Congenital Heart Diseases
Congenital heart diseases refer to a group of structural abnormalities of the heart and/or great vessels that develop before birth.
This article covers the following congenital heart diseases:
- Patent ductus arteriosus (PDA)
- Atrial septal defect (ASD)
- Ventricular septal defect (VSD)
- Atrioventricular septal defect (AVSD)
- Coarctation of the aorta (CoA)
- Tetralogy of Fallot (ToF)
- Transposition of the great arteries (TGA)
- Persistent truncus arteriosus (PTA)
Overview
Epidemiology
Congenital heart disease is the most common birth defect in the UK [NHS England]
At least 8 in every 1,000 babies are born with a heart or circulatory condition [NHS England]
- Ventricular septal defect (VSD) – most common congenital heart disease overall [Ref]
- Atrial septal defect (ASD) – 2nd most common major congenital heart disease [Ref]
- Tetralogy of Fallot (ToF) – most common cyanotic congenital heart disease [Ref]
Normal Physiology
Fetal Circulation
In fetal life, gas exchange occurs in the placenta rather than the lungs. The fetal lungs are fluid-filled and have a high pulmonary vascular resistance, so most blood is directed away from the lungs.
Key fetal shunts:
- Foramen ovale (opening between the right and left atrium) – allows blood to shunt from the right atrium → left atrium to bypass the lungs
- Ductus arteriosus (connection between the pulmonary artery and aorta) – allows blood to shunt from the pulmonary artery → aorta to bypass the lungs
- Ductus venosus (connection between the umbilical vein and IVC) – allows blood to shunt from the umbilical vein → IVC to bypass the immature liver
Fetal circulation pathway:
- Gas exchange takes place in the placenta
- Umbilical vein delivers oxygenated blood from the placenta
- Most blood bypasses the liver through the ductus venosus into the IVC
- Blood enters the right atrium
- Most blood is shunted from the pulmonary circulation to the systemic circulation (right-to-left shunt), due to the high pulmonary vascular resistance
- Right atrium → left atrium (via foramen ovale)
- Pulmonary trunk → aorta (via ductus arteriosus)
- Blood then travels through the systemic circulation and returns to the placenta via umbilical arteries
Neonatal Circulation (After Birth)
At birth:
- The umbilical cord is clamped, which removes the placental circulation
- The lungs expand, causing pulmonary vascular resistance to fall
- Pulmonary blood flow increases, and the lungs take over gas exchange.
- Blood is redirected to the pulmonary circulation due to
- Reduction in pulmonary vascular resistance
- Closure of the foramen ovale (due to increasing left atrial pressure)
- Closure of the ductus arteriosus (due to increasing oxygen levels)
- The ductus venosus also closes following loss of umbilical venous flow
The neonatal circulation therefore becomes: right heart → lungs → left heart → systemic circulation
Classification
| Classification | Subclassification | Description | Common examples |
|---|---|---|---|
| Acyanotic | Left-to-right shunt | Oxygenated blood is shunted from the left (left atrium / left ventricle / aorta) → right (right atrium / right ventricle / pulmonary artery)
This increases pulmonary blood flow but does not initially cause cyanosis, as deoxygenated blood is not entering the systemic circulation |
|
| Obstructive lesion | An anatomical narrowing obstructs blood flow through the heart or great vessels
There is no right-to-left shunt, so systemic oxygen saturation is generally maintained |
|
|
| Cyanotic | Right-to-left shunt | Deoxygenated blood is shunted from the right (right atrium / right ventricle / pulmonary artery) → left (left atrium / left ventricle / aorta) |
|
| Mixing lesion | Oxygenated and deoxygenated blood mix due to abnormal cardiac anatomy → inadequate oxygenated blood reaching the systemic circulation |
|
Alternative classifications (for the purposes of NIPE newborn screening): [NHS England]
- Critical congenital heart disease: includes all potentially life-threatening duct-dependent conditions and those conditions that require procedures within the first 28 days of life
- Major congenital heart disease: includes defects not classified as critical but requiring invasive intervention in the first year of life
- Congenital heart disease requiring intervention but not in the first year of life (e.g. primum atrial septal defect)
- Congenital heart disease that is unlikely to require intervention (e.g. patent ductus arteriosus or small ventricular septal defects)
