[New approach for quantifying left ventricular regional wall motion in ischemic heart disease: motion vector analysis...

To quantify regional wall motion of the left ventricle with two-dimensional echocardiography, the motion of an endocardial surface point in echocardiograms was analyzed throughout systole on frame by frame using video motion analyzer. With a fixed external reference system and in the "69% point (C)" by Ingels et al, the motion vector (M) of a point was expressed in two components; the contracting component (Y) directed toward the point C, and the component vertical to it, the shearing component (X). In the control group, the magnitude of M and its contracting component were widely varied with the location along the endocardial surface (5.6 +/- 1.6, 5.0 +/- 1.5 mm in the apex, 10.9 +/- 2.2, 10.4 +/- 2.0 mm in the inferior base, p less than 0.001 and p less than 0.001, respectively). The shearing component and the angle theta at which M and Y meet, showed narrow normal ranges (1.9 +/- 1.4 mm, 15.1 +/- 1.4 mm, 15.1 +/- 11.2 degrees), and were independent of their locations. In the ischemic group, however, the points of non-ischemic regions showed low values of theta (14.9 +/- 8.9 degrees), which were not significantly different from those of the control group, while the points of ischemic regions showed high values of theta (over 2SD of the control group). The distribution of these points with abnormal theta values was well correlated to that of the segments with asynergic motion evaluated by both real-time two-dimensional echocardiography and left ventriculography (p less than 0.001 and p less than 0.001, respectively). These results suggest that this new approach with quantitative echocardiography is sensitive and specific for the assessment of regional wall motion of the left ventricle and may provide accurate clinical information for the evaluation of ischemic heart disease.