First Pass Left Ventricular Ejection Fraction by Linear Regression Analysis

Abstract

A new method for determination of first pass left ventricular ejection fraction (EF) by linear regression analysis using pairs of end-diastolic (ED) and end-systolic (ES) data points has been developed. By rearrangement of the terms in the expression for EF (EF=(ED–ES)/ED), it can be shown that a straight line relationship is obtained between ES and ED, where the slope is equal to 1–EF. We obtained beat-to-beat time-activity curves from first pass left anterior oblique images of the left ventricle (LV) in 9 patients. A LV region of interest was drawn to obtain pairs of ES and ED data points. The slope of the line obtained by plotting these points was obtained from linear regression analysis, and the EF (EF_RA) was calculated (EF=1–slope). The EFs were compared to standard left anterior oblique images (EF_EQ). The correlation obtained was: EF_RA =0.87 EF_EQ+5.8 (r=0.99; SEE=2.2%). The regression technique for LVEF determination is accurate, and the correlation coefficient obtained can be used for quality control on first pass EF determinations.