The Study Of Myocardial Contrast Stress Echocardiography In Detecting Myocardial Blood Flow

Objective:Myocardial contrast echocardiography(MCE)has been a special method in detecting myocardial microcirculation and myocardial blood flow. Myocardial contrast stress echocardiography(MCSE)may check myocardial contraction restoration ability.The two methods combine together can evaluate myocardial flow,viability and function noninvasively in extensive area.The study compared the results of dobutamine stress test(DST)in the groups of control,syndrom X,myocardial infarction(MI)using real-time MCE,MCSE and global acoustic densitometry(GAD).We also accessment MCSE's clinic value for myocardial blood flow(MBF).Methods:Thirty-five patients were included.According to history, examination,electrocardiograph,myocardial enzyme,ultrasonic cardiography(UCG) and coronary artery angiography(CAG).These patients were divided into MI(8 cases) and no-coronary heart disease(CHD,27 cases)groups.Further we divided no-CHD group into two subgroups with control(19 cases)and syndrome X(8 cases)according to diagnosis standard.In MI group,it showed double or multiply branch stenosis or occluded with CAG.We select 7 patients in control,8 patients in syndrome X and 8 patients in MI to do the test with DST.We got the peak density(PI),time to peak density(TP)and MBF[MBF=(PI/TP).PI]with GAD of selected patients.Results:There was no deference in Sex,ages,cigrate,hyptention and diabetes between the two groups.There was also no deference in heart rate.blood pressure before and after MCE.In the dose of dobutamine 20μg/(kg·min)and 30μg /(kg·min)of DST,the results showed that the heart and blood pressure increased than before the DST(P＜0.05,P＜0.01).PI of MCE was no deference between the group of syndrome X and control (P＞0.05).TP was longer in syndrome X group than the control(P＜0.05).MBF was lower in syndrome X group than the control(P＜0.01).Myocardium was fulled better in control group,but worse in MI group.PI,MBF were significantly lower in MI group than the control(P＜0.005,P＜0.001).TP was significantly longer in MI groupn than the control(P＜0.001).PI was no deference between the syndrome X and MI groups(P＞0.05),but PI had decreasing trend.TP was significantly longer in MI group than the syndrome X (P＜0.005).MBF was lower in MI group than the syndrome X(P＜0.05).In control group,PI and TP were no deference before and afte DST(P＞0.05), but PI had increasing trend,TP had decreasing trend after DST,MBF was significantly larger than before(P＜0.005).In syndrome X group,PI,TP,and MBF were no deference between the before and after DST(P＜0.05).In MI group,in the dose of dobutamine 10～20μg/(kg·min),TP was shorter after DST(P＜0.01)and MBF was significantly longer(P＜0.005),PI was no deference before and after DST(P＞0.05).In infarction regin,TP was shorter after DST(P＜0.05)and MBF was larger (P＜0.01).In no infarction regin,TP was shorter after DST(P＜0.01)and MBF was larger(P＜0.01).In syndrome X group,PI and MBF were larger after DST(P＜0.05),TP was no deference before and after DST(P＞0.05).Conclusions:1 MCE has been a special method in detecting myocardial microcirculation and myocardial blood flow,MCSE may check myocardial contraction restoration ability.The two methods combine together could evaluate myocardial flow,viability and function noninvasively in extensive area.SonoVue was effective and safe without poisonous and side-effective.2 In syndrome X group,myocardial microcirculation could be evulated quantitatively with TP and MBF of MCE.In syndrome X,the function of microvascular endothiliam was abnormal and blood flow was slow,result in MBF was low.PI and MBF of MCSE showed that coronary restoration ability was decreased and could not increased effectively myocardial blood for the needs of myocardium.Mechanism of syndrome X was probably related to abnormal of microvascular endothiliam function,coronary flow restoration ability and the lesion of coronary microcirculation.MBF could be analyzed quantitatively by real-time MCE,MCSE and GAD.MCE,MCSE and GAD have clinc value in detecting abnormal of myocardial microcirculation flow.3 In MI patients,PI,TP and MBF showed that coronary restoration ability of crime vascular of MI was lowly or lack.Ventricle wall of MI was without flow,GAD curve was lower.In MI group,without flow of MI areas was scattered flow after DST. MCSE could showed that there was viable myocardium in MI patients.In MI regin, TP and MBF of MCSE had been showed that there was residual myocardium that related to collateral circulation.In no infarction regin,TP and MBF of MCSE had been showed that there were hibernation myocardium(HM)and stuning myocardium (SM).MCE and MCSE may evulate myocardial viability of MI.MCE and MCSE were methods that could be used to evaluate myocardial viability noninvasively.MCE and MCSE were important to help the therapy and judgement of prognosis for the coronary heart disease.