A cyanotic heart defect is a group-type of congenital heart defects (CHDs). The patient appears blue (cyanotic), due to deoxygenated blood bypassing the lungs and entering the systemic circulation. This can be caused by right-to-left or bidirectional shunting, or malposition of the great arteries.
Cyanotic heart defects, which account for approximately 25% of all CHDs, include:
Tetralogy of Fallot (ToF)
Total anomalous pulmonary venous connection
Hypoplastic left heart syndrome (HLHS)
Transposition of the great arteries (d-TGA)
Truncus arteriosus (Persistent)
Interrupted aortic arch
Pulmonary atresia (PA)
Pulmonary stenosis (critical)
Eisenmenger syndrome(Reversal of Shunt due to Pulmonary Hypertension) .
Patent ductus arteriosus may cause cyanosis in late stage.