Apical 4-chamber view of real-time myocardial contrast echocardiography with contrast pulse sequencing (Siemens Acuson Sequoia, Mountain View, California) was obtained from a patient with significant left anterior descending coronary artery disease during dobutamine stress. Subendocardial wall thickening (WT) within the apex was measured off-line with commercially available software. The end-diastolic and -systolic wall thickness for transmural WT was measured on the pre-MCR images (the first cardiac cycle after the high mechanical index impulse; left panels) as the distance between the endocardial border (arrow) delineated with left ventricular cavity contrast and the epicardial border (arrow). Subendocardial WT was measurable only if a subendocardial perfusion defect was present (arrows) during the replenishment period (MCR; right panels). See the text for calculation formula. ED = end-diastole; ES = end-systole; MCR= myocardial contrast replenishment.

A 65-year-old woman presented with shortness of breath. Apical 40-chamber view of real-time myocardial contrast echocardiography (RTMCE) with contrast pulse sequencing was obtained during dobutamine stress. On the pre-MCR images, WT was normal, whereas during MCR an apical subendocardial WT abnormality was evident, because of the subendocardial perfusion defect. Subendocardial WT measured 20%, whereas transmural WT was measured to be 50%. At complete replenishment (4 s after high MI impulse), the defect disappeared. Abbreviations as in Figure 1.

Apical 3-chamber view of RTMCE with power modulation (iE33, Philips Medical Systems, Bothell, Washington) during peak dobutamine stress in a patient with a significant left anterior descending coronary artery stenosis. Pre-MCR (left panels) WT was normal, as delineated by the blue arrows in the left panels. On the MCR images (right panels), a subendocardial perfusion defect is evident and subendocardial WT appeared abnormal (red arrows). Abbreviations as in Figures 1 and 2.