Evaluation of viability of myocardium by adenosine stress echocardiography combined with quantitative tissue velocity imaging and tissue tracking after acute myocardial infarction / 中华急诊医学杂志

ABSTRACT

Objective To seek a new method to identify viability of myocardium by adenosine stress echocardiography combined with quantitative tissue velocity imaging(QTVI)and tissue tracking(TT).Methods Fifteen healthy canines were selected to establish the models of acute myocardial infarction and reperfusion by ligating anterior descending branch of coronary artery for 90 minutes and then releasing the artery to get reperfusion.After reperfusion.peak velocity in systole(Vs),peak velocity in isovolumic contraction(VIVC)and the displacement in systole(Ds)were measured on anterior wall and anterior septum at baseline.The 2,3,5-triphenyl tetrazolium chloride(TTC)staining was set as a"gold standard"for defining the viable and non-viable groups.The sensitivity and specificity of assessing myocardial viability were determined with QTVI and TT.Comparison of variables between viable and non-viable group was made by using t test.One way analysis of variance and LSD-t test were used to estimate the significance of differences in different states.Results Compared with baseline,Vs,VIVC and Ds decreased significantly(P＜0.01)after reperfusion in both viable and non-viable group.After administration of adenosine,Vs and Ds increased(P＜0.05),but VIVC didn't change significantly compared with that before administration of adenosine in viable group(P＞0.05).Variables in non-viable group didn't change significantly after administration of adenosine(P＞0.05).By receiver operating characteristic(ROC)analysis for predicting myocardial viability,when a cutoff value of △Vs(%)rate was 17.9,the sensitivity and the specificity was 78.6%and 81.1%,respectively,and when the cutoff value of △Ds(%)rate was 18.4,the sensitivity and the specificity was 75.0%,83.6%,respectively.Combined △Vs(%)with △Ds(%),the sensitivity and specificity to prediction of myocardium viability could reach 94.6%and 68.0%,respectively.Conclusions When the viability of myocardium after myocardial infarction is assessed by using the method of adenosine stress echocardiography with QTVI and TT,the sensitivity and the specificity are greatly enhanced.