Tricuspid stenosis is a narrowing of the tricuspid valve opening. Tricuspid stenosis restricts blood flow between the upper (atrium) and lower (ventricle) part of the right side of the heart.
Symptoms and Signs
Tricuspid stenosis is characterized by right heart failure with hepatomegaly, ascites, and dependent edema. In sinus rhythm, a giant a wave is seen in the JVP, which is also elevated.
The typical diastolic rumble along the lower left sternal border mimics mitral stenosis, though in tricuspid stenosis the rumble increases with inspiration.
In sinus rhythm, a presystolic liver pulsation may be found. It should be considered when patients exhibit signs of carcinoid syndrome.
In the absence of atrial fibrillation, the ECG reveals RA enlargement. The chest radiograph may show marked cardiomegaly with a normal PA size. A dilated superior vena cava and azygous vein may be evident.
The normal valve area of the tricuspid valve is 10 cm2, so significant stenosis must be present to produce a gradient. Hemodynamically, a mean diastolic pressure gradient greater than 5 mm Hg is considered significant, although even a 2 mm Hg gradient can be considered abnormal. This can be demonstrated by echocardiography or cardiac catheterization. The 2014 AHA/ACC guidelines suggest a tricuspid valve area of less than 1.0 cm2 and a pressure half-time longer than 190 msec should be considered significant.
Treatment & Prognosis
Tricuspid stenosis may be progressive, eventually causing severe right-sided heart failure. Initial therapy is directed at reducing the fluid congestion, with diuretics the mainstay. When there is considerable bowel edema, torsemide or bumetanide may have an advantage over other loop diuretics, such as furosemide, because they are better absorbed from the gut.
Aldosterone inhibitors also help, particularly if there is liver engorgement or ascites. Neither surgical nor percutaneous valvuloplasty is particularly effective for relief of tricuspid stenosis, as residual tricuspid regurgitation is common.
Tricuspid valve replacement is the preferred surgical approach. Mechanical tricuspid valve replacement is rarely done because the low flow predisposes to thrombosis and because the mechanical valve cannot be crossed should the need arise for right heart catheterization or pacemaker implantation. Therefore, bioprosthetic valves are almost always preferred. Often tricuspid valve replacement is performed in conjunction with mitral valve replacement for rheumatic mitral stenosis or regurgitation. Percutaneous transcatheter valve replacement (stented valve) has been used in degenerative prosthetic valve stenosis and a percutaneous tricuspid valve replacement device is being investigated.