Risk Factors
Key shared risk factors for congenital heart disease: [NHS England]
- Chromosomal / genetic abnormalities (esp. Down syndrome)
- Family history of congenital heart disease (in a first-degree relative)
- Parental consanguinity (where parents are biologically related, most commonly cousins)
- Teratogenic viral infections during pregnancy (classically rubella – associated with patent ductus arteriosus and pulmonary artery stenosis)
- Maternal conditions (e.g. pre-existing maternal diabetes, epilepsy, systemic lupus erythematosus)
- Teratogenic drug exposure during pregnancy (e.g. lithium)
Shared Screening and Diagnostic Concepts
The routine 20-week anomaly scan (as part of the NHS Fetal Anomaly Screening Programme) can detect some major congenital heart defects
ALL newborns are offered a newborn heart examination as part of the routine NIPE screening, which includes: [NHS England]
- Observation (tone, colour, chest size and shape, respiratory rate, symmetry of chest movement)
- Palpation (femoral and brachial pulse, capillary refill time, cardiac apex position, liver, thrill)
- Auscultation
Murmurs and congenital heart diseases: [NHS England]
- Significant murmurs are usually loud (+/- thrill), heard over a wide area, usually harsh +/- with other associated abnormal findings
- Benign murmurs are usually short, soft, systolic with no other added sounds, with no other clinical abnormalities
- Often localised to the left sternal border (but not an absolute rule)
- Benign murmurs in the first 24 hours of life are common in the absence of a cardiac defect, due to physiological changes at birth
Important: congenital heart disease may be present with or without a murmur (the absence of murmur alone CANNOT exclude the presence of congenital heart disease). [NHS England]
Further conditional assessment / tests:
- Pulse oximetry is used to assess for hypoxaemia when there are concerns following observation, palpation or auscultation [NHS England]
- Routine pulse oximetry is NOT recommended as per the newborn and infant physical examination (NIPE) screening [NHS England]
- If congenital heart disease is suspected
- 1st line diagnostic imaging: echocardiography
- ECG / chest X-ray may provide supportive information, but don’t usually provide diagnostic information
- Cardiac MR / CT is used selectively for further anatomical and functional assessment
Acyanotic Congenital Heart Diseases
Patent Ductus Arteriosus (PDA)
Persistent communication between the proximal left pulmonary artery and the descending aorta, just distal to the left subclavian artery [ESC]
After birth, this produces a left-to-right shunt from the aorta into the pulmonary artery
Risk Factors and Associations
- Prematurity – major risk factor
- Maternal infections during pregnancy
- Congenital rubella syndrome
- Zika virus
- Prenatal cannabis exposure
- Chromosomal abnormalities (e.g. trisomies, DiGeorge syndrome) / single-gene dysmorphic syndromes
Clinical Features
Small PDAs are often asymptomatic [Ref]
Typical features of PDA: [Ref]
- Murmur
- Features of haemodynamically significant PDA
- Bounding pulses + wide pulse pressure
- Hyperdynamic precordium
Complications
Left-to-right shunt causes: [ESC]
- Left atrium and ventricle volume overload → left-sided heart failure
- ↑ Pulmonary blood flow → pulmonary vascular remodelling → pulmonary hypertension
Eisenmenger syndrome is a long-term complication of long-standing untreated left-to-right shunting (e.g. ASD, VSD, PDA)
- Over time, increased pulmonary blood flow causes pulmonary vascular remodelling and subsequent pulmonary hypertension
- Right heart pressures steadily rise
- When right heart pressure > left heart pressure → shunt reversal (from the initial left-to-right shunt to right-to-left shunt)
- Deoxygenated blood enters the systemic circulation, resulting in cyanosis
Diagnosis
1st line: echocardiography [ESC]
- Diagnosis confirmed by
- Structural presence of PDA connecting the descending aorta to the pulmonary artery
- Colour Doppler shows flow through the PDA, usually left-to-right
- Also used to assess
- Haemodynamic significance
- Left ventricular volume overload
- Right-heart changes and estimate pulmonary artery pressure
If echo suggests pulmonary hypertension → specialist assessment +/- cardiac catheterisation
Management
Preterm Neonates
Do NOT routinely treat all in preterm infants. Routine early closure has not clearly improved important long-term outcomes.
