Control study of regional left ventricular wall motion abnormality of canine acute myocardial infarction by quantitative tissue velocity imaging,tissue tracking imaging and MRI

Objective To evaluate the segmental left ventricular wall motion abnormalities after acute myocardial infarction in dogs and changes in systolic and diastolic function of infracted myocardium with quantitative tissue velocity imaging(QTVI) technology,tissue tracking imaging(TTI) technology and MRI.Method Using QTVI and TTI technology,the apical left ventricular long-axis,apical two-chamber and apical four chamber view were csanned before and 2h after coronary artery ligation in 8 dogs with acute myocardial infarction.The sample volume was placed at the bottom of the left ventricular base(Bas),mitral annulus level(Mv),the middle level of papillary muscles(Mid) and subendocardial apical(AP),synchronous sampled to obtain the left ventricular anterior wall,posterior wall,inferior wall,and the former and post-interventricular septal cardium movement along the long axis velocity curve and the displacement curve in the above-mentioned levels,to observe the systolic movement speed and displacement of each segment,and to record peak systolic velocity (Vs),peak systolic displacement(D) and peak early diastolic velocity(Ve) changes.MRI detection was made on myocardial infarction dogs,changes of infarcted myocardial wall thickness and range of motion were observed.Detection of the two types of imaging study results were compared.Results After coronary artery ligation in dogs with acute myocardial infarction,Vs and D of affected myocardium were lower than that of preligation(P0.05 or P0.01),early diastolic peak velocity reduced,and Ve lost the normal law of reduce gradually from the bottom to apex.MRI results showed a wide range of left ventricular anterior wall,the former partitions and partial inferior wall with weakened movement and thinning thickness,and regions of weakened movement and thinning thickness were concordance with the regions supplied by the left anterior descending coronary artery.Conclusion QTVI and TTI can evaluate the segmental movement and diastolic,systolic function of left ventricular myocardial infarction area sensitively,intuitively,and quantitatively,shows great significance in early diagnosis of acute myocardial infarction,also has better consistency with MRI in segmental infarction.