DIAGNOSTIC-VALUE OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY IN THE ASSESSMENT OF CONGENITALLY CORRECTED TRANSPOSITION OF THE GREAT-ARTERIES IN ADULT PATIENTS

This study was designed to evaluate the relative diagnostic values of transthoracic (TTE) and transesophageal (TEE) echocardiography in the assessment of congenitally corrected transposition of the great arteri es in adult patients. Twelve patients (mean age 29 years, range 21 to 39 years) with congenitally corrected transposition of the great arter ies underwent both TTE and TEE examinations to assess this complex car diac lesion. Of the 12 patients evaluated, situs solitus and inversus were present in 8 and in 4 patients, respectively. TTE correctly ident ified atrial situs in only 10 patients, whereas TEE, directly evaluati ng the morphologic features of either appendage, correctly determined situs in every patient. In all 11 patients with intact inlet ventricul ar septum, the spatial relationship between the septal leaflets of atr ioventricular valves was correctly evaluated by both techniques. Howev er, the chordal attachments of both valves were clearly elucidated by TEE in all patients, whereas TTE could obtain images of these in only three patients. TTE was able to evaluate the discordant connection bet ween the right ventricle and the anterior vessel (aorta) in 10 patient s, whereas the connection between the left ventricle and the posterior vessel was clearly shown only in 7 patients. Transesophageal longitud inal planes better elucidated these two discordances in all patients i rrespective of the position of the heart in the chest and atrial situs . Four patients had an associated ventricular septal defect (inlet def ect in one, perimembranous in two, and muscular in one); the inlet def ect was unrestrictive and could be easily detected by either imaging t echnique, whereas the membranous was detected by TTE and by the horizo ntal transesophageal planes; the muscular defect was recognized only b y TTE. Three patients had an associated pulmonary stenosis; Doppler tr ansthoracic echocardiography showed a left outflow peak gradient of 10 0 mm Hg in two patients and of 80 mm Hg in one but failed to adequatel y assess the morphologic features of the stenosis, whose features were clearly visualized by transesophageal longitudinal planes in all pati ents. In conclusion, in our experience TEE is superior to transthoraci c imaging in studying congenitally corrected transposition of the grea t arteries in adult patients; the horizontal plane is best suited to t he evaluation of atrial situs and the atrioventricular junction, where as the longitudinal plane is most valuable in the study of the morphol ogic features of the ventriculoarterial connections. These findings sh ould be equally applicable to multiplane transesophageal studies.