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Health condition · Clinically reviewed

Eisenmenger syndrome, when a childhood shunt reverses and cyanosis follows.

A life-limiting complication of uncorrected congenital heart disease. Modern targeted therapy and specialist UK care are changing what living with it looks like.

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Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against ESC, NHS specialised commissioning and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK adult congenital heart disease and pulmonary hypertension pathways.

Key facts

Eisenmenger syndrome at a glance.

The essentials, in plain English. What the condition is, who it affects and how UK specialist services approach it today.

  • What it is

    Severe pulmonary arterial hypertension complicating an uncorrected large left-to-right cardiac shunt, with eventual reversal to right-to-left flow and cyanosis.

  • Underlying defects

    Ventricular septal defect, atrial septal defect, patent ductus arteriosus, atrioventricular septal defect and complex congenital heart disease.

  • How common

    Rare in the UK because most congenital defects are corrected in childhood. More common in adults with late-diagnosed or inoperable disease.

  • Median age at diagnosis

    Around 30 years, though presentation ranges from adolescence into middle age.

  • Prognosis

    Life-limiting with historic median survival into the 30s to 40s. Modern targeted therapy is improving outcomes.

  • Where it is managed

    Specialist-commissioned UK adult congenital heart disease and pulmonary hypertension centres only. Not a primary-care condition.

Why this guide matters

A rare condition that needs the right team.

Eisenmenger syndrome is uncommon, complex and life-limiting. The three points below shape everything else on this page.

  • Physiology drives the picture

    A large uncorrected shunt raises pulmonary vascular resistance until it exceeds systemic, and the shunt reverses. Cyanosis, clubbing and multisystem effects follow.

  • Targeted therapy has changed prognosis

    Endothelin receptor antagonists, PDE5 inhibitors and prostacyclin analogues improve symptoms and survival when started in specialist centres.

  • Specialist care is not optional

    Long-term follow-up belongs in an adult congenital heart disease and pulmonary hypertension centre commissioned by NHS England.

How the diagnosis is made

From first clues to a confirmed diagnosis.

The pathway a UK specialist ACHD and pulmonary hypertension team will follow, from history to right heart catheterisation.

  1. 01

    Assessing

    History and underlying defect

    Known or newly identified congenital heart disease, cyanosis on exertion, syncope, haemoptysis, palpitations and exercise limitation.

  2. 02

    Assessing

    Examination

    Central and peripheral cyanosis, finger and toe clubbing, loud pulmonary component of the second heart sound and characteristic murmurs.

  3. 03

    Assessing

    Pulse oximetry

    Resting SpO2 is typically below 90 per cent, often with a further fall on exertion.

  4. 04

    Confirming

    Bloods

    Full blood count for secondary erythrocytosis, iron studies, urate, urea and electrolytes, liver function and BNP.

  5. 05

    Confirming

    ECG and chest x-ray

    Right ventricular hypertrophy and strain, atrial fibrillation, cardiomegaly and prominent pulmonary arteries.

  6. 06

    Confirming

    Echocardiography

    The gold-standard non-invasive test for the shunt, chamber sizes, right ventricular function and estimated pulmonary pressures.

  7. 07

    Deciding

    Right heart catheterisation

    Confirms pulmonary vascular resistance, tests reversibility and is decisive for treatment planning at a specialist centre.

Typical pathway: from first specialist appointment to a full haemodynamic assessment within weeks.

Symptoms

What Eisenmenger syndrome actually looks like.

A characteristic mix of cyanosis, clubbing, exercise limitation and multisystem effects. Some features are red flags for urgent review.

  • Cyanosis

    Progressive central and peripheral cyanosis reflecting right-to-left shunting and arterial desaturation.

  • Finger and toe clubbing

    A classic sign of long-standing hypoxaemia and right-to-left shunting.

  • Secondary erythrocytosis

    Raised haemoglobin and haematocrit. Selective venesection is only used for symptomatic hyperviscosity.

  • Exercise intolerance

    Breathlessness, fatigue and reduced exercise tolerance are almost universal.

  • Syncope and palpitations

    Exertional or postural syncope and atrial or ventricular arrhythmia can occur.

  • Haemoptysis

    Pulmonary haemorrhage from dilated pulmonary vessels or in-situ thrombosis can be life-threatening.

  • Heart failure

    Right and later biventricular failure with peripheral oedema, ascites and hepatic congestion.

  • Red flag - paradoxical embolism

    A right-to-left shunt allows venous clots to reach the brain. Stroke and TIA need immediate attention.

Treatment

How Eisenmenger syndrome is managed in the UK.

There is no cure. Targeted pulmonary hypertension therapy, careful supportive care and, in selected patients, transplant assessment form the backbone of specialist management.

  • Endothelin receptor antagonists

    Bosentan, ambrisentan or macitentan reduce pulmonary vascular resistance and improve exercise capacity. Started only in specialist centres.

  • PDE5 inhibitors

    Sildenafil or tadalafil are commonly used in combination with an endothelin receptor antagonist.

  • Prostacyclin analogues

    Intravenous epoprostenol, subcutaneous or intravenous treprostinil, inhaled iloprost or oral selexipag for advanced disease.

  • Iron and haematology support

    Iron supplementation is common despite polycythaemia. Venesection is reserved for symptomatic hyperviscosity with haematocrit above 65 per cent.

