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Study Of Myocardial Perfusion And Myocardium Systolic And Diastolic Function When Coronary Artery Stenosis

Posted on:2009-07-28Degree:MasterType:Thesis
Country:ChinaCandidate:D D ChenFull Text:PDF
GTID:2144360272961990Subject:Internal Medicine
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PartⅠStudy of myocardial perfusion and myocardium systolic and diastolic function when Coronary artery stenosisBackground and object:Myocardial perfusion,changes of myocardial systolic and diastolic function and relation between myocardial perfusion and systolic and diastolic function in is a closely concerned problem of the field of cardiovascular research in long time when Coronary artery stenosis at rest and stress.Changes of myocardial systolic function and the relation between perfusion of myocardial segment and systolic function have been systemically researched by non-invasive imaging technology and comprehensively understanding when coronary artery stenosis at rest and stress.But study about changes of diastolic function and the relation between myocardial perfusion and diastolic function,when coronary artery stenosis,is relatively less.In recent years,with the appearance of tissue Doppler technology(DTI) and the strain and strain rate imaging(SRI),people research changes of myocardial systolic and diastolic function and relation between myocardial perfusion and the systolic and diastolic function at coronary artery stenosis by these methods.These studies not only more accurately reflect the changes of systolic and diastolic function when myocardial coronary artery stenosis,but also to further deepen the understanding about the relationship between myocardial perfusion and systolic and diastolic function.At the meantime,they also showed that myocardial perfusion and diastolic function is also closely related.However,because the DTI technology and the strain and strain rate imaging excessively depend on the angle of ultrasound beam,they only accurately quantitatively analyse local myocardial systolic and diastolic function on the long axis,and can not display and compare systolic and diastolic function of all myocardial segment on the same cross section.Recently,Velocity Vector Imaging(VVI),a new technology,quantitatively analyse myocardial systolic and diastolic function on the all directions.It not only evaluate global cardiac function,but also assess the local myocardial systolic and diastolic function on long axis,the short axis and the rotation axis.At the same time, accuracy that myocardial contrast echocardiography(MCE) can quantitatively evaluate the myocardial perfusion has been generally recognized.For the above reasons,this study is planning to assess systolic and diastolic function of myocardial segments and the relationship between myocardial perfusion and the systolic and diastolic function when Coronary artery stenosis at rest and stress by applied VVI and MCE technology.Methods:We prepare different stenosis in anterior descending branch in dogs,mild to moderate coronary artery stenosis(LAD blood flow reduction<70%) and severe stenosis(LAD blood flow reduction>70%).Before and after coronary artery stenosis,we perform two-dimensional imaging and the MCE at rest and in the peak dose of dobutamine.We adjust the probe to attain the satisfied screen.Then we fixed the location of the probe.Two-dimensional images and MCE are performed in the left ventricular mastoid muscle section on the short axis.Contrast agent was continuously infused through femoral,and we use the intermittent trigger imaging, spacing is set to trigger cardiac 1-20 cycle.During the experiment,we continuously monitor blood pressure,heart rate changes.We use syngo US Workplace 2.0 software and MCE analysis software to respectively analyse the two-dimensional image and contrast image.The myocardial blood flow A·βvalues,the direction of the circumference of myocardial strain and systolic and diastolic strain rate peak were measured.Results:1.At rest,the product of A·βwas no significant difference myocardium supplied by stenotic and normal coronary artery when coronary stenosis with mild to moderate grade(P>0.05).However,A·βvalue of area which is supplied by stenotic coronary artery is smaller than the area which is supplied by normal coronary artery when coronary stenosis with severe grade(P<0.05).At dobutamine stress,A·βvalue of area which is supplied by LAD were more increased than the rest when two different levels of stenosis,(P<0.05),but A·βincrease are less than the area which is supplied by normal