"arises from failure of the common pulmonary vein to incorporate into the LA (around 30 days' gestation)."
"results in persisting connections between the primitive pulmonary venous plexus and the cardinal venous systems."
"Type I: supracardiac"
"Type II: cardiac"
"Type IV: mixed pattern"
"pulmonary veins converge to form a left vertical vein which then drains to either brachiocephalic vein, SVC, or azygos vein"
Expected headings
"Type I: supracardiac"
"Type II: cardiac"
"Type III: infracardiac"
"Type IV: mixed pattern"
"Other rare types"
"Associations"
"Echocardiography"
"CT/MRA"
"at the earliest stage of lung development, the primitive lung bud venous drainage occurs via the splanchnic plexus to primitive systemic (cardinal/umbilicovitelline) veins; at this point, the heart is still forming and there is no pulmonary connection"
"the common pulmonary vein joins with the pulmonary veins from each lung, forming the familiar configuration; simultaneously, there is involution of the primitive connection between pulmonary veins and primitive systemic veins"
"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."
"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."