| Because of occlusion or severe stenosis of coronary arteries, the coronary-artery-dominant ischemic myocardium has been damaged. Part of myocardium in the infarct zone was acutely necrotic because of lasting and serious myocardial ischemia. After acute myocardial infarction, patient’s left ventricular systolic function has been decreased and the ejection fraction lower. If the patients with acute myocardial infarction can’t receive effective treatment in time, the left ventricle would be remodeling since then and heart function would be hard to recover due to the progression of myocardial infarction, which would severely affect life quality and prognosis of patients.If we can have a longtime analysis for the left ventricular function of patients with myocardial infarction in the follow-ups, the diagnostic and the prognostic information would be clinically valuable. Pursuing the most accurate assessment and the most effective therapies for patients with myocardial infarction, the characteristics and clinical outcome of the left ventricular function after myocardial infarction have always been the hottest topics for researchers and scientists from domestic and overseas recently. By accurately assessing the changes of left ventricular motion and function, the new technology of echocardiography---two-dimensional speckle tracking imaging has advantages in analyzing the left ventricular damage and diagnosing heart functional improvement of patients with myocardial infarction in the follow-ups.In our study, the left ventricular motion and function of patients after acute myocardial infarction was traced and assessed by speckle tracking imaging in the follow-ups. It is clinically valuable for the diagnosis and prediction of heart functional improvement of the patients.Part1Assessment of left ventricular function and infarct size of acute myocardial infarction by automated function imagingObjective:Left ventricular function of patients with acute myocardial infarction (AMI) and its correlation with cardiac troponin T (cTnT) and specific manifestation of electrocardiogram (ECG) were assessed by automated function imaging (AFI) of two-dimensional speckle tracking imaging.Methods:Infarct group:46AMI patients who had AMI for the first time and had been treated by primary percutaneous coronary intervention from September2010to February2011in our hospital; control group:30healthy controls who were age and sex-related to infarct group. The values of cTnT within24hours after admission of AMI patients were recorded and the values of ST segment elevation were measured accurately. All the subjects were analyzed for longitudinal peak systolic strain (LPSS) values and the bull’s eyes by AFI.Results:Compared to control group, left ventricular ejection fraction (LVEF), global and infarcted LPSS of infarct group were significantly different and the values of ST elevation of infarct group were higher than those of control group. Both global, infarcted segmental LPSS were significant closely correlated to LVEF and cTnT, respectively (P<0.001, all); Both global, infarcted segmental LPSS were correlated to ST elevation (P<0.05, all). Global LPSS had the closest correlation with LVEF (r=-0.565, P<0.001) and so did infarcted LPSS with cTnT (r=0.432, P<0.01).Conclusion:As a procedural simple and rapid diagnostic tool, AFI provides reliable and useful information of the assessment of AMI. Both global and infarcted segmental LPSS have well described left ventricular function of AMI patients. Compared to LVEF, LPSS was more closely correlated to cTnT and ST segment elevation, which meant that LPSS was more sensitive and more closely related to real infarct size and actual involved range of AMI. Part2Assessment of the correlation between time during admission to percutaneous coronary intervention and left ventricular function recovery of acute myocardial infarction by two-dimensional speckle tracking imagingObjective:The correlation between time during admission to percutaneous coronary intervention (PCI) and left ventricular function recovery of acute myocardial infarction (AMI) was assessed by two-dimensional speckle tracking imaging (STI). We discussed the clinical value of STI in assessing therapeutic effect of AMI treated by PCI and estimation of the prognosis.Methods:61AMI patients who had AMI for the first time and had been treated by primary PCI from September2010to March2011in our hospital were enrolled. Dynamic images were acquired before PCI, at7days after PCI and30days after PCI and analyzed by STI. The time (hrs.) during admission to PCI of AMI patients was recorded accurately. Dynamic images were analyzed for longitudinal peak systolic strain (LPSS) values (global, infarcted area) by STI. According to the comparison of LVEF before PCI and30days after PCI, patients were divided into left ventricular function improved group (△LVEF≥5%) and not-improved group and the values of LPSS and time during admission to PCI were compared between the two group respectively.Results: Compared to not-improved group, the time during admission to PCI in improved group was lower (P<0.001); Infarcted segmental LPSS at7days after PCI (P <0.05) and both global (P<0.001) and infarcted segmental LPSS (P<0.001) at30days after PCI in improved group were higher