  • Diuretics

    Careful use for right heart failure. These patients are preload-dependent and overdiuresis quickly causes harm.

  • Anticoagulation

    Controversial and individualised, weighing thromboembolism, atrial arrhythmia and haemoptysis risk.

  • Oxygen and lifestyle

    Supplemental oxygen for hypoxia. Avoid strenuous exercise, dehydration, high altitude and unpressurised flights above 2000 metres.

  • Heart-lung or lung transplant

    With cardiac repair, this is the only definitive treatment. Assessed at specialist-commissioned UK transplant centres.

Targeted therapy is initiated only at a specialist commissioned pulmonary hypertension therapy clinic. Rehabilitation and rhythm care are supported by services such as cardiac rehabilitation, subcutaneous ICD where indicated and catheter ablation electrophysiology for arrhythmia.

What this guide is based on

The sources behind every claim on this page.

UK national guidance, European society standards and NHS specialised commissioning specifications, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your specialist team knows your heart and history and can tell you which parts apply to you. If in doubt, contact your ACHD or pulmonary hypertension centre.

  • European Society of Cardiology (ESC). Guidelines for the management of adult congenital heart disease.

  • European Society of Cardiology / European Respiratory Society. Guidelines for the diagnosis and treatment of pulmonary hypertension.

  • NHS England. Service specification for specialised pulmonary hypertension centres.

  • NHS England. Service specification for adult congenital heart disease.

  • Pulmonary Hypertension Association UK (PHA UK). Patient information on Eisenmenger syndrome.

Red flags

When Eisenmenger syndrome needs urgent attention.

These situations need same-day contact with your specialist team or emergency care.

  • Massive haemoptysis

    Any large-volume haemoptysis in Eisenmenger syndrome is a medical emergency needing hospital assessment.

  • Paradoxical stroke or TIA

    New focal neurological symptoms in a right-to-left shunt suggest paradoxical embolism and need urgent imaging.

  • Syncope

    Any new syncope warrants same-day specialist review because of arrhythmia and haemodynamic risk.

  • Rapid oxygen desaturation

    A sustained fall in SpO2 below the patient’s baseline needs urgent specialist input.

  • Suspected pregnancy

    Pregnancy carries a 30 to 50 per cent maternal mortality. Any positive test needs immediate specialist referral.

  • Non-cardiac surgery

    Elective surgery should be avoided where possible and only performed at a specialist centre with cardiac anaesthesia.

  • Fever with a prosthetic device

    Persistent fever raises concern for infective endocarditis and needs blood cultures before antibiotics.

  • Air travel above 2000 metres

    High-altitude cabin exposure without supplemental oxygen can precipitate a hypoxic crisis.

  • Dehydration and iron deficiency

    Both worsen hyperviscosity symptoms and should be corrected quickly under specialist advice.

Living with it

A life-limiting condition, but not a life without shape.

Four things that make the biggest difference day to day when you live with Eisenmenger syndrome in the UK.

A quiet reminder

The right team, kept close, changes everything.

Regular contact with a specialist ACHD and pulmonary hypertension centre, and support from PHA UK, keeps small problems from becoming big ones.

  1. 01 Team

    Stay linked to a specialist centre

    Long-term care sits with a specialist-commissioned adult congenital heart disease and pulmonary hypertension service.

  2. 02 Lifestyle

    Small daily choices matter

    Avoid dehydration, strenuous exertion, high altitude and unpressurised flights. Keep vaccinations up to date.

  3. 03 Family

    Plan contraception carefully

    Pregnancy is contraindicated. A specialist reproductive and contraception plan is essential from adolescence.

  4. 04 Support

    Ask for psychological and palliative help

    Living with a life-limiting condition is hard. Psychology, peer support and early advance care planning all help.

Frequently asked

Everything we get asked about Eisenmenger syndrome.

Quick answers on physiology, treatment, pregnancy, exercise and where care happens in the UK.

  • What is Eisenmenger syndrome?

    It is severe pulmonary arterial hypertension caused by an uncorrected large left-to-right heart shunt. Over years the pulmonary vessels remodel, resistance rises above systemic levels and blood reverses to flow right-to-left, producing cyanosis.

  • Which heart defects lead to it?

    Large ventricular septal defects, atrial septal defects, patent ductus arteriosus, atrioventricular septal defects and complex congenital heart disease. It is now rare in the UK because most defects are corrected in childhood.

  • Can Eisenmenger syndrome be cured?

    There is no medical cure. Modern targeted pulmonary hypertension therapy improves symptoms and survival. Heart-lung or lung transplantation with cardiac repair is the only definitive treatment and is assessed at specialist UK centres.

  • Why is pregnancy dangerous?

    Pregnancy carries a 30 to 50 per cent maternal mortality in Eisenmenger syndrome. It is contraindicated and specialist contraception and reproductive counselling should be arranged early.

  • Is exercise safe?

    Gentle activity guided by a specialist cardiac rehabilitation team is helpful. Strenuous or competitive exercise should be avoided because it can precipitate arrhythmia and desaturation.

  • Where is Eisenmenger syndrome managed in the UK?

    Care is delivered at specialist-commissioned adult congenital heart disease and pulmonary hypertension centres such as the Royal Free, Papworth, the Golden Jubilee, the Freeman and other designated services.

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