Abstract 3561: A New Speckle Tracking Method for the Assessment of Myocardial Strain: Validation in an Animal Model of Ischemia-Reperfusion
Objectives: Tissue Doppler imaging allows non-invasive assessment of myocardial strain, but is angle-dependent. A new 2-dimensional strain imaging method, AxiusTM Velocity Vector Imaging (VVI), based on speckle and endocardial border tracking has been introduced. The aim of this study was to validate this novel technique as an angle-independent method for the assessment of strain, using sonomicrometry as a reference method.
Methods: Eight dogs were studied during baseline and various interventions causing alterations in regional function: dobutamine, coronary occlusion-reperfusion, followed by dobutamine and esmolol infusion. Echocardiographic images were acquired from short- and long-axis views of the left ventricle. Segment-length sonomicrometry crystals, implanted at the base and apex were used as the reference method. Velocity Vector Imaging analysis were performed off-line and strain measurements from ischemic and non-ischemia zones were compared to sonomicrometry.
Results: Changes in systolic strain in ischemic segments could be tracked well with VVI during the different hemodynamic states (Figure⇓).There was a good correlation between VVI and the reference method for systolic strain in the short axis (r=0.88, p<0.001) and in the long axis (r=0.83, p<0.001). Strain measurements in non-ischemic basal segments also demonstrated a significant correlation between the two methods (r=0.65, p<0.001).
Conclusions: Velocity Vector Imaging, a new speckle tracking method, can accurately assess systolic myocardial strain without angle-dependency, and is a promising clinical tool for the quantification of regional myocardial function.