Bilat. SVC 45% 45%
Bilat. systemic
venous drainage
70% 60%
Absence of coronary
sinus
100% 60%
Interruption of IVC < 2.5% 80%
Juxtaposition of
aorta and IVC
90% 50%
Extracardiac type of
TAPVC with/without
obstruction
50%, with
obstruction in 50%
Rare
Pulm. Venous
connection to
ipsilat. atria
4% 45%