[Straddling and overriding atrio-ventricular valves: echocardiographic and angiographic findings]

Recent advances in surgical technique for correction of positional abnormalities of atrio-ventricular (A-V) valve require accurate preoperative diagnosis of this malformation which can be distinguished into a complete (overriding + straddling) and a partial form (overriding or straddling). In this study, echocardiography and angiocardiography are shown to be complementary to each other for definition of the anatomic details of this pathology. Six cases of positional abnormalities of the A-V valves are reported. Group I includes three patients with tricuspid valve abnormalities: two are complete forms (overriding + straddling) one of which is associated with DORV and the other is associated with d-TGA. The third patient is a partial form: straddling tricuspid valve with only a large ventricular septal defect involving the inlet septum. Group II includes three patients with mitral valve abnormalities: one complete form and two partial ones (straddling), all associated with DORV. We illustrate the best echocardiographic and angiocardiographic projection for the recognition of A-V valve malposition and demonstrate that both techniques greatly add to the diagnostic accuracy. Echocardiography defines better the abnormal attachments of the leaflet apparatus, whereas angiocardiography identifies better the displacement of the A-V valve annulus.