. Once Eisenmenger syndrome develops, shunt closure should be avoided. The clinical manifestations of Eisenmenger syndrome are driven by the systemic effects of the pulmonary hypertension, congenital defect and long-standing cyanosis. Expert care is essential for avoiding pitfalls and preventing disease progression in this severe chronic condition, which is associated with significant morbidity and mortality. Pulmonary arterial hypertension therapies have been used alongside supportive care to improve the quality of life, exercise tolerance and the outcome of these patients, although the optimal timing for their introduction and escalation remains uncertain.