الفهرس 
CARDIAC DEVELQPMENT (With Congenital Defect Implications)Only 14 pages are availabe for public view
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Abstract
ince the first blue baby operation in 1944, conceived by Dr. Helen Taussig and performed by Dr. Alfred Blalock, dramatic diagnostic and therapeutic advances have improved survival for most infants born with cyanotic heart defects.
In neonates with cyanosis related to congenital heart disease, an abnormality is present that allows unoxygenated blood to enter the systemic circulation. Diminished systemic oxygenation and cyanosis may result when there is obstruction to pulmonary blood flow and intra-cardiac right-to-left shunting.
Transposition of the great arteries (TGA) is the most common cause of cyanosis in the newborn with heart disease, accounting for about 10.5% of all congenital heart defects with a marked male preponderance.
The hallmark of TGA is ventriculo-arterial discordance i.e. the aorta arising from the morphologic right ventricle and the pulmonary artery arising from the morphologic left ventricle. The classic TGA is called D-TGA because the aorta is located anteriorly and to the right (dextro) of the pulmonary artery. Circulation in this malformation is considered two completely parallel circuits. The deoxygenated circuit pumps blood from the right atrium to the right ventricle, out the aorta to the body, and back to the right atrium. The oxygenated circuit pumps blood from the left atrium to the left ventricle, out the pulmonary artery, and back to the left atrium.