Laboratory Studies
The following laboratory studies may be useful:
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Complete blood cell count: If the white blood cell count is elevated, infection should be considered. A disproportionately high hemoglobin (polycythemia) level may be indicative of poor pulmonary blood flow.
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Complete chemistry profile: The results of this test may help delineate metabolic abnormalities associated with certain inborn errors of metabolism.
Imaging Studies
A complete evaluation of the heart often necessitates a multimodality approach, including radiography, echocardiography, computed tomography (CT), magnetic resonance (MR) imaging, and invasive angiography. [6]
The following imaging studies may be useful:
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Chest radiography: Cardiac size may range from normal to enlarged (ie, cardiomegaly). Right atrial enlargement may be prominent. Findings specific to a particular associated congenital heart disease may also be seen.
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Echocardiography: This test has become the procedure of choice for the diagnosis of valvular disorders. The test results help delineate the structure of the tricuspid valve and any other intracardiac pathology that may contribute to the pathophysiology of the process. [7]
Other Tests
Electrocardiogram
Arrhythmias are frequent in this patient population. Because of the enlargement of the right atrium, the presence of atrial flutter and/or fibrillation should not be surprising. In sinus rhythm, right atrial enlargement or abnormality (tall P waves on inferior leads) may be noted.
Procedures
Cardiac catheterization
This may be required prior to surgery in older patients to assess for concomitant coronary artery disease. Right heart catheterization can be used to determine the gradient across the valve and valve area (ie, severity of stenosis) and assess the presence of associated congenital defects (eg, septal defects, intracardiac shunts, anomalous veins) if present. Assessment of aortic and mitral valves via left heart catheterization is useful in patients with rheumatic disease.
Histologic Findings
Most commonly, stenotic tricuspid valves are secondary to rheumatic fever. These generally demonstrate fibrous tissue proliferation without calcium deposits. The leaflet tissue is composed of dense collagen and elastic fibers, producing major distortions of the normal leaflet layers. Congenitally abnormal valves can show a wide spectrum of incompletely developed leaflets, abnormal chordae tendineae, or dysplastic papillary muscles.
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Tricuspid Stenosis. A representation of a stenotic tricuspid valve. This image demonstrates fusion of the commissures (shown as dotted lines).