Active management should only be considered if there is a haemodynamically significant , indicated by: [Ref1][Ref2]
- Difficulty weaning from a ventilator [NICE NG124]
- Evidence of pulmonary overcirculation
- Systemic hypoperfusion (e.g. hypotension, oliguria)
- Significant shunting on echo
Choice of management: [Ref1][Ref2]
- 1st line: NSAIDs (ibuprofen preferred, alternative: indomethacin)
- 2nd line (if PDA persists despite 2 courses of pharmacological therapy): transcatheter closure or surgical ligation
Older Children / Adults
Do NOT routinely close all PDAs [ESC]
- Key indication for closure: PDA causing a significant left-to-right shunt with left ventricular volume overload
- Small PDA with no significant haemodynamic changes can be managed conservatively
Intervention of choice: [ESC]
- 1st line: transcatheter device closure
- 2nd line (transcatheter closure inappropriate, e.g. PDA too large, unsuitable anatomy): surgical closure
Special consideration: [ESC]
- If PDA is associated with pulmonary hypertension → specialist-guided management
- If Eisenmenger syndrome has developed → routine closure is generally not performed + specialist-guided management
Atrial Septal Defect (ASD)
An atrial septal defect (ASD) is an abnormal communication between the atria that usually results in left-to-right shunting (as left atrial pressure > right atrial pressure)
Atrial septal defect (ASD) vs patent foramen ovale (PFO)
- Atrial septal defect: a true structural defect allowing communication between the left and right atrium → left-to-right shunting
- Patent foramen ovale: persistence of the normal fetal foramen ovale flap pathway because septum primum and septum secundum fail to fuse completely
- It is usually functionally closed as the higher left atrial pressure keeps the flap shut
Paradoxical embolism: Both ASD and PFO can allow a venous thrombus to cross from the right to the left atrium during transient or sustained right-to-left shunting, potentially causing ischaemic stroke or systemic embolism
Associations
ASD may be associated with: [ESC]
- Mitral valve prolapse
- Ebstein anomaly
- Atrioventricular septal defects (primum ASD forms part of the spectrum of partial atrioventricular septal defects)
- Pulmonary valve stenosis
- Persistent left SVC
- Anomalous pulmonary venous drainage (esp. sinus venosus defects)
Clinical Features
Most patients are asymptomatic during childhood and early adulthood [ESC]
Classic examination findings: [ESC]
- Wide, fixed splitting of S2
- Ejection systolic murmur over the pulmonary area (left upper sternal border)
- Mid-diastolic rumble over the tricuspid area (left lower sternal border) – usually seen in moderate to large shunts
Complications
- Right atrium / right ventricle volume overload → right-sided heart failure
- ↑ Pulmonary blood flow → pulmonary vascular remodelling → pulmonary hypertension
- Atrial tachyarrhythmias (esp. atrial flutter and atrial fibrillation)
Eisenmenger syndrome is a long-term complication of long-standing untreated left-to-right shunting (e.g. ASD, VSD, PDA)
- Over time, increased pulmonary blood flow causes pulmonary vascular remodelling and subsequent pulmonary hypertension
- Right heart pressures steadily rise
- When right heart pressure > left heart pressure → shunt reversal (from the initial left-to-right shunt to right-to-left shunt)
- Deoxygenated blood enters the systemic circulation, resulting in cyanosis
Paradoxical embolism (recognised as a rare complication) [ESC]
- An ASD (and PFO) can allow a venous thrombus to cross from the right to the left atrium during transient right-to-left shunting
- An embolism from a DVT may result in ischaemic stroke or systemic embolism
Diagnosis
1st line: echocardiography
- Directly visualises the ASD and determines the anatomical type and size
- Assesses right ventricular volume overload
If pulmonary hypertension is suspected → specialist referral +/- right heart catheterisation
ECG findings in ASD (supportive features but not diagnostic):
- Right axis deviation