than those in not-improved group. Linear regression analysis showed that both global and infarcted segmental LPSS were significant correlated to LVEF respectively (P<0.001, all); Infarcted segmental LPSS at7days after PCI were correlated to the time during admission to PCI (P<0.05); LVEF (r=0.303, P＜0.05), global (r=0.300, P＜0.05) and infarcted segmental LPSS (r=0.590, P＜0.001) at30days after PCI were correlated to the time during admission to PCI.Conclusions:STI provides reliable and useful clinical information for the assessment of therapeutic effect of AMI treated by PCI and estimation of the prognosis by sensitively presenting the close correlation between time during admission to PCI and left ventricular function recovery of AMI patients. Part3Assessment of left ventricular function early and late improvement of acute myocardial infarction after percutaneous coronary intervention by two-dimensional speckle tracking imagingObjective:To assess left ventricular function early and late improvement of patients with acute myocardial infarction (AMI) treated by percutaneous coronary intervention (PCI) by speckle tracking imaging (STI). The clinical values of the assessment of STI for the prognosis and heart function improvement of AMI patients treated by PCI were discussed. Methods:73AMI patients who had AMI for the first time and had been treated by primary PCI from September2010to July2011and were examined in the follow-ups from December2010to February2012in our hospital were enrolled. Dynamic images were acquired before PCI, at3months and6months after PCI and analyzed by STI. Dynamic images were analyzed for longitudinal peak systolic strain (LPSS), radial peak systolic strain (RPSS) and circumferential peak systolic strain (CPSS) values by STI. According to the comparison of left ventricular ejection fraction (LVEF) before PCI and6months after PCI, patients were divided into left ventricular function improved group (△LVEF6≥5%) and not-improved group; According to the comparison of LVEF before PCI and3months after PCI, improved group were divided into left ventricular function early-improved group (△LVEF3≥5%) and late-improved group.Results:The values of all STI parameters before,3months and6months after PCI in improved group were higher than those in not-improved group (P<0.001, all). LPSS before PCI and at the follow-ups and RPSS at3months after PCI in early-improved group were higher than those in late-improved group (LPSS at3months after PCI:P<0.001; Other parameters:P<0.05). There were significant correlations between all STI parameters and both△LVEF3and△LVEF6. LPSS before PCI was more closely related to△LVEF3(r=-0.781, P<0.001); CPSS at6months after PCI was more closely related to A LVEF6(r=-0.834, P<0.001).Conclusions:Early and late function improvement of left ventricle in AMI patients who was treated by PCI were accurately assessed by STI. The precise analyses of longitudinal and circumferential movements in STI were important for clinical diagnosis. Part4Prediction of left ventricular function improvement of acute myocardial infarction after percutaneous coronary intervention by two-dimensional speckle tracking imagingObjective:Left ventricular function of patients with acute myocardial infarction (AMI) treated by percutaneous coronary intervention (PCI) was assessed by speckle tracking imaging (STI). The clinical value of STI in predicting left ventricular function improvement of AMI treated by PCI was discussed.Methods:75AMI patients who had AMI for the first time and had been treated by primary PCI from September2010to July2011and were examined in the follow-ups from February2011to February2012in our hospital were enrolled. Dynamic images were acquired before PCI, at6months after PCI and analyzed by STI. Dynamic images were analyzed for longitudinal peak systolic strain (LPSS), radial peak systolic strain (RPSS) and circumferential peak systolic strain (CPSS) values by STI. According to the comparison of left ventricular ejection fraction (LVEF) before PCI and6months after PCI, patients were divided into left ventricular function improved group (△LVEF6≥5%) and not-improved group.Results:Compared to non-improved group, LPSS (P<0.001, all), RPSS (P<0.05, P<0.001) and CPSS (P<0.001, all) of improved group were all higher before and6months after PCI. LPSS (r=-0.578, P<0.001) and CPSS (r=-0.817, P<0.001) before PCI were both closely related to△LVEF6. In single parameter mode of receiver operator characteristic curve (ROC curve) analysis, the area under the ROC curve (AUC)(0.867), sensitivity (94.7%) and specificity (74.4%) of CPSS were relatively higher than other STI parameters; In multiple parameters united mode of ROC curve analysis, AUC (0.897), sensitivity (94.7%) and specificity (74.4%) of LPSS, RPSS and CPSS united were the highest among all the combinations of all STI parameters.Conclusions:Left ventricular function improvement of patients with AMI6months after PCI was accurately assessed and predicted by STI. CPSS was a strong predictor for left ventricular function improvement6months after PCI of AMI patients among all the STI parameters and was an effective indicator for the assessment of left ventricular function improvement of AMI patients. |
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