Congenital Heart Disease Flashcards
Changes in the heart/circulation after delivery (3)
- instant decrease in pulmonary vascular resistance (due to oxygen is vasodilator)
- increase in pulmonary blood flow -> fall in pulmonary artery pressure
- as pulmonary artery pressure fall -> LA pressure > RA pressure -> closure of foramen ovale
* initially -> flap closure due to pressure differences
*anatomic closure 4-12 weeks -> will close anatomically in most of the people (sealed)
What happens to ductus arteriosus after delivery?
-10-15 hours of life -> increased oxygen levels -> constriction of ductus arteriosus smooth
muscle
*removal of placenta -> high prostaglandin levels -> aid in duct closure
- complete closure will be in around 3 weeks
Risk factors for CHD (2 categories)
A. Environmental: rubella, DM, alcohol, drugs (illicit and medication e.g. anti-epileptics)
B. Chromosomal abnormalities (e.g. Down’s syndrome increases chances of having CHD)
Can CHD be diagnosed antenatally?
Yes, some of them.
Antenatal diagnosis: specialists foetal cardiologists -> ECHOs etc.
*but not all the conditions can be diagnosed due to nature of foetal physiology
B. Postnatal
Post-natal Dx of CHD
- symptoms
- when
Yes
- acute deterioration at/ soon after birth
- 1st day check
- later (unwell after discharge home, midwife concerned, GP on routine exam may find something
wrong with the heart)
Why CHD may show symptoms during feeding?
- For a newborn baby, their exercise is while being fed; so parents may notice a baby breathing heavily/ differently while being fed
- Classic HF signs that may be seen in an older person
- Child could potentially become ‚blue’ while feeding/ exerting themselves
Ix for CHD
CXR, BP and sats, ECG, ECHO
(2) broad categories of signs of CHD
- too little pulmonary flow
- too much pulmonary flow
Signs ‘too much pulmonary flow’ of CHD
Signs of CHD due to ‘too little pulmonary flow’
CXR -> less blood flow seen
*oligaemia = hypovolaemia
Name some of the most common congenital heart diseases
Blood flow in Ventricular Septal Defect
- shunt often goes from L —> R (as from higher to lower pressure)
- children would be ‚pink’ as oxygenated blood
goes into deoxygenated
Pathology of ventricular septal defect
- how does it affect lungs
- shunt across to RV -> increased pulmonary blood flow (as more blood goes into the lungs
from R ventricle)
- symptoms of heart failure
- pulmonary vessels damaged (by increased pulmonary flow) -> pulmonary resistance will
increase -> this will become eventually irreversible -> pulmonary hypertension
* therefore even if VSD would be closed -> pulmonary hypertension will remain
What’s Eisenmenger Syndrome?
Eisenmenger (shunt would reverse from R to L due to hypertrophy of R side of the heart caused by pulmonary hypertension) -> it will become cyanotic and both, heart and lung transplant would be needed
*nowadays, with increased technology (imaging) we can pick up VSD quicker (e.g. in childhood), in the past many people would develop Eisenmenger
Possible presentation of VSD
- Symptoms of cardiac failure (but may be mild in newborn)
- cardiac murmur may be heard *but it’s not always the case; e.g. if the hole is big -> then
children will become sicker faster but we may not hear the murmur that quick
Management of VSD
Management:
A. Medication
- diuretics: furosemide and spironolactone
B. Surgery
- sometimes we need to grow babies bigger before surgery but need to act now -> Pulmonary artery band (PA band) -> to protect the lungs (as not much blood gets to the lungs, less damage to the arteries there)
this is only temporary solution, VSD would still need to be corrected
- Corrective surgery -> defect will be sealed
What’s a classic murmur in VSD?
VSD = pansysolic murmur
What are (4) cardiac defects in Tetralogy of Fallot?
- Pulmonary stenosis = Pulmonary tract obstruction
- R ventricular hypertrophy is a result of pulmonary tract obstruction (heart muscle
remodels)
(2) types of surgical management of ToF
A.Palliative procedure - not a curative
Shunt created between R subclavian and R pulmonary artery
*this is only a temporary thing
B. Transannular patch -> pulmonary artery is opened up/widened and patch is
sticked
General management point (modes and timeframes) for ToF
What’s murmur is characteristic of ToF?
