Primary TR (caused by structural alterations of the valve) can be caused by
Myxomatous disease (leading to prolapse of the valve leaflets)
Rheumatic heart disease,
Iatrogenic causes (occasionally TR occurs after pacemaker implantation or after endomyocardial biopsy)
Carcinoid syndrome( carcinoid syndrome, is a type of neuroendocrine tumor, usually in the small bowel or appendix, with metastases to the liver, which releases serotonin metabolites into the bloodstream. These metabolites are responsible for the formation of endocardial plaques in the right heart chambers. Involvement of the tricuspid valve causes thickening and immobilization of the leaflets, resulting in significant tricuspid regurgitation and, less often tricuspid stenosis.)
Ebstein’s anomaly is a congenital malformation characterized by apical displacement of the annular insertion of the septal and posterior leaflets of the tricuspid valve and atrialization of a portion of the ventricular myocardium.
Physical examination in TR
The most common physical signs of severe TR are prominent v waves in the jugular veins and a pulsatile liver. Both these signs are due to regurgitation of right ventricular blood into the systemic veins.
regurgitant jet in the right atrium.
Significant tethering of the valve, in secondary TR, is characterized by a coaptation distance > 8 mm. This is the distance between the tricuspid annular plane and the point of coaptation of the valve leaflets in mid-systole from the apical 4-chamber view.
Regurgitant jet area correlates roughly with the severity of regurgitation:mild <5 cm2
moderate 6-10 cm2
severe >10 cm2.
Other more accurate indications of severe TR are:
Vena contracta ≥ 7 mm
In continuous wave Doppler examination of TR, a dense/triangular TR Doppler signal with early peaking.
The surgical operation performed is usually annuloplasty with a prosthetic ring, but in advanced forms of tethering and RV dilatation, or in a severe valve deformity that cannot be corrected, valve replacement should be considered. Valve replacement is performed with large bioprostheses (these are preferred than mechanical valves in the tricuspid position).
Tricuspid regurgitation (color doppler echocardiography). A video-link (by dr Luke Howard) :