Paediatric cardiology Flashcards
Where does foetal blood get oxygen and nutrients and dispose of CO2 an lactate?f
-The placenta
What is the ductus arteriosus?
-Shunt in foetal circulation that allows blood to pass from the aorta to the pulmonary artery.
what is the foramen ovale?
-Foetal shunt that allows blood to pass from the right to the left atrium
What is the ductus venosus ?
-Foetal shunt that allows blood to pass from the umbilical vein the to inferior vena cava and bypass the liver
What happens to the patent foramen ovale at birth ?
- When the baby takes its first breath, the alveoli expand decreasing pulmonary vascular resistance
- This causes the pressure in the right atrium to fall
- As left atrial pressure is then greater than right atrial pressure, it squashes the atrial septum closing the foramen ovale
What happens to the ductus arteriosus at birth ?
- The increased blood oxygenation causes a drop in prostaglandins
- As prostaglandins are required to keep it open, it causes it to close
What is a patent ductus arteriosus ?
-When the ductus arteriosus fails to close at birth
How does a PDA present? (5)
- SOB
- Difficulty feeding
- Poor weight gain
- LRTI
- Murmur picked up on newborn examination
What murmur does a significant PDA cause?
- Continuous crescendo-decrescendo ‘machinery’ murmur that may continue to the second heart sound.
- Murmur heard at upper left sternal edge
- Normal first heart sound
How is a PDA managed ?
- Monitored with echoes until 1 yr
- Indomethacin / ibuprogen to inhibit prostaglandins and also closure
- Trans catheter or surgical closure
Explain the pathophysiology as to why a PDA leads to heart failure
- It creates a left to right shunt : pressure is greater in the aorta and so blood flows from here to the pulmonary vessels
- This leads to pulmonary hypertension and right sided heart strain as the RV struggles to contract against the increased resistance
- This leads to right ventricular hypertrophy
- Increased blood flow through pulmonary vessels returning to the left side of the heart leads to left ventricular hypertrophy
Give 2 RF for PDA
- Prematurity
- Maternal infections such as rubella
What is the most common kind of ASD?
-Ostium secondum : the septum secondum fails to fully close leaving a hole in the wall
Name 2 other kinds of ASD
- Patent foramen ovale
- Ostium primum : this tends to lead to an atrioventricular valve defect, making it an atrioventricular septal defect
What is the most common congenital heart defect in adults?
-Ostium secundum
What kind of ASD is seen in 25% of people with downs syndrome ?
-Ostium primum
Is an ASD an acyanotic or cyanotic heart defect?
- Acyanotic
- Blood still flows to the pulmonary vessels and lungs to get oxygenated
What murmur is heard in an ASD?
-Mid systolic, crescendo-descrendo murmur heart loudest at the upper left sternal border
What happens to the 2nd heart sound in an ASD?
- Fixed split second heart sound
- This is because there is a greater volume of blood passing by the pulmonary valve
- This means there is a slight delay in it closure compared to the aortic valve
- However, this is on both inspiration and expiration
If an ASD is not picked up on newborn examinations, how might it present in childhood ?
- SOB
- Difficulty feeding
- Poor weight gain
- LRTI
If asymptomatic in childhood, how might an ASD present in adulthood ?
- Dyspnoea
- Heart failure
- Stroke
Why is stroke a common complication of patients with an ASD who develop a venous thromboembolism ?
- The clot travels to the right atrium passes through the ASD to the left atrium
- From here, left ventricle, aorta and up to the brain
Give 4 complications of an ASD
- Stroke
- AF and atrial flutter
- Pulmonary HTN and right sided HF
- Eisenmenger syndrome
What medications are given to adults with an ASD to reduce the risk of clots and strokes
-Anticoagulant : aspirin, warfarin, DOACs
What 2 genetic conditions are commonly associated with VSD?
- Down’s syndrome
- Turner’s syndrome
What murmur is often heard in antenatal scans in VSD?
- Pan-systolic
- More prominent at the left lower sternal border in the third and fourth intercostal spaces
- Possible systolic thrill on palpation
Give 3 causes of a pan-systolic murmur
- Ventricular septal defect
- Mitral regurgitation
- Tricuspid regurgitation
If not picked up as a newborn, how might a VSD present?