- Incomplete RBBB
Management
Do NOT routinely close all ASDs [ESC]
- Key indication for closure: ASD causing a significant left-to-right shunt with right ventricular volume overload
- Small ASDs with no significant haemodynamic changes can be managed conservatively
Intervention of choice: [ESC]
- 1st line: transcatheter device closure
- 2nd line (transcatheter closure inappropriate, e.g. large ASD, non-secundum ASD): surgical closure
Special consideration: [ESC]
- If ASD is associated with pulmonary hypertension → specialist-guided management
- If Eisenmenger syndrome has developed → routine closure is generally not performed + specialist-guided management
Ventricular Septal Defect (VSD)
A ventricular septal defect (VSD) is an abnormal communication between the ventricles that usually results in left-to-right shunting (as left ventricular pressure > right ventricular pressure)
Associations
VSD may occur as an isolated defect or as part of more complex congenital heart disease, including: [ESC]
- Atrioventricular septal defect
- Tetralogy of Fallot
- Transposition of the great arteries
Atrioventricular septal defects (AVSDs) are associated with Down syndrome [ESC]
Clinical Features
Many small VSDs are asymptomatic
Typical examination findings:
- Harsh pansystolic murmur, best heard at the left lower sternal border
- +/- Precordial thrill
- Larger VSDs may also produce
- Hyperdynamic precordium
- Apical mid-diastolic flow murmur (due to ↑ pulmonary venous return, thus ↑ flow across the mitral valve)
“Paradoxical” murmur in VSD: [Ref]
- Small VSD → louder, harsher murmur
- Large VSD → quieter, softer murmur
Rationale: the murmur loudness is primarily driven by the pressure gradient and jet velocity rather than simply by the anatomical size of the defect
- In smaller VSDs, the pressure gradient is larger, thus a louder, harsher murmur
- In larger VSDs, the pressure gradient is smaller, thus a quieter, softer murmur
Complications
- Left ventricle volume overload → left-sided heart failure
- ↑ Pulmonary blood flow → pulmonary vascular remodelling → pulmonary hypertension
- ↑ Risk of infective endocarditis
- Aortic cusp prolapse → aortic regurgitation
Eisenmenger syndrome is a long-term complication of long-standing untreated left-to-right shunting (e.g. ASD, VSD, PDA)
- Over time, increased pulmonary blood flow causes pulmonary vascular remodelling and subsequent pulmonary hypertension
- Right heart pressures steadily rise
- When right heart pressure > left heart pressure → shunt reversal (from the initial left-to-right shunt to right-to-left shunt)
- Deoxygenated blood enters the systemic circulation, resulting in cyanosis
Diagnosis
1st line: echocardiography [ESC]
- Directly visualises the VSD and determines the anatomical type and size
- Assesses left ventricular volume overload
Management
Do NOT routinely close all VSDs, key indications for closure: [ESC]
- Significant left-to-right shunt causing left ventricular volume overload
- Progressive aortic regurgitation (due to VSD-related aortic cusp prolapse)
- Recurrent infective endocarditis related to VSD
Intervention of choice: [ESC]
- 1st line: surgical closure
- 2nd line (e.g. residual VSD after surgery, difficult surgical access): transcatheter closure
Special consideration: [ESC]
- If VSD is associated with pulmonary hypertension → specialist-guided management
- If Eisenmenger syndrome has developed → routine closure is generally not performed + specialist-guided management
Atrioventricular Septal Defect (AVSD)
An atrioventricular septal defect (AVSD) is characterised by a common AV junction, with abnormalities of the atrial / ventricular septa and AV valves, [ESC]
- Complete AVSD: ASD + VSD + single common AV valve / orifice → large left-to-right shunt + significant AV valve regurgitation
- Partial AVSD: primum ASD + abnormal AV valve anatomy but separate AV valve openings → atrial level left-to-right shunt +/- left AV valve regurgitation
It was historically known as an AV canal defect or endocardial cushion defect.
