Total anomalous pulmonary venous return

Total anomalous pulmonary venous return (TAPVR) is a cyanotic congenital heart anomaly with an abnormal drainage anatomy of the entire pulmonary venous system. This contrasts with partial anomalous pulmonary venous return (PAPVR) where only part of the pulmonary venous anatomy is abnormal.

In TAPVR, all systemic and pulmonary venous blood enters the right atrium and nothing drains into the left atrium. A right-to-left shunt is required for survival and is usually via a large patent foramen ovale (PFO) or less commonly atrial septal defect (ASD).

Affected infants develop cyanosis and congestive heart failure in the early neonatal period.


There is embryological failure of pulmonary venous development that results in persistent patency of primitive systemic veins.


TAPVR can be classified into four types (in decreasing order of frequency) depending on the site of anomalous venous union 1:

Type I: supracardiac
Type II: cardiac
  • second most common (~30% of cases)
  • pulmonary venous connection at the cardiac level
  • drainage is into the coronary sinus and then the right atrium
Type III: infracardiac
  • connection at the infracardiac level
  • the pulmonary veins join behind the left atrium to form a common vertical descending vein
  • the common descending vein courses anterior to the oesophagus passes through the diaphragm at the oesophageal hiatus and then usually joins the portal system
  • drainage is usually into the ductus venosus, hepatic veins, portal vein or IVC
Type IV: mixed pattern
  • least common type
  • anomalous venous connections at two or more levels

Approximately one-third of those with TAPVR also have other associated cardiac lesions; many have heterotaxy syndrome, particularly asplenia. Type III (infracardiac) is also associated with thoracic lymphangiectasia and pulmonary congestion.

Radiographic features

Plain radiograph

The right heart is prominent in TAPVR because of the increased flow volume, but the left atrium remains normal in size. Types I and II result in cardiomegaly.

The supracardiac variant (type I) can classically depict a snowman appearance on a frontal chest radiograph, also known as figure of 8 heart or cottage loaf heart 2-3. The dilated vertical vein on the left, brachiocephalic vein on top, and the superior vena cava on the right form the head of the snowman; the body of the snowman is formed by the enlarged right atrium.


Direct visualisation of anomalous venous return.

Ultrasound: echocardiography

May show blind ended left atrium with no connecting veins.

Congenital heart disease

There is more than one way to present the variety of congenital heart diseases. Whichever way they are categorised, it is helpful to have a working understanding of normal and fetal circulation, as well as an understanding of the segmental approach to imaging in congenital heart disease.

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