Evaluation of the effect of CABG

1994 Fiscal Year Final Research Report Summary

• Project/Area Number: 05671133
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Thoracic surgery
• Research Institution: KITASATO UNIVERSITY
• Principal Investigator: HANYA Shizuo KITASATO UNIVERSITY,SCHOOL OF MEDICINE,LECTURER, 医学部, 講師 (80075522)
• Project Period (FY): 1993 – 1994
• Keywords: Doppler catheter / CABG / Zero flow pressure / Coronary flow resistance

Research Abstract

To assess the effect of coronary artery bypass graft surgery (CABG), we studied diastolic coronary artery pressure-flow relationships in 18 bypass grafts to left coronary arteries (11 saphenous vein grafts (SVG) and 7 interthoracic artery grafts (LITA)) and on 12 normal left coronary arteries using a 20MHz Doppler catheter.
Zero flow pressure intercept of the diastolic pressure-flow curves were obtained as Pfz. Furthermore, coronary flow resistance (CR) were calculated from the formula : CR=Pm-Pfz/Vm, where Pm and Vm is randomly measured aortic pressure and coronary flow velocity at the same time in diastole. There were no significant differences, in Pfz between coronary bypass grafts (SVG 56<plus-minus>22.2, LITA 50<plus-minus>21.3) and normal left coronary arteries (58<plus-minus>12.0). On the contrary, CR were significantly higher in SVG (8.0<plus-minus>3.6) the those in LITA (5.3<plus-minus>2.8) and those in normal left coronary arteries (4.5<plus-minus>2.4). Pfz is postulated to reflect the tonus of the intramyocardial coronary vasculatures, which is believed to play a major role in coronary autoregula
It is concluded that LITA is superior to SVG as a conduit to supply blood from epicardial side to intramyocardial coronary circulation from the view point of flow resistance.