Cardio Flashcards
What is the aetiology of congenital heart disease?
-
Often genetic causes
- Chromosomal abnormalities
- E.g. Down’s → AVSD, VSD;
- Edward’s and Patau → complex malformations
- Point mutations
- Polygenic abnormalities
- Having a child with congenital heart disease doubles the risk in subsequent children
- Chromosomal abnormalities
-
Maternal disorders
- Congenital infections
- DM, SLE
-
Maternal drugs
- Warfarin → PDA, pulmonary valve stenosis
- Foetal alcohol syndrome → ASD, VSD, tetralogy of Fallot
What are the circulatory changes in the foetus?
- The L atrial pressure is low, because relatively little blood returns from the lungs
- The pressure in the R atrium is higher than the L, as it receives all the systemic venous return including blood from the placenta
- The flap of the foramen ovale is held open (hole between atria)
- Blood flows across the atrial septum into the L atrium, and then into the L ventricle, which in turn pumps it to the body
- The ductus arteriosus connects the pulmonary artery to the aorta (so any blood pumped from the R ventricle bypasses the lungs)
What are the circulatory changes that occur at birth?
- With the first few breaths, resistance to pulmonary blood flow falls and the volume of blood flowing through the lungs increases x6
- This results in a rise in L atrial pressure
- Meanwhile, the volume of blood returning to the R atrium falls as the placenta is excluded from the circulation
- The change in pressure difference causes the flap of the foramen ovale to close
- The ductus arteriosus closes within the first few hrs or days
- Some babies with congenital heart lesions rely on blood flow through the ductus arteriosus (duct-dependent circulation) à their clinical condition deteriorates dramatically when the duct closes at around 1-2d of age
What are the different presentations of congenital cardiac abnormalities?
- Antenatal cardiac USS diagnosis
- Detection of a heart murmur
- Heart failure
- Shock
- Cyanosis
Summarise the antenatal detection of a congenital cardiac abnormality
- Part of routine anomaly scan at 18-20wks
- 70% infants who require surgery in the first 6 months of life are diagnosed antenatally
- If an abnormality is detected, detailed foetal echo is done by paediatric cardiologist
- Any foetus at increased risk, e.g. suspected Down’s, is also checked
- Management can be planned antenatally (some mothers choose TOP)
Summarise the murmur presentation of congenital cardiac abnormalities
- Most common presentation of congenital heart disease
- The vast majority of children with murmurs have a normal heart → ‘innocent’ murmurs
- If a murmur is thought to be pathological, or there is uncertainty → paediatric cardiology
- CXR and ECG may help
- Many newborns with shunts, e.g. VSD, do not have symptoms or a murmur at birth (because resistance is still high) → may only become apparent when pulmonary vascular resistance falls (at several weeks of age)
Summarise innocent murmurs
- Heard in 30% children
- Hallmarks of an innocent ejection systolic murmur: (all have an S – innoSent)
- aSymptomatic
- Soft blowing murmur
- Systolic murmur only (not diastolic)
- left Sternal edge
-
Also:
- Normal heart sounds with no added sounds
- No parasternal thrill
- No radiation
- Often heard during febrile illness or anaemia (due to increased CO) → look for this
Summarise the shock presentation of congenital cardiac abnormalities
- When the duct closes in severe L heart obstruction
Summarise the cyanotic presentation of congenital cardiac abnormalities
- Peripheral cyanosis may occur when a child is cold or unwell from any cause
- Central cyanosis (slate-blue colour on tongue) is caused by a fall in arterial blood oxygen tension
- Persistent cyanosis in an otherwise well infant is almost always due to structural heart disease
-
In newborn infants with respiratory distress, it may be due to:
- congenital heart disease (cyanotic congenital heart disease),
- respiratory disorders (resp distress syndrome, meconium aspiration),
- persistent pulmonary HTN of the newborn,
- infection or inborn errors of metabolism
Give examples of each of the presentations of congenital cardiac disease
Name the types of congenital heart disease
- Left-to-right shunts:
- Right-to-left shunts:
- Common mixing:
- Outflow obstruction in the well child:
- Outflow obstruction in the sick infant:
Give some examples of left to right shunts
- Left-to-right shunts:
- Atrial septal defects (ASD)
- Ventricular septal defects (VSD)
- Persistent ductus arteriosus (PDA)
Give some examples of right to left shunts
- Right-to-left shunts:
- Tetralogy of Fallot (ToF)
- Transposition of the great arteries (ToGA)
- These cause cyanotic congenital heart disease
Give some examples of common mixing conditions
- Common mixing:
- Atrioventricular septal defect (complete) (AVSD)
- Complex congenital heart disease, e.g. tricuspid atresia
Give some examples of outflow obstruction in the well child
- Outflow obstruction in the well child:
- Aortic stenosis
- Pulmonary stenosis
- Adult-type coarctation of the aorta
Give some examples of outflow obstruction in the sick infant
- Outflow obstruction in the sick infant:
- Coarctation of the aorta
- Interruption of the aortic arch
- Hypoplastic left heart syndrome
What are some findings in ECGs in children that are unhelpful/normal?
