Optimal Coronary Perfusion Flow for the Distal Coronary Area During Off-Pump Coronary Artery

目的：非体外循环冠状动脉旁路移植术中，冠状动脉远端灌注是避免冠状动脉吻合术中心肌缺血的必要措施。然而，最佳冠状动脉血流（CF）尚未阐明。本研究的目的是确定最佳的CF的基础上评估区域工作的myocardial.Methods：我们使用了七个猪。用导管尖端压力计测量左室压力，用两对超声晶体分别置于左室前后和心尖部，计算左室容积，得到左室压力-容积环（P-V环）。另外两对超声晶体以1cm的距离对角放置，得到区域张力-面积环（T-A环）。将与伺服泵相连的CF管插入左前降支分支。左室每搏作功（PVA）为P-V环内的面积，局部作功（TAA）为T-A环内的面积。结果：CF 30 ml/min时PVA和TAA较对照值明显降低（P<0.05），结论：CF 30 ml/min是维持整体和局部心肌作功的必要条件，可避免心肌缺血。

Objective : Distal coronary perfusion is necessary to avoid myocardial ischemia during coronary anastomosis in Off-pump Coronary Artery Bypass. However, optimal coronary flow (CF) is not elucidated. The purpose of this study was to determine the optimal CF based on the assessment of regional work of the myocardium.Methods : We used seven porcines. We obtained pressure-volume loop (P-V loop) of the left ventricle (LV) with the LV pressure measured by a catheter tip manometer and the LV volume calculated with two pairs of ultrasonic crystals placed anterior-posterior and base-apex of the LV. Regional tension-area loop (T-A loop) was obtained with other two pairs of ultrasonic crystals placed with 1 cm distance diagonally. The CF tube connected to servo-pump was inserted into the left anterior descending branch. LV stroke work (PVA) was the area within P-V loop and regional work (TAA) was the area within T-A loop. CF was decreased from 100 ml/min as a control and PVA and TAA were obtained at each CF.Results : PVA and TAA decreased significantly at CF 30 ml/min from the control value (p<0.05).Conclusion : CF 30 ml/min was necessary to maintain global and regional myocardial work and possibility to avoid myocardial ischemia.