Congenital heart disease in adults

• Congenital heart disease no longer belongs to paediatrics. Improved diagnosis and surgery mean that most children born with structural heart disease now survive into adult life; adulthood is now the commonest setting in which these lesions are followed.
• In adults the original anatomy still matters, but the clinical picture is governed by what was repaired, how it was repaired, and what haemodynamic burden remains years later.
• The common lesions in adult clinics are atrial septal defect, repaired tetralogy of Fallot, coarctation of the aorta, and the residual problems of transposition after repair, together with the slow evolution of pulmonary vascular change in any large unrepaired shunt.
• The single most common dangerous transition in this field is a large left-to-right shunt that slowly raises pulmonary vascular resistance until the shunt reverses and becomes Eisenmenger syndrome. Once that point is reached, closing the defect is unsafe.
• Most adults with congenital heart disease should be followed in a specialist congenital heart centre, but the general clinician still has to recognise them, protect their right-sided circulation, and know when to refer.

By the end of this page you should be able to:

1. Explain why congenital heart disease now presents mainly in adults and what "grown-up congenital heart disease" means.
2. Describe the natural history of a left-to-right shunt, from a silent lesion in childhood to possible Eisenmenger syndrome in adult life.
3. Recognise and manage atrial septal defect, ventricular septal defect, patent ductus arteriosus and coarctation of the aorta in an adult, including indications for closure or relief.
4. Explain the anatomy and adult follow-up of repaired tetralogy of Fallot and of transposition of the great arteries.
5. Recognise Eisenmenger syndrome, explain why the defect is no longer closed, and outline its medical treatment and contraindications.
6. Plan the investigation of an adult with suspected or known congenital heart disease, including shunt quantification and pulmonary vascular resistance.
7. Identify the special problems of pregnancy, ageing and endocarditis risk in this population.

A useful mental model is that adult congenital heart disease combines three categories. First, unrepaired lesions (a small, restrictive defect that was never closed). Second, repaired lesions (tetralogy of Fallot after total correction, transposition after an arterial switch). Third, palliated lesions (a Fontan circulation for single-ventricle physiology). Each carries a different late risk, and "the patient has been operated on" is not the same as "the heart is normal". ^[1]

Clinically it is also useful to group lesions by their functional effect: left-to-right shunts, which volume-load the pulmonary circulation; obstructive lesions, which pressure-load the ventricle behind them; cyanotic or shunt-reversal states, where deoxygenated blood reaches the systemic circulation; and the complex single-ventricle pathways.

The standard nomenclature used here follows the 2020 European Society of Cardiology Guidelines for the management of adult congenital heart disease and the contemporary American Heart Association/American College of Cardiology adult congenital heart disease framework; the clinical thresholds quoted below come from the open-access sources listed in the references. ^[2][3]

Congenital heart disease is the leading cause of neonatal mortality: it accounts for about 3% of neonatal deaths and 46% of deaths from all congenital malformations. ^[1] Because survival has improved so much, the adult population with these lesions now exceeds the childhood population in many countries. ^[1]

Lesions are graded by complexity, which predicts follow-up need.

• Mild (simple): small isolated atrial septal defect, small isolated muscular ventricular septal defect, mildly stenotic bicuspid aortic valve, successfully ligated patent ductus arteriosus, repaired secundum atrial septal or ventricular septal defect without residua.
• Moderate: unrepaired or repaired but haemodynamically significant defects, repaired tetralogy of Fallot, coarctation of the aorta (repaired or not), Ebstein anomaly, pulmonary valve disease requiring intervention.
• Severe: cyanotic defects (other than isolated tetralogy after repair), single ventricle physiology with a Fontan circulation, transposition of the great arteries after repair, pulmonary atresia, severe pulmonary hypertension/Eisenmenger syndrome.

A lesion can move from mild to severe over decades through a complication (pulmonary hypertension, conduit failure, arrhythmia) rather than through the original anatomy. This is the central reason follow-up never truly stops.