ECG in children:
- P-wave morphology is rarely helpful in children
- Partial RBBB – most are normal in children (but it is common in ASD)
- Sinus arrhythmia is a normal finding
Name the non-cyanotic congenital heart conditions
- Patent ductus arteriosus (PDA)
- Ventricular septal defect (VSD)
- Atrial septal defect (ASD)
- Atrioventricular septal defect (AVSD)
- Coarctation of the aorta
Name the cyanotic congenital heart conditions
- Transposition of the great arteries
- Tetralogy of Fallot
- etc
What is patent ductus arteriosus (PDA)?
Persistence of a foetal structure, the ductus arteriosus, after birth
What is the aetiology of patent ductus arteriosus (PDA)?
- The ductus arteriosus connects the pulmonary artery to the descending aorta → allows blood to bypass the lungs in utero In term infants, it usually closes shortly after birth
- In the foetus, its patency is maintained by a low O2 environment and circulating prostaglandins produced by the placenta (PGE2 and PG12)
- After birth, O2 sats increase (constriction of duct through K-mediated channels) and level of circulating prostaglandins falls (as placenta is removed from circulation)
- In PDA, it has failed to close by 1 month after the expected date of delivery
- Due to a defect in the constrictor mechanism of the duct
- The blood flow across the PDA is then from the aorta to the pulmonary artery (L to R) due to the fall in pulmonary vascular resistance at birth (so pressure in aorta is higher)
- Larger ducts can lead to pulmonary HTN (due to lots of blood being shunted) In preterm infants, the presence of a PDA is not due to congenital heart disease (it is due to prematurity)
What are the RFs for patent ductus arteriosus?
- prematurity,
- maternal rubella,
- FHx,
- living at high altitude
Summarise the epidemiology of patent ductus arteriosus
- 1/1000 in term infants (very common in preterm infants)
- F>M
What are the signs and symptoms of patent ductus arteriosus?
- Usually asymptomatic
- If the duct is large → increased pulmonary blood flow with HF and pulmonary HTN
- On examination:
-
Continuous murmur at upper left sternal edge/beneath left clavicle - sounds ‘mechanical’
- Murmur is continuous because pulmonary artery pressure is lower than aortic throughout the cardiac cycle
-
Continuous murmur at upper left sternal edge/beneath left clavicle - sounds ‘mechanical’
- Increased pulse pressure → causes a collapsing or bounding pulse
What are the Ix for ?PDA?
-
CXR
- Usually normal
- If large, same features as large VSD
-
ECG
- Usually normal
- If large, same features as large VSD
-
Echo and Doppler USS
- Diagnostic
What is the Mx of PDA?
In preterm infants: COX inhibitors (IV indometacin or ibuprofen) to help closure
In all infants:
- Pharmacological treatment of HF until correction (if necessary) e.g. Diuretics, captopril, digoxin
-
Closure with coil or occlusion device introduced via cardiac catheter
- At 1yo
- Recommended regardless of shunt size to reduce lifelong risk of infective endocarditis and pulmonary HTN
- Occasionally, surgical ligation is required (if large ducts or symptomatic infants too small for device closure)
What is the Mx of PDA?
In preterm infants: COX inhibitors (IV indometacin or ibuprofen) to help closure
In all infants:
- Pharmacological treatment of HF until correction (if necessary) e.g. Diuretics, captopril, digoxin
-
Closure with coil or occlusion device introduced via cardiac catheter
- At 1yo
- Recommended regardless of shunt size to reduce lifelong risk of infective endocarditis and pulmonary HTN
- Occasionally, surgical ligation is required (if large ducts or symptomatic infants too small for device closure)
What are the complications of PDA?
- Faltering growth (if duct starts to dilate)
- Infective endocarditis, endarteritis
- Pulmonary HTN
- Congestive HF
- In preterm infants, associated with RDS, NEC and pulmonary haemorrhage
What is the prognosis of PDA?
Prognosis is excellent if closed
What is an ASD?
An opening in the atrial septum, excluding a parent foramen ovale
What are the 2 types of ASD?
There are 2 main types → presentation is similar but anatomy is different:
-
Secundum ASD (80%)
- Defect in the centre of the of the atrial septum, in the region of the foramen ovale
-
Partial atrioventricular septal defect (AVSD or primum ASD)
- Defect of the atrioventricular septum, characterised by:
- An interatrial communication between the bottom end of the atrial septum and the atrioventricular valves (primum ASD)
- Abnormal atrioventricular valves, with a L AV valve which has 3 leaflets and tends to leak (regurgitant valve)
- Defect of the atrioventricular septum, characterised by:
What is the aetiology/pathophysiology of ASD?
In infancy, the R heart is relatively thick and non-compliant and has higher pressure than the L side, so there is minimal L to R shunting
- As pulmonary vascular resistance decreases, the R heart becomes more compliant → L to R shunt increases
- With age, the L to R shunt is exacerbated by increasing stiffness of the L ventricle (due to ageing and systemic HTN) à R atrium, R ventricle and pulmonary arteries enlarge due to the increased volume load
What are the RFs for an ASD?
- maternal alcohol consumption,
- FHx (some causative mutations have been found)
- Most are spontaneous with no FHx of congenital heart defects
What are the signs and symptoms of an ASD?
