Common congenital heart lesions

11 min read Last updated April 9, 2026

Surgical approach (typical operations you may see)

  • ASD closure
    • Transcatheter device closure (secundum ASD) via femoral venous access, TOE/fluoro guidance
    • Surgical patch closure (often pericardial patch) via sternotomy/thoracotomy, CPB if open repair
  • VSD closure
    • Open patch closure on CPB (perimembranous/muscular), may require tricuspid valve detachment for exposure
    • Pulmonary artery banding as palliative in selected infants (reduce pulmonary overcirculation) prior to definitive repair
  • PDA closure
    • Transcatheter coil/device occlusion (common in older infants/children)
    • Surgical ligation/division via left thoracotomy (common in small preterm infants)
  • Tetralogy of Fallot (TOF) repair
    • Definitive repair on CPB: VSD closure + relief of RVOT obstruction (infundibular resection, pulmonary valvotomy, transannular patch if needed)
    • Palliative systemic-to-pulmonary shunt (e.g., modified Blalock–Taussig shunt) if not suitable for early complete repair
  • Transposition of the great arteries (TGA)
    • Arterial switch operation (ASO) in neonatal period: transect great arteries, switch, reimplant coronaries
    • Balloon atrial septostomy (Rashkind) to improve mixing pre-op
  • Coarctation of the aorta (CoA) repair
    • Surgical: resection with end-to-end anastomosis, extended end-to-end, or subclavian flap via left thoracotomy
    • Catheter: balloon angioplasty/stenting (more common in older children/adolescents, recoarctation)
  • Atrioventricular septal defect (AVSD) repair
    • On CPB: patch closure of ASD/VSD components + repair/cleft closure of AV valves, aim reduce AV valve regurgitation
  • Single ventricle palliation (HLHS / tricuspid atresia etc.)
    • Stage 1 (Norwood/Sano) → Stage 2 (Glenn) → Stage 3 (Fontan), physiology changes at each stage

Anaesthetic management (overview by lesion type and common procedures)

  • Type of anaesthesia
    • Most congenital cardiac surgery: GA with controlled ventilation, invasive monitoring, CPB common for intracardiac repair
    • Catheter procedures (ASD/PDA device, balloon septostomy): GA or deep sedation depending on age/centre, immobility and airway control often favour GA in infants
  • Airway
    • ETT for most cases (especially neonates/infants, CPB, thoracotomy/sternotomy, pulmonary hypertension risk)
    • SGA occasionally for short low-risk catheter cases in older children, avoid if aspiration risk, pulmonary hypertension, or need for precise ventilation/CO2 control
  • Duration (very approximate, centre and complexity dependent)
    • PDA ligation: ~1–2 h, ASD device: ~1–2 h, ASD/VSD open repair: ~3–6 h, TOF repair: ~4–7 h, ASO: ~5–8 h, CoA repair: ~2–4 h
  • Pain
    • Thoracotomy/sternotomy: severe, catheter/device: mild–moderate, consider regional adjuncts where appropriate
    • Analgesia: opioid-based + paracetamol, consider ketamine/dexmedetomidine, regional options include paravertebral/erector spinae/caudal (care with anticoagulation/CPB)
  • Core physiological goals (shunt and PVR/SVR management)
    • Left→right shunts (ASD/VSD/PDA): avoid large drops in SVR and avoid rises in PVR, aim maintain systemic perfusion and limit pulmonary overcirculation
    • Right→left shunts / cyanotic lesions (TOF): avoid ↓SVR and avoid ↑PVR, maintain preload, treat hypercyanotic spells promptly
    • Parallel circulation (TGA) and duct-dependent lesions (HLHS/critical CoA): maintain ductal patency (PGE1), ensure mixing, avoid excessive oxygen/ventilation that may unbalance Qp:Qs
    • Pulmonary hypertension/Eisenmenger: avoid hypoxia, hypercarbia, acidosis, pain, hypothermia, maintain SVR, avoid air embolism, consider iNO/vasopressors
  • Monitoring (typical)
    • Standard + arterial line (pre-induction if unstable) + central access, NIRS often, TOE in many repairs, temperature, urine output, lactate
    • In duct-dependent systemic flow (e.g., CoA/HLHS): pre- and post-ductal SpO2 and BP (right hand vs lower limb) to assess differential perfusion

