Abstract 2431: Global Strain with Speckle Tracking Method is Next Generation Index of Left Ventricular Systolic Function
Background. Myocardial strain is an index of regional function, whereas global left ventricular (LV) systolic function is generally assessed with ejection fraction (EF). Recent development of speckle tracking analysis software allows angle-independent and less time-consuming measurement of whole LV strain. Our objective was to assess whether the method is useful as another index of global LV systolic function.
Methods. In 54 patients (LVEF 36±19%, 7–72%), digital gray-scales cine-loops were acquired from the apical 4-, 2-chamber, and long-axis views (GE Vivid7). After defining a region of interest (ROI) by tracing the LV endocardial border with several points at each view, a bull’s eye map was automatically constructed based on longitudinal strain and an averaged value of systolic peak strain was easily determined (EchoPAC Dimension AFI, GE). The strain value multiplied by −1 was used as global strain. Nineteen of the 54 patients underwent dobutamine stress and global strain value was calculated at baseline and during administration of 10 μg/kg/min.
Results. Figure at left shows a bull’s eye strain map in a case of anterior myocardial infarction with regional dyskinetic wall motion. The blue area indicates the dyskinetic region. Despite of low dose, dobutamine increased global strain value (from 15.3 ± 5.3 to 17.1 ± 6.0, P<0.001) as well as LVEF. Figure at right shows global strain value was well correlated with LVEF (r=0.917, P<0.001).
Conclusion. Global strain is a new index which reflects the location, severity and extent of myocardial damage in addition to global LV systolic function.