Fig. 7

Activation mapping. a: Propagation images in a normal subject by activation imaging with 3D speckle tracking echocardiography. The upper panel shows propagation of myocardial contraction viewed from the left ventricular (LV) septal side from end-diastole (ED) to end-systole (ES), and the lower panel shows it viewed from the LV free wall. The color bar refers to a color-coded time scale that corresponds to the timing of the onset of regional contractions. In this case, the range is set from 0 ms (dark blue) to 320 ms (red) via green and yellow. The onset of myocardial contraction in the entire left ventricle is almost synchronized, reflecting light green colored area spreading rapidly. b: Propagation images in a patient with left bundle branch block. The upper panel shows propagation of LV myocardial contraction viewed from the septal side, and the middle panel shows it viewed from the LV free wall. The lower panel is a bull’s eye map displaying the spread of contraction. The upper panel shows early contraction in the septum colored in blue, which is earlier than septal contraction timing in normal subjects, and corresponds to “septal flash” during the pre-ejection period. The propagation of septal contraction is blocked at the anterior wall, but propagates toward the apex. The delayed propagation from the apex to the lateral wall is shown in a red-colored area in the basal to mid lateral wall, characterizing U-shaped propagation. A, anterior wall; AS, anterior septum; I, inferior wall; L, lateral wall; P, posterior wall; S, septal wall