Assessment of regional myocardial function in dogs with acute myocardial ischemia using velocity vector imaging combined with myocardial contrast echocardiography

Objective To explore the value of velocity vector imaging(VVI) in assessing left ventricular regional myocardial systolic functions in dogs with acute myocardial ischemia.Methods ten dogs,RT-MCE with Contrast media and VVI were performed at baseline and 30 minutes after occlude left anterior descending coronary arteries(LAD) respectively.The regional myocardial contrast intensity versus refilling time plots were fitted to an exponential function:y = A·(1-exp-k·t)+B,the product of A and βrepresented myocardial blood flow.using VVI measure the VSYS、S SYS、SRSYS.Results RT-MCE showed that normalized A·k in the regional myocardial of acute ischemia decreased severely(P0.05).The peak systolic velocities and stain、strain rate recorded by VVI declined significantly(P0.001).Conclusion Longitudinal peak systolic velocity,stain,strain rate are accurate and sensitive indices for detection myocardial ischemia.