Multiplanar review of three-dimensional echocardiography gives new insights into the morphology of Ebstein's malformation

Abstract

Introduction: We aimed to assess the ability of the multiplanar review modality of three-dimensional echocardiography to examine the dynamic morphology and the functional characteristics of malformed tricuspid valves in patients previously identified as having Ebstein's malformation. Based on these characteristics, we attempted to differentiate Ebstein's malformation from tricuspid valvar dysplasia.

Methods: Using three-dimensional multiplanar review, analysed with either Qlab 6.0 or Tomtech Image Arena 3.0, we studied 23 patients, aged from 1 day to 70 years, previously diagnosed using cross-sectional echocardiography as having Ebstein's malformation.

Results: Using the features of rotational abnormality, and the orientation, of the effective tricuspid valvar orifice as diagnostic features of Ebstein's malformation, we reclassified 11 patients (48 per cent) as exhibiting tricuspid valvar dysplasia. In addition, we studied the dynamic morphology as well as the function of the tricuspid valve. Surgical treatment was undertaken on 10 patients, revealing good correlation with the findings obtained using three-dimensional multiplanar review. In those with Ebstein's malformation, we found varying degrees of rotation, with the effective valvar orifice always directed towards the right ventricular outflow tract. The opening of the orifice of dysplastic tricuspid valves, in contrast, was towards the apex of the right ventricle. The degree of delamination, and abnormalities of subcordal apparatus, were similar in the two groups.

Discussion: Three-dimensional multiplanar review permits accurate definition of the dynamic morphology of Ebstein's malformation, permitting clear differentiation from tricuspid valvar dysplasia.