- Usually asymptomatic
- Recurrent chest infections/wheeze
- Failure to thrive (10%)
- On examination:
- Ejection systolic murmur at upper L sternal edge (due to increased flow across pulmonary valve)
- Fixed widely split 2nd HS; doesn’t become single with expiration (due to RV SV being equal in inspiration and expiration)
- Pansystolic murmur at apex in partial AVSD (due to AV valve regurgitation)
What are the Ix for ?ASD?
-
CXR
- Cardiomegaly
- Enlarged pulmonary arteries; increased pulmonary vascular markings
-
ECG
- Secundum ASD:
- Partial RBBB is common (but may occur in normal children)
- R axis deviation due to RV enlargement
- Partial AVSD:
- Superior (left) axis deviation (mainly negative in AVF)
- Occurs because there is a defect of the middle part of the heart where the AVN is à displaced AVN conducts to the ventricles superiorly, giving the abnormal axis
- Superior (left) axis deviation (mainly negative in AVF)
- Secundum ASD:
-
Echo and Doppler USS
- Diagnostic
What is the Mx of an ASD?
Observation:
- For all patients à defect may close or shrink
- If small, closure is not required
- Treatment is done if significant ASD (large enough to cause RV dilatation), around 3-5yo
Secundum ASD:
- Cardiac catheterisation with insertion of an occlusive device
Partial AVSD:
- Surgical correction
Prophylactic antibiotics (amoxicillin) to prevent endocarditis
- For 6 months after catheterisation/surgical closure
- Also given before any procedure that could cause bacteraemia
What are the complications of ASD?
Complications:
- Device erosion (after repair)
- Infective endocarditis
- Eisenmenger’s syndrome
- Arrhythmias (from 4th decade)
- Congestive HF (in <10% infants; or 5th decade)
What is Eisenmenger’s syndrome ?
- Eisenmenger syndrome (ES) refers to the combination pulmonary HTN and abnormal blood flow through the heart.
- ES most often occurs in those with congenital heart defects that are not repaired in childhood.
- The most common type of heart defect associated with Eisenmenger syndrome is a ventricular septal defect, but other types of heart defects can lead to Eisenmenger syndrome.
- The symptoms include cyanosis, clubbing and SOB. T
- The symptoms of ES typically get worse over time.
- Tx for severe ES: heart and lung transplant
What is the prognosis of ASD?
- Excellent prognosis for uncomplicated ASDs closed surgically
- Poor prognosis for later complications, e.g. Eisenmenger’s syndrome
What is a ventricular septal defect (VSD)?
Defects in the inter-ventricular septum that allow shunting of blood between the L and R ventricles
What is the aetiology of VSD?
There is a defect anywhere in the ventricular septum →
- perimembranous (adjacent to the tricuspid valve – 70%)
- or muscular (completely surrounded by muscle)
Categorised according to size:
- Small (80%): smaller than the aortic valve in diameter (up to 3mm)
- Leads to minimal L to R shunting, and doesn’t cause increased pulmonary vascular resistance
- Large: same size or bigger than aortic valve
- Leads to L to R shunting à pulmonary HTN
- Gradually, the pulmonary vascular resistance rises à decreased shunting (and ultimately shunt reversal) à R HF (Eisenmenger’s syndrome)
How are VSDs categorised?
Categorised according to size:
-
Small (80%): smaller than the aortic valve in diameter (up to 3mm)
- Leads to minimal L to R shunting, and doesn’t cause increased pulmonary vascular resistance
-
Large: same size or bigger than aortic valve
- Leads to L to R shunting → pulmonary HTN
- Gradually, the pulmonary vascular resistance rises à decreased shunting (and ultimately shunt reversal) à R HF (Eisenmenger’s syndrome)
What are the RFs for VSD?
- FHx,
- some genetic abnormalities (e.g. Down’s),
- maternal alcohol consumption during pregnancy
What is the epidemiology of VSD?
Common → 30% of congenital heart disease
What are the signs and symptoms of a small VSD?
Small VSD:
- Asymptomatic
- On examination:
-
Loud pansystolic murmur at lower L sternal edge
- Loud murmur implies smaller defect due to increased resistance to flow
-
Loud pansystolic murmur at lower L sternal edge
What are the signs and symptoms of a large VSD?
Large VSD:
- HF after 1wk old → breathlessness, growth faltering
- Recurrent chest infections
- On examination:
- Tachypnoea, tachycardia, hepatomegaly (from HF)
- Active precordium
- Soft murmur or no murmur (implies large defect)
- Loud pulmonary component of 2nd HS (sign of pulmonary HTN)
What are the Ix of a VSD?
-
CXR
- Small VSD: normal
- Large VSD:
- Cardiomegaly
- Enlarged pulmonary arteries, increased pulmonary vascular markings
- Pulmonary oedema
-
ECG
- Small VSD: normal
- Large VSD:
- Biventricular hypertrophy by 2mo
- Upright T wave in V1 suggests pulmonary HTN
-
Echo and Doppler USS
- Diagnostic
- Shows the precise anatomy of the defect and its haemodynamic effects (using Doppler)
- Small VSD: no pulmonary HTN
- Large VSD: pulmonary HTN (due to high flow)
What is the Mx of a small VSD?
Small VSD:
- Don’t need correction (they close spontaneously)
- Follow-up:
- Disappearance of murmur
- Normal ECG and echo
- Prevention of bacterial endocarditis by maintaining good dental hygiene
What is the Mx of a large VSD?
