Abstract
Left ventricular ejection fraction is frequently quantitated by M‐mode echocardiography despite limitations, including 1) the ability to measure an accurate left ventricular short axis, 2) the mathematic and geometric assumptions used to derive the volumes from which the ejection fraction is calculated, and 3) the lack of applicability to asynergic ventricles. Nevertheless, using a cubed function or correction formula, ejection fraction can be calculated for symmetrically contracting, normally sized, and enlarged left ventricles. A table and accompanying comments are presented.