Quantitative assessment of paradoxical motion of the interventricular septum.

<p>Panels A, B and C show short axis images of the left ventricle at three cardiac phases of a patient with PH. From the end-diastolic phase (A) to the early systolic phase (B), the interventricular septum moves outward (toward right ventricle) in a paradoxical manner (B, arrows). Subsequently, from early systole (B) to end-systole (C), the interventricular septum moves inward in a manner similar to that of the other segments of the LV wall (panel C, arrows). However, the maximum inward motion was less than that of the other LV wall segments (D). To quantify the paradoxical interventricular septal motion indicated by arrows in panel B, we used speckle-tracking echocardiography by which the left ventricular free walls and interventricular septum were automatically divided into six segments, and each motion pattern was visualized by six lines (D). Yellow and red lines indicate the motion of the anterior and inferior interventricular septum, respectively, during a single cardiac cycle. The dips in the early systolic phase (a1 and b1) indicate their paradoxical motion. For quantitative assessment, the maximum depths of the yellow and red lines (a1+ b1) were added. Next, the entire distance of the two interventricular septal segments [early systole (a1 and b1) and end-systole (a2 and b2)] were added. Then, (a1+ b1) was divided by (a1+ a2+ b1+ b2), and the result was used as the paradoxical motion index of the interventricular septum.