TRANSTHORACIC 2D ECHO COLOR DOPPLER ASSESSMENT OF INTERNAL MAMMARY ARTERY TO LEFT ANTERIOR DESCENDING CORONARY-ARTERY GRAFT

For noninvasive evaluation of anatomy and flow characteristics of inte rnal mammary artery graft (IMA-graft), 2D echo-Color-Doppler (CDE) was performed in 60 patients (54 M, 6 F, mean age 54.1 +/- 6.9 y), who un derwent coronary angiography 20.1 +/- 13 months after a coronary arter y bypass graft (CABG). CDE was performed, using an echocardiographic u nit equipped with a 5 MHz linear transducer. In all patients, measurem ents of IMA-graft diameter (mm), and peak systolic and diastolic flow velocity (cm/sec) were obtained at baseline and also in 16 patients af ter dipyridamole infusion (0.54 mg/Kg/min) and in 10 patients after su blingual nitroglycerin (NTG) (0.4 mg). Angiography showed the IMA-graf t patency in 58/60 patients (96.8%). A typical biphasic flow was displ ayed by CDE in 49/58 patients (84.4%) with angiographic patency. Dipyr idamole infusion increased both IMA-graft diameter and peak diastolic flow velocity (PDFV) from 2.28 +/- 0.51 mm to 2.9 +/- 0.42 mm and from 19.4 +/- 6.2 cm/sec to 93.9 +/- 29 cm/sec, respectively (p < 0.0001). No significant modifications of peak systolic flow velocity (PSFV) we re observed. NTG increased PDFV from 29.11 +/- 8 cm/sec to 41.88 +/- 7 .20 cm/sec (p < 0.005), while diameter and PSFV showed no statisticall y significant modifications. CDE is a useful diagnostic tool for nonin vasive evaluation of IMA-graft patency both early after surgery and du ring long-term follow-up. CDE pharmacological stress improves the sens ibility of the technique and it can provide indirect information about pathophysiology of recipient coronary vessel.