- Poor feeding
- Dyspnoea
- Tachypnoea
- Failure to thrive
What a patients with a VSD at increased risk of ?
- Infective endocarditis
- If having surgery, prophylactic antibiotics should be given
What is Eisenmenger syndrome ?
-When blood flows from the right to the left side of the heart through a structural lesion, bypassing the lungs
What 3 underlying lesions can cause Eisenmenger syndrome ?
- Atrial septal defect
- Ventricular septal defect
- Patent ductus arteriosus
Explain the pathophysiology behind why Eisenmenger syndrome develops
- ASD or VSD allows left -> right shunt
- This leads to pulmonary HTN
- Eventually pulmonary pressure > systemic pressure
- This creates right -> left shunt
- Deoxygenated blood bypasses the lungs and enters the body
- This causes cyanosis
Give 4 examination findings associated with the pulmonnary HTN seen in Eisenmenger syndrome
- Right ventricular heave
- Loud P2
- Raised JVP
- Peripheral oedema
Explain the cyanosis seen in Eisenmenger syndrome
- Blue discoloration of the skin due to low oxygen sats in the blood
- BM will produce more RBC and haemoglobin leading to polycythaemia
- Polycythaemia = plethoric complexion
Give 4 examination findings associated with the right to left shunt and chronic hypoxia in Eisenmenger syndrome
- Cyanosis
- Clubbing
- Dyspnoea
- Plethoric compexion (red complexion related to polcythaemia)
What is the only definite treatment for Eisenmenger syndrome ?
Heart-lung transplant -> it is too late to reverse underlying cause
Define cyanotic heart disease
-When blood is able to bypass the pulmonary circulation and the lungs
Give 4 heart defects that cause a right to left shunt and so cyanotic heart disease
- ASD
- VSD
- Patent ductus arteriosus
- Transposition of the great arteries
What is a flow murmur ?
-Innocent murmur heard in children and are caused by fast blood flow through various areas of the heart during systole.
Give the 5 S’s of flow murmurs
- Soft
- Short
- Systolic
- Symptomless
- Situation dependent : E.g. quieter on standing or only appears when child is unwell or feverish
Give 3 causes of ejection-systolic murmurs
- Aortic stenosis
- Pulmonary stenosis
- Hypertrophic obstructive cardiomyopathy
Explain the pathophysiology behind splitting of the second heart sound
- During inspiration, the lungs and heart are pulled open = negative intra-thoracic pressure
- The right side of the heart then fills faster
- The increased volume in the right ventricle causes it to take longer to empty = delay in pulmonary valve closing.
- Pulmonary valve closing later than aortic valve = ‘split’ second heart sound
What is transposition of the great arteries ?
- Attachments of the aorta and pulmonary trunk to the heart are swapped
- The RV pumps blood into the aorta
- The LV pumps blood into the pulmonary vessels
What 3 conditions can transposition of the great arteries be associated with ?
- VSD
- Coarctation of the aorta
- Pulmonary stenosis
How does transposition of the great arteries present ?
- Usually diagnosed on antenatal USS
- If not : baby will present with cyanosis at birth
How is transposition of the great arteries managed ?
- Prostaglandin infusion to maintain ductus arteriosus to allow blood to flow from aorta to pulmonary arteries for oxygenation
- Balloon septostomy
- Open heart surgery = definitive. A cardiopulmonary bypass machine is used to perform an atrial switch within a few days of birth
What is a balloon septostomy ?
-A catheter is inserted into the foramen ovale via the umbilicus and a balloon is inflated to create a large atrial septal defect.
How is PDA managed ?