Classification and key concepts

  • Useful physiological grouping
    • Acyanotic with left→right shunt: ASD, VSD, PDA, AVSD
    • Obstructive lesions: CoA, aortic stenosis, pulmonary stenosis
    • Cyanotic with reduced pulmonary blood flow: TOF, pulmonary atresia
    • Cyanotic with increased pulmonary blood flow/mixing: TGA (needs mixing), truncus arteriosus, TAPVC (esp obstructed)
  • Shunt magnitude depends on relative resistances
    • Left→right increases with ↓SVR or ↓PVR, decreases with ↑PVR or ↑SVR (but ↑SVR increases LV work)
    • Right→left increases with ↓SVR or ↑PVR, decreases with ↑SVR or ↓PVR
  • Pulmonary vascular resistance (PVR) rises with
    • Hypoxia, hypercarbia, acidosis, high airway pressures/PEEP, hypothermia, sympathetic stimulation/pain
  • Duct-dependent lesions
    • Systemic flow dependent on PDA: critical CoA/interrupted arch, HLHS, critical aortic stenosis
    • Pulmonary flow dependent on PDA: pulmonary atresia, critical pulmonary stenosis, severe TOF variants
    • Maintain patency with prostaglandin E1, anticipate apnoea, hypotension, fever, secure airway early if unstable

ASD (Atrial septal defect)

  • Types
    • Secundum (most common, device closure possible), primum (AVSD spectrum), sinus venosus (often anomalous pulmonary venous drainage)
  • Pathophysiology
    • Left→right shunt at atrial level → RA/RV volume overload, increased pulmonary blood flow, often asymptomatic until later
    • Shunt increases with ↓PVR and with compliant RV, may reverse with severe pulmonary hypertension (Eisenmenger, rare in isolated ASD)
  • Clinical features/complications
    • Fixed split S2, systolic flow murmur (pulmonary), atrial arrhythmias, paradoxical embolus risk
  • Anaesthetic implications
    • Avoid air in IV lines (paradoxical embolus possible), maintain normoxia/normocapnia, usually well tolerated
    • If pulmonary hypertension present: manage as PHTN (avoid ↑PVR, maintain SVR, consider iNO)

VSD (Ventricular septal defect)

  • Types and size matters
    • Perimembranous (common), muscular, inlet/outlet, restrictive (small) vs non-restrictive (large)
  • Pathophysiology
    • Left→right shunt at ventricular level → pulmonary overcirculation + LV volume overload, large VSD can cause heart failure and failure to thrive
    • Chronic ↑PBF → pulmonary vascular disease → Eisenmenger (right→left shunt, cyanosis)
  • Anaesthetic implications
    • Aim avoid ↓SVR (would increase L→R shunt) and avoid ↑PVR, maintain adequate depth/analgesia to prevent sympathetic surges
    • If Eisenmenger: treat as high-risk (fixed high PVR): maintain SVR, avoid hypovolaemia, avoid air, cautious neuraxial/vasodilators

PDA (Patent ductus arteriosus)

  • Pathophysiology
    • Postnatal L→R shunt from aorta to pulmonary artery → pulmonary overcirculation, LV volume overload, in preterm can cause significant respiratory compromise
    • Large PDA can lead to pulmonary hypertension and Eisenmenger with differential cyanosis (lower limbs more cyanosed if R→L through PDA)
  • Anaesthetic implications
    • Maintain SVR and avoid excessive FiO2/overventilation in large shunts if systemic perfusion compromised, treat heart failure (diuretics, inotropes as needed)
    • Thoracotomy ligation: one-lung ventilation rarely feasible in small infants, anticipate haemodynamic change after ligation (↑SVR/afterload, ↓pulmonary overcirculation)

AVSD (Atrioventricular septal defect) and Down syndrome

  • Definition
    • Endocardial cushion defect: primum ASD + inlet VSD + common AV valve (complete) or partial variants
  • Associations
    • Trisomy 21 common, early pulmonary vascular disease risk, AV valve regurgitation contributes to heart failure
  • Anaesthetic implications
    • Manage as significant L→R shunt with possible pulmonary hypertension, avoid ↑PVR, consider airway issues in Down syndrome (OSA, subglottic stenosis, atlanto-axial instability considerations)

TOF (Tetralogy of Fallot)

  • Components
    • VSD, overriding aorta, RVOT obstruction (pulmonary stenosis), RV hypertrophy
  • Pathophysiology
    • Degree of RVOT obstruction determines shunt direction, severe obstruction → R→L across VSD → cyanosis
  • Hypercyanotic (Tet) spells
    • Mechanism: sudden ↑R→L shunt due to infundibular spasm/↓SVR/↓preload/↑PVR → worsening hypoxia and acidosis
    • Treatment: knee-chest position, 100% O2, fluid bolus, deepen anaesthesia, morphine, phenylephrine (↑SVR), beta-blocker (propranolol/esmolol) to relieve infundibular spasm, correct acidosis, consider iNO if PVR high
  • Anaesthetic goals
    • Maintain/increase SVR, maintain preload, avoid ↑PVR, avoid tachycardia, gentle induction (ketamine often useful), avoid air embolism

