Evaluation Of Myocardial Viability And Left Ventricular Remodeling After Myocardial Infarction With Intravenous Real-time Myocardial Contrast Echocardiography

PARTⅠEvaluation of myocardial viability after myocardialinfarction with intravenous real-time myocardial contrastechocardiographyObjective We attempted to evaluate the myocardial viability after myocardialinfarction with intravenous myocardial contrast echocardiography.Methods Intravenous real-time myocardial contrast echocardiography was performedin 18 patients with myocardial infarction before coronary revascularization. Fellow-upechocardiography was performed 3 months after coronary revascularization. Segmentalwall motion was assessed using 18-segment LV model and classified as normal,hypokinesis, akinesis and dyskinesis. Viable myocardium was defined by evidentimprovement of segmental wall motion 3 months after coronary revascularization.Myocardial perfusion was assessed by visual interpretation and devided into 3 conditions:homogeneous opacification; partial or reduced opaciflcation or subendocardial contrastdefect. The former two conditions were used as the standard to define the viablemyocardium.Results Totally 109 abnormal wall motion segments were detected among 18patients with myocardial infarction. Forty-seven segments were hypokinesis, 56 segmentswere akinesis and 6 segments were dyskinesis. The wall motion of 2 segments with hypokinesis before coronary revascularization which showed homogeneous opacification,14 of 24 segments with hypokinese and 20 of 24 segments with akinese before coronaryrevascularization which showed partial or reduced opaciflcation or subendocardial contrastdefect improved 3 months after coronary revascularization. In our study, the sensitivity andspecificity of evaluation of myocardial viability after myocardial infarction by intravenousreal-time myocardial contrast echocardiography are 94.7%, 78.9%, respectively.Conclusion Intravenous real-time myocardial contrast echocardiography canaccurately evaluate myocardial viability after myocardial infarction.PARTⅡEvaluation of myocardial viability after myocardialinfarction with the reperfusion parameters of intravenousreal-time myocardial contrast echocardiographyObjectives We attempted to evaluate the improvement of myocardial perfusion aftercoronary revascularization and the myocardial viability after myocardial infarction with thereperfusion parameters of intravenous real-time myocardial contrastechocardiography(RT-MCE).Methods Intravenous RT-MCE was performed in 18 patients with myocardialinfarction 1-5 days before coronary revascularization. Fellow-up echocardiography wasperformed 3 months after coronary revascularization. Segmental wall motion wasassessed using 18-segment LV model and classified as normal, hypokinesis, akinesis anddyskinesis. Viable myocardium was defined by evident improvement of segmental wallmotion 3 months after coronary revascularization. Quantitative analysis of RT-MCE wasperformed by constructing the reperfusion curves of 15 cardiac cycles after FLASH andfitting to an exponential function: y(t) =A[1-e^-kt]+B to calculate A value, k value, and A×kvalue. Receiver-operating characteristic curves were constructed to evaluate the accuracy of the different parameters in predicting myocardial viability after myocardial infarction.Results (1) 109 abnormal wall motion segments were detected among 18 patientswith myocardial infarction. 47 segments were hypokinesis, 56 segments were akinesis and6 segments were dyskinesis. The numbers of the improved segment of wall motion 3months after coronary revascularization were 16, 22, and 0, respectively. (2) Thereperfusion parameters A value, k value, and A×k value of myocardial segments whichwere identified the improvement of the wall motion 3 months after coronaryrevascularization were greater than those which were identified no improvement (5.48±1.73vs 4.41±1.45, 0.34±0.09 vs 0.26±0.06, 2.12±1.71 vs 1.15±0.76, P＜0.01). (3) A cutoffvalue of A＞3.75 at baseline to predict the improvement of wall motion 3 months aftercoronary revascularization showed a sensitivity of 80.0%and a specificity of 79.2%. Acutoff value of k＞0.28 at baseline to predict the improvement of wall motion after 3months after coronary revascularization showed a sensitivity of 85.5 %and a specificity of81.1%. A cutoff value of A×k＞1.32 at baseline to predict the improvement of wallmotion after months after coronary revascularization showed a sensitivity of 85.0% and aspecificity of 84.9%.Conclusions Reperfusion parameters of RT-MCE could accurately assess themyocardial perfusion of abnormal wall motion segments and predict the myocardialviability after myocardial infarction.PARTⅢEvaluation of the left ventricular remodelingin patients with myocardial infarction after revascularizationwith intravenous real-time myocardial contrastechocardiography Objective We attempted to evaluate the left ventricular remodeling in patientswith myocardial infarction after revascularization with intravenous real-time myocardialcontrast echocardiography (RT-MCE).Methods Intravenous RT-MCE was performed in 20 patients with myocardialinfarction before coronary revascularization. Fellow-up echocardiography was performed3 months after coronary revascularization. Segmental wall motion was assessed using18-segment LV model and classified as normal, hypokinesis, akinesis and dyskinesis.Myocardial perfusion was assessed by visual interpretation and divided into 3 conditions:homogeneous opacification=1; partial or reduced opaciflcation or subendocardial contrastdefect=2; constrast defect=3. Myocardial perfusion score index (MPSI) was calculated bydividing the total sum of contrast score by the total number of segments with abnormal wallmotion. 20 patients was classified into 2 groups according to the MPSI: MPSI≤1.5 asgood myocardial perfusion, MPSI＞1.5 as poor myocardial perfusion. To assess the leftventricular remodeling, the comparison of left ventricular ejection fraction (LVEF), leftventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume(LVEDV) between before and 3 months after revascularization in 2 groups was performed;the comparison of LVEF, LVESV, and LVEDV before operation between two groups and ofthese 3 moths after operation between two groups were performed; the comparison of△LVEF,△LVESV, and△LVEDV between 2 groups was performed; the linearregression analysis between△LVEF and MPSI,△LVESV and MPSI,△LVEDV andMPSI were also performed.Results The LVEF 3 months after revascularization in patients with MPSI＞1.5 isobvious lower than that in patients with MPSI≤1.5. The LVEDV 3 months afterrevascularization in patients with MPSI＞1.5 is obvious larger than that in patients withMPSI≤1.5. (P value were 0.002 and 0.04) The difference of△LVEF and△LVEDVbetween patients with MPSI＞1.5 and MPSI≤1.5 were significant (P value were 0.002 and0.001). Linear regression analysis showed that MPSI were negative correlation with △LVEF a nd positive correlation with△LVESV,△LVEDV (P value were＜0.004,0.008, and 0.016, respectively)Conclusions RT-MCE can accurately evaluate the left ventricular remodeling inpatients with myocardial infarction after revascularization.