Risk Factors and Associations
Strongly associated with Down syndrome (>75% of complete AVSDs occur in patients with Down syndrome) [ESC]
AVSD can also occur alongside more complex congenital heart diseases like Tetralogy of Fallot
Clinical Features and Complications
Clinical presentation of AVSD depends on the size of the ASD / VSD components and the degree of AV valve regurgitation [ESC][Ref]
- Infants with complete AVSD may develop heart failure within the first few months of life
- Murmurs vary according to the haemodynamics
- Systolic murmur may result from increased pulmonary flow
- Pansystolic murmur may occur with significant AV valve regurgitation
- An apical mid-diastolic flow murmur may occur with a large left-to-right shunt
Key complications include: [ESC][Ref]
- Heart failure due to significant left-to-right shunting and/or AV valve regurgitation
- Pulmonary hypertension
- AV valve regurgitation
- Arrhythmias / conduction abnormalities
Eisenmenger syndrome is a long-term complication of long-standing untreated left-to-right shunting (e.g. ASD, VSD, PDA)
- Over time, increased pulmonary blood flow causes pulmonary vascular remodelling and subsequent pulmonary hypertension
- Right heart pressures steadily rise
- When right heart pressure > left heart pressure → shunt reversal (from the initial left-to-right shunt to right-to-left shunt)
- Deoxygenated blood enters the systemic circulation, resulting in cyanosis
Diagnosis
1st line: echocardiography [ESC]
ECG findings: [ESC]
- Left axis deviation
- Prolonged PR interval
- +/- Incomplete RBBB
Management
Definitive management: surgical repair (closure of the septal defect + repair of abnormal AV valve) [ESC]
- Complete AVSD → routine repair during infancy
- Partial AVSD → repair if haemodynamically significant and/or significant AV valve regurgitation
Transcatheter closure is NOT feasible for AVSD. [ESC]
Special consideration: [ESC]
- If AVSD is associated with pulmonary hypertension → specialist-guided management
- If Eisenmenger syndrome has developed → routine closure is generally not performed + specialist-guided management
Coarctation of the Aorta (CoA)
Coarctation of the aorta (CoA) is a congenital narrowing of the aorta, usually occurring around the aortic isthmus near the insertion of the ductus arteriosus [ESC]
Pathophysiology
The narrowing obstructs left ventricular outflow into the descending aorta: left ventricle → ascending aorta → narrowed segment → descending aorta
This causes: [ESC]
- ↑ Perfusion and pressure to the upper limbs and cerebral circulation (proximal to the coarctation)
- ↓ Perfusion and pressure to the lower limbs (distal to the coarctation)
- ↑ Left ventricle afterload → left ventricular hypertrophy
Collateral arterial circulation may develop in longstanding disease
Traditional classification: preductal, juxtaductal or postductal according to the relationship with the ductus arteriosus. [ESC]
Clinically, severity of obstruction is more important than this classification. [ESC]
Risk Factors and Associations
Classic CoA associations: [Ref][ESC]
- Bicuspid aortic valve
- Turner syndrome
- Males
- Intracranial aneurysms
- Other left-sided obstructive lesions (e.g. subaortic stenosis, supravalvular aortic stenosis)
Clinical Features
Key examination findings: [ESC]
| Category | Findings | Rationale |
|---|---|---|
| Pulse changes | Weak / absent femoral pulse (and other lower limb pulses) | ↓ Blood flow and pressure distal to the coarctation |
| Radiofemoral delay | Pulse transmission to the lower body is delayed by the coarctation | |
| Rare: unequal upper limb pulses | Occurs if the coarctation involves or lies proximal to the left subclavian artery | |
| BP changes | Upper limb BP > lower limb BP
Systolic BP gradient of >20 mmHg suggests significant CoA |
↑ Blood flow and pressure proximal to the coarctation (involving the subclavian arteries)