Congenital heart disease accounts for about 3% of neonatal deaths and 46% of deaths from all congenital malformations and is the leading cause of neonatal mortality. ^[1] A genetic or chromosomal contribution is found in roughly 10 to 30% of structural congenital heart disease. ^[1] Parental smoking and alcohol during pregnancy both raise risk; active maternal smoking in particular is associated with atrial septal defect and right ventricular outflow tract obstruction. ^{[1] [2]}

Overall survival has changed dramatically: most patients born with congenital heart disease now survive into adulthood. ^[1] However, long-term morbidity remains substantial, with a sudden cardiac death rate around 0.28 to 2.7% per year, which is 20 to 30 times the population rate. ^[1]

The lesion mix seen in adult clinics reflects both birth prevalence and survival:

• Atrial septal defect 8 to 13% of all congenital heart disease. ^[2]
• Ventricular septal defect 20 to 25%, of which perimembranous defects are about 80%. ^[2]
• Patent ductus arteriosus 6 to 11%. ^[2]
• Coarctation of the aorta 5 to 8%. ^[2]
• Aortic valvular stenosis 5 to 6%. ^[2]
• Tetralogy of Fallot is the commonest cyanotic lesion beyond infancy. ^[3]
• Transposition of the great arteries is the commonest cyanotic lesion in the newborn. ^[3]

A patent foramen ovale is found in about a quarter of adults. ^[1] Its prevalence falls from roughly 34% in the first three decades to about 20% in the ninth decade. ^[1]

Most lesions arise from multifactorial disruption of cardiac development in the first 6 to 8 weeks of gestation. Recognised influences include maternal smoking, alcohol, infection and teratogens, together with chromosomal conditions such as Down syndrome and Turner syndrome, and single-gene disease such as 22q11.2 deletion. ^[1][2]

Specific associations that change the adult picture:

• Down syndrome. Atrioventricular septal defect is the characteristic lesion; pulmonary vascular disease develops earlier than in other infants, so repair must be early. ^[2]
• Turner syndrome. Coarctation of the aorta, bicuspid aortic valve, and septal defects are over-represented; cardiology and aortic imaging continue into adult life. ^[2]
• Congenital rubella. Patent ductus arteriosus and peripheral pulmonary artery stenosis are the cardiac features.
• Maternal diabetes mellitus. Transposition of the great arteries is more common in infants of diabetic mothers.
• Maternal lithium. First-trimester lithium exposure, especially in the first 8 weeks, is strongly associated with Ebstein anomaly of the tricuspid valve. ^[3]
• 22q11.2 deletion (DiGeorge/velocardiofacial syndrome). The conotruncal defects cluster here: tetralogy of Fallot, truncus arteriosus, interrupted aortic arch and ventricular septal defect are all over-represented.
• Prematurity. Patent ductus arteriosus is common and behaves differently from the term infant's ductus.

The explanation for why a lesion can be harmless at birth but devastating decades later is the fall in pulmonary vascular resistance. In the fetus the lungs are bypassed by the foramen ovale and ductus arteriosus, and pulmonary resistance is high. At birth the placenta is removed, systemic resistance rises, the lungs expand, and pulmonary resistance falls. The direction and size of any shunt are governed by the balance between systemic and pulmonary vascular resistance and by the size of the defect.

A moderate ventricular septal defect is usually described by a pulmonary-to-systemic flow ratio (Qp:Qs) of about 1.5 to 2:1; a ratio above 2:1 indicates a large shunt. ^[2]

1. Pulmonary overcirculation. Extra volume returns to the lungs; in a large defect Qp:Qs rises well above 1.
2. Left heart volume overload. The left atrium and left ventricle receive the shunted volume and dilate.
3. Pulmonary vascular change over time. Chronic high flow injures the pulmonary arterioles. Resistance rises, and if nothing is done the shunt reverses.

When an unrepaired large shunt has remodelled the pulmonary vasculature sufficiently that the shunt reverses right-to-left, with central cyanosis and multi-organ disease, this is Eisenmenger syndrome. Once that physiology is established, closing the defect is dangerous; treatment is directed at the pulmonary vasculature rather than at the defect. ^[4]

In adults, many defects have been closed in childhood, and the problem is residual haemodynamic load (a mildly leaky aortic valve after ventricular septal defect repair), arrhythmia substrate (atrial flutter after atrial septal repair), or conduit degeneration (right ventricle to pulmonary artery conduit in transposition). Adults also accumulate acquired disease - coronary atherosclerosis, systemic hypertension, atrioventricular valve degeneration - on top of the congenital lesion.

