Segmental Model for Estimating Left Ventricular Ejection Fraction by Two-Dimensional Echocardiography: Comparison with Gated Blood Pool Scanning

Left ventricular ejection fraction was determined by two-dimensional echocardiography in 54 patients using a new method, and the results were compared with the ejection fraction by gated blood pool scanning. The ventricle was modelled as a tubular base section joined to a hemielliptical apex section, each containing four quadrants. Segmental contraction was scored in twelve regions of the ventricle by visual assessment of wall motion during videotape playback of echocardiograms. The twelve contraction scores were converted to dimensional shortening and used to calculate separate ejection fractions for each of the eight quadrants. These eight values were averaged to obtain the left ventricular global ejection. Fifty-eight patients with echocardiograms and gated scans within 7 days of each other were selected retrospectively from among the routine studies in the clinical laboratory. Image quality was adequate for wall motion scoring in 54 patients. The correlation coefficient between echocardiography and gated scanning was 0.92 with a standard error of 7.5. The accuracy of the method was very similar for studies with the most homogeneous wall motion compared to those with the most dyssynergy and in patients with the lowest ejection fractions compared to those with the highest ejection fractions. In 31 patients, scoring of contraction was performed independently by two different observers. Both observers attained an identical correlation with gated scan of 0.92. The interobserver correlation coefficient was also 0.92 with a standard error of 7.8. It is concluded that this method of estimating left ventricular ejection fraction is simple to use and may provide a clinically acceptable degree of accuracy in a wide variety of conditions of left ventricular function.