↓ Blood flow and pressure distal to the coarctation (involving the lower limb arteries) |
| Rare: unequal arm BP | Occurs if the coarctation lies proximal to the left subclavian artery | |
| Murmur | Systolic murmur – best heard over the interscapular region / back
+/- Suprasternal thrill |
Turbulent flow across the narrowed aortic segment |
Age-specific presentations:
| Neonates / young infants [Ref] | The following findings are more likely present in neonates / young infants:
Critical / duct-dependent CoA in neonates Characterised by a severe aortic narrowing in which adequate blood flow to the descending aorta depends on a patent ductus arteriosus (where extra blood flows from the pulmonary artery into the descending aorta, bypassing the coarctation), resulting in a duct-dependent systemic circulation Clinical manifestation:
|
| Older children / adults [ESC] | In addition to the above-shared examination findings:
Other findings:
|
Complications
Key complications: [ESC]
- Secondary systemic hypertension and associated complications
- Left ventricular hypertrophy → heart failure (HFpEF) – from ↑ afterload
- Premature cardiovascular disease
- Aortic complications
- Aortic aneurysm +/- rupture
- Aortic dissection
- Intracranial aneurysm → intracranial haemorrhage
Diagnosis
| Clinical assessment [ESC] |
|
| Diagnostic tests (imaging) [ESC] | Initial imaging: echocardiography
Definitive imaging: CT angiography or cardiac MR
|
| Chest X-ray [ESC][Ref] | Classic chest X-ray findings (supportive radiographic signs but NOT diagnostic by themselves)
|
Management
Do NOT routinely intervene in all patients with CoA [ESC]
Key indications / considerations for interventions: [ESC]
- Hypertension with haemodynamically significant CoA
- Severe aortic narrowing (≥50% narrowing of the aorta relative to the aortic diameter at the diaphragm)
Choice of intervention: [ESC]
- 1st line: transcatheter stenting
- 2nd line (when stenting is not appropriate e.g. difficult or complex anatomy): surgical repair
Balloon angioplasty is only indicated for re-dilation of a previously stented aorta needing re-intervention [ESC]
Cyanotic Congenital Heart Disease
Tetralogy of Fallot (ToF)
ToF consists of 4 (“tetra”) characteristic abnormalities: [ESC]
- Ventricular septal defect (VSD) (usually large and non-restrictive)
- Overriding aorta (the aorta lies just above the ventricular septal defect and receives blood from both ventricles)
- Right ventricular outflow tract obstruction (RVOTO)
- Right ventricular hypertrophy (RVH)
The clinical severity of ToF is determined by the degree of right ventricular outflow tract obstruction (RVOTO) [Ref]
- Due to the presence of a VSD, the left and right ventricular pressures become similar
- As a result, the degree of the RVOTO determines the degree of right-to-left shunting: more severe obstruction → less pulmonary blood flow → more right-to-left shunting → more deoxygenated blood mixing into the systemic circulation → cyanosis
Risk Factors and Associations
~20% of ToF cases are syndromic, important associations: [Ref]
- Down syndrome
- DiGeorge syndrome (22q11.2 deletion)
- Noonan syndrome
- Williams syndrome
- Alagille syndrome
Clinical Features
Classic examination findings:
| Variable cyansois | Phenotype depends on the severity of RVOTO (rationale explained above):
Timing of cyanosis: [Ref]
However, severe ToF with marked RVOTO can also present with significant cyanosis from birth |
| Murmur [Ref] | Harsh ejection systolic murmur best heard at the left upper sternal border
Other possible findings:
Paradoxical murmur: more severe RVOTO produces a softer murmur as very little blood is passing through the obstructed pulmonary outflow tract |
| Clubbing [Ref] | Clubbing may occur with longstanding unrepaired disease, but is uncommon nowadays |
| Hypercyanotic (“Tet”) spells [Ref] | Episodes of sudden worsening of right-to-left shunting, that can cause:
Common triggers:
