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 an 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: supra cardiac
- most common type (over 50% of cases)
- anomalous pulmonary veins terminate at the supra cardiac level
- pulmonary veins converge to form a left vertical vein which then drains to either brachiocephalic vein, SVC or azygous vein
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: infra cardiac
- connection at the infra cardiac 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 (infra cardiac) is also associated with thoracic lymphangiectasia and pulmonary congestion.
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 supra cardiac 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.
May show blind ended left atrium with no connecting veins.
Direct visualisation of anomalous venous return.
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.
congenital heart disease
- normal relationship between chambers and valves
- atrioventricular valves
- outflow tract
- great vessels
- venous inflow
- anomalous valves
- abnormal relationship of chambers and valves
- atrioventricular abnormality
- great vessel connection abnormality
- congenital heart disease - chest x-ray approach
- surgical repairs (mnemonic)
- 1. Demos TC, Posniak HV, Pierce KL et-al. Venous anomalies of the thorax. AJR Am J Roentgenol. 2004;182 (5): 1139-50. AJR Am J Roentgenol (full text) - Pubmed citation
- 2. Ferguson EC, Krishnamurthy R, Oldham SA. Classic imaging signs of congenital cardiovascular abnormalities. Radiographics. 27 (5): 1323-34. doi:10.1148/rg.275065148 - Pubmed citation
- 3. Somerville J, Grech V. The chest x-ray in congenital heart disease 1. Total anomalous pulmonary venous drainage and coarctation of the aorta. Images Paediatr Cardiol. 2009;11 (1): 7-9. - Free text at pubmed - Pubmed citation