fig20
![Echocardiography: an overview - part I](https://image.oaes.cc/cc687935-2f85-4acd-a841-b9406f0a744a/4652.fig.20.jpg)
Figure 20. Selected video frames from apical four-chamber location demonstrating the left ventricle in end-diastole (LVED) in (A) and in end-systole (LVES) in (B). Left ventricle (LV) area shortening may be calculated utilizing Simpson’s rule. Area shortening of the LV in this example is 52% (see insert in B). Standard values are 55% to 75% (see text for details). Reproduced from Ref.[19].