TGA (Transposition of the great arteries)

  • Key concept: parallel circulations
    • Aorta from RV and PA from LV → systemic and pulmonary circuits in parallel, survival depends on mixing (ASD/VSD/PDA)
  • Anaesthetic implications (pre-repair)
    • Maintain ductal patency (PGE1) and mixing, avoid sudden changes that reduce mixing, balance Qp:Qs (excessive oxygen/ventilation can increase Qp and reduce systemic perfusion in some mixing lesions)
    • Balloon atrial septostomy often performed under GA/sedation, be prepared for arrhythmias, perforation, embolic events, ensure meticulous de-airing
  • Definitive repair
    • Arterial switch (neonatal) with coronary transfer, post-op issues include myocardial ischaemia, low cardiac output, arrhythmias

Coarctation of the aorta (CoA)

  • Pathophysiology
    • Narrowing typically juxtaductal, upper limb hypertension with lower limb hypoperfusion, in neonates may be duct-dependent for systemic flow
  • Clinical features
    • Radio-femoral delay, differential BP, metabolic acidosis/shock when duct closes, association with bicuspid aortic valve, Turner syndrome, cerebral aneurysms (older patients)
  • Anaesthetic implications
    • Monitor proximal and distal pressures (right radial + femoral/umbilical), avoid hypotension distal to clamp, manage afterload changes at cross-clamp/unclamp
    • If duct-dependent: continue PGE1, avoid excessive oxygen/ventilation if it compromises systemic perfusion, treat acidosis and support cardiac output

Eisenmenger syndrome (end-stage pulmonary vascular disease from L→R shunt)

  • Definition and consequences
    • Irreversible ↑PVR causing shunt reversal (R→L) and cyanosis, fixed PVR means limited ability to augment pulmonary blood flow
    • Complications: polycythaemia, hyperviscosity, thrombosis/haemoptysis, arrhythmias, RV failure, paradoxical emboli, high maternal mortality in pregnancy
  • Anaesthetic principles
    • Maintain SVR (vasopressors early), maintain preload, avoid hypoxia/hypercarbia/acidosis/pain, avoid air, cautious with neuraxial due to SVR drop, consider invasive monitoring
    • Treat pulmonary hypertensive crisis: 100% O2, correct acidosis, deepen anaesthesia, iNO/inhaled prostacyclin, vasopressors/inotropes as needed

Test yourself…

Explain how changes in SVR and PVR affect left-to-right and right-to-left shunts. How does this influence your anaesthetic plan?

Examiners typically want a clear statement of direction of shunt change with SVR/PVR and practical implications (ventilation, vasoactive drugs).

  • Left→right shunt (ASD/VSD/PDA): shunt increases with ↓SVR and/or ↓PVR, shunt decreases with ↑PVR (but this is harmful if it reflects pulmonary hypertension) and with ↑SVR (at cost of increased LV work).
  • Right→left shunt (TOF/Eisenmenger): shunt increases with ↓SVR and/or ↑PVR, decreases with ↑SVR and/or ↓PVR.
  • Anaesthetic implications: avoid vasodilation and hypovolaemia in cyanotic lesions, avoid hypoxia/hypercarbia/acidosis/high airway pressures (all ↑PVR), use vasopressors (e.g., phenylephrine/noradrenaline) to support SVR when needed, controlled ventilation to maintain normocapnia and adequate oxygenation.
A 6-month-old with unrepaired TOF becomes suddenly more cyanosed during induction. What is happening and how do you treat it?

This is a classic hypercyanotic (Tet) spell scenario.

  • Diagnosis: hypercyanotic spell due to acute increase in R→L shunt (infundibular spasm ± ↓SVR/↓preload/↑PVR).
  • Immediate actions: 100% O2, deepen anaesthesia, ensure airway patency and controlled ventilation, call for help.
  • Increase SVR: phenylephrine boluses/infusion (or noradrenaline) to reduce R→L shunt.
  • Increase preload: fluid bolus, consider knee-chest positioning (increases SVR and venous return).
  • Relieve RVOT spasm: beta-blocker (esmolol/propranolol) if tachycardic and persistent spell.
  • Reduce PVR and metabolic drive: correct acidosis, treat pain, avoid high airway pressures, consider iNO if PVR suspected high.
Describe the physiology of transposition of the great arteries (TGA) and the immediate perioperative priorities before definitive repair.

