This historical paper highlights the early developmental phase of echocardiography for evaluating left ventricular function, noting it was considered investigational at the time.
Echocardiography may make substantial contributions to the definition and measurement of left ventricular function in man. Several unique features of this method make it attractive, but less obvious limitations have been recognized recently. Echocardiography has been applied to measurement of the extent of left ventricular function only within the past few years, so that it is not surprising that its application is still very much in a developmental phase. Although echocardiography is in daily clinical use for a great many cardiac conditions, most experts classify measurement of left ventricular function by this means as investigational.Measurements of cardiac dimensions and . . .
Richard L. Popp (1977) studied this question.