Etiology, Pathogenesis, and Differential Diagnosis

Tricuspid stenosis is uncommon. Most cases are due to rheumatic heart disease. When rheumatic tricuspid stenosis is present, it is generally associated with mitral stenosis, which usually accounts for most of the presenting signs and symptoms. Carcinoid heart disease may also cause tricuspid stenosis, and the signs and symptoms may be mimicked by tumors (myxoma or metastasis), or vegetations that obstruct right ventricular (RV) inflow, particularly those associated with pacemaker leads (Box 38-1).

Clinical Presentation

The symptoms of tricuspid stenosis are mainly due to increased systemic venous pressure that results from a hemodynamically significant tricuspid valve lesion (Fig. 38-1). Peripheral edema, ascites, hepatic enlargement, and right upper quadrant discomfort may develop with chronic tricuspid stenosis or regurgitation. Decreased cardiac output may cause pronounced fatigue, and an occasional patient will complain of the appearance or sensation of the prominent a wave in the jugular veins, which results from increased jugular venous pressure due to impaired RV filling during atrial systole. The murmur of tricuspid stenosis is a low-pitched diastolic murmur at the lower left sternal edge. However, this is often obscured by or difficult to differentiate from the usually associated mitral stenosis murmur. The physical examination, however, may demonstrate the presence of tricuspid stenosis in patients with mitral stenosis, including when there is accentuation of the diastolic murmur during inspiration (as is the case for most right-sided murmurs), a prominent a wave in the jugular venous pulse, or both. An opening snap is occasionally appreciated but may be difficult to distinguish from that of coexistent mitral stenosis. When appreciated, it is usually heard following and more medial to the mitral opening snap.

Figure 38-1 Tricuspid stenosis and/or insufficiency.

Diagnostic Approach

Useful diagnostic studies include chest radiography, ECG, and echocardiography with Doppler evaluation. Right atrial (RA) enlargement is frequently evident on radiographs and is manifest on the ECG as a large peaked P wave in lead II (Fig. 38-2). Because of the increased RA pressure, atrial fibrillation is often present.

Figure 38-2 Right atrial enlargement.

COPD, chronic obstructive pulmonary disease.

Echocardiography typically reveals thickened tricuspid leaflets, decreased mobility, scarred chordae, and sometimes doming, if the tricuspid valve leaflets remain pliable. Carcinoid heart disease is associated with a distinctive morphology of a thickened tricuspid valve that is narrowed and fixed in the open position. Doppler evaluation allows estimation of the diastolic pressure gradient by the modified Bernoulli equation. Cardiac catheterization is generally not necessary for the diagnosis of tricuspid stenosis, but when performed it calls for separate, simultaneous catheters in the right atrium and ventricle. If cardiac output is low, tricuspid gradients may also be low and are not adequately evaluated with use of a catheter pullback. Clinically significant tricuspid stenosis is usually associated with a valve area 1.5 cm² or less.

Management and Therapy

Initial treatment of tricuspid stenosis includes diuretics and nitrates to relieve venous congestion. Refractory cases have traditionally required open tricuspid valve repair or replacement, and concomitant mitral valve disease has primarily determined the indication and timing for surgery. A surgical approach may also be indicated for debulking of obstructive tumors or myxoma. However, while no randomized trials are available given the relatively low prevalence of this condition, published studies do suggest that percutaneous techniques are effective and safe, either as therapy for isolated tricuspid stenosis or for combined mitral and tricuspid disease, and referral to experienced centers should be considered. Percutaneous therapy should generally not be undertaken, however, if there is more than mild associated tricuspid regurgitation, as is often the case.

Etiology and Pathogenesis

Tricuspid regurgitation may be due to primary disease of the valve apparatus or diseases causing pulmonary hypertension with secondary annular dilatation. Secondary tricuspid regurgitation is seen in any condition associated with increased pulmonary artery pressures, and is the predominant cause of tricuspid regurgitation. The most common secondary causes are left ventricular failure, mitral regurgitation, mitral stenosis, primary pulmonary disease, and primary pulmonary hypertension. The rare causes of primary tricuspid regurgitation include rheumatic heart disease, myxomatous disease (prolapse), infective or marantic endocarditis, carcinoid heart disease, iatrogenic injury during endomyocardial biopsy or placement of pacemaker or defibrillator leads, and trauma.

Clinical Presentation

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