Congenital heart disease - ASD, AVSD, CoA, PDA, PS, ToF, ToGA, VSD

Question 1

What is the cause of a ‘machinery-like murmur’ in a neonate?

Answer 1

Patent ductus arteriosus

Question 2

Which medications can be used to manage PDA?

Answer 2

Indomethacin/ibuprofen - blocks prostaglandin production which keep the duct open so blocking them causes the duct to close

Refer to surgery only if this is unsuccuessful.

Question 3

Does PDA cause cyanosis?

Answer 3

No, it is generally ‘acyanotic’. But if left uncorrected it can cause late cyanosis in the lower extremities (‘differential cyanosis’).

Question 4

What is the anatomy of PDA?

Answer 4

• Ductus arteriosus connects the pulmonary (artery) trunk and descending aorta
• This should usually close with the first breath as pulmonary flow enhances prostalandin clearance

Question 5

What are the risk factors for PDA?

Answer 5

• Prematurity
• Birth at high altitude
• Maternal rubella infection in first trimester

Question 6

What are the findings on examination in PDA?

Answer 6

Palpation:

• Wide pulse pressure
• Large volume, bounding collapsing pulse
• Heaving apex beat
• Left subclavicular thrill

Auscultation:

• Continuous machinery murmur

Question 7

When would you give PG E1 in PDA?

Answer 7

• If there is another congenital heart defect amenable to surgery
• This means that PG E1 can keep the duct open until surgical repair

Question 8

Define Ebstein’s anomaly.

Answer 8

Congenital heart defect characterised by low insertion of the tricuspid valve resulting in a large atrium and small ventricle. Sometimes called ‘atrialisation’ of he right ventricle.

Question 9

What is the cause of a systolic murmur with right arterial hypertrophy and posterior leaflet tricuspid valve attachment to the right ventricle?

Answer 9

Ebstein’s anomaly - congenital heart defect

It occurs when the posterior leaflets of the tricuspid valve are displaced anteriorly towards the apex of the right ventricle

Question 10

What other heart conditions is Ebstein’s anomaly associated with?

Answer 10

• patent forament ovale (PFO) and atrial septal defect (ASD) seen in 80% of patients –> a shunt between right and left atria
• WPW syndrome

Question 11

What are the clinical features of Ebstein’s anomaly?

Answer 11

Exam:

• cyanosis
• prominent ‘a’ wave in JVP
• hepatomegaly
• tricuspid regurgitation

ECG:

• RBBB –> widely split S1 and S2

Question 12

What is the cause of a tricuspid regurgitation murmur (pansystolic murmur, worse on inspiration) in a neonate?

Answer 12

Ebstein’s anomaly

Question 13

Which drug taken by the mother can increase risk of development of Ebstein’s anomaly/

Answer 13

Lithium during the first trimester of pregnancy

Question 14

Is PDA cyanotic?

Answer 14

No it is acyanotic

Question 15

List the main acyanotic congenital heart defects.

Answer 15

• ventricular septal defects (VSD)
• atrial septal defect (ASD)
• patent ductus arteriosus (PDA)
• coarctation of the aorta (CoA)
• aortic valve stenosis

Question 16

Which congenital heart defects are most likely to be diagnosed in adulthood?

Answer 16

ASDs as they generally present later

Question 17

Which of the acyanotic congenital heart defects is the most common?

Answer 17

VSD is most common, accounts for 30%

Question 18

What are the main cyanotic congenital heart defects?

Answer 18

1. truncus arteriosus - vessels join to make 1
2. transposition of the great arteries (TGA) - 2 major vessels switched
3. tricuspid atresia - 3 valves
4. tetralogy of Fallot - 4 defects
5. total anomalous pulmonary vascular return (TAPVR - 5 letters)

Question 19

Summary

Question 20

What presents earlier: TGA or Fallot?

Answer 20

TGA usually presents at birth

Tetralogy of Fallot presents at 1-2 months and is more common than TGA

Question 21

How can you classify congenital heart disease other than acynaotic/cyanotic?

Answer 21

Cyanotic

• Decreased pulmonary flow
• Increased pullmonary flow

Acyanotic

• L->R shunts
• Obstructive

Question 22

Acyanotic defects

Question 23

Cyanotic defects

Answer 23

Question 24

What are the 4 defects in Tetralogy of Fallot?

Answer 24

(overriding aorta)

Question 25

How is TGA repaired?

Answer 25

Question 26

What is TGA?

Answer 26

Question 27

How is TGA managed before corrective surgery can be done?

Answer 27

Prostaglandin E1 - to maintain the ductus arteriosus open through dilation of smooth muscle. Placenta is rich in prostaglandins which is why it remians open during gestation. Given soon after birth

2nd line is ACE inhibitors (catopril) - only given if PGE1 doesn’t work

Question 28

Which drugs prevent prostaglandin synthesis?

Answer 28

NSAIDs e.g. indomethacin

Question 29

What is the pathophysiology of TGA?

Answer 29

=failure of the aorticopulmonary septum to spiral during septation.

Basic anatomical changes

• aorta leaves the right ventricle
• pulmonary trunk leaves the left ventricle

Question 30

Which maternal medical condition increases risk of TGA?

Answer 30

Children of diabetic mothers are at an increased risk of TGA.

Question 31

What are the clinical features of TGA?

Answer 31

• cyanosis
• tachypnoea
• loud single S2
• prominent right ventricular impulse
• ‘egg-on-side’ appearance on chest x-ray

Question 32

What are the features of an innocent murmur?

Answer 32

• Asymptomatic child
• Systolic murmur - no diastolic component
• May change with position
• soft-blowing murmur in the pulmonary area or short buzzing murmur in the aortic area
• No click or other added sounds
• No thrill, no radiation, no other abnormality

Question 33

Name 2 innocent murmurs.

Answer 33

Venous hum - due to the turbulent blood flow in the great veins returning to the heart. Heard as continuous blowing noise heard just below the clavicles

Still’s murmur - low-pitched sound heard at the lower left sternal edge

Question 34

Which pulse abnormality is associated with PDA?

Answer 34

Collapsing pulse