coronary artery(P<0.05) when coronary artery with mild to moderate and severe grade;A·βincrease of the area which is supplied by LAD at Severe coronary artery stenosis was smaller than mild to moderate coronary artery stenosis(P<0.05).2.At rest,strain and systolic and diastolic strain rate peak value was no significant difference myocardial segment supplied by stenotic and normal coronary artery when coronary stenosis(LAD blood flow reduction<70%) with mild to moderate grade(P>0.05).However,strain and systolic and diastolic strain rate peak value of myocardial segment which is supplied by stenotic coronary artery is smaller than the myocardial segment which is supplied by normal coronary artery when coronary stenosis(LAD blood flow reduction>70%) with severe grade(P<0.05).At dobutamine stress,strain and systolic and diastolic strain rate peak value of myocardial segment which are supplied by normal coronary artery are more increased than the rest(P<0.05).Strain and systolic and diastolic strain rate peak value of myocardial segment which is supplied by stenotic coronary artery are also significant increase comparing with the rest when coronary stenosis(LAD blood flow reduction<70%) with mild to moderate grade(P<0.05),but the increase value was smaller than the myocardial segment which are supplied by normal coronary artery(P<0.05).However,comparing with the rest,strain and systolic and diastolic strain rate peak value of myocardial segment which are supplied by stenotic coronary artery have no significant increase when coronary stenosis(LAD blood flow reduction>70%) with severe grade(P>0.05).There are also no significant increase comparing with the normal at the rest(P>0.05).3.Three-dimensional image of Strain and strain rate shows:At rest,before coronary stenosis and when the coronary stenosis with mild to moderate grade, Stress of myocardial segments appeared as a blue wave mainly to the negative and positive with a small amount of red-(Three-dimensional image of strain),and systolic stress rate mainly to the negative yellow-blue and diastolic stress rate mainly to the positive wave(three-dimensional of images strain rate).At the rest,when the cases of severe coronary artery stenosis and the dobutamine stress,two different degrees of coronary artery stenosis,Symmetry of the blue negative wave of stress and the blue negative wave of systolic strain rate and the yellow positive wave of diastolic strain rate between the ischemic myocardial segments and the normal myocardial segments disappeared.4.Correlation analysis shows:At rest,the standard A·βvalues of the area which are supplied by LAD and myocardial strain,the systolic strain rate peak and the diastolic strain rate peak on the direction of the circumference have a good correlation;The correlation between the standard of A·βvalues and strain:y= 13.59572x+4.7698(r=0.553,P<0.001),the correlation between the standardized A·βvalue and systolic strain rate peak:y=1.316233x+0.570462(r=0.560,P<0.001),the correlation between the standard A·βvalue and diastolic strain rate peak:y=1.311623X+0.652567(r=0.567,P<0.001).At dobutamine stress situation,the standard A·βvalues of the area which are supplied by LAD and myocardial strain,the systolic strain rate peak and the diastolic strain rate peak on the direction of the circumference have also a good correlation; The correlation between the standard of A·βvalues and strain:y=5.565819x +14.04001(r=0.683,P<0.001),the correlation between the standardized A·βvalue and systolic strain rate peak:y=0.722061x+1.617544(r=0.714,P<0.001),the correlation between the standard A·βvalue and diastolic strain rate peak:y= 0.793923x+1.794039(r=0.715,P<0.001).Conclusion:1.At rest,myocardial perfusion of the area which are supplied by stenotic coronary artery and systolic and diastolic function of myocardium of the short axis circular direction has not significant changes comparing with the area which are supplied by normal coronary artery when coronary stenosis with mild to moderate grade;Only in severe coronary artery stenosis,myocardial perfusion of the area which are supplied by stenotic coronary artery are decreased,and systolic and diastolic function of myocardium are weaken;2.At dobutamine stress,decrease of myocardial perfusion of the area which are supplied by stenotic coronary artery and weakness of systolic and diastolic function can be found when the coronary artery mild to moderate stenosis,and when coronary artery severe stenosis,myocardial perfusion and systolic and diastolic function are clearly lower.VVI technology combining with dobutamine