Eisenmenger syndrome in a pregnant woman with an unrepaired atrial septal defect
A 29-year-old woman, gravida 2 para 1, presents at 13 weeks' gestation with progressive breathlessness and palpitations. She has never had cardiac surgery. Examination: central cyanosis, clubbing, a loud pulmonary component of the second heart sound, a right ventricular heave, and a soft pulmonary ejection murmur without a fixed split. Resting oxygen saturation is 86% on air, haemoglobin 178 g/L, platelets 120 × 10⁹/L, and creatinine 88 µmol/L. Echocardiography shows a 3.1 cm secundum atrial septal defect with bidirectional shunting, right ventricular dilatation, estimated pulmonary artery systolic pressure 95 mmHg and a flattened septum in systole. Right heart catheterisation confirms mean pulmonary artery pressure 62 mmHg, pulmonary vascular resistance 11 Wood units, systemic vascular resistance 16 Wood units, and no vasoreactivity on inhaled nitric oxide. She is adamant about continuing the pregnancy and there is no local adult congenital heart disease centre.
1. Is she a candidate for ASD closure, and how do you explain this to her?
Read the worked answer
No - closure is contraindicated. She has Eisenmenger syndrome: a large unrestrictive shunt with pulmonary vascular resistance (11 Wood units) above two-thirds of systemic resistance (16 Wood units), bidirectional shunting, cyanosis and clubbing. Closing the defect would remove the pressure-relief valve for the right ventricle, precipitate acute right heart failure and increase mortality.
The relevant rules to explain to her are:
- Defect closure is generally contraindicated when PVR ≥5 Wood units, or when PVR exceeds two-thirds of systemic resistance, or when there is net right-to-left shunting with systemic desaturation.
- A vasoreactivity test is used in selected patients; she had no response to nitric oxide, so a calcium channel blocker trial is not appropriate and could cause fatal systemic hypotension.
- Surgery is not an option for the same physiological reasons, and there is no role for a fenestrated closure here.
The explanation must be clear and non-technical: "Your lung blood vessels are permanently narrowed; the hole is now protecting your right heart. Closing it would be dangerous." Document the discussion and ensure she understands that this is a lifelong condition requiring specialist follow-up - ideally referral to an adult congenital heart disease/pulmonary hypertension centre.
2. How would you counsel and manage her pregnancy?
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This is a very high-risk pregnancy - maternal mortality in Eisenmenger syndrome is reported in the range of 20–50%, with additional risks of thromboembolism, haemorrhage, arrhythmia, pre-eclampsia and fetal growth restriction/cyanotic fetus. Counselling must be multidisciplinary and documented, and must include the option of termination by a safe method early in pregnancy. If she continues:
- Delivery planning in a tertiary centre with cardiac ICU, obstetric anaesthesia and neonatology, ideally a planned caesarean or induced vaginal delivery with epidural anaesthesia and continuous monitoring.
- Avoid falls in systemic vascular resistance: no prolonged Valsalva, careful blood loss replacement, avoid hypotension and dehydration, avoid systemic vasodilators, and avoid drugs that increase PVR.
- Oxygen to maintain saturations; treat iron deficiency; consider prophylactic anticoagulation on an individual basis, balancing the high bleeding risk from thrombocytopenia and haemoptysis.
- Pulmonary hypertension therapy: an endothelin receptor antagonist or PDE5 inhibitor may be continued/started under specialist supervision; calcium channel blockers are contraindicated in non-responders.
- Postpartum: high-risk period for the first 6–8 weeks; monitor in ICU, encourage early mobilisation, avoid oestrogen-containing contraception (use progestogen-only or sterilisation).
- Discuss the fetus: growth restriction, preterm delivery, and neonatal cyanosis.
3. What long-term therapy and surveillance does she need after delivery?
Read the worked answer
Eisenmenger physiology is lifelong and the goals are to preserve pulmonary blood flow, avoid crises and detect complications early.
- Pulmonary vasodilator therapy: endothelin receptor antagonists (bosentan/ambrisentan) and/or PDE5 inhibitors (sildenafil) improve exercise capacity and haemodynamics; riociguat is an alternative. They do not reverse the disease. Avoid calcium channel blockers unless there is documented vasoreactivity.
- Phlebotomy only for symptomatic hyperviscosity (haematocrit >65%, headache, visual disturbance), with isovolaemic replacement; routine phlebotomy for a high haemoglobin is harmful.
- Anticoagulation: individualise; not routine, because haemoptysis and thrombocytopenia increase bleeding risk.
- Avoid: pregnancy (offer reliable contraception), dehydration, high altitude, strenuous Valsalva, and oestrogen-containing contraceptives. Antibiotic prophylaxis is not routinely recommended for secundum ASD, but good dental hygiene is encouraged.
- Surveillance: annual review with oxygen saturation, FBC, renal and iron studies, 6-minute walk, echocardiography and ECG, plus screening for arrhythmias, haemoptysis and gout. Refer to a specialist pulmonary hypertension/ACHD centre, and discuss transplantation assessment if there is progressive decline.