How is global left ventricular function assessed?

Qualitatively: the examiner evaluates wall thickening in each myocardial segment and uses this as a basis for describing left ventricular function in general terms (i.e., normal, mildly diminished, moderately diminished, severely diminished).
Quantitatively: the percent fractional shortening index (diastolic area minus systolic area divided by diastolic area) may be measured in the parasternal short-axis plane at the midpapillary level. This measurement is the echocardiographic representation of the ejection fraction.