Congenital Heart Disease

Question 1

Define congenital heart disease.

Answer 1

A heart disease present at birth caused by a malformation.

Question 2

Explain the aetiology of left-to-right shunts (“Acyanotic”) congenital heart disease.

Answer 2

• Atrial septal defects: Secundum ASD; Partial atrioventricular septal defect
• Atria-ventricular septal defect
• Ventricular septal defects

In both ASDs, VSDs or AVSDs blood flows from the left side of the heart to the right side as the pressure is greater on the left-hand side. This means less oxygenated blood flows around the body. It also means more blood flows through the pulmonary artery which can lead to increased resistance and ultimately to pulmonary stenosis.

• Persistent ductus arteriosus The blood flows from the aorta into the pulmonary artery as the pressure is greater in the aorta. Similar consequences as in ASDs, VSDs, and AVSDs.

Question 3

Explain the aetiology of right-to-left shunts (“Cyanotic”) congenital heart disease.

Answer 3

• Tetralogy of Fallot
  
  • Pulmonary valve stenosis
  • Right ventricular hypertrophy
  • VSD
  • Over-riding of aorta.
• Transposition of great arteries

In both TOF and ToGA the blood is flowing from right to left – effectively bypassing the lungs. True ToGA is when the pulmonary artery is connected to the left ventricle and the aorta to the right ventricle which means no oxygenation at all. This is fatal which why ToGA must also present with a VSD for it to be compatible with life.

Question 4

Explain the aetiology of obstructive congenital heart disease.

Answer 4

• Coarctation of aorta
  
  • Arterial duct tissue encircling the aorta at the point of insertion of the duct. When the PDA closes so does the artery.
• Pulmonary stenosis – Fusing of the pulmonary artery valve leaflets.

Question 5

Summarise the epidemiology of congenital heart disease.

Answer 5

1% of live births. TOF is the most common cyanotic disorder.

Question 6

What are the presenting symptoms for left-to-right congenital heart disease?

Answer 6

None, except for large left-to-right congenital heart disease which presents with heart failure.

Question 7

What are the signs for secundum left-to-right congenital heart disease?

Answer 7

ESM at ULSE
Fixed split S2

Question 8

What are the signs for partial AVD left-to-right congenital heart disease?

Answer 8

ESM at ULSE
Fixed split S2
Pansystolic murmur at apex

Question 9

What are the signs for small left-to-right congenital heart disease?

Answer 9

Pansystolic murmur at LLSE

Question 10

What are the signs for large left-to-right congenital heart disease?

Answer 10

Active precordium
Loud P2
Soft murmur
Tachypnoea
Hepatomegaly

Question 11

What are the signs for PDA left-to-right congenital heart disease?

Answer 11

Continuous mumur at ULSE
Bounding pulses

Question 12

What are the signs and symptoms of Tetralogy of Fallot right-to-left congenital heart disease?

Answer 12

Loud murmur at upper left sternal edge
Clubbing of fingers and toes (older)
Hypercyanotic spells

Question 13

What are the signs and symptoms of transposition of the great arteries right-to-left congenital heart disease?

Answer 13

Neonatal cyanosis
No murmur

Question 14

What are the signs and symptoms of Eisenmenger’s syndrome right-to-left congenital heart disease?

Answer 14

No murmur
Right heart failure (late

Question 15

What are the signs and symptoms of pulmonary stenosis obstructive congenital heart disease?

Answer 15

Asymptomatic

Cyanosis

Ejection systolic murmur heard at the upper left sternal edge, thrill may be present.

Heave.

Question 16

What are the signs and symptoms of duct-dependent coarctation of aorta obstructive congenital heart disease?

Answer 16

Acute circulatory collapse 2 days of age when the duct closes.

Severe heart failure signs.

Absent femoral pulses.

Severe metabolic acidosis.

Question 17

What are some appropriate investigations for congenital heart disease?

Answer 17

• Bloods
• ECG – May show axis deviation, ventricular hypertrophy.
• Echocardiography
• CXR
• Nitrogen washout test- To diagnose right-to-left shunts.
  
  • The patient is placed on a ventilator with 100% oxygen for 10 minutes. If the PaO2 still remains low after 10 minutes it is diagnostic of cyanotic heart disease.

Question 18

What is the management plan for acute cyanosis in congenital heart disease?

Answer 18

• ABCDE approach
• Start prostaglandin infusion (5 ng/kg per min) to promote mixing blood and keep the ductus arteriosus open.
• Consider balloon atrial septostomy.

Question 19

What is the management plan for Tetralogy of Fallot?

Answer 19

Initial management is medical.

If there is a lot of cyanosis introduce a shunt between the subclavian artery and pulmonary artery (effectively a surgical ductus arteriosus).

Surgery at 6 months to repair the pulmonary valve, closing the VSD and relieving right ventricular outflow tract obstruction.

Question 20

What is the management plan for transposition of the great arteries?

Answer 20

Same as above

Surgery to switch the arteries

Question 21

What are potential complications associated with congenital heart disease?

Answer 21

In left-to-right there is an increased risk of Eisenmenger syndrome.

Cyanotic complications.

Death if not identified early.

Shorter life expectancy.

Question 22

What is the prognosis of congenital heart disease?

Answer 22

Dependent on early detection but due to association with other syndromes life expectancy is usually reduced.