Evaluation Of Viable Myocardyium By Tissue Doppler Imaging And Derivative Technologies Combined With Adenosine Stress Echocardiography

The research included two parts:1.Evaluation of viable myocardium by quantitative tissuevelocity imaging and tissue tracking combined with adenosinestress echocardiographyObjective: To seek a new method to identify viable myocardium by quantitativetissue velocity imaging and tissue tracking combined with adenosine stressechocardiography.Methods: We made acute myocardial infarction and reperfusion model by ligatinganterior descending coronary artery and performing a reperfusion. Variables ofsegmental tissue velocity imaging and tissue tracking including peak velocity insystolic(Vs),peak velocity in isovolumic contraction (VIVC) and the displace insystolic(Ds) were measured on anterior wall and anterior septum. TTC staining wasserved as a"gold standard"to define viable and non-viable myocardium.Results: There were no significant changes of VS,VIVC and DS between viable andnon-viable group at baseline(P>0.05). Compared with baseline VS,VIVC and DSdecreased significantly(P <0.01)after reperfusion in both viable and non-viablegroup. After adenosine administered, Vs and DS increased(P<0.05),but VIVC had nosignificant change compared with before adenosine administered in viable group(P>0.05).Each variable had no significant change before and after adenosineadministered in non-viable group(P>0.05). A cutoff value of△Vs(%) rate was17.9,with a sensitivity of 78.6%,a specificity of 81.1%, a cutoff value of△DS(%)rate was 18.4,with a sensitivity of 75.0%,a specificity of 83.8%. Combined△Vs(%)with△DS(%), the sensitivity and specificity to prediction of myocardium viabilitycould reach 94.6%,68.0%.Conclusions: Quantitative tissue velocity imaging and tissue tracking could identifyviable and non-viable myocardium combined with adenosine stress echocardiography.QTVI in combined with TT could improve the sensitivity.2. Evaluation of viable myocardium by strain and strain rateimaging combined with adenosine stress echocardiographyObjective: To seek a new method to identify viable myocardium by strain and strainrate imaging combined with adenosine stress echocardiography.Methods: We made acute myocardial infarction and reperfusion model by ligatinganterior descending coronary artery and performing a reperfusion. Variables ofsegmental strain and strain rate imaging including the maximum strain during theentire heart cycle (ε_max),strain during ejection time(ε_et),post-systolic strain (ε_PSS)and peak systolic strain rate (SRpeak sys) were measured on anterior wall and anteriorseptum.The ratios ofε_PSS /ε_max andε_PSS /ε_et were calculated. TTC staining wasserved as a"gold standard"to define viable and non-viable myocardium.Results: There were no significant changes of strain, strain rate and the ratio ofsegments existing PSS between viable and non-viable group atbaseline(P>0.05).Compared with baselineεmax,εet and SRpeak sys decreasedsignificantly (P<0.01) whileε_PSS /ε_max,ε_PSS /ε_et, the ratio of segments existingPSS andε_PSS significantly increased(P<0.05)after reperfusion in both two groups. There were no significant changes of strain, strain rate and the ratio of segmentsexisting PSS between viable and non-viable group after reperfusion. Thoughε_max,εet and SRpeak sys decreased significantly(P<0.01)whenε_PSS /ε_max ,ε_PSS /ε_et andε_PSS increased(P <0.05 and <0.01,respectively)compared with baseline, SRpeak sysandε_et significantly increased(P<0.01)whileε_PSS /ε_et and the ratio of segmentsexisting PSS reduced(P<0.05)after adenosine administered compared with thevariables after reperfusion in viable group. There were no significant changes beforeand after adenosine administered(P >0.05)in non-viable group.Conclusions: Strain and strain rate imaging could identify viable and non-viablemyocardium combined with adenosine stress echocardiography.