Paediatric Cardiology

Question 1

Via what vessel does oxygenated blood get from the placenta to the foetus? Where does this vessel anastamose onto?

Answer 1

Umbilical vein

Becomes the ductus venosus and then anastamoses onto the inferior vena cava

Question 2

Where is the ductus venosus? What is its function? What does it become after birth?

Answer 2

It passes through the fetal liver

It transports blood from the umbilical vein to the inferior vena cava

Closes and becomes the ligamentum rotundum of the liver

Question 3

What sort of blood (oxygenated / deoxygenated) enters the right atrium of the fetus? Where does most of it tend to go from there?

Answer 3

A mixture - deoxygenated from the SVC, oxygenated from the IVC

Goes through the foramen ovale into the left atrium - left ventricle

Question 4

How does the foetal circulation account for the fact that the lungs don’t require much oxygen?

Answer 4

Any blood into the pulmonary artery faces high resistance due to the lungs not being developed

It gets forced through the ductus arteriosus, an anastamosis between the pulmonary artery and the aorta

Question 5

What are the changes in fetal circulation that occur at birth?

Answer 5

• Pulmonary vascular resistance falls & blood flow rises
• Systemic vascular resistance is increased
• Ductus arteriosus closes
• Foramen ovale closes
• Ductus venosus closes

Question 6

How is patent ductus arteriosus treated in preterm infants?

Answer 6

• Fluid restriction / diuretics
• Prostaglandin inhibitors: ibuprofen / indometacin
• Surgical: ligation of the patent duct

Question 7

How is patent ductus arteriosus treated in in term infants?

Answer 7

Spontaneous closure often happens within a year, so would reassess at a year:

• If “silent” patent DA: would not treat, haemodynamically irrelevant
• If symptomatic duct: catheter closure with umbrella device

Question 8

How do you decide if the patent DA is symptomatic or silent?

Answer 8

If it is silent you won’t hear the murmur, if it is symptomatic you will

Question 9

How do children with pulmonary valve stenosis tend to present? What clinical signs may be seen? Investigations?

Answer 9

Mild stenosis - asymptomatic
Moderate-severe - exertional dyspnoea & fatigue

Ejection systolic murmur may be heard on upper left sternal border with radiation to back

ECHO to investigate

Question 10

Treatment for pulmonary stenosis in children?

Answer 10

Balloon valvoplasty

Catheter placed through the femoral vein, to the pulmonary valve. Then inflate the balloon at the end of the catheter when there

Question 11

What is one complication associated with balloon valvoplasty for aortic stenosis in children?

Answer 11

Pulmonary regurgitation occurs

Tends to be well tolerated in children

Valve replacement may be necessary eventually but try to delay these until after growth has stopped, due to the change in size of the heart as the child grows

Question 12

What is one complication to be aware of that may occur when performing valve replacement surgery?

Answer 12

Scar tissue formation leading to interruption in conductance in the electrical system of the heart

Question 13

How long do replacement heart valves tend to last?

Answer 13

10-15 years

(20 if you’re lucky)

• Surgery becomes more complex after each replacement

Question 14

How do children with aortic valve stenosis tend to present? What clinical signs may be seen? Investigations?

Answer 14

Mild - asymptomatic
Mod-severe - reduced exercise tolerance, exertional chest pain, syncope

Ejection systolic murmur at the upper right sternal border, radiation to carotids

ECHO

Question 15

How is aortic stenosis treated? What is different about its management when compared to pulmonary stenosis?

Answer 15

Balloon valvoplasty

Aortic regurgitation due to valvoplasty isnt as well tolerated and so valve replacement is often required much earlier on

Question 16

What is the Ross-Konno procedure?

Answer 16

Replacing the aortic valve with the pulmonary valve and then placing a biosynthetic valve in place of the pulmonary valve

The pulmonary valve isn’t meant for high pressure environments though so will need to be replaced again eventually

Question 17

Where does the coarctation of the aorta tend to occur?

Answer 17

Where the ductus arteriosus closes

Delayed closing of the duct can delay recognition of aortic coarctation in babies

Question 18

What is the clinical presentation of coarctation of the aorta?

Answer 18

Weak or absent femoral pulses

Radio-femoral delay (only in chronic coarctation - late sign)

Systolic murmur heard loudest on the back

Sudden deterioration and collapse of the patient

Question 19

What investigations should be done for suspected coarctation of the aorta?

Answer 19

ECG - RV hypertrophy in the neonate, LV hypertrophy in older child

CXR - rib notching from collaterals

ECHO**

MRI

Question 20

What conditions tend to occur with coarctation of the aorta?

Answer 20

Common in children with Turner syndrome

Often occurs alongside VSD

Question 21

If a baby is in critical condition due to coarctation of the aorta what treatment should be given?

Answer 21

Prostaglandin E1 or E2 to keep the ductus arteriosus open, reduces the load on the LV

Then get the baby to cardio surgery centre: end to end resection and anastamosis

Question 22

Aortic coarctation is often associated with hypoplasia of the aortic arch, how does this change treatment?

Answer 22

Often have to augment the aortic arch with part of the left subclavian to provide structural integrity

Then either end to end resection and anastamosis or balloon arthroplasty

Question 23

Two main treatment options for coarctation of the aorta?

Answer 23

End to end resection and anastamosis

Balloon arthroplasty + stenting

Question 24

What is the main sign of cyanotic heart defects?

Answer 24

Central cyanosis (blue lips + tongue)

Question 25

What are some examples of cyanotic heart defects?

Answer 25

Transposition of the great arteries

Question 26

What is transposition of the great arteries? How does it present?

Answer 26

Where the aorta comes out of the RV and the pulmonary artery comes out of the LV

Presents with cyanosis

Question 27

What is the first step in managing the transposition of the great arteries?

Answer 27

IV prostaglandin to keep the ductus arteriosus open

If it isn’t kept open the likelihood of the babies survival is very low

Question 28

What is a Rashkind procedure?

Answer 28

Insertion of a balloon catheter through the femoral vein into the RA, can be used to prevent the leaflets of the fossa ovalis from joining, allowing blood flow between atria

Done for congenital cyanotic heart defects such as transposition of the great arteries to allows blood mixing

Question 29

What surgical procedure is done to treat transposition of the great arteries? What is the main challenge with the procedure & brief overview?

Answer 29

Switch procedure

Baby placed on cardiopulmonary bypass, aorta and pulmonary trunk are switched

The main challenge is switching the coronary arteries which are thread sized in babies, cut out a patch off the base of the new pulm. trunk and sew onto new aorta, then fill in patches in the lower pressure system

Question 30

What are the four conditions that make up the tetralogy of Fallot?

Answer 30

1. VSD
2. Overriding aorta (into space of RV)
3. Pulmonary stenosis
4. RV hypertrophy (due to stenosis)

Question 31

When does the tetralogy of Fallot need to be treated?

Answer 31

Usually babies do alright with it and are only treated at around 6 months when they’re about 5kg heavy

Question 32

What is a Blalock-Taussig shunt?

Answer 32

A shunt created between the subclavian artery and the ipsilateral pulmonary artery

Allows greated blood flow to the lungs in babies suffering from tetralogy of fallot (needed bc pulm stenosis)

Question 33

After the surgical correction of the tetralogy of Fallot how do babies tend to get on?

Answer 33

They tend to become uncyanosed

They require lifelong checkups though because the risk of the right ventricular outflow tract closing again is quite high