An atrial septal defect (ASD) is an opening in the atrial septum. The common types are ostium secundum (the majority), ostium primum (part of the atrioventricular septal defect spectrum) and sinus venosus, often with anomalous pulmonary venous drainage. ^[2]

• Natural history. Most secundum defects are asymptomatic in childhood. Small defects under 5 mm often close spontaneously. ^[2] Adults present with right heart enlargement, exertional breathlessness, palpitations or, less commonly, paradoxical embolism.
• Examination. Wide fixed splitting of the second heart sound with a systolic ejection murmur at the left upper sternal border from increased pulmonary flow; a low mid-diastolic rumble at the lower sternal border if the shunt is large.
• Complications. Pulmonary arterial hypertension and Eisenmenger syndrome late in life, atrial arrhythmia, and paradoxical embolism or stroke when right-sided pressures rise.

Management in adults. Atrial septal defects in adults should be closed at presentation, electively, irrespective of age or symptoms, as soon as they are haemodynamically significant. ^[2] Closure is usually considered when there is right ventricular volume overload on echocardiography (dilated right heart with flat or paradoxical interventricular septal motion) and/or a Qp:Qs of at least 1.5:1: the 2018 AHA/ACC adult congenital heart disease guideline uses a Qp:Qs of at least 1.5:1 together with acceptable pulmonary pressures and resistance, while the 2020 ESC guideline bases the decision on a Qp:Qs above 1.5:1 stratified by pulmonary vascular resistance (class I at under 3 Wood units; closure with right ventricular volume overload and no pulmonary hypertension is recommended regardless of symptoms; fenestrated closure may be considered at 3 to 5 Wood units). This differs from the paediatric criterion in Ref 2, where a Qp:Qs greater than 2:1 is required for closure. ^[2] Even in the absence of symptoms, closure of moderate to large defects is recommended to prevent pulmonary vascular obstructive disease in adulthood, to reduce later supraventricular arrhythmia, and to prevent symptoms appearing in adolescence and adult life. ^{[2] [4]}

Small defects (less than 5 mm) are likely to close spontaneously and do not need closure. ^[2]

• Closure method. Secundum defects with adequate rims can be closed by catheter device; primum and sinus venosus defects need surgery. ^[2]
• Eisenmenger physiology. If the shunt has already reversed, closure is not undertaken; see Eisenmenger syndrome below.

A ventricular septal defect (VSD) is an opening in the ventricular septum. It is the commonest congenital heart lesion. Defects are perimembranous (about 80%), muscular, supracristal or atrioventricular septal in position. ^[2]

In children, small defects need only observation, moderate and large defects are closed before 6 to 12 months and never later than 18 months, and closure in Down syndrome is performed before 6 months. ^[2] By the time a patient reaches adulthood, one of three situations remains.

1. Small, haemodynamically insignificant (restrictive) VSD. The defect has closed spontaneously or its shunt is trivial. These patients usually need only periodic review and endocarditis prophylaxis advice.
2. Repaired VSD. Most significant defects have been closed in childhood, but late issues include residual shunt, patch dehiscence, aortic valve prolapse with regurgitation, right ventricular outflow obstruction, and arrhythmia.
3. Unrepaired moderate or large VSD in an adult. This is uncommon because such a defect usually causes symptoms or pulmonary vascular change early. If pulmonary vascular resistance is still favourable, closure is considered; if fixed pulmonary hypertension has developed, see the criteria in the pulmonary vascular section.

VSDs tolerate pulmonary overcirculation badly: pulmonary vascular obstructive disease can appear as early as 18 months to 2 years if a large defect is not repaired (sooner in Down syndrome), whereas in atrial septal defect it usually manifests only in adulthood. ^[2]

Closure with elevated pulmonary vascular resistance is possible only when resistance is still acceptable: a pulmonary vascular resistance index under 6 Wood units, or a pulmonary-to-systemic vascular resistance ratio (Rp:Rs) under 0.35. If resistance falls below 6 to 8 units with inhaled oxygen or nitric oxide, closure is indicated. ^[2] Large ventricular septal defects with irreversible pulmonary vascular obstructive disease are not candidates for closure. ^[2]

The ductus arteriosus normally closes within hours to days after birth. When it persists it creates a left-to-right shunt from aorta to pulmonary artery, volume-loading the left ventricle.

