Levotransposition of the great arteries
Overview
levo-Transposition of the great arteries (l-Transposition of the great arteries, levo-TGA, or l-TGA), also commonly referred to as congenitally corrected transposition of the great arteries (CC-TGA), is an acyanotic congenital heart defect (CHD) in which the primary arteries (the aorta and the pulmonary artery) are transposed, with the aorta anterior and to the left of the pulmonary artery; and the morphological left and right ventricles are also transposed.
Symptoms
Simple l-TGA does not immediately produce any visually identifiable symptoms, but since each ventricle is intended to handle different blood pressures, the right ventricle may eventually hypertrophy due to increased pressure and produce symptoms such as dyspnea or fatigue. Complex l-TGA may produce immediate or more quickly-developed symptoms, depending on the nature, degree and number of accompanying defect(s). If a right-to-left or bidirectional shunt is present, the list of symptoms may include mild cyanosis.
Diagnosis
l-TGA can sometimes be diagnosed in utero with an ultrasound after 18 weeks gestation. However, many cases of simple l-TGA are "accidentally" diagnosed in adulthood, during diagnosis or treatment of other conditions.
Prognosis
Simple l-TGA has a very good prognosis, with many individuals being asymptomatic and not requiring surgical correction. In a number of cases, the (technically challenging) "double switch operation" has been successfully performed to restore the normal blood flow through the ventricles.