what is truncus arteriosus
Truncus arteriosus is a congenital (present at birth) defect that occurs due to abnormal development of the fetal heart during the first 8 weeks of pregnancy.The heart begins as a hollow tube, and the chambers, valves, and great arteries develop early in pregnancy.lick Image to Enlarge. Truncus arteriosus is a congenital (present at birth) defect that occurs due to abnormal development of the fetal heart during the first 8 weeks of pregnancy. The heart begins as a hollow tube, and the chambers, valves, and great arteries develop early in pregnancy.