• Examination. Continuous machinery murmur loudest at the left infraclavicular area; bounding pulses with a wide pulse pressure; a left ventricular heave.
• Very small and small ducts should be closed even when not haemodynamically significant, mainly to remove the risk of infective endocarditis. ^[2]
• Medium and large ducts should be closed to avoid left ventricular volume overload, to treat heart failure and to prevent pulmonary vascular obstructive disease, in addition to removing the endocarditis risk. ^[2]
• Closure is avoided once pulmonary vascular disease (Eisenmenger physiology) is established. ^[2]
• Timing. Closure can be undertaken at any age; most adults with a patent ductus arteriosus were either missed in childhood or have a duct discovered incidentally. Large ducts should be closed before 18 months of age in children; in adults with a favourable pulmonary vascular resistance the same logic applies, with device or surgical closure. ^[2]
• Method. In term infants and children, catheter closure with coils or occluder devices, or surgical ligation or division; in premature infants, medical closure with indomethacin or ibuprofen first. ^[2]

Coarctation is a narrowing of the aortic arch, usually near the ductus arteriosus, and accounts for 5 to 8% of congenital heart disease. ^[2] In adults it declares itself in three ways: chronic hypertension in the right arm, a radio-femoral delay, and a systolic murmur in the left interscapular area radiating to the back. Many patients are first found during hypertension work-up in young adults.

• Significant coarctation. Significant hypertension and/or heart failure with a peak-to-peak systolic gradient in excess of 20 mmHg across the coarctation. ^[2]
• Management. In stable older children and adults: surgery, balloon angioplasty, or stenting. In adolescents and adults, stent implantation is the usual catheter approach; surgical repair is reserved for complex or aneurysmal anatomy; balloon angioplasty alone has a higher recurrence rate but is used in some settings. ^[2] (National and European frameworks differ on the exact gradient that should trigger intervention, and some North American practice uses higher cut-offs; local cardiology advice is essential.)
• Associations. Turner syndrome (especially 45,X), bicuspid aortic valve, and a circle of Willis aneurysm. Every coarctation needs imaging of the whole aorta and the intracranial circulation.
• Late problems. Persistent or late hypertension despite successful repair is common and is the main determinant of morbidity; recoarctation, aortic aneurysm and dissection, coronary disease. Hypertension often needs lifelong treatment even after a technically excellent repair.

Tetralogy of Fallot (ToF) combines a large ventricular septal defect with right ventricular outflow tract obstruction, an overriding aorta, and right ventricular hypertrophy. It is the commonest cyanotic lesion beyond infancy. ^[3] The degree of cyanosis depends on the severity of right ventricular outflow obstruction: "pink" (acyanotic) tetralogy with mild obstruction has largely been repaired in childhood, and the adults you meet have had surgical repair.

Adult issues in repaired ToF

• Pulmonary regurgitation from a transannular patch leads over decades to right ventricular dilatation and dysfunction, arrhythmia, exercise intolerance and sudden death risk.
• Residual or recurrent right ventricular outflow obstruction, branch pulmonary artery stenosis, ventricular septal defect patch leak, and aortic root dilatation with aortic regurgitation.
• Arrhythmia. Ventricular tachycardia from the surgical scar or from severe right ventricular dysfunction, and atrial flutter or fibrillation.
• Need for reintervention. Pulmonary valve replacement (surgical or, increasingly, transcatheter) when right ventricular size or function crosses accepted thresholds on serial imaging. Timing is decided from magnetic resonance imaging of right ventricular volumes and ejection fraction, not from symptoms alone.
• Pregnancy. Repaired ToF is usually well tolerated, but residual pulmonary regurgitation, right ventricular dysfunction or pulmonary hypertension reduces tolerance.

Hypercyanotic spells (Tet spells) are a paediatric problem but matter for transition counselling: sudden infundibular spasm in a young unrepaired patient produces deep cyanosis, hyperpnoea and sometimes syncope. Management is knee-chest positioning, humidified oxygen, morphine sulphate 0.1 mg/kg subcutaneously, rest, correction of acidosis, anaemia and dehydration, then phenylephrine or beta blockade to raise systemic vascular resistance, with anaesthesia or surgery if the spell persists. ^[3]

In transposition (d-transposition), the aorta arises from the right ventricle and the pulmonary artery from the left ventricle, so the systemic and pulmonary circuits run in parallel rather than in series. It is the commonest cyanotic lesion in the newborn. ^[3] Survival without intervention is short; mixing through an atrial septal defect, ventricular septal defect or patent ductus arteriosus is essential. ^[3]

