CHD Lesions that present with Cyanosis

1. Truncus arteriosus

Examination/Investigations

• Examination
  • Wide pulse pressure
  • Systolic ejection murmur – increased flow across semilunar valve
  • Single second heart sound
• Investigation

Management → Surgical repair via a Rastelli procedure. This involves a patch to close the VSD and allow the LV to communicate with the common trunk. A Conduit is then made from the RV to the pulmonary artery.

2. Transposition of the great arteries

This occurs due to failure of septation of the pulmonary artery and aorta.

Investigations

• ECG – usually normal
• CXR: may show egg on string appearance or signs of CCF

Management

• Where there is no VSD, when the Ductus Arteriosus closes → cyanosis → ABCDE, prostaglandin infusion
• If there is a VSD, patients are usually well oxygenated however they are more prone to developing CCF so require surgical repair within the first few weeks
• Some infants with TGA and an intact ventricular septum will remain excessively cyanotic despite initiation of PGE infusion and these patients require a balloon atrial septostomy to create an ASD

The definitive management is an arterial switch operation. This is often carried out in the first few weeks to avoid left ventricular deconditioning.

Learning bite

Without a shunt (VSD/ASD/PDA), Transposition of the Great Arteries is incompatible with life as there is no entry for oxygenated blood to the systemic circulation

3. Tricuspid atresia

Examination and Investigation findings

• Examination: Harsh systolic murmur
• ECG: superior axis, absent RV voltages, large P-waves
• CXR: May have increased or decreased pulmonary vascular markings

Management

• If the lesion presents with cyanosis →BT shunt or RV to Pulmonary artery conduit shortly after birth
• If it presents with CCF, medical management is used initially followed by surgical correction with a Pulmonary Artery band to reduce pulmonary vascular resistance and pressure.
• Definitive management is to establish Fontan circulation by 3-5 years of age

Learning bite

Truncus arteriosus and Tricuspid atresia are both lesions that can present with cyanosis at birth and a harsh systolic murmur due to flow through a semilunar valve/VSD

4. Tetralogy of Fallot

TOF presentation depends on degree of RV outflow obstruction as this determines the extent of mixing of oxygenated and deoxygenated blood.

• If there is a large degree of pulmonary stenosis the entire right ventricle output passes through the VSD. Pulmonary flow is only supplied by the DA → presents with cyanosis when the DA closes
• If there less pulmonary stenosis, pulmonary blood flow will be higher → CCF and cyanosis later in life (hypercyanotic “tet spells”)

Pathophysiology and Management of “Tet Spells”

• This occurs when there is hypoxemia of sudden onset E.g following systemic vasodilation after a meal or warm bath
• Hypoxemia → ↓in systemic vascular resistance →↓afterload→ ↑right to left shunting →worsens hypoxemia →metabolic acidosis → respiratory distress → May progress to unconsciousness /convulsions due to acidosis

Below is a short video detailing the pathophysiology and management of acute hypercyanotic spells

Investigations

• ECG: RA and RV enlargement
• CXR: boot shaped heart due to RA and RV enlargement resulting in an upturned apex with an absent or diminished pulmonary artery
• Echo/cardiac MRI +/- cardiac catheterisation – gold standard for diagnosis

Management 

• 10% require BT shunt or RV to Pulmonary Artery conduit in newborn if severely cyanosed
  • Acute cyanosis at birth is managed with Prostaglandins
• Most have elective surgical repair at 6-9 months
  • This involves using a patch to close the VSD and surgical widening of the stenosed pulmonary valve.

Following surgery 85% progress to adulthood

Learning bite

Management of hypercyanotic “tet spells” involves:

• Placing the child in a knee to chest position
• Administration of high flow oxygen
• Morphine
• Get senior help – the child is likely to require an admission to PICU

5. Total anomalous pulmonary venous drainage

When this occurs, the four pulmonary veins do not drain into the left atrium but drain into the innominate vein(Supracardiac), liver (Infracardiac ) or coronary sinus/right atrium (cardiac).

Presentation

• Depends on the degree of obstruction between pulmonary veins and right heart
• In Supracardiac and Infracardiac lesions, there is usually a higher degree of obstruction which presents at birth with pulmonary oedema, pulmonary hypertension and cyanosis →collapsed cyanotic neonate
• In cardiac lesions there is less obstruction → Develop symptoms within weeks to months – mild cyanosis and CCF

Investigation findings

• ECG: Right axis deviation, RVH
• CXR: snowman sign
• Definitive imaging: Echo, cardiac MRI, angiography

Management

• If patients present obstructed – emergency surgical correction
• If non obstructed – medical management of CCF (see section on the breathless baby) followed by elective surgical repair

Learning bite

In Supracardiac and Infracardiac lesions, the pulmonary veins must pass through accessory vessels and structures such as the diaphragm and liver therefore there is a higher degree of obstruction to flow. These lesions therefore present earlier.