-Indomethacin/ibuprofen can be given as a neonate to inhibit prostaglandin synthesis
-Monitor to 1 year - trans-catheter or surgical closure if it looks like it won’t close on its own
What is seen on ECG in on ostium secundum ASD
RBBB with RAD
What is seen on ECG in an ostium primum ASD
RBBB with LAD, prolonged PR interval
Give 4 complications of an ASD
-Eisenmenger syndrome
-Stroke in the context of a VTE
-AF or atrial flutter
-Pulmonary HTN and right sided heart failure
what is the most common cause of congenital heart disease
VSD
Give 3 causes of a pan systolic murmur
VSD
Mitral regurg
Tricuspid regurg
what is coarctation of the aorta
Congenital narrowing of the aorta
12 week old infant
Ejection systolic murmur
Sat on right arm : 99%
Sat on left foot : 90%
Coarctation of the aorta
How may coarctation of the aorta present in a neonate
-Neonate : weak femoral pulses , differing BP/O2 sats in arms and legs. Ejection sytstolic mumur
Where would the murmur be heard in coarctation of the aorta
Left infraclavicular area and below the left scapula
How would coarctation of the aorta present in infancy
Infancy : heart failure -> tachypnoea, poor feeding, grey and floppy
What additional signs may develop over time in coarctation of the aorta
-Left ventricular heave
-Underdeveloped left arm in reduced subclavian artery blood flow
-Underdevelopment of the legs
How is severe coarctation of the aorta managed
Prostaglandin E to keep ductus arteriosus open while awaiting surgery
What are the signs of more significant aortic valve stenosis
Fatigue
SOB
Dizziness
Fainting
All worse on exertion
what murmur is heard on aortic valve stenosis
Ejection systolic
Loudest at second intercostal space, right sternal border
Crescendo decrescendo
Radiates to carotids
What are 4 other signs of aortic valve stenosis
Ejection click before murmur
Palpable thrill in systole
Slow rising pulse
Narrow pulse pressure
How can aortic valve stenosis be managed
Percutaneous balloon aortic valvuloplasty
Surgical aortic valvotomy
Valve replacement
Give 5 complications of aortic valve stenosis
Left ventricular outflow tract obstruction
HF
Ventricular arrhythmia
Bacterial endocarditis
Sudden death on exertion
Give 4 associations with pulmonary valve stenosis
TOF
Williams
Noonan’s
Congenital rubella syndrome
what murmur is heard in pulmonary valve stenosis
Ejection systolic : second intercostal space left sternal border
What are 3 other signs of pulmonary valve stenosis
Palpable thrill in pulmonary area
Right ventricular heave
Raised JVP with giant a waves
How is mild pulmonary valve stenosis managed
‘watching and waiting’
How is symptomatic pulmonary valve stenosis managed
-> Balloon valvuloplasty
what 4 things make up the TOF
-> Pulmonary valve stenosis
-> Overriding aorta
-> Right ventricular hypertrophy
-> VSD
What determines the severity of TOF
- Degree of pulmonary valve stenosis
- The greater it is, the greater the resistance and more blood is pumped through the right -> left shunt -> cyanosis
Give 4 RF for TOF
Rubella infection
Increased maternal age
Alcohol in pregnancy
Diabetic mother
what would a chest x ray show in TOF
Boot shaped heart -> right ventricular thickening
what murmur is heard in TOF
Ejection systolic
Left
2nd intercostal space
Due to pulmonary value stenosis
Give 5 signs of TOF
Tet spells
Cyanosis
Clubbing
Poor feeding
Poor weight gain
what are tet spells
- Intermittent cyanotic episode when a child is exerting themselves (e.g. crying,exercise)
-Tacynpnoea
How is conservative management of a tet spells
Children - squat
Babies -position knees to chest
How can TOF be managed in neonates ?
Prostaglandin infusion to maintain ductus arteriosus
What medication can be used in cyanotic episodes in TOF
BB
what can be used in transposition of the great arteries to maintain until surgery
-> Prostaglandin : maintain ductus arteriosus
-> Balloon septostomy to create a large ASD through the foramen ovale
what is the definite management of transposition of the great arteries
Open heart surgery
what is ebstein’s anomaly
Tricuspid valve is set lower than the right
what can cause ebetein’s anomaly
Lithium in-utero
What is associated with ebstein’s anomaly
Wolff-Parkinson White syndrome
PFO or ASD
Give 5 features of ebstein’s anomaly
Cyanosis
Prominent ‘a’ wave in JVP
Hepatomegaly
Tricuspid regurg -> pansystolic murmur
RBBB -> widely split S1 and S2