• Definitive repair in the newborn. With an intact ventricular septum, arterial switch (Jatene procedure, with the LeCompte manoeuvre) is performed at about one week of age; a balloon atrial septostomy (Rashkind procedure) creates mixing when oxygenation remains inadequate. With a ventricular septal defect, arterial switch with defect closure; with a ventricular septal defect and pulmonary stenosis, the Rastelli procedure. ^[3]
• Venous switch era. Patients who had Senning or Mustard operations in the 1960s to 1980s now reach adulthood with the right ventricle as the systemic ventricle, and they carry a high late burden: right ventricular dysfunction and failure, tricuspid (systemic) regurgitation, atrial switch baffle leaks or obstruction, sinus node disease and atrial flutter. These patients need specialist surveillance for life.
• Arterial switch era. Medium-term outcomes are good, but late issues include neoaortic root dilatation and regurgitation, coronary ostial stenosis, and right ventricular outflow obstruction from the LeCompte arrangement or pulmonary stenosis.
• Congenitally corrected transposition (l-transposition) leaves the right ventricle as the systemic pump and is often not detected until adult life; it carries a high incidence of complete heart block and tricuspid regurgitation.

Eisenmenger syndrome is the advanced end stage of a large, unrepaired systemic-to-pulmonary shunt: pulmonary vascular resistance rises over years until the shunt reverses, producing cyanosis and pulmonary arterial hypertension. ^[4] It is a multisystem disease beyond the pulmonary vasculature, with cyanosis, haematologic and coagulation abnormalities, arrhythmias and progressive heart failure. ^[4]

• Why the defect must not be closed. Once Eisenmenger physiology is established, the defect has become a necessary pop-off for the right ventricle; eliminating it removes that decompression and can precipitate right heart failure. Closure is therefore generally contraindicated. ^[4]
• Medical treatment. Pulmonary arterial hypertension (PAH)-directed therapy. The 2022 ESC/ERS guidance recommends bosentan to improve exercise capacity in symptomatic patients and iron (replete iron stores) in those with iron deficiency. Bosentan is the best-studied agent in Eisenmenger syndrome; more recent evidence supports sequential and, in selected patients, upfront combination regimens (endothelin receptor antagonists, phosphodiesterase type-5 inhibitors, and prostacyclin analogues). Exercise capacity is the usual yardstick for these therapies. Phlebotomy for symptom relief in hyperviscosity is used sparingly, because iron depletion and rebound polycythaemia follow aggressive venesection; the emphasis is on maintaining adequate haemoglobin and iron. ^[4]
• Pregnancy is absolutely contraindicated in women with Eisenmenger syndrome. ^[4]
• General measures. Avoid dehydration, isometric exercise, high altitude, significant hypoxia, and peripheral vasodilators that can worsen the right-to-left shunt. Prophylactic venesection without symptoms is not recommended. Patients should receive standard endocarditis counselling.
• Curative option. Heart-lung or (lung plus repair) transplantation in carefully selected patients.
• Treat and repair. In some patients with a shunt and elevated but not fixed pulmonary vascular resistance, PAH-targeted therapy followed by reassessment can permit a decision about closure: closure is generally supported when PVR is under 3 Wood units and may be considered at 3 to 5 Wood units if anatomy, ventricular physiology and clinical context are favourable; for atrial septal defects, fenestrated closure may be considered after PAH-targeted therapy has lowered PVR below 5 Wood units, with complete closure not recommended when PVR remains above 5 Wood units. ^[4]
• Whether PAH therapy alters the underlying vascular disease in Eisenmenger syndrome is uncertain; functional and haemodynamic improvement is established, long-term modification of vascular remodelling is not. ^[4]

It is worth distinguishing two high-risk adult situations.

• Uncorrected secundum ASD discovered in middle or later life. If non-invasive and invasive assessment shows the defect is still left-to-right with acceptable (or reactive) pulmonary vascular resistance, closure is recommended in adults irrespective of age. ^[2]
• ASD with PAH that has progressed far. If pulmonary vascular resistance is fixed and the defect has become right-to-left, the situation is Eisenmenger physiology and closure must not be performed; manage as Eisenmenger syndrome. ^[4]

Many adults with congenital heart disease are initially mislabelled as acquired cardiac disease. The table compares the common pitfalls.

Investigation in adults has two questions: what is the anatomy, and what is the haemodynamic burden now.

