Speckle tracking imaging in evaluation of radial strain of subendocardial and epicardial myocardium in canine acute myocardial ischemia and reperfusion

Objective To evaluate the radial strain function of subendocardial and epicardial myocardium in acute myocardial ischemia and reperfusion canine with speckle tracking imaging.Methods The first diagonal branch of left coronary artery of 20 adult healthy hybrid dogs were ligated.Radial strain of subendocardial and epicardial myocardium at basal,apical and papillary muscle level were compared by speckle tracking imaging before ligation,ligation immediately,60,120,180 min after ligation,reperfusion immediately,and 60,120 min after reperfusion,respectively.Results Radial strain of basal level elevated by compensatory role in canine acute ischemic process.Radial strain of apical and papillary muscle level decreased obviously.Myocardial reverse movement was even found at apical level.In acute ischemia and reperfusion process,subendocardial myocardium was more sensitive to ischemia.After reperfusion,radial strain of subendocardial and epicardial myocardium at apical and papillary muscle level were still lower than that in basic status.Conclusion Speckle tracking imaging can objectively quantify regional and overall heart function and transmural extent of myocardial infarction in canine.