Does Postoperative Flow Reserve in Internal Mammary Artery Grafts Depends on the Area Under Supply

During a prospective study 28 left (LIMA) and 22 right internal mammary arteries (RIMA) were investigated in 29 pts Bto 10 days postoperatively. Using 6F catheters LIMA and RIMA were selectively intubated and after diagnostic angiography flow velocity was measured with a 1B/l 000 inch flow wire (12 MHz. Cardiometricsl. Average peak velocity (AP\/, cm/secl and diastolic/ systolic ratio (DSVR) at rest (R). after 0.2 mg ritroglycerin (NTG) and after 12.5 mg papaverine (PAP), administerd directly into the graft. was assessed. Luminal diameter (LD. mm) was measured by quantitative coronary angiography (DCI, Philipsl and blood flow (0, ml/min) was calculated. There were no significant differences between RIMA and LIMA concerning APV. DSVR and O. The table gives the results for IMA to LAD (n=24) and IMA to LCX (n=26): mean±SOIMALDAPVQDSVRLAD-R2.81±05924±1149±32117±031-NTG291±05643±14*96±74*157±048*-PAP303±0.6246±16*113±85*1.63±047*LCX-R283±0.3922±742±18096±0.29-NTG298±04039±12*87±39*129±0.37*-PAP308±04141±14*99±46*1.31±031**P<0.05 vs. RConclusionIn contrast to native coronary arteries and venous bypass grafts LIMA/RIMA show a DSVR of 1.0. wich may be due to the length of the arterial graft. 0 at rest is lower in IMA-grafts to the LCX than in those to LAD. NTG and PAP yield a sign. Increase in 0 for both IMA-grafts independent of the coronary vessel supplied by the graft