TRANSPOSITION OF THE GREAT-ARTERIES WITH DISPLACED ATRIOVENTRICULAR VALVES OR CHORDAE - ECHOCARDIOGRAPHIC APPEARANCES AND SURGICAL CORRELATIONS

The authors report the echocardiographic appearances of 27 cases of tr ansposition of the great arteries (TGA) with ventricular septal defect (VSD) (including the Taussig-Bing malformation) complicated by displa cement of one or both atrioventricular valves and/or chordae tendinae diagnosed between September 1985 and September 1994. An anatomical rep air was performed in 21 cases and allowed accurate correlation of the echocardiographic and peroperative findings; a cavo-bipulmonary condui t or a palliative procedure was performed in 6 cases. The cases were c lassified in 3 groups: group I: 16 children with isolated tricuspid va lve abnormalities; group II: 7 cases of mitral valve straddling; group III: 4 cases of displacement of both atrioventricuspid valves and/or their chordae. The cases of group I were divided into 3 subgroups: sub group Ia with insertion of the tricuspid chordae on the infundibular s eptum (7 cases); subgroup Ib with isolated overriding of the tricuspid valve (2 cases); subgroup Ic straddling with or without overriding of the tricuspid valve (7 cases). In all three groups, there were 10 cas es of straddling of the tricuspid and 11 cases of straddling of the mi tral valve: 9 type A, 3 type B and 9 type C of Tabry's classification. Echocardiography misdiagnosed one case of type A straddling of the tr icuspid valve for a type A overriding and straddling of the mitral val ve. The ventricular septal defect was situated in the admission septum in the 10 cases of straddling of the tricuspid; in the 11 cases of st raddling of the mitral valve the chordae passed through the superior a nterior part of the interventricular septum. Two cases of straddling w ith overriding of the mitral valve were associated with left ventricul ar hypoplasia. The anatomical repair could not be performed in three c ases because of straddling of an atrioventricular valve; two type C st raddling of the tricuspid valve and one case of straddling of both atr ioventricular valves. The recognition of straddling of an atrioventric ular valve by echocardiography modified the surgical strategy in 5 cas es and led to palliative procedures. The results of this series show t hat the presence of a type C straddling or the presence of a double st raddling and ventricular hypoplasia are poor prognostic factors for an atomical repair of TGA with VSD.