心肌声学造影触发间期对“危险区”范围测定的影响

摘要

Objective:To test the hypothesis that the evaluation of risk areasize may be influenced by different trigger intervals during intravenous myocardial contrast echocardiography.Methods：Left anterior descending arteries were ligated in 4 dogs.The sizes of the contrast deficit of risk areas in different trigger intervals with intermittent harmonic imaging technique were compared when contrast agents were continuously infused from peripheral veins.Results:The longer the trigger interval lengthened,the more the contrast deficit of risk areas decreased.The deficit size was supposed as 100%when the trigger interval was set to one cardiac cycle,while the deficit size was decreased 52.7%，42.9%，30.6%，28.3%，27.1% or 24.2% when the trigger interval was set to 5,9,18,27,36 or 45 cardiac cycles respectively.Excellent logarithmic equation was found between the contrast deficit area sizes and the trigger intervals(y＝0.9106－0.1916×ln(x)，R2＝0.822，P＜0.001).Conclusions:The evaluation of risk area size is influenced by different trigger intervals during myocardial contrast echocardiography.The longer the trigger interval is,the smaller the deficit area would be.%目的：探讨利用间断谐波成像行静脉心肌声学造影过程中触发间期长短对心肌梗塞后“危险区”范围测定的影响。方法：结扎犬前降支近段建立急性心肌梗塞模型。经静脉持续滴注微泡造影剂，采用不同触发间隔的间断谐波成像方式记录声学造影图像。以触发间期为1RR(心动周期)时测得的危险区面积为100%，分别定量其它不同触发间隔成像时声学灌注缺损范围，判定触发间期长短对“危险区”范围测量的影响。结果：随着触发间期的延长，心肌灌注缺损范围减小。触发间期延长至5RR、9RR、18RR、27RR、36RR、45RR时，危险区面积分别减小为52.7%、42.9%、30.6%、28.3%、27.1%及24.2%。“危险区”面积与触发间期呈对数函数关系y＝0.9106－0.1916×Ln(x)，R2＝0.822，P＜0.001。结论：持续滴注法行声学造影过程中，心电触发间隔越长，“危险区”范围测值越小。