• Transthoracic echocardiography is the first test. It defines anatomy, shunt direction, ventricular function, valve function, and an estimate of pulmonary artery pressure.
• Transoesophageal echocardiography adds detail when transthoracic windows are poor, and guides percutaneous closure (atrial septal defect, patent ductus arteriosus).
• Cardiac magnetic resonance imaging is the reference standard for right ventricular size and function after tetralogy, for quantifying shunts (Qp:Qs) and regurgitant fractions, and for aortic imaging in coarctation.
• Cardiac computed tomography is useful for coronary anatomy in transposition and for aortic anatomy in coarctation and aortopathy.
• Cardiac catheterisation is used when non-invasive data are insufficient, for measuring pulmonary vascular resistance and testing reversibility with oxygen or nitric oxide, and for intervention.
• Cardiopulmonary exercise testing quantifies functional capacity, which correlates poorly with imaging and is essential for timing reintervention and for PAH response monitoring.
• ECG and 24-hour monitoring screen for arrhythmia in repaired tetralogy, transposition and Fontan patients.
• B-type natriuretic peptide, renal and hepatic function, iron studies (especially in cyanosis) and oxygen saturations at rest and on exercise.

The values below are the ones that drive decisions. They are approximate and guideline-dependent; use local cardiology input. ^[2][4]

• Atrial septal defect. Closure in adults is undertaken for a haemodynamically significant defect; criteria differ by guideline: right ventricular volume overload and/or a Qp:Qs of at least 1.5:1 in the 2018 AHA/ACC guideline, and a Qp:Qs above 1.5:1 stratified by pulmonary vascular resistance in the 2020 ESC guideline (class I at under 3 Wood units, fenestrated closure at 3 to 5 Wood units), with closure recommended when right ventricular volume overload and no pulmonary hypertension are present regardless of symptoms. The paediatric criterion is a Qp:Qs greater than 2:1. Adults: close haemodynamically significant defects at presentation. ^[2]
• Ventricular septal defect. Small shunt with Qp:Qs under 1.5:1; moderate shunt at 1.5 to 2:1 and large shunt when Qp:Qs exceeds 2:1; repair in childhood when Qp:Qs exceeds 1.5:1 with acceptable pulmonary vascular resistance. In adults with an unrepaired defect, closure is feasible with PVR index under 6 Wood units or Rp:Rs under 0.35. ^[2]
• Pulmonary vascular resistance. Elevated pulmonary resistance reduces closure eligibility; values under 6 to 8 units on oxygen or nitric oxide support closure. ^[2]
• Coarctation. Significant when there is hypertension and/or heart failure with a peak-to-peak systolic gradient exceeding 20 mmHg. ^[2]
• Aortic stenosis. Intervention at a peak-to-peak gradient exceeding 50 mmHg with symptoms or ECG ST-T changes, or a peak gradient exceeding 70 mmHg irrespective of symptoms. ^[2]
• Pulmonary (valvar) stenosis. Intervention considered for peak-to-peak gradients in excess of 50 mmHg. ^[2]
• Eisenmenger and shunt-related PAH. Closure generally supported when PVR is under 3 Wood units; may be considered at 3 to 5 Wood units if anatomy and clinical context are favourable; complete closure not recommended when PVR remains above 5 Wood units; in atrial septal defect, fenestrated closure may be considered after PAH therapy has reduced PVR below 5 Wood units. ^[4]
• Pregnancy. Eisenmenger syndrome is an absolute contraindication to pregnancy. ^[4]

• A newly diagnosed adult with a large unrepaired shunt and breathlessness: assess shunt direction and pulmonary vascular resistance echocardiographically first, before planning closure; if Eisenmenger physiology is present, do not close the defect. ^[2][4]
• Critically ill neonates with duct-dependent lesions are managed with prostaglandin E1 to keep the duct open, followed by definitive relief. Most adults will not need this, but they may present as grown-up survivors whose repair is now failing. ^[3]
• Adults with repaired tetralogy and ventricular arrhythmia, or symptomatic right ventricular dysfunction, need prompt specialist assessment for possible pulmonary valve replacement.
• Endocarditis prophylaxis is not blanket. Adults with unrepaired cyanotic disease, previous endocarditis, or prosthetic material or valved conduits need standard advice about dental and other procedures; a patent but small ductus or defect repaired with a device needs procedure-specific guidance.

• Atrial septal defect. Catheter device closure when rims and size allow; surgery for primum and sinus venosus defects. Adults with haemodynamically significant defects are closed at presentation. ^[2]
• Ventricular septal defect. In children, closure before 6 to 12 months if moderate or large; in adults, residual small defects observed, significant ones with favourable pulmonary vascular resistance closed, and defects with fixed pulmonary hypertension managed only as part of Eisenmenger care. ^[2]
• Patent ductus arteriosus. Catheter device or coil closure, or surgical ligation/division, for any duct that is not trivial, provided pulmonary vascular resistance allows it. ^[2]
• Coarctation. Stenting in adolescents and adults; surgery for complex or aneurysmal anatomy; balloon angioplasty in selected children. ^[2]
• Tetralogy. Reintervention guided by imaging: pulmonary valve replacement for severe pulmonary regurgitation with right ventricular dilatation or dysfunction, or for right ventricular outflow obstruction. Arrhythmia ablation or device therapy when indicated.
• Transposition. Venous switch patients need lifelong surveillance of the systemic right ventricle, tricuspid valve and baffles, with intervention for baffle obstruction or leak; arterial switch patients need surveillance of the neoaortic root and coronaries.

