左心辅助不同插管途径对心肌氧代谢的影响

目的对左心辅助的两种插管引流途径(左心室引流与左心房引流)的氧代谢情况进行对比研究,为临床选择合适的引流途径提供实验依据。方法将12条犬随机分成两组,分别建立左心房-主动脉(LA组)和左心室-主动脉(LV组)的左心室辅助动物模型,并测定左心辅助后各时相的心率、冠状静脉窦血流量,计算冠状静脉窦的氧含量、冠状动静脉血氧含量差和心肌的耗氧量。结果两组心率在各时点差别无统计学意义(P>0.05);两组的心肌耗氧量、冠状静脉窦血流量和冠状动静脉血氧含量差辅助后均较辅助前显著降低;左心室引流途径对降低心肌耗氧量的作用比左心房引流更明显(P<0.01)。结论两种引流途径均能明显降低心肌的耗氧量,以左心室引流更为明显。

Effects of Cannulation Site on Myocardial Oxygen Metabolism During Left Ventricular Assistance

Objective To compare the effects of two kinds of cannulation sites on the myocardial oxygen metabolism during left ventricular assistance to provide experimental basis for clinical selection of proper cannulation sites.Methods Twelve mongrel dogs were randomized equally into the left atrium to aorta group(LA group) and left ventricle to aorta group(LV group),and underwent left ventricular assistance.At different times before and during left ventricular assistance,the heart rate,coronary sinus flow rate and blood gas were determined and coronary sinus oxygen saturation,arteriovenous oxygen difference and myocardial oxygen consumption were calculated.Results There was no statistical difference of heart rate in both groups(P>0.05).The coronary sinus flow rate and mean myocardial oxygen consumption reduced in both groups after left ventricular assistance,whereas the effect was more remarkable in the LV group(P<0.01).Conclusion Both cannulation methods could reduce the myocardial oxygen consumption during left ventricular assistance,and the effect is more apparent in left ventricular cannulation.