Objective To analyze the mean flow in left internal m am mary artery ( L IMA) graft and the influencing factors in off- pump coronary artery bypass grafting ( OPCAB) in the Chinese. Methods One hundred and eighty patients with OPCAB were studied.Transit- tim e flowmeter( TTFM) was utilized to measure and record the L IMA’s blood flow wave,pulsatility index( PI) ,value of mean flow,systolic and diastolic peak flow,vascular resistance,insufficiency ratio and mean blood pressure and to analyze the relationship between mean flow of LIMA and other factors. Results Total mean flow calculated from that of all patients was2 8.19± 2 .89ml/ min( 6 - 178 ml/ m in) .Majority m ean value ( 6 4 .4 % ) was in the range of 10 - 30 ml/ min.Statistics showed that mean flow was significantly related to systolic and diastolic peak flow and vascular resistance rather than the other factors( r=0 .75 , 0 .94 ,- 0 .95 ) . Conclusions For the Chinese,over 10 ml/ min mean flow of L IMA graftis acceptable and ov...更多er 2 2 ml/ min is satisfactory.The diastolic peak flow and vascular resistance are two most important factors in influencing mean flow.