• Pulmonary arterial hypertension therapy in Eisenmenger syndrome. Bosentan improves exercise capacity; phosphodiesterase type-5 inhibitors and prostacyclin analogues are used alone or in combination, usually under a pulmonary hypertension specialist. ^[4]
• Afterload reduction and heart failure therapy in unrepaired shunts or repaired lesions with ventricular dysfunction follow standard adult heart failure principles, adapted to the congenital anatomy (avoid reducing systemic vascular resistance abruptly in right-to-left shunts).
• Anticoagulation is considered in patients with documented atrial arrhythmia, prosthetic valves or conduits, or after certain repairs, but routine anticoagulation in cyanotic disease is not automatic because bleeding risk is higher.
• Antiarrhythmic and device therapy for late Tet spells are not an adult issue, but ventricular tachycardia after Tetralogy repair may need ablation or implantable defibrillator.

• Regular exercise is encouraged to tolerance in stable patients; avoid extreme isometric exertion in cyanotic or severe disease.
• Pregnancy counselling should happen early. Most simple repaired lesions tolerate pregnancy well; complex lesions (Fontan, uncorrected cyanotics, Eisenmenger) need specialist pre-conception assessment, and Eisenmenger syndrome is an absolute contraindication to pregnancy. ^[4]
• Dental and procedural endocarditis advice.
• Transition from paediatric to adult cardiac care should be planned deliberately, with written handover.

• Mild simple lesions with no residua can be discharged from specialist clinic with general follow-up.
• Moderate and severe lesions should be followed in an ACHD centre: repaired Tetralogy requires lifelong periodic specialist follow-up with imaging frequency set by the residual lesions and right ventricular size and function (rather than a fixed interval), transposition patients lifelong, Fontan patients lifelong, unrepaired shunts with pulmonary hypertension in specialist hands, and coarctation patients for late hypertension.
• Follow-up should include periodic imaging of the lesion-specific target (right ventricle in ToF, aorta in coarctation, baffles in transposition), arrhythmia surveillance, functional class and exercise testing.

Refer urgently for: new cyanosis in a patient with a previously stable lesion, worsening exercise tolerance, palpitations or syncope in repaired complex lesions, haemoptysis (Eisenmenger), signs of heart failure in an adult with a known shunt, pregnancy in complex disease, and any suspicion of endocarditis.

• Pulmonary arterial hypertension and Eisenmenger syndrome from unrepaired or late-corrected systemic-to-pulmonary shunts. ^[4]
• Heart failure from volume or pressure overload and from late ventricular dysfunction in complex repairs. ^[1]
• Arrhythmia: atrial flutter and fibrillation after atrial-level repair; ventricular tachycardia after ventricular repair, especially in repaired Tetralogy with a dilated right ventricle.
• Endocarditis on any structural lesion or prosthetic material, a lifelong risk that patients and dentists both need to know about.
• Thromboembolism and paradoxical embolism through shunts, presenting as stroke, myocardial infarction, or systemic embolus. In young adults with a patent foramen ovale and cryptogenic stroke, the association is strong: a patent foramen ovale can be found in about half of cases of cryptogenic stroke. ^[1]
• Brain abscess in cyanotic disease, because right-to-left shunting bypasses the pulmonary filter.
• Polycythaemia, hyperviscosity and iron deficiency in chronic cyanosis. Iron deficiency is often hidden by a high haemoglobin and should be sought and corrected.
• Late aortic disease in coarctation (aneurysm, dissection, recoarctation, persistent hypertension) and after arterial switch.
• Pregnancy complications in women with complex lesions or pulmonary hypertension.

Adults with simple lesions (small isolated defects, successful early repair without residua) have a normal or near-normal life expectancy. ^[2] Repaired moderate lesions (Tetralogy, coarctation, simple transposition after arterial switch) now carry good medium-term survival, but late re-intervention, arrhythmia and heart failure are expected in a substantial minority and follow-up is lifelong. Complex disease (Fontan, Eisenmenger, systemic right ventricle) has reduced life expectancy, with the highest burden from heart failure, arrhythmia, thrombosis and liver disease.

