Evaluation of regional myocardial viability in rats after acute myocardial infarction with two-dimensional speckle tracking imaging / 中国医学影像技术

ABSTRACT

Objective To observe the value of two-dimensional speckle tracking imaging (2D-STI) in assessing regional myocardial viability of rats after acute myocardial infarction. Methods Twenty Wistar rats were randomly divided into acute myocardial infarction group and sham-operation group (each n=10). Echocardiography was performed at baseline and 24 h after reperfusion. High frame rate two-dimensional images were recorded from the left ventricular short-axis views at the papillary muscle level. Peak radial strain (PRS) and peak circumferential strain (PCS) of each segment were measured at systolic period. Left ventricular internal diameter at diastole (LVID_d) and systole (LVID_s), fractional shortening (FS), ejection fraction (EF), wall thickening rate (TR) were measured with anatomical M-model echocardiography. Area of necrosis (AN) of each segment was measured after triphenyl tetrazolium chloride (TTC) staining. Based on TTC staining, ROC curve was used to analyze the accuracy of two-dimensional strain and TR index in identifying infarcted segment. Results ①Compared with acute myocardial infarction group at baseline and sham-operation group after operation, LVID_d and LVID_s of acute myocardial infarction group after operation increased significantly respectively (P50%. Using a cut-off of -6.14%, PCS had a sensitivity of 93.75% and specificity of 90.91% for distinguishing infarcted from viable myocardium. Conclusion 2D-STI can accurately quantify regional myocardial function, providing a sensitive and noninvasive means to assess regional myocardial viability.