Abstract 1625: Assessment of Left Ventricular Radial Deformation by High Resolution Speckle Tracking Imaging
Background: This study was performed to evaluate the left ventricular (LV) radial strain in the subendocardial region using 2 dimensional (2D) speckle tracking imaging in comparison to tissue Doppler imaging (TDI).
Methods: We studied 19 piglets. Tissue Doppler and their 2D images were acquired at the midventricular level at steady constant hemodynamic states directly from the surface of the LV short axis views using a 10 MHz pediatric sector probe on a GE Vivid 7 Dimension ultrasound system, and then transferred to EchoPac for offline analysis. Peak systolic radial strain was measured at anteroseptal (12 o’clock) and posterior (6 o’clock) segments in the inner and outer layers using 2D and TDI, respectively. The peak positive first derivative (dP/dt) of LV pressure was compared to the radial strain from 2D and TDI.
Results: Tracking the sample value so it stayed in the innermost myocardial layer, all of the mean values from 2D strain for the subendocardium were higher than those from TDI based strain (31.20 ± 15.50 vs 27.82 ± 7.86 and 20.50 ± 15.40 vs 16.28 ± 7.45 for anteroseptum, 28.01 ± 16.80 vs 24.35 ± 10.07 and 17.51 ± 8.85 vs 12.80 ± 7.24 for posterior segment, p<0.05). The correlation between 2D and dP/dt for the anteroseptal and posterior segments was higher than that between TDI and dP/dt (r =0.90 vs r =0.74 and r =0.65 vs r =0.16 for anteroseptum, r =0.84 vs r =0.68 and r =0.42 vs r =0.26 for posterior segment).
Conclusions: This 2D speckle tracking technique is more sensitive and accurate than TDI for evaluating the differences of LV radial myocardial strain between subepicardium and subendocardium.