Evaluation of mouse models of myocardial dysfunction and myocardial fibrosis by speckle tracking imaging / 中华超声影像学杂志

ABSTRACT

Objective To investigate the value of two-dimensional speckle tracking imaging (STI) in assessing regional myocardial dysfunction and myocardial fibrosis in a mouse model of myocardial infarction.Methods Twenty C57/B6 mice were randomly divided into two groupsmyocardial infarction (MI) group (n =10) and sham-operation (SO) group (n =10).Echocardiography was performed four weeks after surgery.High frame rate two dimensional images were recorded in the left ventricular short axis views at the papillary muscle level and analysised at EchoPac workstation.Peak radical strain (PRS) and peak radical strain rate (PRSR) of each segment were measured at systolic period.Percent segmental fibrosis (PSF) was assessed from histological left ventricular cross sections stained by Masson trichrome.Results Compared with SO group,PRS and PRSR decreased significantly in all segments of MI group (P ＜ 0.01),especially in anterosepetal,anterior and lateral segments (P ＜0.05).PSF of anterosepetal,anterior,lateral and posterior segments in MI group increased significantly than those in SO group(P ＜0.01),and were negatively correlated with PRS and PRSR of these segments(r =-0.88,P ＜0.001 ; r =-0.77,P ＜0.001).Conclusions STI could accurately quantify regional myocardial function in a mouse model of myocardial infarction.Segmental radial strain and strain rate measured by STI were significantly correlated with PSF,which can be a non-invasive tool for monitoring myocardial fibrosis after myocardial infarction.