Study of strain rate imaging and dobutamine stress echocardiography in detecting ischemic myocardium

Objective To assess the value in detecting ischemic myocardium by strain rate imaging(SRI) combined with dobutamine stress echocardiography(DSE). Methods Fifty subjects with suspected coronary artery disease(CAD) underwent DSE and coronary angiography. According to the results of coronary angiography, all subjects were divided into two groups: CAD group and normal group. The systolic peak strain rate was respectively measured on middle segment of the left ventricular anterior wall and lateral wall from apical four chamber and two chamber view in rest and every stress stage, and their results were compared with those from coronary angiography. Results In normal group, the systolic peak strain rate values increased correspondingly with dobutamine dose(P(0.05)), reaching the highest values at the peak dose of dobutamine. In CAD group, strain rate values increased at low dose, and significantly reduced ((P)(0.05)) at peak dose 40 μg·kg~(-1)·min~(-1).The sensitivity and specificity of SRI with DSE for detecting ischemic myocardium were (90.0)% and (91.7)%, respectively. Conclusions SRI combined with DSE will increase the prevalence of ischemic myocardium. In 40 μg·kg~(-1)·min~(-1) dose, strain rate was the most sensitive to detect the ischemic myocardium.