经食道多普勒超声对心肌顿抑犬的心输出量监测

Monitoring cardiac output of dogs with myocardial stunning by transesophageal echocardiography

目的 探讨在心肌顿抑时用经食道超声心动图监测心输出量的价值。方法 将14条犬随机分为二组(每组7条),即对照组与心肌顿抑组。心肌顿抑组开胸阻断LAD15min,再灌注2～3h,对照组仅开胸不阻断LAD。两组均通过温度稀释法、电磁流量法及经食道多普勒超声法监测心输出量的变化。结果 ①心肌顿抑组所有犬阻断LAD5分钟后均发生前壁心肌顿抑,室壁运动减弱,心输出量减低,而对照组则无相应改变。②经食道超声心动图与温度稀释法(r=087)和电磁流量法(r=084)在心输出量监测方面具有较好的相关性,在再灌注10～30分钟时,三种方法测得的心输出量值分别为14±008L/min,15±005L/min和16±018L/min,经食道超声法测得的心输出量值平均低于后两者方法。结论 经食道超声心动图法具有动态连续监测心输出量及室壁运动变化的特点,结果可靠,在对心肌顿抑病理过程的监控中具有重要意义。

Objective To evaluate the value of transesophageal echocardiography(TEE)in determining the cardiac output of dogs with myocardial stunning(MS).Methods 14 dogs were divided into MS group and control groups with each one having 7 dogs.Thoracotamy were performed for all 14 dogs with left anterior descending coronary artery(LAD)blocked for 15 min for 7 MS dogs followed by 2～3 hours of reperfusion.All dogs were monitored using TEE,thermodilution and electromagnetic methods to observe CO.Results The results showed the CO and wall motion decreased after 5 min of blocking LAD in MS group,while no apparent changes in control group.Close positive correlations between either TEE and thermodilution( r =0 87)or TEE and electromagnetic group( r =0 84)were found in measuring CO,the results were 1 4±0 08 L/min,1 5±0 05 L/min and 1 6±0 18 L/min respectively in TEE,thermodilution and electromagnetic groups after 10 min of reperfusion,with an average lower level in TEE than in the other twos.Conclusion As a means for dynamic and continuous monitoring of CO and wall motion with reliable results,TEE application in examining the process of MS is of great significance. [