Key phrase: parallel circulations, survival depends on mixing.

  • Physiology: aorta from RV and PA from LV → parallel circulations, without mixing, oxygenated blood recirculates to lungs and deoxygenated blood recirculates systemically.
  • Mixing sites: ASD/PFO, VSD, PDA, inadequate mixing → profound hypoxaemia.
  • Immediate priorities: maintain ductal patency with PGE1, optimise mixing (consider balloon atrial septostomy), avoid factors that worsen haemodynamics (hypotension, acidosis, hypoxia).
  • Ventilation/oxygen: aim adequate oxygen delivery but avoid extreme changes that may unbalance Qp:Qs in complex mixing lesions, maintain normocapnia and avoid high airway pressures.
How would you anaesthetise a patient with Eisenmenger syndrome for non-cardiac surgery? Include monitoring and haemodynamic goals.

This is a common FRCA viva theme: fixed high PVR, maintain SVR, avoid air and hypovolaemia.

  • Goals: maintain SVR (avoid vasodilation), maintain preload, avoid ↑PVR triggers (hypoxia, hypercarbia, acidosis, pain, hypothermia, high airway pressures).
  • Technique: GA often preferred for control, regional/neuraxial only with extreme caution due to sudden SVR drop (if used, incremental dosing and vasopressors ready).
  • Monitoring: arterial line (beat-to-beat BP), large-bore IV access, consider CVC if vasoactive infusions required, continuous SpO2 and capnography, consider echo if unstable.
  • Drugs: early vasopressors (phenylephrine/noradrenaline/vasopressin) to support SVR, cautious induction (avoid profound vasodilation), maintain sinus rhythm and avoid tachycardia.
  • Safety: meticulous de-airing of all lines (paradoxical embolus), avoid dehydration, consider thromboprophylaxis plan individually (thrombosis vs bleeding).
  • Pulmonary hypertensive crisis plan: 100% O2, correct acidosis, deepen anaesthesia, iNO/inhaled prostacyclin, vasopressors/inotropes as needed, treat RV failure.
A neonate with suspected critical coarctation collapses when the duct closes. Explain why and outline immediate management.

This tests duct-dependent systemic circulation and pre/post-ductal assessment.

  • Mechanism: in critical CoA, systemic blood flow to lower body may be duct-dependent, duct closure → severe LV afterload, low cardiac output, distal hypoperfusion, metabolic acidosis/shock.
  • Immediate management: start/continue PGE1 to reopen/maintain duct, support circulation (fluids cautiously, inotropes/vasopressors), correct acidosis, manage ventilation/oxygenation.
  • Monitoring: pre- and post-ductal SpO2 and BP (right hand vs lower limb), arterial line if possible, lactate/ABGs.
  • Airway: anticipate apnoea with PGE1 and shock physiology, early intubation and controlled ventilation often required.
Compare ASD, VSD and PDA in terms of clinical signs and haemodynamic consequences.
  • ASD: often asymptomatic, fixed split S2, systolic flow murmur at pulmonary area, RA/RV volume overload, pulmonary hypertension late.
  • VSD: pansystolic murmur (LLSB) if restrictive, large defects → heart failure, pulmonary overcirculation, LV volume overload, risk of pulmonary vascular disease/Eisenmenger.
  • PDA: continuous “machinery” murmur, bounding pulses/wide pulse pressure (large PDA), pulmonary overcirculation + LV volume overload, can cause differential cyanosis if Eisenmenger via PDA.
What are the common causes of increased PVR in the perioperative period and how do you reduce PVR?
  • Causes: hypoxia, hypercarbia, acidosis, pain/sympathetic stimulation, hypothermia, atelectasis, high mean airway pressure/PEEP, pulmonary embolism, sepsis.
  • Reduction: optimise oxygenation (recruitment, adequate FiO2), maintain normocapnia, correct acidosis, adequate analgesia/anaesthesia, avoid hypothermia, reduce airway pressures where possible, consider iNO or inhaled prostacyclin in crises.
Outline key anaesthetic considerations for transcatheter ASD/PDA closure in a child.
  • Technique: GA often preferred in infants/young children (immobility, airway control, TOE), older children may tolerate deep sedation depending on centre.
  • Risks: arrhythmias, device embolisation, vascular injury, perforation/tamponade, air/thromboembolism, ensure meticulous de-airing and readiness for resuscitation.
  • Monitoring: arterial line not always required but low threshold if significant shunt/PHTN, ensure good IV access, consider blood availability for complications.

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