SEGMENTAL ANALYSIS OF COLOR KINESIS IMAGES - NEW METHOD FOR QUANTIFICATION OF THE MAGNITUDE AND TIMING OF ENDOCARDIAL MOTION DURING LEFT-VENTRICULAR SYSTOLE AND DIASTOLE

Background We describe a method for objective assessment of left ventr icular (LV) endocardial wall motion based on Color Kinesis, a new echo cardiographic technique that color-encodes pixel transitions between b lood and myocardial tissue. Methods and Results We developed a softwar e that analyzes Color Kinesis images and provides quantitative indices of magnitude and timing of regional endocardial motion. Images obtain ed in 12 normal subjects were used to evaluate the variability in each index. Esmolol, dobutamine, and atropine were used to track variation s in LV function in 14 subjects. Objective evaluation of wall motion w as tested in 20 patients undergoing dobutamine stress testing. Regiona l fractional area change, displacement, and radial shortening were dis played as histograms and time curves. Global function was assessed by calculating magnitude and timing of peak ejection or filling rates and mean time of ejection or filling. Patterns of endocardial motion were consistent between normal subjects. Fractional area change and peak e jection rate decreased with esmolol and increased with dobutamine. Tim e to peak ejection and mean time of contraction were prolonged with es molol and shortened with dobutamine. Using atropine, we proved that ou r findings with dobutamine were not secondary to its chronotropic effe cts. Dobutamine induced regional wall motion abnormalities in 10 patie nts in 38 segments diagnosed conventionally. Segmental analysis detect ed abnormalities in 36 of these 35 segments and in an additional 5 of 322 segments. Conclusions Analysis of Color Kinesis images allows fast , objective, and automated evaluation of regional wall motion sensitiv ely enough to evaluate clinical dobutamine stress data. This method ha s significant potential in the diagnosis of myocardial ischemia.