Click on image to view larger version.

Figure 1 Strain rate maps at baseline and during ischemia, and corresponding perfusion-stained specimen, in apical long-axis view. (A) Baseline strain rate imaging frame (left image) and the corresponding longitudinal M-mode strain rate map over one cardiac cycle (right image). Orange represents compression, blue expansion and green low motion. The two vertical straight lines approximate the time of the aortic valve closure and of the mitral valve opening (identified from gray-scale two-dimensional loops). The compression/expansion crossover is indicated by the solid black line as the color transition from orange to blue. The time from the electrocardiographic peak R-wave to the compression/expansion crossover (T_CEC) is measured for each pixel line in the image. (B) Ischemic strain rate maps from the same view. A prolonged compression pattern (black arrows) can be observed in the apical and mid anteroseptal segments (supplied by the occluded left anterior descending coronary artery), while the rest of segments have normal compression/relaxation pattern. Note also the delayed onset of systolic compression (white arrows) in the same ischemic segments. (C) Computer reconstruction of the stained cardiac specimen at the same level in the heart. Myocardium at risk is represented by the white region (arrows), while the normally perfused myocardium is stained in red. The location of the apical postsystolic compression pattern in the strain-rate maps matches the location of the ischemic myocardium (Segments are abbreviated: bIL = basal inferolateral; mIL = mid inferolateral; aIL = apical inferolateral; aAS = apical anteroseptal; mAS = mid anteroseptal; bAS = basal anteroseptal).