Assessment of left internal mammary artery grafts using dipyridamole Doppler echocardiography.

Color Doppler echocardiography of the left mammary artery was combined with dipyridamole testing in order to assess the presence of significant (>70%) graft stenosis in 87 patients with a mammary artery graft to the left anterior descending coronary artery presenting with chest pain. Occluded grafts are detected by absent diastolic flow velocities at baseline, whereas the response of the diastolic flow velocity to dipyridamole distinguishes patients with critical versus noncritical stenosis of a patent graft.