Usefulness of automated quantitation of regional left ventricular wall motion by a novel method of two-dimensional echocardiographic tracking.

A novel 2-dimensional (2-D) echocardiographic tracking method enables the automated tracking of displacement between 2 points of interest in echocardiographic images. The purpose of this study was to evaluate whether this 2-D tracking method could be used to measure left ventricular (LV) wall thickness and percent systolic wall thickening (%WT) in parasternal short-axis views, in comparison with conventional manual measurement, and to determine whether this system can be used to quantitatively assess regional LV wall motion in echocardiography. In 24 subjects (12 with LV wall motion abnormalities), 6 segments in the short-axis images were assessed by this method. Two sample points at the endocardium and epicardium were tracked automatically during 1 cardiac cycle. Then, LV wall thickness and %WT were calculated. In 50 subjects (32 with LV wall motion abnormalities), average %WT as an average of all %WT in every degree of angle in each of the 6 segments was measured by this method, and the results were compared with the visual assessment of LV wall motion scores. There was excellent agreement between the 2-D tracking and manual methods for LV wall thickness (r = 0.99) and %WT (r = 0.97). The mean differences in LV wall thickness and %WT were 0.1 +/- 0.4 mm and 0 +/- 5.4%, respectively. Average %WT was significantly decreased in the regions of hypokinetic or akinetic wall motion compared with those of normal motion (18 +/- 4% and 4 +/- 4% vs 39 +/- 10%, p <0.001). In conclusion, this 2-D tracking method can be used for the noninvasive, automated quantitation of LV wall motion in 2-D echocardiography.