Large VSD:
- Additional calorie input
- Pharmacological treatment of HF prior to surgery:
- Diuretics (furosemide)
- Captopril
- Digoxin
- Surgery:
- At 3-6mo
- Prophylactic antibiotics (amoxicillin) to prevent endocarditis
- For 6 months following closure, and consider in any procedures that can cause bacteraemia
What are the complications and prognosis of VSDs?
Complications:
- Small VSD:
- Infective endocarditis
- Large VSD:
- Infective endocarditis
- Eisenmenger’s syndrome
- Aortic regurgitation (if defect is near aortic valve)
- Heart block (if surgery affects conducting tissue)
Small VSD has excellent prognosis à 50% close spontaneously; asymptomatic even if they persist
Lage VSD has excellent prognosis if closed early, but lead to Eisenmenger’s syndrome if not repaired
What is a complete atrioventricular septal defect?
A congenital heart defect where there is a large hole between the atria and ventricles in the middle of the heart
This is a common mixing condition
What are the two types of AVSD?
AVSD can be partial or complete
- Partial is a primum ASD (discussed in ASD)
-
Complete AVSD:
- Defect in the middle of the heart with a single five-leaflet (common) valve between the atria and ventricles à this large hole in the centre of the heart means blood can flow between all 4 chambers
- It stretches across the entire AV junction
- The valves tend to leak (may not be formed correctly)
- As there is a large defect, there is pulmonary hypertension
What are the RFs for ASVD?
- Down’s,
- FHx,
- maternal DM/alcohol etc.
What is the epidemiology of ASVD?
Most common in children with Down’s syndrome (40% of children with Down’s)
4-5% of all congenital heart disease
What are the signs and symptoms of ASVD?
- Usually presents on antenatal USS screening, or on routine echo of patient with Down’s
- Cyanosis at birth or HF at 2-3wks of life
- On examination:
- No murmur (because large defect)
What are the Ix for an ASVD?
-
CXR
- Cardiomegaly
- Increased pulmonary vascular markings
-
ECG
- Superior (left deviation) axis
- Echo and Doppler USS
What is the Mx of an ASVD?
Medical management of HF:
- Furosemide
- Captopril
- Digoxin
Surgery:
- Repair at 3-6mo
- Common valve is separated into 2 valves (pulmonary and mitral)
Life-long follow-up for complications
What are the complications and prognosis of an ASVD?
Complications:
- Pulmonary HTN
- Eisenmenger syndrome
- Congestive HF
- Progressive AV valve regurgitation
Prognosis is generally good with surgical correction
What is coarctation of the aorta?
Narrowing of the aorta, most commonly at the site of insertion of the ductus arteriosus (just distal to the L subclavian artery)
What are the 3 types of coarctation of the aorta?
May be adult-type (postductal) or infantile (juxtaductal)
Adult-type (postductal):
- A cause of outflow obstruction in the well child
- Not duct-dependent
- Gradually becomes more severe over many years (can be clinically silent for a long time)
- Collateral blood vessels often enlarge to provide a route for blood to bypass the narrowed aorta
- Associated with HTN
Infantile (juxtaductal):
- A cause of outflow obstruction in the sick infant
- Due to arterial duct tissue encircling the aorta just at the point of insertion of the duct
- When the duct closes, the aorta also constricts, causing severe obstruction of left ventricular outflow
- Leads to low-output HF and shock when duct closes
May also be pre-ductal → seen in 5% infants with Turner’s syndrome
- Associated with hypoplasia of the aortic arch
What are the RFs for coarctation of the aorta?
- FHx,
- male,
- Turner’s syndrome,
- DiGeorge syndrome
What are the signs and symptoms of adult-type coarctation of the aorta?
Adult-type:
- Asymptomatic
- On examination:
-
HTN in arms (presenting at young age, resistant to treatment)
- Higher BP in arms than legs (because BP increases above the constriction (subclavian arteries supplying the arms branch before constriction but there is less blood flow to aorta after the constriction, which supplies the legs)
-
Radio-femoral delay
- Due to blood bypassing the obstruction via collaterals in chest wall → pulse in legs is delayed
- Ejection systolic murmur at upper sternal edge
- Continuous murmur between scapulae
-
HTN in arms (presenting at young age, resistant to treatment)
What are the signs and symptoms of infantile coarctation of the aorta?
Infantile:
- Examination on 1st day of life is usually normal
- Acute circulatory collapse at 2 days of age (when duct closes) à severe HF
- Absent femoral pulses
- Severe metabolic acidosis
What are the Ix for coarctation of the aorta?
-
Adult-type:
- Rib-notching due to development of large collateral intercostal arteries running under the ribs posteriorly to bypass the obstruction
- In teenagers and adults
- ‘3 sign’ – visible notch in the descending aorta at the site of coarctation
- Infantile:
- Cardiomegaly from HF and shock
- Rib-notching due to development of large collateral intercostal arteries running under the ribs posteriorly to bypass the obstruction
-
ECG
- Adult-type:
- L ventricular hypertrophy à deep S in V2, tall R in V6, upright T wave
- Infantile:
- Normal
- Adult-type:
-
Echo and Doppler USS
- For diagnosis
What is the Mx of coarctation of the aorta?
