Tricuspid regurgitation: noninvasive techniques for determining causes and severity.

Tricuspid regurgitation is often not apparent on physical examination and several methods are now available to aid in this difficult assessment. Cardiac catheterization using right ventriculography, previously considered the diagnostic standard, has several limitations. Currently available noninvasive tools such as M-mode and two-dimensional echocardiography (with or without contrast), Doppler techniques and even radionuclide cardiologic imaging have added significantly to the precise assessment of the presence and severity of tricuspid regurgitation. This review examines the comparative use and limitations of these various techniques.