Asymmetrically short tendinous cords causing congenital tricuspid regurgitation: improved understanding of tricuspid valvar dysplasia in the era of color flow echocardiography

Background. Tricuspid regurgitation as a manifestation of an isolated conge nital anomaly of the tricuspid valve is rare. Cross-sectional and color Dop pler echocardiography allow improved evaluation of tricuspid valvar functio n. As a result, the heterogeneous category of congenital tricuspid valvar d ysplasia may be better understood from a functional point of view. We are r eporting a distinct entity in which tricuspid valvar regurgitation results from failure of coaptation due to short tendinous cords tethering the septa l leaflet. Patients and Results. Three children with significant primary tricuspid reg urgitation were evaluated, treated, and followed. On echocardiographic eval uation, a central regurgitant jet of moderate or severe degree was directed toward the atrial septum through poorly coapting tricuspid valvar leaflets , which did not approximate due to tethering of the septal leaflet by abnor mally short cords. In one patient, the tricuspid valve was otherwise normal ; in the other two the leaflets and cords were also thickened. Two patients underwent surgery at 9 and 11 years of age. The cords tethering the septal leaflet were augmented by interposing appropriate lengths of expanded poly tetrafluoroethylene suture and performing commissural annuloplasty. Both pa tients are asymptomatic 33 and 42 months postoperatively, with mild residua l tricuspid regurgitation that has not changed since surgery. The other pat ient, an 8 month-old infant, has not yet undergone surgery. Conclusions. Asymmetric tendinous cords of the tricuspid valve causing teth ering of the septal leaflet is a distinct cause of tricuspid regurgitation that can be recognized with echocardiography. Although rare, the importance of recognizing this lesion lies in its being readily amenable to surgical repair.