Isolated prolapse of the tricuspid valve.

Tricuspid valve prolapse has remained a poorly defined entity. Some authors have stated that prolapse isolated to the tricuspid valve has not been documented. This report contains three cases of isolated tricuspid valve prolapse including the first pathologically confirmed case. A review of worldwide literature including all reported cases of isolated tricuspid valve prolapse is also presented. Although signs and symptoms are similar to those found with mitral valve prolapse, tricuspid valve prolapse may occasionally be differentiated by auscultation. The diagnostic criteria of tricuspid valve prolapse are thoroughly discussed for each of the presently available invasive and noninvasive techniques. Right heart catheterization can define such prolapse but is invasive and requires meticulous technique. Two-dimensional echocardiography supersedes M-mode because of the superior spatial evaluation of the tricuspid leaflets in relation to the right atrium and ventricle. Multiple views including a long-axis view of the right ventricular inflow are often required. This parasternal echocardiographic window is often the only one which permits adequate visualization of the posterior leaflet. The pathologic findings of tricuspid valve prolapse are similar to those of mitral valve prolapse. This report concludes with a description of associated conditions. Severe tricuspid regurgitation has not been noted with tricuspid valve prolapse in the absence of superimposed disease, yet much remains undefined concerning the clinical significance of this condition.