Foetal Circulation and heart problems

Question 1

Name the most important functions of the placenta?

Answer 1

Transport of IgG – maternal antibodies

Produces PGE2 – which gives the duct patency

Question 2

How does the foetal heart pump blood to the placenta?

Answer 2

umbilical arteries

Question 3

How does blood from the placenta returns to the foetus?

Answer 3

umbilical vein

Question 4

What is the role of the ductus venosus?

Answer 4

Connects the umbilical vein to the inferior vena cava

Takes oxygenated blood past the liver and into the heart

Question 5

What is the role of the foramen ovale?

Answer 5

Opening in atrial septum connecting RA to LA

Allows blood to pass from the right side of the circulation into the left side

Question 6

What is the role of the ductus arteriosus?

Answer 6

Connects pulmonary bifurcation to the descending aorta

Question 7

What are the initial circulation changes when a baby is born?

Answer 7

pulmonary vascular resistance decreases (increasing oxygen circulation)
systemic vascular resistance increases (more cardiac output to lungs)

Question 8

After the duct anatomically closes after 7-10 days - what does it end up as?

Answer 8

fibrous ligament – ligamentum arteriosum

Question 9

What are the treatment options when the duct fails to close?

Answer 9

wait and see
NSAIDs (inhibit prostaglandin production)
surgery (surgically ligated)

Question 10

What is IV prostaglandin E2 used for?

Answer 10

to keep the duct open until an alternative shunt established or definitive surgery carried out

Question 11

Describe the common failure of adaption disease, Persistent pulmonary hypertension of the newborn?

Answer 11

failure of the pulmonary vascular resistance to drop
Causes:
- Sepsis
- Hypoxic ischaemic insult
- Meconium aspiration syndrome
- Cold stress
- related to an underlying congenital abnormility
Mixing of blood, at the duct, more blue blood joins and you get even more blue blood in the descending aorta

Question 12

What defines a neonatal congential heart disease?

Answer 12

Abnormality of the structure of the heart - present at birth

Question 13

Describe the severity spectrum of congenital heart disease?

Answer 13

Mild – asymptomatic, may resolve spontaneously (may progress to moderate or severe in adulthood in some specific conditions)
Moderate – require specialist intervention and monitoring in a 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 14

How is a congenital heart disease diagnosed?

Answer 14

Screening
–Antenatal
–Newborn baby check
Well baby with clinical signs – cardiac murmur
Unwell baby
–Cyanosis
–Shock
–Cardiac failure

Question 15

What is the typical age for a baby to present with a congenital heart disease?

Answer 15

4-6 weeks

Question 16

Describe cyanosis

Answer 16

Any condition causing deoxygenated blood to bypass the lungs and enter the systemic circulation
OR where mixed oxygenated and deoxygenated blood enters the systemic circulation from the heart

Question 17

What is the most common cyanotic condition?

Answer 17

Transposition of the great arteries

Question 18

Name some duct developmental conditions?

Answer 18

Systemic Circulation
-  Hypoplastic left heart
-  critical aortic stenosis
-  interrupted aortic arch
-  critical coarctation of aorta
Pulmonary circulation
-   Tricuspid atresia
-   Pulmonary atresia

Question 19

What are the clinical signs of cardiac failure?

Answer 19

Failure to thrive
Slow / reduced feeding
Breathlessness (especially when feeding)
Sweatiness
Hepatomegaly
Crepitations

Question 20

Describe a moderate/large ventricular septal defect?

Answer 20

Often no murmur at baby check
Murmur develops as pulmonary pressures drop over first weeks
Increased pulmonary circulation, congestive cardiac failure
Give diuretics and high calorie formula to help baby grow before they do surgery
Longer term management