The following cardiac defects are characterized by ductus dependent blood flow except –
Transposition of great arteries with intact septum
Interrupted aortic arch
Truncus arteriosus
Hypoplastic left heart syndrome
Congenital heart disease in the newborn can be broadly categorized by the relationship between the patients cardiac defect and the patent ductus arteriosus; this categorization yields four distinct groups:

I. Pulmonary flow ductal dependence.

Newborns with congenital heart disease who are dependent on the potency of their ductus for pulmonary blood flow present with varying degrees of cyanosis.
Critical Pulmonary Valve Stenosis with Intact Ventricular Septum.

Li Tricuspid Atresia:

Tetralogy of Fallot 
	Ni Systemic flow ductal dependence.


These newborns are dependent on their ductus arteriosus for systemic blood flow and unlike the babies who are pulmonary flow dependent, these newborns present with severely decreased cardiac output.
This decreased systemic flow is characterized by pallor, diminished peripheral pulses, low urine output, cool extremities and varying degrees of metabolic acidosis.
This includes newborns with left ventricular outflow tract obstruction at various levels.


Congenital Valvular Aortic Stenosis
Coarctation of the Aorta
Interrupted Aortic Arch
Hypoplastic Left Heart Syndrome (HLHS)

IlL     xygenation ductal dependence.

These are babies who are born with congenital heart disease that requires a patent ductus for adequate mixi g of saturated and desaturated blood.


Transposition of the Great Vessels (TGV) 
	IV J uctal independence.


These are neonates who are not dependent on a patent ductus but still require urgent operation.


Total anomalous pulmonary venous return (TAPVR)
Truncus Arteriosus
Anomalous origin of the left main coronary alloy from the pulmonaly artery.