d-transposition of the great arteries, the aorta arises in an
anterior position from RV and the pulmonary artery arises from
LV (see figure 23e). In two thirds of cases the ductus arteriosus
(see figure 22) and foramen ovale allow communication between
the aortic and pulmonary circulations. Severe cyanosis is present.
The one third with other defects that permit intracardiac mixing
(i.e. ASD figure 20, VSD figure 21, PDA figure 22) are less
critically ill with loss ofsevere cyanosis, but they are at
risk of LV failure.
include cyanosis and heart murmur. RVH (increased RV wall thickness)
or LVH (increasedLV wall thicckness) may be present. Chest X
ray shows heart enlargement.
management involves creating intracardiac mixing or increasing
1) use of infusing of medication, prostaglandine E, to maintain
or restore patency of ductus arterioses, the creation of an
ASD or both. Also, oxygen is administered to most patients (to
decrease pulmonary [lung] vascular (blood vessel) resistance
and to increase lung blood flow), as are digoxin and diuretic
drugs like diuril or lasix (to treat heart failure).
surgical operations have been used (see figure 23e regarding
the atrial switch operation). The atrial switch operation as
shown in figure 23 E has been replaced by the arterial switch
operation in which the pulmonary artery and ascending aorta
are transected above the semilunar valves and coronary arteries
(see figure 23e), and then switched, so that the aorta is connected
to the neoaortic valve (formerly the pulmonary valve) arising
from the left ventricle (LV), and the pulmonary artery is connected
to the neopulmonary valve (formerly the aorta valve) arising
from the RV (see figure 23e). The coronary arteries are relocated
to the neoaorta to restore normal coronary circulation. This
operation can be performed in neonates (newly born) and is associated
with a low operative mortality and an excellent long-term outcome.