stress can early evaluate the changes of regional myocardial systolic and diastolic function when coronary artery stenosis,then they can early evaluate the coronary artery stenosis;3.Three-dimensional image of strain and strain rate of VVI technology can intuitively,qualitatively and quantitatively show the changes of systolic and diastolic function of myocardial segment;4.Index which can reflect myocardial systolic and diastolic function on the short axis:strain,systolic strain rate peak and diastolic strain rate peak on the circle direction and myocardial blood perfusion have a good correlation,This shows that VVI technology not only evaluate systolic and diastolic function of myocardial segments on the short Axis,but also reflect the myocardial perfusion changes to a certain extent. PartⅡComparative study of homemade phospholipids-and albumin-coated microbubbles in efficiency of myocardial opacificationBackground:Because the commercial ultrasound contrast agents which can be used for clinical diagnosis are foreign products and high prices,and Nanfang Hospital developed human serum albumin ultrasound contrast agent(called quanfuxian),has been through phaseⅢclinical trial and the national Food and Drug Administration new drug certificate,will soon be used for commercial production and clinical diagnosis.Nevertheless,the lack of a domestic independently developed and stable performance of lipid ultrasound contrast agent,still can not meet the maximum clinical needs.Comparing with the albumin contrast agent:(1) Lipid is easy to form double-biofilm which is similar with molecular structure in liquid and has a good variability.This advantage makes it ease to combine with ligand;(2) Comparing with albumin,shell made of lipid has a characteristic which is easy to be chemical modification and connect with peptide fragments,and other ligand.Lipid micro-bubble has unique advantages in the structure of targeted microbubbles.So,it is a need to develop domestic lipid contrast agent.Objective:Preparation of a new type of lipid contrast agent,and human serum albumin contrast agent(quanfuxian) compared to the evaluation of myocardial lipid contrast agent enhancement of the effectiveness and hemodynamic.Method:We put cholesterol,DPPC and PEG-4000,and other lipid joined by a certain proportion of distilled water mixed at constant temperature water bath tank containers full bottle dissolved Access perfluoropropane(C3F8) gas saturated solution using sonicated,a parcel of perfluoropropane gas lipid microbubbles, packed in the ampoule in the cold-storage backup.Produced varying degrees single coronary artery(anterior descending and circumflex) narrow dogs were randomly successively made by intravenous continuous infusion of lipid contrast agents and human serum albumin contrast agent(all significant fluoride),the qualitative and quantitative Two of myocardial perfusion imaging agent,as well as the blood pressure and heart rate changes,and to detect ultrasound contrast agent and the size of concentration.Results:The success of lipid contrast agent,The concentration of the homemade phospholipid-coated microbubble contrast agents was(1.06±0.22)×109/mland the diameter was(3.04±0.34)μm.The concentration of the homemade albumin-coated microbubble contrast agents(Quanfuxian) was(1.31±0.33×109/ml and the diameter was(2.88±0.58)μm.Compared to the albumin-coated microbubble group,the phospholipid-coated group has similar concentration and diameter(P>0.05).Both agents graded three in myocardium opacification,and had no obvious effecton heart rate and blood pressure of dogs.There is no significant difference between phospholipid-coated microbubble contrast agents and Quanfuxian.Quantitative analysis in myocardium opacification in terms of myocardium bloodvolume(A),blood velocity(β),and blood flow(A×β) between two agents(P>0.05).The parameters derived from two agents have good correlation(P<0.05,rA=0.809,rβ=0.932,rA·β=0.925).Discussion:The effect of homemade phospholipid-coated microbubble contrast agents in myocardium opacification was good and there is no significant difference compared with Quanfuxian.Homemade phospholipid-coated microbubble good ul-trasound contrast agents to quantify myocardium blood flow and had no obvi-ous effecton for heart rate and blood pressure.
Keywords/Search Tags:Ultrasound contrast agent, myocardial contrast echocardiography, Velocity vector imaging, Doppler tissue imaging, strain and strain rate imaging, Contrast enhanced ultrasound, ultrasound contrast agent, lipid, albumin
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