Older children may squat after exertion or worsening cyanosis. Squatting increases systemic vascular resistance, reducing R→L shunting and improving pulmonary blood flow |
Diagnosis
1st line: echocardiography [ESC]
Other supportive tests (not diagnostic): [ESC]
- Chest X-ray
- Boot-shaped heart (coeur en sabot) → due to RVH producing an upturned apex
- Reduced pulmonary vascular markings – due to ↓ pulmonary blood flow from RVOTO
- ECG: RVH changes
Management
Definitive management: surgical repair during infancy [Ref]
- Repair aims to close the VSD and relieve the RVOTO
- Long-term management post-repair [ESC]
- Lifelong specialist follow-up
- Important later complications include pulmonary regurgitation, residual / recurrent RVOTO, right ventricular dilatation / dysfunction
- The main late intervention is often pulmonary valve replacement, especially where significant pulmonary regurgitation or RVOTO is causing symptoms or affecting ventricular function
Acute management of hypercyanotic (“Tet”) spells: [Ref]
- Knee-chest position (↑ systemic vascular resistance → right-to-left shunting)
- Oxygen +/- IV fluids
- Keep the patient calm and minimise distress
Transposition of Great Arteries (TGA)
Transposition of the great arteries (TGA) is characterised by ventriculo-arterial discordance
- Aorta arises from the right ventricle
- Pulmonary artery arises from the left ventricle
This creates 2 parallel circulations:
- Systemic: body → right atrium → right ventricle → aorta → body
- Pulmonary: lungs → left atrium → left ventricle → pulmonary artery → lungs
Survival therefore depends on mixing between the circulations, usually through an ASD, VSD and/or PDA.
Clinical Features
Typical presentation: [Ref]
- Marked cyanosis shortly after birth
- Often within the first hours of life
- Examination findings
- Single, loud S2
- No characteristic murmur in simple TGA (if a murmur is present, consider associated lesions e.g. VSD, outflow obstruction)
Timing of cyanosis:
- Classic ToF often has no / mild cyanosis at birth, and becomes progressively more apparent during infancy
- TGA more classically causes marked cyanosis within the first hours of life
Diagnosis
1st line: echocardiography [Ref]
Classic chest X-ray finding (non-diagnostic): egg-on-a-string cardiac sihouette [Ref]
Management
Immediate management goal is to increase mixing between the parallel circulations [Ref]
- 1st line: prostaglandin E1 to maintain or reopen the ductus arteriosus
- If mixing remains inadequate: balloon atrial septostomy (creates / enlarges an ASD to improve mixing)
Definitive management: surgical correction (arterial switch operation / Jatene procedure) [Ref]
- Usually performed in the neonatal period
- Disconnects the aorta and pulmonary artery, then reconnect them to the correct ventricles
Persistent Truncus Arteriosus (PTA)
Persistent truncus arteriosus (PTA) is characterised by a single arterial trunk arising from both ventricles (instead of separate aorta and pulmonary artery), usually accompanied with a large VSD
As a result: oxygenated + deoxygenated blood mix → common arterial trunk → systemic + pulmonary circulations
Risk Factors and Associations
DiGeorge syndrome (22q11.2 deletion) is strongly associated with PTA [Ref]
Associated cardiovascular abnormalities: [Ref]
- Right-sided aortic arch
- Interrupted aortic arch
- Abnormalities of the truncal valve
Clinical Features
Examination findings: [Ref]
- Mild to moderate cyanosis
- Wide pulse pressure / bounding pulses
- Ejection systolic murmur possible
- Features of heart failure / pulmonary overcirculation
Diagnosis
1st line: echocardiography
Associated chest X-ray findings (non-diagnostic): [Ref]
- Cardiomegaly
- ↑ Pulmonary vascularity
- Possible right-sided aortic arch
Management
Definitive management: surgical repair usually in the neonatal period [Ref]
References
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