Evaluation of regional systolic function in dogs with acute myocardial infarction by quantitative tissue velocity imaging

Objective To evaluate the characteristics of the regional systolic wall motion features during isovolumic contraction time and left ventricular systolic time in dogs with acute myocardial infarction. Methods We studied 24 healthy dogs before and after acute myocardial infarction (coronary artery ligation) with quantitative tissue velocity imaging. The apical four chamber, five chamber and two chamber views were used and the sample volumes were within the endocardium. Myocardial velocity profiles were taken at the basal, mid and apical segments. Peak myocardial velocity (Vs) and time of LV segments during isovolumic contraction time and systolic time were measured. Mean acceleration was calculated during isovolumic contraction time (Aivs) and systolic time(As). Results The Vs and As were significantly reduced in the abnormal segments in the dogs during ischemia(P0.05, P0.01), while the acceleration was increased in the infarct segment and decreased in the normal segment. Conclusions QTVI objectively can sensitively quantify directional changes in the myocardial movement that are useful in evaluating regional myocardial function, and it may play a role in the detection of early myocardial ischemia.