Clinical use of echocardiography: a review.

The clinical usefulness of echocardiography can be considered under a few broad categories: (a) measurement of internal structures and their changing relationships to each other throughout the cardiac cycle; (b) demonstration of abnormalities of function which are dependent on motion--for example, the prolapsing mitral leaflet or the paradoxical septal motion in right ventricular volume overload; and (c) changes within the heart such as pericardial effusion which lead to the development of echo-free spaces or the appearance of echo within a normally echo-free chamber as in myxoma.