| Objective:To measure the index of left ventricular circumferential strain and twist in patients with acute myocardial infarction (AMI) by two-dimensional speckle tracking imaging (STI), analyze the charateristics of movement that LV ischemic muscle, and preliminarily assess AMI effect on the myocardial strain and left ventricular twist; To evaluate the clinical value of STI in clinical treatment and prognosis of AMI patients.Methods:143 patients with AMI are selected. They are divided according to different objectives:1. Be divided into two groups according to different parts of myocardial infarction:anterior myocardial infarction group (n=59) and inferior myocardial infarction group (n=67); 2. Be divided according to different left ventricular ejection fraction (LVEF) of anterior myocardial infarction patients:normal LVEF group (LVEF>50%, n=37) and abnormal LVEF group (LVEF<50%. n=27); 3. Be divided according to different therapeutic methods:emergeney percutancous intervention group (n=95), selecting time percutancous intervention group (n=27) and conservative treatment group (n=14), and do a follow-up of them, on average 10 months after discharge; 4. Be divided separately according to different LV global peak twist (Ptw) and LV global circumferential strain (GCS):To Ptw12°for critical value, Ptw≥12°group (n=63) and Ptw<12°group (n=41); To GCS-12% for critical value, GCS≤-12% group (n=68) and GCS>-12% group (n=36).To do the conventional two-dimensional echocardiography with GE Vivid 7 ultrasound diagnostic applications, and conventional data including the LV diastolic diameter (LVDd), LV systolic diameter (LVDs), LVEF, E/A and E peak deceleration time (EDT); circumferential strain (Cs) and rotation were measured in the left ventricular short-axis views using 2D-strain software. To measure Cs of every section and calculate GCS, and then separately measure apical peak rotation (PAR), basal peak rotation (PBR), LV global peak twist (Ptw) and the time to peak. Results:1. The characteristic of Cs and rotation curve in AMI patients:the Cs curve of every section are disordered in left ventricular short-axis view (mitral, papillary muscle, apex level), GCS is negative wave, which means the peak is negative. The rotation of apical is anticlockwise, the rotation of basal is clockwise, and the rotation of left ventricular is anticlockwise in systole.2. Be divided according to different parts of myocardial infarction:(1) The Cs of anterior, ventricular septal and apex in anterior myocardial infarction group is lower than them in inferior myocardial infarction group, while the Cs of posterior and inferior in inferior myocardial infarction group is lower than them in anterior myocardial infarction group, and the GCS of anterior myocardial infarction group is much lower than inferior myocardial infarction group.P<0.05; (2) Compared with inferior myocardial infarction, the value of PAR have significantly decreased in anterior myocardial infarction, but the values of PBR and Ptw have no significant difference; (3) For analysis of LVEF>50% patients, the results are the same as above.3. Be divided according to different LVEF of anterior myocardial infarction patients: (1) Compared with the normal LVEF group, many sections Cs peak of basal, papillary muscle, apex level decreased in LVEF<50% group, the anterior and ventricular septal decreased primarily, p<0.05; GCS also significant decreased; (2) The value of PAR, PBR and Ptw in two groups, LVEF<50% group all significant decreased; (3) The negative correlation was found between GCS of anterior and inferior myocardial infarction patients and LVEF.4. Ptw is correlated with LVEF, r=0.345,P<0.01.5. Be divided according to different therapeutic method:Every index of patients in emergeney percutaneous coronary intervention (PCI) group and selecting time PCI group have no significant difference during in hospital; the value of GCS, PAR, Ptw in the follow-up improved in emergeney PCI group and selecting time PCI group, p<0.05. but improved degree of the two groups have no significant difference; these indexes in conservative treatment group have no significant difference.6. To Ptw12°and GCS-12% for critical value:The mortality significantly increased in lower GCS group, while be divided according to Ptw, the mortality have no significant difference.Conclusions:1. Cs can accurately position infarcted section, and can serve as quantitative index of evaluating regional motion of infarcted myocardium.2. GCS can reflect LV global systolic function, and maybe more accurate than LVEF.3. The value of rotation and twist are good indexes that can reflect LV systolic function, and the rotation of apical is very important in LV twist.4. The prognosis of patients with AMI that timely relieving of infarct-related artery is better, but needing increase the sample for research.5. The value of GCS maybe can assess prognosis of patients with AMI, GCS-12% can serve as a index that assess prognosis of patients with AMI. but the number of the samples must be increased for futher research. Keywords:Speckle tracking imaging Acute myocardial infarction Circumferential strain Left ventricular twist Left ventricular ejection fraction... |
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