Simon P, Mohl W, Neumann F, Owen A, Punzengruber C, Wolner E
Second Surgical Clinic, University of Vienna, Austria.
J Thorac Cardiovasc Surg. 1992 Jul;104(1):40-5.
The immediate effect of coronary artery bypass grafting on global and regional myocardial function was studied by means of epicardial two-dimensional echocardiography during operations in 20 patients. Echocardiograms were recorded before cardiopulmonary bypass and 5 and 30 minutes after bypass. Global left ventricular function was expressed as percent short-axis area change and regional function as percent fractional area change. Segments were classified according to their baseline function as normal (percent fractional area change greater than 40%), moderately hypokinetic (percent fractional area change 21% to 40%), or severely dysfunctional (percent fractional area change less than 20%). Percent short-axis area change was significantly reduced immediately after cardiopulmonary bypass (from 42.0% +/- 4.6% to 34.9% +/- 3.0%, p less than 0.05) but had returned to baseline 30 minutes after bypass (42.6% +/- 4.0%). Similarly, function of normal and moderately hypokinetic segments decreased significantly immediately after cardiopulmonary bypass (normal segments: percent fractional area change 56% +/- 0.9% before bypass to 42.3% +/- 1.5% after bypass, p less than 0.0001; moderately hypokinetic segments: 31.0% +/- 0.9% to 25.1% +/- 1.4%, p less than 0.002). Both normal and moderately hypokinetic areas regained baseline function by 30 minutes after bypass (normal segments: 53.4% +/- 1.6%; moderately hypokinetic segments: 35.4% +/- 2.0%). In contrast, severely dysfunctional segments were found to be significantly improved immediately after bypass (14.7% +/- 0.9% before bypass to 27.7% +/- 2.1% after bypass, p less than 0.0001). This improvement was maintained 30 minutes after bypass (22.8% +/- 1.5%, p less than 0.001). We conclude that coronary revascularization exhibits an immediate beneficial effect on chronically underperfused myocardium having severely depressed baseline function. However, in normal and moderately hypokinetic areas, the depressant effects of global ischemia and reperfusion prevail in the immediate postbypass period, leading to a global depression of cardiac function.
采用心外膜二维超声心动图对20例患者手术过程中冠状动脉搭桥术对整体和局部心肌功能的即时影响进行了研究。在体外循环前以及体外循环后5分钟和30分钟记录超声心动图。整体左心室功能用短轴面积变化百分比表示，局部功能用面积变化分数百分比表示。各节段根据其基线功能分为正常（面积变化分数百分比大于40%）、中度运动减弱（面积变化分数百分比为21%至40%）或严重功能障碍（面积变化分数百分比小于20%）。体外循环后短轴面积变化百分比立即显著降低（从42.0%±4.6%降至34.9%±3.0%，p<0.05），但在体外循环后30分钟恢复至基线水平（42.6%±4.0%）。同样，正常节段和中度运动减弱节段的功能在体外循环后立即显著下降（正常节段：体外循环前面积变化分数百分比为56%±0.9%，体外循环后为42.3%±1.5%，p<0.0001；中度运动减弱节段：31.0%±0.9%至25.1%±1.4%，p<0.002）。正常节段和中度运动减弱节段在体外循环后30分钟均恢复至基线功能（正常节段：53.4%±1.6%；中度运动减弱节段：35.4%±2.0%）。相比之下，严重功能障碍节段在体外循环后立即有显著改善（体外循环前为14.7%±0.9%，体外循环后为27.7%±2.1%，p<0.0001）。这种改善在体外循环后30分钟仍保持（22.8%±1.5%，p<0.001）。我们得出结论，冠状动脉血运重建对基线功能严重受损的慢性灌注不足心肌具有即时有益作用。然而，在正常和中度运动减弱区域，整体缺血和再灌注的抑制作用在体外循环后即刻占主导，导致心脏功能整体下降。