Adult-type:
- When severe → percutaneous angioplasty and stent insertion
- Sometimes surgical repair is needed
Infantile:
- ABCDE
- Prostaglandin infusion to maintain ductal patency
- Referral to cardiac centre for early surgical intervention
- Surgical repair performed ASAP after diagnosis
- Surgical repair is preferred in neonates (as opposed to stent) because fewer repeat interventions
What are the complications and prognosis of coarctation of the aorta?
Complications:
- Systemic HTN
- Coronary artery disease (if persistent HTN due to delayed repair)
- Recoarctation after repair
- Aortic aneurysm (due to surgery/stent)
Good prognosis
- May need long-term HTN treatment (even after repair)
- Careful follow-up with cardiologist is needed (as higher incidence of CHD and may have recoarctation)
What is transposition of the great arteries?
A congenital heart defect where the aorta is connected to the R ventricle and pulmonary artery is connected to the L ventricle
What is the aetiology of transposition of the great arteries?
The aorta and pulmonary artery are connected the wrong way around (discordant ventriculo-arterial connection)
- Therefore, the deoxygenated blood is returned to the body and the oxygenated blood is returned to the lungs à there are 2 parallel circulations
- Unless there is mixing of blood between them, this is incompatible with life
- There are various naturally-occurring associated anomalies, e.g. VSD, ASD, PDA, and therapeutic interventions which can achieve this mixing in the short-term
What are the RFs of transposition of the great arteries?
- FHx
- maternal age >40yo
- maternal DM/rubella/alcohol consumption
What is the epidemiology of transposition of the great arteries?
5% of all congenital heart disease à 20/100,000 live births
M>F
What are the signs and symptoms of transposition of the great arteries?
-
Cyanosis
- Usually on day 2 (when ductus arteriosus closes)
- May be profound and life-threatening
- Less severe and presentation delayed if there is mixing from another abnormality, e.g. ASD
- On examination:
- 2nd HS loud and single
- R ventricular heave
- Usually no murmur
What are the Ix for transposition of the great arteries?
-
CXR
- Narrow upper mediastinum with ‘egg on side’ appearance of the cardiac shadow
- Due to anteroposterior relationship of great vessels, narrow vesicular pedicle and hypertrophied R ventricle
- Increased pulmonary vascular markings
- Narrow upper mediastinum with ‘egg on side’ appearance of the cardiac shadow
-
ECG
- Usually normal
-
Echo and Doppler USS
- For diagnosis à shows the abnormal connections and associated abnormalities
What is the Mx for transposition of the great arteries?
Management of the cyanosed neonate:
- ABCDE approach: stabilise the airway, breathing and circulation; artificial ventilation if necessary
- Start prostaglandin infusion (5ng/kg/min)
-
Balloon atrial septostomy
- Emergency; may be life-saving à done in 20%
- Catheter with inflatable balloon at its tip is passed through the umbilical or femoral vein through the R atrium and foramen ovale → inflated in the L atrium and pulled back through the atrial septum → tears the atrial septum and makes the flap of the foramen ovale incompetent → mixing of blood
Surgery:
- For all patients, usually in first few days of life
- Arterial switch procedure → aorta and pulmonary artery are swapped; coronary arteries are also transferred to the new aorta
What are the complications of transposition of the great arteries?
Complications:
- Neopulmonary stenosis (stenosis of the new pulmonary valve)
- Neoaortic regurgitation
- Neoaortic root dilatation
- Coronary artery disease
- Sudden cardiac death (due to arrhythmias)
- Neurodevelopmental abnormalities
What is the prognosis of transposition of the great arteries?
Survival is >90% at 20yo
What is tetralogy of fallot?
A congenital heart malformation:
- VSD with over-riding aorta, and
- RV outflow tract obstruction, and
- resulting RV hypertrophy
What are the 4 cardinal features of tetralogy of fallot?
There are 4 cardinal anatomical features:
- Large VSD
- Overriding of the aorta with respect to the ventricular system (i.e. aorta is in the middle)
- Subpulmonary stenosis causing R ventricular outflow tract obstruction
- R ventricular hypertrophy (as a result of outflow obstruction)
What is the aetiology of tetralogy of fallot?
Cyanosis is due to R to L shunting of deoxygenated blood at the VSD (as the blood from the RV can’t be pumped through the pulmonary artery)
- If there is a large pulmonary obstruction, blood is shunted from the R to L ventricle through the VSD à into the systemic circulation without being oxygenated
- If a small obstruction, there is less cyanosis because more blood is oxygenated and less is shunted
- Until the ductus arteriosus closes, there is shunting from the aorta through the pulmonary circulation à no cyanosis
Hypercyanotic spells are episodes of severe cyanosis associated with hyperpnoea
- They are due to an increase in R ventricular outflow tract obstruction, causing decreased pulmonary blood flow and increased R to L shunting across the VSD
Aetiology is unknown à genetics and environmental
What are the RFs for tetralogy of fallot?
- chromosomal abnormalities (trisomy 21, 18, 13, DiGeorge),
- FHx,
- maternal DM,
- teratogens (retinoic acid)
What is the epidemiology of tetralogy of fallot?
