Paediatric Cardiology Flashcards
State and describe the 3 types of foetal shunts
- Foramen ovale - links right atrium to left atrium (bypass right ventricles and pulmonary circuit)
- Ductus arteriosus - links pulmonary artery to aorta (bypass pulmonary circuit)
- Ductus venous - links umbilical vein to inferior vena cava (bypass liver)
For the 3 types of foetal shunts, describe how they are closed
- Foramen ovale
- First breaths of life expand the alveoli, decreasing pressure in pulmonary circuit and subsequent fall in right atrial pressure
- This causes the LA pressure > RA pressure, squashing the atrial septum
- Structurally closes some weeks later to become the fossa ovalis - Ductus arteriosus
- When the baby takes it’s full breath, the blood becomes more oxygenated
- This causes prostaglandin levels to drop (prostaglandins are needed to keep ductus arteriosus to remain open)
- Drop in prostaglandin level causes closes of the ductus arteriosus, which becomes the ligamentum arteriosum - Ductus venosus
- Immediately after birth, umbilical cord is clamped
- There is no flow in the umbilical veins, therefore the ductus venosus stops functioning
- Ductus venosus becomes the ligamentum venosum a few days later
State some ‘S’s of innocent / flow murmurs in children
- Short
- Soft
- Systolic
+ - Symptomless
- Situation dependent e.g. quieter with standing, or only present when child is ill
State when incidental innocent / flow murmurs should be investigated in children and suggest some investigations
Indications for investigation:
May not need any if clear innocent murmur with no concerning features
- Additional symptoms e.g. failure to thrive, cyanosis, SOB, feeding difficulties
- Diastolic murmur
- Murmur louder than 2/6
Investigations:
- ECG
- Echocardiogram
- Chest x-ray
Suggest some cardiac abnormalities which could cause a pan-systolic murmur
- Mitral regurgitation (loudest mitral area)
- Tricuspid regurgitation (loudest tricuspid area)
- Ventricular septal defect (left lower sternum)
Suggest some cardiac abnormalities which could cause an ejection-systolic murmur
- Aortic stenosis
- Pulmonary stenosis
- Hypertrophic obstructive myopathy
State the murmur heard in atrial septal defects
Mid-systolic, crescendo-decrescendo
Loudest at upper left sternal border, fixed split secondary heart sound
State the murmur heard in patent ductus arteriosus
May not cause any abnormal heart sounds
Continuous crescendo-decrescendo ‘machinery’ murmur (can make second heart sound hard to hear)
State the murmur heard in Tetralogy of Fallot
Ejection systolic murmur
Loudest in pulmonary area, left 2nd ICS at sternal border
Categorise which congenital heart defects cause
1. Left-to-right shunt (acyanotic heart disease)
2. Right-to-left shunt (cyanotic heart disease)
- Left-to-right shunt (acyanotic heart disease)
- Atrial septal defect (ASD)
- Ventricular septal defect (VSD)
- Patent ductus arteriosus (PDA)
- Obstructive lesions e.g. coarctation of the aorta, aortic / pulomnary / mitral stenosis - Right-to-left shunt (cyanotic heart disease)
- Tetralogy of Fallot
- Transposition of the great arteries
Why aren’t patients with atrial septal defects, ventricular septal defects or patent ductus arteriosus always cyanotic
Because the pressure on the LEFT side of the heart is greater than the right, therefore blood still flows from the LEFT to the right
However if pulmonary pressure increases, then blood flows from RIGHT to left causing cyanosis = Eisenmenger Syndrome
Patent ductus arteriosus - state the following:
- Normal situation (non-patent)
- Pathophysiology
- Presentation
- Murmur heard
- Diagnosis
- Management
Normal situation (non-patent):
- At birth, corticosteroid production drops which causes a closure of the ductus arteriosus
- By 2-3 weeks, this has structurally closed
Pathophysiology:
- Patent ductus arteriosus occurs due to a failure of the ductus arteriosus to close
- Unclear why, but linked to prematurity, genetics or maternal infections e.g. Rubella
- Shunt of blood from LA to RA
- Overtime this leads to right sided overload and right heart strain
- Small PDAs may be asymptomatic and close spontaneously, or may not close and cause adult heart failure
Presentation:
Can be picked up on newborn examination
- Heart murmur
- SOB
- Recurrent LRTIs
- Poor weight gain
- Difficulty feeding
Murmur heard:
- Continuous ‘machinery’ crescendo-decrescendo murmur
Diagnosis:
- Echocardiogram
- Doppler flow studies
Management:
- Referral to paediatric cardiologist
- Monitored until 1 year, with echos (after 1 year, unlikely to close spontaneously)
- Trans-catheter or open surgical closure
Atrial septal defect - state the following:
- Normal situation (non-patent)
- Pathophysiology
- Presentation
- Murmur heard
- Diagnosis
- Management
Normal situation (non-patent)
- First breaths of life decreases the pressure in pulmonary circuit
- This causes the LA pressure > RA pressure, squashing the atrial septum
- Structurally closes some weeks later to become the fossa ovalis
