BACKGROUND:We hypothesized that transthoracic echocardiography(TTE) could provide information on left internal mammary artery(LIMA) patency and its severity of stenosis. PURPOSE;To investigate the relation of the LIMA-left anterior descending(LAD) coronary artery anastomosis site diameter stenosis and pattern of LIMA flow. METHOD:Using High-frequency(5 MHz) probe, TTE was performed in supra clavucular fossa of 60 consecutive patients who had had LIMA grafts to the LAD and were undergoing follow-up coronary angiography. The indices were compared between patients with significant(���70%) anastomosis site stenosis(stenosis group, n=38, mean age 63짹8 years) and without(<70%) significant stenosis(normal group, n=14, mean age 62짹10 years). The relation of stenosis severity and Doppler flow indices were examined. RESULTS:The ratio of diastolic to systolic flow velocity time integral(VTI), the ratio of diastolic to systolic peak flow velocity were significantly decreased in stenosis group. The systolic peak flow velocity was significantly increased in stenosis group(Table) and systolic peak flow velocity was the most useful tool for detection of significant stenosis at the cut off value of 0.705m/sec.(Figure) CONCLUSION:Compared with patent grafts, severe stenosis demonstrated different Doppler patterns. Use of this technique may allow noninvasive detection of significant stenosis of the LIMA graft