Most common cause of cyanotic congenital heart disease
Accounts for 4-9% of congenital heart defects
What are the signs and symptoms of tetralogy of fallot?
- Degree of cyanosis varies (may not be obvious)
- Classical presentation is in late infancy with severe cyanosis, hypercyanotic spells and squatting on exercise
- Hyper-cyanotic spells are characterised by a rapid increase in cyanosis, with irritability or inconsolable crying, and breathlessness or pallor; there is a very short murmur during a spell
- Rare in developed countries (due to earlier diagnosis; often detected antenatally)
- On examination:
-
Loud ejection systolic murmur at L sternal edge from day 1 of life
- With increasing RV outflow tract obstruction, the murmur shortens and cyanosis increases
- Clubbing (in older children)
- Tachypnoea
-
Loud ejection systolic murmur at L sternal edge from day 1 of life
What are the Ix for tetralogy of fallot?
-
Hyperoxia (nitrogen washout) test
- To help determine presence of heart disease in a cyanosed neonate
- Infant placed in 100% O2 (headbox or ventilator) for 10mins
- If the R radial arterial PaO2 from a blood gas remains low (<15kPa) after this time à diagnosis of cyanotic congenital heart disease can be made if lung disease and persistent pulmonary hypertension of the newborn have been excluded
- If PaO2 >20kPa, it is not cyanotic heart disease
-
CXR
- Relatively small heart
- Uptilted apex (boot shaped) due to R ventricular hypertrophy
- More prominent in older children
- Pulmonary artery ‘bay’
- Concavity on L heart border where the convex-shaped main pulmonary artery and R ventricular outflow tract would usually be
- Decreased pulmonary vascular markings (as reduced pulmonary blood flow)
-
ECG
- Normal at birth
- R ventricular hypertrophy when older
-
Echo and Doppler USS
- For definitive diagnosis → shows carinal features
What is the Mx of a cyanosed neonate with tetralogy of fallot?
Management of the cyanosed neonate:
- ABCDE approach: stabilise the airway, breathing and circulation; artificial ventilation if necessary
- Start prostaglandin infusion (5ng/kg/min)
- Most infants with cyanotic heart disease presenting in the first few days of life are duct-dependent (i.e. there is reduced mixing between the oxygenated blood returning from lungs and deoxygenated blood from the body) à maintenance of ductal patency is key to survival
- Observe for SEs: apnoea, jitteriness, seizures, flushing, vasodilation, hypotension
- Consider balloon atrial septostomy
What is the Mx of hypercyanotic spells in an infant with tetralogy of fallot?
Management of hypercyanotic spells:
- They are self-limiting and followed by sleep
-
If prolonged (>15mins) treat promptly with:
- Sedation and pain relief (morphine)
- IV fluids
- IV propranolol (for peripheral vasoconstriction and to relieve the subpulmonary obstruction)
- Bicarbonate to correct acidosis
- Muscle paralysis and artificial ventilation to reduce metabolic oxygen demand
What is the surgical Mx of tetralogy of fallot?
- Definitive surgery for all patients at around 6mo
- VSD is closed and R ventricular outflow tract obstruction is relieved
- Neonates who are very cyanosed need a shunt to increase pulmonary blood flow → surgical placement of a tube between the subclavian artery and pulmonary artery (modified Blalock-Taussig shunt)
- Antibiotics to reduce risk of infective endocarditis (e.g. cefalexin, amoxicillin)
- Before surgery and before surgical procedures (incl dental) if unrepaired TOF
What are the complications and prognosis of tetralogy of fallot?
Complications:
- Hypercyanotic spells can lead to MI, CVAs and death
- Progressive pulmonary regurgitation and RV failure (in adulthood)
- Arrhythmias later in life
- Sudden cardiac death (from VT/VF)
93% survival at 5yo; 80% survival at 35yo
What is the Mx of an ASVD?
Medical management of HF:
- Furosemide
- Captopril
- Digoxin
Surgery:
- Repair at 3-6mo
- Common valve is separated into 2 valves (pulmonary and mitral)
Life-long follow-up for complications
What is the Mx of an ASVD?
Medical management of HF:
- Furosemide
- Captopril
- Digoxin
Surgery:
- Repair at 3-6mo
- Common valve is separated into 2 valves (pulmonary and mitral)
Life-long follow-up for complications
What is the Mx of an ASVD?
Medical management of HF:
- Furosemide
- Captopril
- Digoxin
Surgery:
- Repair at 3-6mo
- Common valve is separated into 2 valves (pulmonary and mitral)
Life-long follow-up for complications
What are the complications and prognosis of coarctation of the aorta?
Complications:
- Systemic HTN
- Coronary artery disease (if persistent HTN due to delayed repair)
- Recoarctation after repair
- Aortic aneurysm (due to surgery/stent)
Good prognosis
- May need long-term HTN treatment (even after repair)
- Careful follow-up with cardiologist is needed (as higher incidence of CHD and may have recoarctation)
What is pulmonary stenosis?
Obstruction of the blood flow from the R ventricle into the pulmonary artery
A cause of outflow obstruction in the well child
What is the aetiology of pulmonary stenosis?
