Evaluation Of Left Ventricular Systolic Function Of Stunned Myocardium After Ischemia And Reperfusion In Canines With3D-STI

ObjectiveThere were ischemia-reperfusion Dog Stunned myocardium modelestablished, and Three-dimensional speckle tracking imaging (3D-STI) used toevaluate the local left ventricular function and overall, in this way, There wasthe structural and functional changes of stunned myocardial was clarified. Thisstudy will provide a new idea about the early and non-invasive diagnosis onangina.MethodsLeft anterior descending arteries of9canines were ligated to inducemyocardial ischemia for15min, followed by reperfusion. collected a series oftwo-dimensional and real-time three-dimensional ultrasound images strainresults of the left ventricle before ischemia,5min and15min after ischemia,30min、60min、90min and120min after reperfusion. Apply biplane Simpson’smethod to measure conventional indicators in the apical two-chamber view andfour-chamber view: left ventricular end of the diastolic volume (LVEDV), leftventricular end of the systolic volume (LVESV), left ventricular diastolic diameter(LVDD), left ventricular systolic diameter (LVDS), left ventricular ejection fraction(LVEF). Using Three-dimensional speckle tracking imaging to detect peaklongitudinal strain,peak radial strain, peak circumferential strain and peak area strain(LSpeak, RSpeak, CSpeak, ASpeak) in ischemia (basal anterior（BA）, midanterior(MA), basal anteroseptal(BAS), mid anteroseptal（MAS） segment) andnon-ischemic (basal posterior(BP)，mid posterior (MP) segment), the globalpeak strain (GLSpeak, GRSpeak, GCSpeak, GASpeak), and to analyze thecorrelationship of global peak strain with LVEF, so that we can evaluate thelocal left ventricular function and overall.Results1、 Comparison of left ventricular conventional indicators：LVESV、LVEDV、LVDS、LVDD increased during ischemia，the parameters have significantdifference(P＜0.05);LVEF decreased during ischemia，the parameters havesignificant difference(P＜0.05),all parameters reached to normal value with30min reperfusion, there is no significant difference compared with beforeischemia(P＞0.05).2、 Real time3D-STI measure left ventricular total systolic function：The leftventricle global strain parameters are decreased during ischemia, there issignificant difference compared with before(P＜0.05). With the prolongation ofreperfusion gradually restored. GASpeaktake the longest recovery time(120min),there is no significant difference compared with before(P＞0.05).The globalstrain parameters of3D-STI before and after ischemia were positively correlatedwith LVEF, GASpeakhas the highest correlation with LVEF.3、Real time3D-STI measure left ventricular regional systolic function：SpeakChanges of the ischemia segment: The ischemia segments strain parameters ofleft ventricle are decreased during ischemia, there is significant differencecompared with before(P＜0.05), With the prolongation of reperfusion graduallyrestored, however, none of the LSpeak, RSpeak, CSpeak, ASpeakrecovered even in120min, there is significance compared with before (P＜0.05).SpeakChangesof the non-ischemia segment: The non-ischemia segments strain parameters ofleft ventricle are increased during ischemia, reached to normal value with30min reperfusion,there is no significant difference compared with before (P＞0.05).Conclusions1、Conventional ultrasound can only evaluate global left ventricular systolicfunction during ischemia, and3D-STI is a better index to assess the localfunction of the stunned myocardium after ischemia and reperfusion。2、Total systolic function of left ventricular delayed recover after reperfusion,the myocardial stunning phenomenon.3、Regional systolic function of left ventricular stunned myocardial delayedrecover after reperfusion, and local function recovery takes longer time than thetotal function.4、Area strain is the most sensitive3D-STI parameter.