Objective: to analysis longitudinal motion of infarcted myocardium and ischemic myocardium with a new echocardiographic technology, velocity vector imaging(VVI), and assess its accuracy.
Methods: 6 patients suffered acute anterior myocardial infartion (MI group), 9 patients had myocardial ischemia (over 70% stenosis of LAD,MS group) and 16 healthy subjects (control group) were included. The long axis view and 2-chambers view of left ventricle at the apex of heart were acquired. The longitudinal velocity, displacement, strain and strain rate were analyzed with off-line.
Results: in control group, longitudinal peak systolic velocity(Vs)and peak displacement(D)decreased progressively from base level to apex level in anterior wall and anterior septal wall (P<0.05), while peak strain (S) and peak systolic strain rate (SRs) kept the same in three levels. S and SRs significantly decreased in all segments of infarcted myocardium (P<0.05), compared with normal and ischemic myocardium. In ischemic myocardium, only base and middle segments strain of anterior wall decreased (P<0.05). A myocardial S lower than -6.94% in at least one segment showed best sensitivity (100%) and specificity (100%) for detecting an infarcted left ventricle. A myocardial SR lower than -0.81% in at least one segment showed 100% sensitivity and 80% specificity, and lower than -0.46% showed 83% specificity and 100% sensitivity.
Conclusion: VVI is a useful tool for assessing myocardial regional function. Especially, S and SR were useful predictors of the presence of regional dysfunction in infarcted myocardium.
Key Words velocity vector imaging (VVI); infarted myocardium; ischemic myocardium; echocardiography