4- congenital heart disease

Question 1

what is congenital heart disease?

Answer 1

= abnormality of structure of the heart, present at birth

“a gross structural abnormality of the heart or intrathoracic great vessels that is actually or potentially of functional significance”

Question 2

what is spectrum of severity for congenital heart disease?

Answer 2

mild = asymptomatic, may resolve spontaneously (may progress to moderate or severe in adulthood in some specific conditions)

moderate = require specialist intervention and monitoring in cardiac centre

severe = present severely ill / die in newborn period or early infancy

Major congenital heart disease = requires surgery within the first year of life

Question 3

what are examples of
a) mild
b) moderate
c) severe

Answer 3

a) - Small ventricular septal defect, patent foramen ovale/small atrial septal defect, small patent ductus arteriosus. (Bicuspid aortic valve (2 cusps instead of 3) may progress in adulthood to severe aortic stenosis or aortic regurgitation and need surgery)
b) mild or moderate aortic stenosis, pulmonary stenosis. Larger or complex atrial septal defect, ventricular septal defect
c) all cyanotic lesions, all duct dependent lesions, truncus

Question 4

what are signs of an unwell baby?

Answer 4

cyanosis, shock, cardiac failure

Question 5

what are times that congenital heart disease can be identified?

Answer 5

• antenatally
• soon after birth = cyanosis
• day 1-2 baby checks = murmurs, abnormal pulses, cyanosis
• day 3-7 = sudden circulatory collapse, shock, cyanosis, sudden death
• 4-6 weeks = Signs of cardiac failure – reduced feeding, failure to thrive, breathlessness, sweatiness
• 6 -8 week GP check, incidental finding of murmurs at other clinical contacts

Question 6

what is involved in antenatal screening to detect congenital heart disease?

Answer 6

ultrasound at 18-20 weeks
- 4 chamber heart view & outflow tract view
- sensitivity variable on operator training & maternal characteristics

Question 7

what is management of antenatally diagnosed congenital heart disease?

Answer 7

finding out before birth means:
- you can plan to deliver in cardiac surgical centre
- means you can have expert team & counselling available for plan (especially if palliative care or termination needed)

*you can know if prostaglandin infusion required if duct dependant lesion

Question 7

what is newborn screening - baby check?

Answer 7

= clinical exam at around 24 hours of age

check: femoral pulses, heart sounds, presence of murmurs

also can do oxygen saturation check on right arm and left leg

Question 8

is newborn screening effective at identifying congenital heart disease?

Answer 8

hmm sort of
- about half are missed with clinical exam
- about 3rd leave hospital undiagnosed
- only about half of babies that have murmurs actually have underlying heart disease (murmurs can be common normally)

*adding saturation screening helps effectiveness

small ventricular septal defect can be detected as makes murmur early in life

Question 9

what is cyanosis?

Answer 9

• Any condition causing deoxygenated blood to bypass the lungs and enter the systemic circulation
• Any condition where mixed oxygenated and deoxygenated blood enters the systemic circulation from the heart
• Clinically causes bluish discolouration – we are not very good at detecting this

Question 10

what happens when transposition of great vessels?

Answer 10

great arteries have developed the wrong way around so aorta out of RV and back in RA and pulmonary artery out of LV and back in LA which means 2 circulations working completely separate

• usually has septal defect to allow some mixing (without septal defect - immediate death)
  = blue colour depends on extent of mixing

Question 11

what are clinical signs of problem after patent arteriosum duct closes if another underlying heart disease that depended on open duct?

Answer 11

• pallor
• prolonged capillary refill time
• poor or absent pulses
• hepatomegaly
• crepitations
• increased work of breathing

Question 12

when does ductus arteriosus close?

Answer 12

• usually physiologically within first few hours to days
• if duct dependant heart disease then it takes longer, 2-7 days

Question 13

what is treatment of collapse of duct in duct dependant disease?

Answer 13

• ABC – support airway and breathing as necessary
• Prostaglandin E2 to open duct
• Multisystem supportive treatment
• Transfer to cardiac surgical centre for definitive management

Question 14

what is duct dependant systemic circulation?

Answer 14

any condition where blood reaching the aorta is dependant on duct being open
e.g. hypoplastic left heart, critical aortic stenosis, interrupted aortic arch, critical coarctation of aorta

Question 15

what is duct dependant pulmonary circulation?

Answer 15

any condition where blood reaching the pulmonary arteries is dependant on the duct being open
e.g. tricuspid atresia, pulmonary atresia

Question 16

what is hypoplastic left heart syndrome?

Answer 16

= left side of heart is underdeveloped
- while duct is open, the aorta is supplied by RV via ductus arteriosus
- when duct close there is no route from heart to aorta

*can’t survive without atrial septum defect - they will seem normal day 2 of life but when duct stops working at day 5.6.7 they will not be good

Question 17

what is pulmonary atresia?

Answer 17

= affects pulmonary valve

• When the duct is open the blood supply to the lungs comes from the aorta via the ductus arteriosus
• When the duct closes there is no way for blood to get to the lungs

= when duct closes no way for blood to get to lungs

• Retrograde filling of the branch pulmonary arteries via ductus arteriosus
• May not be very cyanosed while duct open

Question 18

what happens with newborns with small shunts?

Answer 18

• present after a few weeks as pulmonary pressures drop to adult levels
• The flow of blood from left to right increases as the pulmonary vascular resistance drops

Flow from left to right across the defect increases as the pulmonary pressures drop

Question 19

what are clinical signs of failure in babies?

Answer 19

• failure to thrive
• slow/reduced feeding
• breathlessness (especially when feeding)
• sweatiness
• hepatomegaly
• crepitations

Question 20

what is a large ventricular septal defect?

Answer 20

a large whole in between the ventricles
- the bigger whole means less gradient so often no murmur at baby check
- increased pulmonary circulation means congestive heart failure as lungs see too much blood which means more comes back to heart making heart congested & overworked

Question 21

what is long term management for congenital heart disease?

Answer 21

• surgical management (repair vs palliation)
• developmental problems (hypoxia & bypass time)
• need for further surgery (valves, stenosis and transplant)
• emotional/social issues

Question 22

what is patent ductus arteriosus repair?

Answer 22

= fairly easy (duct has failed to close)

• Catheter procedure and puts catheter in duct to close
• Couple of follow up appointment to ensure flow stopped and that the device is in correct position
• Discharged

Question 23

what is VSD repair?

Answer 23

= ventricular septal defect

• usually when like 6 months old, put a patch on
• might have rhythm problems or valve problems
• generally expect to go on to normal life but will need multiple follow ups

Question 24

what is HLHS surgery?

Answer 24

hypoplastic left heart surgery

• 3 stage complex surgery
• Significant mortality at each stage and between
• Ends with RV supplying systemic circulation
• Will fail over time
• Transplant by teenage years

Question 25

what is atrioventricular canal defect?

Answer 25

= large defect in atrial septum, ventricular septum & common AV valve

• Antenatally detected, May prompt genetic testing (downs syndrome)
• Murmur, Not usually present at baby check but might be there later
• Cyanosis, Quite subtle
• Cardiac failure = By around 4-8 weeks of age

Question 26

what is tetralogy fallot?

Answer 26

= narrow pulmonary outflow tract with large ventricular septal defect overriding aorta (RV hypertrophy)

• Antenatal diagnosis
• Murmur
• Cyanosis
• Congestive cardiac failure
• Collapse at duct closure