A New Echocardiographic Formula to Calculate Ejection Fraction by Using Systolic Excursion of Mitral Annulus

The correlation between echocardiographically and angiographically calculated ejection fraction and systolic excursion of the mitral annulus was studied in 81 patients. Knowing that the mitral annulus changes its size, shape, and position during the cardiac cycle, the authors measured systolic excursion of the annulus by 2D echocardiography. Displacement of the mitral annulus was measured from four different points (medial, lateral, anterior, posterior) by apical four-chamber and apical two-chamber approaches. Patients with and without regional wall motion abnormalities were included. Left ventricular volumes and ejection fraction (EF) were calculated in the standard manner introduced by Teichholz et al and also with biplane left ventriculography. As a result, EF calculated by cineangiography, was moderately correlated with the Teichholz method (r = 0.66) while it was highly correlated with measurements of mitral annular motion (MAM) (r = 0.87). The correlation can be expressed by the regression equation, EF (angiography) = 5.7 MAM (in mm) -6.5. They conclude that measurements of annular motion is an easy and reliable index of left ventricular function as an alternative to traditional methods.