Fusion imaging of three-dimensional echocardiographic speckle-tracking with cardiac computed tomography for identification of myocardial ischemia

摘要

A 73-year-old woman was referred to our institution because of exertional chest pain. Electrocardiogram and transthoracic echocardiography showed no abnormalities. Cardiac computed tomography (CT) showed coronary artery stenosis at the distal-segment and the proximal-segment of left anterior descending artery (LAD). Dobutamine stress threedimensional (3D) echocardiographic speckle-tracking was performed using Aplio (Canon Medical Systems, Otawara, Japan). Myocardial ischemia was evaluated by dyssynchrony imaging of area change ratio, which assessed the delays of strain value peaks from end-systole, indicating postsystolic shortening,1 and was shown on the color-coded polar map. The delays of strain value peaks were shown from green (no delay) to red (delay greater). The images of 3D echocardiographic speckle-tracking and coronary artery tree derived by CT were automatically combined on the single display using Vitrea systems (Canon Medical Systems) to match the size and location of the left ventricle such as the anterior and inferior walls. The fusion imaging at rest showed no myocardial ischemia (Figure 1A), while the fusion imaging at stress indicated myocardial ischemia in the territories of the distalsegment and the proximal segment of LAD, involving the first diagonal branch (Figure 1B). Coronary angiography revealed significant stenosis at the distal-segment, the proximal-segment, and the first diagonal branch of LAD, which were confirmed as ischemia by fractional flow reserve. The patient underwent percutaneous revascularization of these lesions.