The pulmonary valve leaflets are partly fused together, causing a restrictive exit from the R ventricle
- The increased pressure in the R ventricle may lead to hypertrophy
- Mild-moderate obstruction is usually well-tolerated à asymptomatic
- If severe-critical → symptoms (because not enough blood is getting oxygenated)
NB a small amount is acquired, due to carcinoid syndrome, myocardial tumours and external compression
What are the RFs for pulmonary stenosis?
- Noonan syndrome,
- other syndromes (e.g. LEOPARD, William’s),
- congenital rubella syndrome
What is the epidemiology of pulmonary stenosis?
8% of all congenital heart disease; up to 30% when in association with other lesions
Commonly associated with other forms of congenital heart disease
What are the signs and symptoms of pulmonary stenosis?
- Usually asymptomatic
- Occasionally neonates present with critical pulmonary stenosis (very severe narrowing) → duct-dependent pulmonary circulation → cyanosis in the first few days of life
- On examination:
- Ejection systolic murmur at upper L sternal edge
-
Ejection click at upper left sternal edge
- The most severe the stenosis, the earlier in systole the click occurs (if very severe it my merge with the 1st HS and become inaudible)
- Thrill
- R ventricular heave (if severe)
What are the Ix for pulmonary stenosis?
-
CXR
- May be normal
- May show post-stenotic dilation of the pulmonary artery
-
ECG
- R ventricular hypertrophy (upright T wave in V1)
- R axis deviation
- Echo and Doppler USS
What is the Mx of pulmonary stenosis?
Management of the cyanosed neonate (in critical disease):
- ABCDE
- Prostaglandins (to maintain patency of ductus arteriosus)
Mx of all patients
-
Transcatheter balloon dilatation (percutaneous balloon pulmonary vavuloplasty)
- Intervention is needed when the pressure gradient across the pulmonary valve becomes markedly increased (>64mmHg), or in critical disease in neonates
- In mild disease no treatment is necessary
- Intervention is needed when the pressure gradient across the pulmonary valve becomes markedly increased (>64mmHg), or in critical disease in neonates
- Antibiotics for endocarditis prophylaxis (for 6 months after repair)
What are the complications of pulmonary stenosis?
- Complications of valvuloplasty: vascular lacerations, tearing of pulmonary valve, arrhythmias, pulmonary valve insufficiency, cardiac perforation
- R HF
- Sudden death (due to limited pulmonary blood flow)
What is the prognosis of pulmonary stenosis?
Excellent prognosis with treatment
- 90% success rate for treatment in infants with critical pulmonary stenosis; 5% complications
What is cardiac failure?
Impaired ability of the ventricles to fill with and/or eject blood
What is the aetiology of cardiac failure?
Causes of HF vary with age:
-
Neonates: obstructed (duct-dependent) systemic circulation à L heart obstruction means flow of blood is predominantly by R-to-L flow by ductus arteriosus à closure of the duct leads rapidly to severe acidosis, collapse and death unless ductal patency is restored
- Caused by hypoplastic left heart syndrome, critical aortic valve stenosis, severe coarctation of aorta, interruption of the aortic arch
-
Infants: high pulmonary blood flow due to L to R shunt à as pulmonary vascular resistance falls over a few weeks of life there is increased shunting à pulmonary oedema and breathlessness à these symptoms increase until 3mo and then may improve as pulmonary resistance rises in response
- Caused by VSD, ASD, AVSD, large PDA
-
Older children/adolescents (R or L HF)
- Eisenmenger syndrome (R HF only)
- In children with a L to R shunt or common mixing à increased pulmonary resistance à irreversibly raised pulmonary vascular resistance due to chronically raised pulmonary arterial pressure and flow à shunt occurs from R to L (reversal) à de-oxygenated blood flows to systemic arterial circulation à cyanosis
- Rheumatic heart disease
- Cardiomyopathy
- Eisenmenger syndrome (R HF only)
Causes that are not related to congenital heart disease include:
- Cardiomyopathy, myocarditis (usually due to viral infection), arrhythmias
- Non-cardiac causes: sepsis, CKD, respiratory disorders (obstructive sleep apnoea, CF), SLE
What are the signs and symptoms of cardiac failure?
- Breathlessness (esp on feeding or exertion)
- Poor feeding/anorexia
- Poor weight gain/growth faltering
- Recurrent chest infections
- On examination:
- Tachypnoea, tachycardia
- Heart murmur, gallop rhythm, enlarged heart
-
Signs of R HF: hepatomegaly, ankle/sacral oedema, ascites
- JVP is not reliable in young children
- Uncompensated CHF: cool peripheries, prolonged capillary refill tie, decreased urine output
What are the Ix for cardiac failure?
- Basic obs
-
Bloods:
- BNP,
- FBC (anaemia may contribute),
- U&Es (renal impairment may contribute, monitor baseline),
- LFTs (may be raised in R HF),
- ABG
-
CXR
- Cardiomegaly
- Increased pulmonary vascular markings
- Pulmonary oedema
-
ECG
- Evidence of myocarditis/cardiac ischaemia or ventricular strain
-
Echo
- Diagnostic for congenital heart disease; assess cardiac function
-
Cardiac catheterisation
- Measures intracardiac pressures and shunts
What is the Mx of acute cardiac failure?
