Subjective visual echocardiographic estimate of left ventricular ejection fraction as an alternative to conventional echocardiographic methods: Comparison with contrast angiography

Left ventricular ejection fraction (LVEF) is a measure of ventricular function with clinical and prognostic significance and can be reliably calculated with various M‐mode and two‐dimensional echocardiographic formulas in selected, good quality echocardiographic formulas in selected, good quality echocardiograms. Subjective visual echocardiographic estimate of LVEF is a potentially less time consuming and more widely applicable method. In order to test its reliability, we performed a prospective blind trial in 40 consecutive patients undergoing biplane contrast ventriculography (BCV), to compare the visual estimate of LVEF during a complete echocardiogram of three independent observers with (1) cubed M‐mode formula, (2) Teichholz M‐mode formula, (3) length‐area method from the four‐chamber view, and (4) Simpson's single plane formula. BCV was the reference method. The best correlation with BCV was obtained by visual estimate [r of the three observers, respectively=0.75; 0.84; 0.81] and M‐mode measurements [r (1)=0.8; r(2)=0.8], but the most sophisticated methods provided the poorest estimate [r (3)=0.54; r(4)=0.49]. All correlation coefficients improved when good studies, defined as a definition of the endocardial surface of more than 75%, were selected (n=23), but the differences persisted. One observer systematically estimated higher values than the other two (Friedman's test, p<0.01) and this interobserver variability suggests that each echocardiographer should test himself against BCV in his lab in order to apply the visual estimate method reliably.