Value Of Three-dimensional Speckle-Tracking Strain For Predicting Improvement Of Ejection Function After Acute Myocardial Infarction

Objective: To assess the left ventricular function of patients with myocardial infarction by 4D Auto LVQ,and correlation with 4D strain to positioning and quantitative analysis of the infarction area and size. To evaluate right ventricular(RV) function of acute myocardiol infarction(MI) after primary percutaneous coronary intervention(PCI) with Real-time three-dimensional echocardiography(RT-3DE)and tissue Doppler imaging and Tei index.Methods: A total of 86 patients who at the Armed Police Hospital of Tianjin Logistics College hospital from November 2013 to November 2014 admitted with ?rst ST-segment elevation AMI were included. All patients underwent coronary angiography and primary percutaneous coronary intervention(PCI) in our hospital. All patients without old myocardial infarction or stent implantation, no congenital, high blood pressure,valvular heart disease, no primary cardiomyopathy, without pulmonary hypertension or pulmonary embolism, no pacemaker implantation, were in sinus rhythm without atrial fibrillation and atrioventricular block and other serious arrhythmias, and with the exception of poor image quality and endocardial contours were fuzzy incomplete. Within72 hours after percutaneous coronary intervention, all patients underwent 4D echocardiography for assessment of LV volumes and LVEF as part of the routine evaluation for all patients with AMI. After the software identi?es the endocardial border in each frame for the entire 3-dimensional dataset, a left ventricular 3-dimensional model is generated and left ventricular volumes and ejection fraction are calculated. Afterward, the software traces the epicardial border to include the entire myocardial wall, as shown in the 4-, 2-, 3-chamber apical views and short-axis view, at 3 different levels(apical, mid, and basal); myocardial deformation is therefore analyzed by speckle tracking within the 3-dimensional region of interest. Global 3-dimensional left ventricular area strain is automatically provided by the software and calculated as the weighted average of the segmental peak area strain values which is based on 4D Auto LVQ. At three-month follow-up, 4D echocardiographic examination were repeated and LV volumes, LVEF, and area strains were reassessed. At three-month follow-up, improvement in global LV function was de?ned as an absolute improvement ≥5% of 3D LVEF. Fourty patients with a first acute anterior MI and thirty-two patients with a first acute inferior MI(without right ventricular MI) and fourteen patients with a first acute inferior MI with right ventricular MI were prospectively compared with fourty age-matched healthy individuals. From the echocardiographic apical 4-chamber views, peak systolic velocities(Sm)and peak early diastolic velocity(Em) and late diastolic velocities(Am)of the tricuspid annulus was recorded at the RV free wall and septal by tissue Doppler imaging,as well as basal segment and middle segment and apical segment of the RV free wall.The Tei index by TDI were calculated respectively at the same site. Right ventricular end-diastolic volume(RVEDV),right ventricular end-systolic volume(RVESV) and right ventricular ejection fraction(RVEF) were measured by using RT-3DE. Statistical analysis was performed with SPSS 16.0.Results: During three-month follow-up, 16 patients did not have follow-up assessment or they have more than 3 segments,which could not be visualized or the dataset contained visible translation artefacts and were excluded from the study. Therefore, 70 patiens were included in this study. 1. No signi?cant differences in baseline clinical characteristics were demonstrated in two groups. 2. Patients with an absolute improvement in LVEF of at least 5% showed a significant decrease in LVESV(43±17 m L vs 38±11 m L, p <0.05)and increase in LV global area strain(-19.8±6.2%vs-24.5±5.2%, p <0.01) at three-month follow-up. 3. Logistic regression analysis(improvement in LVEF≥5% as a binary value) showed that baseline LV global area strain, baseline ESV, and ESV at three-month follow-up are related to change in LVEF at three-month follow-up after acute myocardial infarction. 4. In ROC curve analysis, LV global area strain cut-off value of-22.5% allowed the identi?cation of recovery of LV function at three-month follow-up after acute myocardial infarction with a sensitivity of 66% and a specificity of 79%. 5. An overview of LV global area strain at baseline and the change in LVEF at three-month follow-up is provided per infarct-related artery. patients with the LAD as infarct-related artery had the lowest(less negative) baseline LV global area strain and demonstrated the smallest increase in LVEF at three-month follow-up. 6. At multivariate linear regression analysis, the basement of lateral wall(beta-0.454, P<0.01),the apex of septum(beta-0.447, P<0.01)and apex of LV(beta-0.185, P<0.05) were independent determinants of the improvement of LVEF. Moreover,the change of the basement of lateral wall is the strongest predictor to the recovery of LV function after AMI. 7. When compared with healthy individuals(groupⅠ), Sm of the tricuspid annulus at the RV free wall was reduced(P<0.05)and Tei index was increased(P<0.01), the Em and Sm of the apical segments of the RV free wall was reduced(P<0.05) in acute anterior MI patients(groupⅡ). 8. When compared with healthy individuals(groupⅠ), the Sm and Am of the tricuspid annulus at the septal was reduced(P<0.05) in acute anterior MI patients(groupⅡ)and acute inferior MI patients( groupⅢ) and acute inferior MI with right ventricular MI patients(groupⅣ), the Em was reduced(P<0.01) in groupⅡand groupⅢ, Tei index was increased(P<0.01)in groupⅡ. 9. When compared with groupⅠ, RVEDV and RVESV was increased(P<0.05)in groupⅢ and groupⅣ,and RVEF was reduced(P<0.01) in groupⅣ.Conclusions: 1.Area strain assessed by 3D speckle-tracking analysis predicts recovery of LV function after AMI at three-month follow-up. 2. RT-3DE combined with Tissue Doppler imaging can show the impaired RV function in association with the acute MI,it may become a new technology to assess RV function.