The evaluation of chest pain in patients with recurrence of anginal symptoms after coronary artery bypass surgery may represent a problem because symptoms are often atypical and the result of provocative tests may be dubious or non diagnostic.All LIMA grafts to LAD can be identified using the color Doppler (with a sensitivity of 100 % and specificity of 85 %), as it is possible to localize the origin of the LIMA (close to the chest wall), then to measure the flow (which changes after the anastomosis from a dominant systolic flow pattern to mainly diastolic determined velocity). Velocity measurements are calculated and interpreted allowing identification of patent grafts or those with different degrees of stenoses.