One percent of all congenital heart defects.

TAPVD, the severe form, or PAPVD, the less severe form, exists when pulm veins drain into the venous circulation.

M:F 4:1 in infradiaphragmatic type.

Rapid CV deterioration secondary to hypercapnia and resultant acidosis

Sudden pulm Htn and RHF during hypoventilation

Periop mortality: 2-20% depending on preop status

Rapid CV deterioration secondary to hypercapnia and resultant acidosis

Sudden pulm Htn and RHF during hypoventilation

Periop mortality: 2-20% depending on preop status

Air bubbles entering the venous circuit

Endocarditis risk

Concurrent pneumonia with hypoxemia or hypercarbia

Polycythemic hyperviscosity attack with:

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  Periop dehydration

  
  
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  Cold OR environment

TAPVD incompatible with life unless an ASD allows adequate R-to-L shunting of blood. TAPVD pts with small ASDs are more critically ill and often require balloon septostomy as a bridge to surgery. Some cyanosis, usually with O ₂ saturations of 85-95%.

Increased flow through pulm vascular beds results in pulm Htn.

Four types of TAPVD:

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  Supracardiac: Pulm veins connect to the left innominate vein via an anomalous “vertical vein” or connect to the right SVC via an anomalous “short connecting vein,” or connect to the left SVC (45%).

  
  
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  Cardiac: Pulm veins drain into the coronary sinus or directly into the right atrium (23%).

  
  
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  Infracardiac: Pulm veins drain into IVC, portal veins, hepatic veins, or ductus venosus (21%).

  
  
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  Mixed: Combined supracardiac, cardiac, and infracardiac connections (11%).

Embryologic atresia or malformation of the common pulm venous system resulting in persistence of abnormal connections

Severe TAPVD with little systemic shunt needs immediate cardiac correction after birth. Most children with TAPVD require cardiac correction before 1 y of age.

Cardiac correction of PAPVD may be postponed into childhood.