Value and Limitations of Continuous-Wave Doppler Echocardiography in Estimating Severity of Valvular Stenosis

DOPPLER echocardiography is a valuable new technique that provides a noninvasive method of detecting both direction and velocity of intracardiac blood flow. Perhaps the single most important use of Doppler echocardiography today is in the quantitation of valvular stenosis. Clinical clues and traditional noninvasive tests such as phonocardiography and echocardiography are quite useful for the detection of aortic and mitral stenosis, yet have been shown to have serious limitations in the quantitation of such lesions. 1,2 Doppler echocardiography provides physiologic information concerning flow across an orifice and allows for the estimation and location of pressure gradients. Nevertheless, application of Doppler for this purpose requires considerable expertise, and care must be taken to avoid common pitfalls in performance and interpretation of the Doppler examination. The purpose of this article is to explain the technical basis of Doppler echocardiography, to examine its role in estimating pressure gradients, and to point out some