ABCDE approach
- Sit patient up
- Oxygen, consider CPAP
-
Fluid restrict
- If volume depleted, give fluids slowly (boluses of 5-ml/kg)
- Prostaglandin infusion for infants with unexplained shock
Medical management:
- Furosemide (reduce preload)
- ACEi (reduce afterload)
- Beta blockers
- Inotropes (e.g. dobutamine) in decompensated HF (improve CO)
- Digoxin
Management of the underlying condition
What is the Mx of chronic cardiac failure?
For chronic HF:
- Correct anything contributing (anaemia, obesity)
- Nutritional support (may need intermittent or continuous NG feeds)
- Promote exercise
What is the Mx of Eisenmenger syndrome?
Eisenmenger syndrome:
- Treatment is aimed at prevention → early intervention for high pulmonary blood flow
- Only treatment is heart-lung transplant
-
Medication can palliate the symptoms until transplantation
- CCBs (nifedipine, amlodipine)
- Phosphodiesterase type 5 (PDE5) inhibitors (sildenafil)
- Endothelin receptor antagonists (bosentan)
- Prostacyclin analogues (iloprost)
What is the prognosis of cardiac failure? incl Eisenmenger syndrome
Depends on the cause
Eisenmenger syndrome:
- If untreated, death due to R HF (usually in 4th/5th decade)
What is Kawasaki disease?
Acute childhood febrile illness with systemic small and medium vessel vasculitis
What is the aetiology of Kawasaki disease?
Aetiology is unknown but it is thought that an infectious agent may induce disease in genetically susceptible people
- 3 hypotheses:
- Infectious hypothesis: winter-spring seasonality
- Genetic susceptibility hypothesis: more common in Japanese people
- Superantigen hypothesis
- Marked cytokine cascade stimulation and endothelial cell activation leads to systemic vasculitis
What are the RFs for Kawasaki disease?
- Asian ancestry (esp Japanese),
- age 6 months – 4yrs,
- male
What are the signs and symptoms of Kawasaki disease?
-
Fever >5d, usually >39⁰C
- Suspect Kawasaki in prolonged fever; unresponsive to antibiotics
-
4 of the other 5 features of:
- Conjunctivitis
- Mucous membrane changes (pharyngeal injection, red/dry/cracked lips, strawberry tongue)
-
Cervical lymphadenopathy
- The above symptoms are present at the start of the illness for around 2wks
-
Rash (polymorphous)
- Usually a diffuse, maculopapular, erythematous rash
- Begins after a few days; present until middle of 3rd week
-
Extremities:
- Red and oedematous palms and soles (first few days – 2wks)
- Peeling of fingers and toes (desquamation) (after around 2wks)
What are the signs and symptoms of Kawasaki disease?
-
Fever >5d, usually >39⁰C
- Suspect Kawasaki in prolonged fever; unresponsive to antibiotics
-
4 of the other 5 features of:
- Conjunctivitis
- Mucous membrane changes (pharyngeal injection, red/dry/cracked lips, strawberry tongue)
-
Cervical lymphadenopathy
- The above symptoms are present at the start of the illness for around 2wks
-
Rash (polymorphous)
- Usually a diffuse, maculopapular, erythematous rash
- Begins after a few days; present until middle of 3rd week
-
Extremities:
- Red and oedematous palms and soles (first few days – 2wks)
- Peeling of fingers and toes (desquamation) (after around 2wks)
What are the Ix for Kawasaki disease?
- Clinical diagnosis
-
Bloods:
- FBC: anaemia, high WCC with L shift, platelets rise in 2nd week of illness
- ESR/CRP (high)
-
Echo
- For coronary artery dilatation or aneurysm
What is the Mx of Kawasaki disease?
Aims to prevent coronary artery disease and relieve symptoms, by controlling the inflammatory process
- IVIG
- Best results when treatment is started within 10d
- Also indicated in patients who present >10d with RFs for complications (e.g. fever, raised ESR/CRP)
- Single infusion; give 2nd dose if fever persists after 36-48hrs
- If no response to 2nd dose à consider corticosteroids, infliximab or cyclosporin
2. Aspirin
- To lower risk of thrombosis
- Given at a high anti-inflammatory dose (80-100mg/kg/d) until fever subsides and inflammatory markers return to normal; continued at a low antiplatelet dose (3-5mg/kg/d) until echo at 6wks
- If aneurysms on echo à continue aspirin until they regress; start warfarin and thromboprophylaxis (with cardio input)
If child presents after 10d without persistent fever and RFs for coronary aneurysms (normal CRP/ESR, normal echo) → just give aspirin (no IVIG)
What are the complications of Kawasaki disease?
Complications:
-
Myocarditis
- Common
- Rarely causes clinical problems; responds promptly to IVIG
-
Pericarditis with small pericardial effusions
- Occurs in 25% before IVIG; resolves completely with IVIG
-
Coronary artery aneurysm
- Due to development of an acute coronary vasculitis
- Develop in 20-25% untreated patients; 3% if treated with IVIG (prompt treatment reduces incidence)
- Subsequent narrowing of the vessels from scar formation can lead to myocardial ischaemia and sudden death
What is the prognosis of Kawasaki disease?
- It is self-limiting
- Unless there is coronary artery aneurysm → increased risk ischaemia or thrombosis
- Overall mortality with treatment 0.5%