The authors present an optional use for a traditional echocardiographic parameter measuring the distance from the mitral valve anterior cusp to the interventricular septum (E-S) to estimate the left ventricle ejecti¬on fraction in a cohort of 115 unselected patients undergoing invasive cardiologic investigation. The best correlation to the left ventricle ejection fraction estimated by echocardiography is found by E-S measure-ment in the five-chamber view (correlation ratio 0.78). Determining the minimum E-S distance is a quick, easy to perform, and reproducible tool in almost all patients presenting for echocardiography in a sample of the generál population, having only a minimum of limitations. This tool could be especially useful in emer-gencies and intensive care. Certain limitations of this tool are addressed in the discussion.

        Key words: E-S distance, left ventricle ejection fraction estimate.