Double outlet right ventricle (DORV) is a serious congenital (present at birth) heart defect that causes the aorta — the main artery that carries blood from the heart — to attach to the right ventricle, instead of the left one. Since DORV happens while a baby is growing in the womb, it’s sometimes found during prenatal tests. Babies born with DORV have their first surgery when they are weeks or even days old.