Origin and Site of the Tricuspid Regurgitant Jet Determined by Color Flow Imaging in Ebstein's Anomaly

Fifty patients with tricuspid regurgitation due to a variety of causes including rheumatic heart disease, pulmonary hypertension, atrial septal defect, and tricuspid valve endocarditis (group 1); and seven patients with Ebstein's anomaly of the tricuspid valve (group 2) had color Doppler flow imaging performed. The position of the tricuspid annulus and the site of origin of the turbulent tricuspid regurgitant jet were determined from the apical four-chamber view. The site of origin of the tricuspid regurgitant jet was at or within 0.5 cm of the level of the tricuspid annulus in all group 1 patients. In contrast, all patients in group 2 had tricuspid regurgitant jets that originated deep in the right ventricle and at a considerable distance from the tricuspid annulus (3.8 ± 1.4 cm, mean ± SD). The distance from the origin of the tricuspid regurgitant jet to the tricuspid annulus was measured and expressed as a ratio to that of the distance from the right ventricular apex to the tricuspid annulus in groups 1 and 2. This ratio was 0.94 ± 0.2 in group 1 and 0.61 ± 0.10 in group 2 patients. In conclusion, the tricuspid regurgitant jet originates at or near the level of the tricuspid annulus except in patients with Ebstein's anomaly. Origin of the tricuspid regurgitant jet distal to tricuspid annulus is a clue to the diagnosis of Ebstein's anomaly and is particularly helpful in those patients in whom the displaced tricuspid leaflet cannot be convincingly demonstrated on the two dimensional echocardiogram.