Objective: To analyze the features of Doppler flow velocity curve of left internal mammary artery by-pass grafts in relation with their permeability as assessed by selective angiography.
Methods: Twenty-five consecutive patients with a left mammary artery graft were studied by angiography and transcutaneous Doppler technique. From the Doppler tracings, peak velocity and time-velocity integral of the systolic and diastolic components were determined. Patency of the graft and the characteristics of the distal native coronary artery were evaluated at angiography.
Results: Doppler flow signal was obtained in 23 (92%) of 25 analyzed patients. The graft was angiographically patent in 17 (68%) of 25 patients; in 15 (88%) of them the Doppler flow velocity signal was mainly diastolic and in only 2 (12%) it was predominantly systolic. In 8 (32%) of the 25 patients the graft was angiographically occluded, 6 (75%) of these patients showing a predominantly systolic Doppler signal, while the remaining 2 (25%) patients were those in whom the signal could not be elicited. Sensitivity and specificity of a predominantly diastolic Doppler flow pattern for the presence of graft patency was 88% and 100% respectively, with a predictive positive value of 100% and a negative one of 80%.
Conclusions: Doppler flow velocity pattern of internal mammary artery by-pass grafts is related with patency of the graft, the presence of a predominantly diastolic curve being highly indicative of a patent graft.