Early detection and timely closure of shunts, before pulmonary vascular change, remain the strongest modifiable determinant of prognosis. ^[2][4]

Pre-conception assessment is mandatory for women with congenital heart disease. Simple repaired lesions usually tolerate pregnancy. Women with Fontan physiology, uncorrected cyanotic disease or pulmonary hypertension (including Eisenmenger syndrome) are at high risk of maternal death: pregnancy is contraindicated in Eisenmenger syndrome. ^[4] Delivery planning belongs to a cardio-obstetric team, and non-cardiac surgery in these patients also needs specialist anaesthetic advice.

Older adults with congenital heart disease now present with acquired disease (coronary, valvular, systemic hypertension) superimposed on the congenital lesion. Lifelong follow-up imaging must be balanced against polypharmacy, renal function, and competing risks. Cognitive decline or loss to follow-up is itself a risk factor for late complications.

Antibiotic prophylaxis advice, influenza and pneumococcal vaccination, and prompt treatment of respiratory infections are particularly important in cyanotic disease and pulmonary hypertension.

• A transthoracic echocardiogram is the one investigation that changes management; even a single portable study at a bedside or in an adult medical clinic is enough to confirm or exclude most of the lesions discussed here.
• Where echocardiography is unavailable, upper limb and lower limb blood pressures, palpation of femoral pulses, and careful auscultation separate coarctation and large shunts from acquired disease; chest radiography (pulmonary vascularity and cardiac shape) supports the diagnosis of more complex lesions.
• Heart failure in an adult with an unrepaired shunt is managed with diuretics, nutritional support and correction of anaemia while arranging referral; avoid over-diuresis when physiology depends on preload.
• Start treatment for pulmonary hypertension only in consultation with a specialist centre if possible; bosentan and PDE5 inhibitors may not be available, and sometimes the realistic plan is supportive care, infection and iron repletion, and prompt referral.
• Each resected or implanted material should be followed up for life; a written summary for the patient (anatomy, operation, residual lesion) helps prevent loss to follow-up when care is fragmented.

• Most people born with congenital heart disease now reach adulthood; the common clinics are for adults with repaired or residual disease.
• Atrial septal defects in adults should be closed electively at presentation when haemodynamically significant, with right ventricular volume overload or a Qp:Qs of at least 1.5:1 (guideline wording differs; paediatric criterion is greater than 2:1); small defects under 5 mm usually need no closure.
• Small or trivial ventricular septal defects need only review and endocarditis advice; unrepaired moderate or large defects with acceptable pulmonary vascular resistance can still be closed in adults.
• Very small or small patent ductus arteriosus is closed to remove endocarditis risk even if not haemodynamically significant; medium and large ducts are closed to protect the left ventricle and prevent pulmonary vascular disease; closure is avoided once Eisenmenger physiology exists.
• Coarctation is significant with a peak-to-peak gradient exceeding 20 mmHg; adults are treated with stenting, surgery or balloon, and late hypertension is the rule rather than the exception.
• Tetralogy of Fallot is now an adult repair disease: late pulmonary regurgitation, right ventricular enlargement, arrhythmia and pulmonary valve replacement timing dominate follow-up.
• After transposition repair, the venous-switch cohort carries a systemic right ventricle for life; the arterial-switch cohort has good medium-term outcomes with surveillance of the neoaorta and coronaries.
• Eisenmenger syndrome is the reversed-shunt end stage of an unrepaired large shunt. Closure of the defect is contraindicated; treatment is pulmonary arterial hypertension therapy, iron repletion, and avoidance of pregnancy, dehydration, high altitude and peripheral vasodilatation.
• Pregnancy is contraindicated in Eisenmenger syndrome and must be planned in all complex congenital heart disease.
• Every patient with congenital heart disease whose lesion is more than simple needs lifelong specialist follow-up.

Read next: acyanotic congenital heart disease, cyanotic congenital heart disease, heart disease in pregnancy, pulmonary hypertension and Eisenmenger syndrome, infective endocarditis, valvular heart disease, cardiomyopathies and heart failure. Within cardiology see also: echocardiography, cardiac magnetic resonance imaging, arrhythmias and their management, sudden cardiac death prevention, and hypertension. Low-resource readers should focus on clinical recognition, echocardiography access, and timely referral.