Pathophysiology:
- Failure of the foramen ovale to close
- Shunt of blood from LA to RA
- Overtime this leads to right sided overload and right heart strain
- Eventually pulmonary hypertension can lead to Eisenmenger syndrome and cyanosis
Presentation:
Can be picked up on newborn examination
- Heart murmur
- SOB
- Tachypnoea
- Recurrent LRTIs
- Poor weight gain
- Difficulty feeding
Murmur heard:
- Mid-systolic crescendo-decrescendo
- Loudest at upper left sternal border
- Fixed split second heart sound
Diagnosis:
- Echocardiogram
- Cardiac MRI and CT
Management:
- Referral to paediatric cardiologist
- If small and asymptomatic, watch and wait
- Trans-catheter or open surgical closure
- Anticoagulation to reduce risk of strokes in adults
List 3 types of atrial septal defect (from most common to least common)
- Ostium secondum - septum secondum fails to completely close, leaving a hole in the wall
- Patent foramen ovale - foramen ovale fails to fully close
- Ostium primum - septum primum fails to completely close, leaving a hole in the wall
State some potential complications of atrial septal defects
- Stroke from DVT
- Atrial fibrillation
- Right sided heart failure and pulmonary HTN
- Eisenmenger syndrome
State some risk factors for development of atrial septal defects
- Diabetes
- Rubella
- Maternal smoking in 1st trimester
- Maternal drug use e.g. cocaine & alcohol
- Treacher-Collins syndrome
- Thrombocytopenia-absent radii syndrome (TAR syndrome)
Name 2 genetic conditions that are associated with ventricular septal defects
- Down’s syndrome
- Turner’s syndrome
Ventricular septal defects - state the following:
- Pathophysiology
- Presentation
- Murmur heard
- Management
Pathophysiology:
- Hole in the septum separating the ventricles
- Can be either a partial or entire septal defect
Presentation:
Can be picked up on newborn examination
Often initially asymptomatic and can present in adulthood
- Heart murmur
- SOB
- Tachypnoea
- Poor weight gain
- Difficulty feeding
Murmur heard:
- Pan-systolic murmur
- Left lower sternal border, 3rd and 4th ICS
- May be systolic thrill on palpation
Management:
- Referral to paediatric cardiologist
- If small and asymptomatic, watch and wait
- Trans-catheter or open surgical closure
Higher risk of infective endocarditis - will need prophalactic antibiotics during surgery
- May use diuretics e.g. Furosemide or ACEi
State 3 differentials for a pan-systolic murmur
- Ventricular septal defect
- Mitral regurgitation
- Tricuspid regurgitation
State some risk factors for developing a ventricular septal defect
- Diabetes
- Rubella
- Maternal alcohol use
- Family history of VSD
- Chromosomal trisomys (Down’s syndrome, Patau syndrome and Edwards syndrome)
Briefly describe Eisenmenger’s Syndrome and at what age it can occur
Condition where the pressure in the right ventricle exceeds that of the left ventricle
- Caused by a gradual increase in the pulmonary vascular resistance (pressure in pulmonary circuit)
- The change in pressure reverses the shunt (from LV to RV) to RV to LV
- This causes deoxygenated blood from the right ventricle to enter the systemic circulation
= Cyanosis
Can occur after 1-2 years with a significant shunt
Can occur in adulthood if the shunt is small
List 3 defects that can lead to Eisenmenger’s Syndrome
- Atrial septal defect (ASD)
- Ventricular septal defect (VSD)
- Patent ductus arteriosus (PDA)
List examination findings for patients with pulmonary hypertension and if they’ve had chronic hypoxia (R to L shunt)
- Raised JVP
- Peripheral oedema
- Right ventricle heave
- Loud second heart sound
- Heart murmur associated with underlying septal defect
If chronic hypoxia (R to L shunt):
- Cyanosis
- Clubbing
- SOB
- Red complexion (related to polycythaemia)
Outline some complications of Eisenmenger syndrome and how having the condition impacts on life expectancy
- VTE / thromboembolism
- Heart failure
- Infection
- Haemorrhage
Reduces life expectancy by ~20 years :(
Outline some management steps for Eisenmenger syndrome
Ideally, steps need to be taken to prevent the development by correcting underlying defect
Only definitive management: heart-lung transplant (high mortality!)
Other options:
- Oxygen (symptomatic relief)
- Anticoagulation (thrombosis)
- Prophylactic antibiotics (infective endocarditis)
- Sildenafil (for pulmonary HTN)
- Venesection (polycythaemia)
Coarctation of the aorta - state the following:
- Pathophysiology
- Presentation
- Management
Pathophysiology:
- Narrowing of the arch of the aorta, commonly around the area of the ductus arteriosus
- Reduces the pressure distal to the narrowing, but decreases the pressure proximal to the narrowing
- Severity of the narrowing can vary
- Associated with Turner’s syndrome in particular
Presentation:
- Weakness of femoral pulses
- May have systolic murmur
- Tachypnoea
- Poor feeding
- Grey/floppy baby
Over time, may have underdevelopment of legs and left arm
Management:
Depends on severity!
