Cardiac: Congenital Heart Disease (CHD)

Defects resulting in left to right shunting

Relative incidence:

• Ventricular septal defect (VSD) 28%
  
• Patent ductus arteriosus 10%
  
• Atrial septal defect 7%

Defects resulting in bi-directional shunting

Relative incidence:

• Transposition 6%
• Tetralogy of Fallot 5%
• Truncus arteriosus 1%

Defects resulting in complete mixing shunting

Relative incidence:

• Pulmonary atresia 2%
  
• Mitral atresia 1%
  
• Tricuspid atresia 1%

e.g. Tetralogy of Fallot

• With no shunt
  
• With a simple left to right shunt

The following list shows defects which result in acyanotic shunting:

• Ventricular septal defect (VSD)
  
• Atrial septal defect (ASD)
  
• Patent ductus arteriosus (PDA)
  
• Congenital aortic stenosis
  
• Coarctation of aorta

• With a bi-directional shunt
  
• Cyanotic with complete mixing

The following list shows defects which result in cyanotic shunting:

• Transposition of the great vessels (TGV)
  
• Fallot’s tetralogy (VSD, over-riding aorta/pulmonary stenosis and right ventricular hypertrophy)
  
• Tricuspid atresia
  
• Single ventricle
  
• Atrioventricular canal defect