Abnormality of the structure of the heart/great vessels present at birth

Cyanotic defects

• Conditions which cause deoxygenated blood to bypass the lungs and enter systemic circulation, or a mix of oxygenated and deoxygenated blood to enter circulation
• ‘All the Ts’ - truncus arteriosus, tetraology of Fallot, transposition of the great vessels, tons of others
  • Tetralogy of Fallot: ventricular septal defect, pulmonary stenosis, overriding aorta and right ventricular hypertrophy

Acyanotic defects

• Involve left to right shunting or no shunting
• Septal defects - ASD, VSD, AVSD
• Patent ductus arteriosus - incidence very high in pre-term infants
• Aortic and pulmonary stenosis

Clinical features

Antenatally

• USS at 18-22 weeks
• If duct dependent lesion is diagnosed antenatally → PGE2 infusion

Newborn screening

• Clinical examination at around 24hr
• Femoral pulses, heart sounds, and the presence of murmurs
• Some regions do pre and post ductal saturations

Cyanosis

• Evident shortly after birth
• Can also be a symptom of respiratory disease and persistent pulmonary hypertension of the newborn