Echocardiographic evaluation of left ventricular function.

The ability of echocardiography to assess left ventricular function is entering an era of transition. Most existing data have been derived from M-mode measurements made along a single echo beam axis and, as such, were based on the assumption that the performance of the sampled segment represented that of the whole ventricle. The recent availability of two dimenensional echocardiography lessens the need to rely on this assumption.