Common congenital heart lesions

11 min read Last updated April 8, 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
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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