TOF = ejection systolic murmur
What’s x-ray finding is characteristic of ToF?
‘Boot shaped heart’ - apex is pointing upwards due to R ventricular hypertrophy *rarely seen in practice
What’s ‘spelling’ in ToF?
‘Spelling’ already narrowed R ventricular outflow tract goes into spasm -> all of blood supply to the lungs is cut off
Management of ‘spelling’ (ToF)
Aim: We want to decrease pulmonary vascular resistance and increase systemic resistance (to encourage the blood going to the lungs)
- Push baby’s knees up to the chest -> to achieve the above
- High flow oxygen -> as oxygen is potent vasodilator -> we want to dilate pulmonary
vasculature
- Morphine -> to calm baby down and to vasodilate
4. B-blocker -> help with R vent outflow tract spasm
Patent ductus arteriosus
- patophysiology (simple)
- symptoms
- management
Arterial Septal Defect (ASD)
- symptoms
- management
What’s AVSD?
How does AVSD look like? (picture)
Pathology of Transposition of Great Arteries
Pathology: blood vessels connected to wrong ventricles -> ventricles are in correct
arrangement but great arteries are not
- Aorta comes of R ventricle
- pulmonary arteries from L
Result: in uterus it is fine, as we have got shunting, so blood mixes together; but when
we are born, shunts close down -> serious issue
Surgery for transposition of great arteries
‘Arterial switch’ -> arteries are chopped off and plugged to the other sides
problem is:
coronary arteries are connected to aorta -> therefore if someone had that operation may show sign of myocardial ischaemia (due to damage to coronary artery)
Classical x ray finding in transposition of great arteries
‘Egged shaped heart’ - it does not really look like -> narrow mediastinum due to different
arrangement of vessels
Criteria for a diagnosis of Kawasaki disease
Management of Kawasaki disease
A. Immunoglobulins
B. Aspirin (although normally contraindicated in children (Reyes) -> here it will be needed
anyway
Pathophysiology of hypertrophic cardiomyopathy
Hypertrophic: cause smaller than normal ventricular cavities -> filling of the heart is impaired
+ contractile function enhanced
*often cause of sudden death in young athletes (when the point is reached that cardiac muscle is so big and aorta is pressing on it and obstructing; on exertion it may just not eject properly)
- is 50% AD condition
- L ventricle hypertrophied
Symptoms of hypertrophic cardiomyopathy
angina pain, lightheaded, syncope, arrhythmia
Dilated cardiomyopathy
- what happens
- symptoms
Dilated: contractile function is decreased + dilation
- most common cardiac myopathy
- majority idiopathic
Symptoms: fatigue, weakness, previous viral infection
What happens in restrictive cardiomyopathy (structural changes)
Restrictive: restricted diastolic filling (stiff heart), marked atrial dilatation
Organisms that commonly cause bacterial endocarditis in:
A. neonates
B. children
Risk factors (3) for bacterial endocarditis
May happen in both, structurally normal and abnormal hearts
- often it is a complication of central venous lines in NICU/PICU
- pressure gradients and turbulent blood flow that is created in CHD will predispose the valve to get damaged and therefore be colonised by bacteria
Possible causes of myocarditis (paediatrics)
Possible presentation of myocarditis in neonate
Neonate -> sudden onset:
- anorexia/vomiting/lethargy
- HF signs
- Cardiomegaly on CXR
*mortality in neonates is 75%
Advice for adult patient with cyanotic CHD
- more likely to develop thrombo-embolism -> contraception needed
- advice not to get pregnant if pulmonary HTN
- risk of endocarditis: oral hygiene, better not to get piercing or tattoos etc.
- in some cardiac conditions, e.g. TOF, although treated there is a risk of malignant arrhythmias-> therefore advice the patient that if something like that develops (e.g. palpitations) it requires
urgent medical attention
