Echocardiographic criteria for Ebstein's anomaly of tricuspid valve.

The diagnostic echocardiographic features of Ebstein's malformation of the tricuspid valve have been evaluated in two groups of patients, using M-mode and two-dimensional techniques.The first group consisted of nine patients in whom previous M-mode studies had suggested the existence of Ebstein's anomaly.The second group consisted of 20 patients, all suffering from right heart overload, in whom Ebstein's malformation was excluded at open heart surgery.The M-mode studies disclosed that none of the criteria currently employed could be considered diagnostic.A delay in tricuspid valve closure of more than 65 ms, considered the most reliable indicator, was also present in eight of 20 'controls'.The characteristic anatomical feature, that is distal displacement of the septal tricuspid leaflet, was never identified with certainty using M-mode echograms, in contrast to two- dimensional echograms which showed a high degree of accuracy.Two-dimensional techniques disclosed an abnormal insertion in six of nine patients in the first group, while a normal insertion was positively identified in 13 of 14 patients with right heart overload.In two of the nine patients in whom Ebstein's anomaly was suggested by M-mode criteria, a normal septal origin was identified and all further attempts to substantiate this diagnosis failed.In one patient from the first group, the two-dimensional studv was inconclusive regarding positive identification of the septal origin.Open heart surgery showed a normal origin of the septal leaflet, though the valve was plastered to the septal surface by short chordae.Only once among 14 'controls' was the septal attachment inconclusively identified with the two-dimensional echograms.Surgery, however, excluded the presence of Ebstein's anomaly in this patient.Two- dimensional echocardiography, aiming at visualising the septal origin of the tricuspid valve, thus seems to be useful in establishing a diagnosis of Ebstein's malformation of the tricuspid valve.