- Mild = may be asymptomatic until adulthood
- Severe = may require emergency surgery after birth (give prostaglandin E)
Aortic valve stenosis - state the following:
- Pathophysiology
- Presentation
- Diagnosis
- Management
Pathophysiology:
- Narrow aortic valve, restrict blood from left ventricle to aorta
Presentation:
May be asymptomatic if mild
- Ejection systolic murmur, radiating to carotids (loudest in aortic area)
- SOB
- Fatigue
- Dizziness
- Fainting
Symptoms are typically worse on exertion
Diagnosis:
- Echocardiogram
Management:
- Referral to paediatric cardiologist
- Regular follow ups with ECGs, exercise testing and echocardiograms
- Percutaneous balloon valvoplasty
- Surgical aortic valvotomy / valve replacement
Pulmonary valve stenosis - state the following:
- Pathophysiology
- Presentation
- Diagnosis
- Management
Pathophysiology:
- Narrow aortic valve, restrict blood from right ventricle to pulmonary artery
- Occurs if the normal 3 leaflet valve develops abnormally (thickened or fused)
Presentation:
Often completely asymptomatic, found on routine baby checks
- Ejection systolic murmur (loudest in pulmonary area)
- Palpable thrill (in pulmonary area)
- Right ventricle heave
- Raised JVP
- SOB
- Fatigue
- Dizziness
- Fainting
Diagnosis:
- Echocardiogram
Management:
- Referral to paediatric cardiologist
- If mild, generally don’t need intervention, can take watch and wait approach
- If significant or symptomatic, percutaneous balloon valvoplasty (open surgery if fails)
State some complications of aortic valve stenosis
- Left ventricular outflow tract obstruction
- Heart failure
- Ventricular arrhythmias
- Infective endocarditis
- Sudden death
State some conditions that are associated with pulmonary valve stenosis
- Rubella
- Tetralogy of Fallot
- William syndrome
- Noonan syndrome
Tetralogy of Fallot - state the following:
- Pathophysiology
- Presentation
- Diagnosis
- Management
Pathophysiology:
Congenital condition with 4 concurrent issues
1. Ventricular septal defect
2. Overarching aorta
3. Pulmonary valve stenosis
4. Right ventricular hypertrophy
- Causes a right to left shunt and cyanosis (level depends on severity of TOF)
Presentation:
- Ejection systolic murmur (loudest in pulmonary area)
- Cyanosis
- Clubbing
- Poor feeding
- Poor weight gain
- ‘Tet’ spells
Diagnosis:
- Echocardiogram
- Doppler flow study
Management:
- Referral to paediatric cardiologist
- In neonates, use prostaglandin infusion to maintain the ductus arteriosus
- Open heart surgery to repair at around 6 months
State some potential risk factors for developing Tetralogy of Fallot
- Rubella
- Diabetes
- Maternal age > 40
- Alcohol during pregnancy
Describe what change might be seen on chest x-ray in Tetralogy of Fallot
Boot shaped heart (due to right ventricle thickening)
Describe what a ‘tet’ spell is in Tetralogy of Fallot, how it presents and how it can be managed in the acute phase
Periods where a Tetralogy of Fallot patient becomes temporarily symptomatic, caused by the right-to-left shunt worsening = cyanotic episode
Precipitating episodes:
- Crying
- Physical exercise
- Waking
Caused by either an increase in the pulmonary resistance or a fall in the systemic resistance, causes more blood to be pumped to the aorta (rather than the pulmonary artery)
Presentation:
- Cyanosis
- SOB
- Irritable
In severe cases: reduced consciousness, seizures, death
Management = aim to increase systemic pressure:
- Squat / bring knees to chest
- Supplementary O2
- Beta blockers
- IV fluids
- Morphine (reduced respiratory rate)
- Sodium bicarbonate
- Phenylephrine infusion
State some potential complications of Tetralogy of Fallot if left untreated
- Infective endocarditis
- Congestive cardiac failure
- Stroke
- Polycythaemia
- Cerebral abscess
Death (up to 25% in the 1st year of life)
Transposition of the great arteries - state the following:
- Pathophysiology
- Presentation
- Diagnosis
- Management
Pathophysiology
- Condition where the right ventricle connects to the aorta attaches and the left ventricle connects to the pulmonary artery
- This creates 2 separate circuits, one is a systemic circuit (right ventricle) and the other is a pulmonary circuit (left ventricle)
Presentation:
Often picked up during antenatal scans during pregnancy
If not, babies will develop the following a few days after birth
- Cyanosis
- Respiratory distress
- Tachycardia
- Poor feeding
- Sweating
Management:
- Prostaglandin infusion
- Emergency balloon septostomy (creates atrial septal defect)
- Definitive management = open heart surgery, arterial switch operation
State some rough potential causes of a blue baby
- Congenital heart problems (most commonly Tetralogy of Fallot or also transposition of the great arteries)
- Respiratory distress from lung disease e.g. asthma or foreign body
